texts: Is it true that as of 2014, flight reviews are waived for current flight instructors under FAA rules?

texts:
I'm assuming this is false, or I wouldn't be asking...

Just the other day, another flight instructor in my local area, whom I know, told me:

  "... new rule as of 2014: if you keep your CFI current, you don't need
  a flight review!"

This is in regards to the FAA system.

I couldn't find a source for that, and I have never heard this before.

I am aware that a requirement to have one hour of ground instruction as a part of the flight review is waived for current CFIs, but I have never heard that the flight portion is waived as well.

My flight review is coming up, so it has been almost two years since I have personally received a flight review, which was in 2014.  I'm just wanting to verify this information and receive a source if it is true.


texts: Where is there an FAA source that states that squall lines are non-frontal?

texts:
There's a question in the FAA commercial question bank that indicates that squall lines are nonfrontal, and the reference for the question points to the Aviation Weather Advisory Circular.
The word, "nonfrontal" (or any variation of it ie "non-frontal") does not appear in that document.  Also, the word "squall" appears four times, and none of those seem to have information that indicates that they are nonfrontal.
Where is the FAA providing this information?  Is it actually correct?


texts: How accurate are these Stall Diagrams depictions of relative wind?

texts:
Why in diagrams of a stall, the relative "wind" comes in horizontally no matter how the airplane is orientated? Doesn't the engine, which produces the thrust for the "wind", stay parallel to the wing making the diagrams of wind at higher AoAs much more inaccurate because of the direction of thrust?

Image source


texts: What does the 'hp' rating actually signify, with respect to an aircraft engine?

texts:
Let's say I've got a Cessna C172S with a Lycoming IO-360-L2A engine that produces 180 hp (that's the power output for sure). Let's say I've also got a water pump, that is rated at 1 hp (power input or output?).

  Is the Lycoming engine 180 times more powerful than my water pump?

Can they be compared with each other - one's based on electricity, and the other is based on fuel combustion)? Or have I got it all wrong? The Airbus E-Fan has 2x30 kW (2x40hp) electric motors, and it's slow (with respect to the 172S), cruising at only around 86 kn.

  1 Horsepower = 745.7 Watts

that means 180 HP = 134244 W (or) 134.244 kW! Did I get that right? Again, is that the power draw or the power it can produce (they are kinda different right)? In order to get the same power, should an equivalent electric motor be rated at around 135 kW ?

Let's say I have another (read experimental) aircraft of just a quarter the weight of the 172S and very similar drag-profile. Does that mean I only need a 45 hp engine to achieve similar performance?


texts: Getting data from Existing ADSB Receivers

texts: Is there any way to get data from existing ADSB receivers installed around the world?


texts: Quadcopter: would putting 3 blades on the same level and the other blade below the first three work?

texts:
Most quadcopters have their propeller blades all on the same level, or in some cases, a pair of blades placed a little above the other pair.

However, I was wondering if three propellers of a quadcopter can be put on the same level and the other propeller a little lower. Would it just make the quadcopter inefficient?


texts: Do I need a PPL license for a CPL license?

texts:
Do I need a PPL license to get a CPL/ATPL license?

I could not find anything on the net regarding my question.


texts: The numerical method used by F.X Wortmann for inverse design

texts:
Apologies in advance for a long-winded question.

Can someone who understands some airfoil theory and German language please help me understand the method outlined in this paper from Prof. FX Wortmann.

I have back-quoted what I've got so far with Google translate but it doesn't appear to be accurate especially with the given context.

  If you reduce the work of E. Truckenbrodt [8] to calculate the profile shape from the speed distribution to the mere calculation, you come to the following series of formulas: 1. At the n positions of the dimensionless profile depth

  Table 3 contains the constants bm for N24. The following applies to
  the pth approximation step

  Table 3 contains the constants is the slope of the tangent to the
  profile shape and results from

  The values amn are listed in Tables 4 and 5. The values amn for
  even-numbered m - n disappear. The table amn with m = 2, 4, ... is
  therefore used to calculate the values y, 'for n = 1, 3, ... A good
  estimate of the correction values x, which greatly abbreviates the
  approximation, can be obtained if one starts from the examples already
  calculated. Eq. (A2) includes (N-1) 2 232 529 operations that can be
  performed in about two hours with a simple electrical calculator. 2.
  The skeleton line of a curved profile, in which the speeds on the top
  of the profile (index o) and underside (index u) are different, is
  calculated

  Table 3 contains the constants dmn. The value for z is already known
  from the above calculation. This skeletal line still needs a minor
  correction, which is reflected in

  The constants pa, qn are given in Table 6. The values y, and are
  according to Eq. (A2) and (A5) known. The angle of attack a is
  calculated

  The values d are also shown in Table 3. The final coordinates of a
  curved profile then result from (A11) = y (s) 4ys) + y (). The
  positive sign applies to the top of the profile.

Also with my very limited understanding with possibly incorrect translation, I've got the following questions so far

What is the $(t)$ in $\bar{y}_n^{(t)}$ in (A-2)
what is the $p^{th}$ approximation in (A-3)
What is the $(s)$ in $\bar{y}_n^{(s)}$ in (A-2)
Does (A-6) refers to the camber line calculation?


texts: Why can't you turn off GA aircraft like a car?

texts:
The Cessna 172S Aircraft Flight Manual states the following for securing airplane after commencing a flight:

SECURING AIRPLANE

Parking Brake -- SET.
Electrical Equipment, Autopilot (if installed) -- OFF.
Avionics Master Switch -- OFF.
Mixture -- IDLE CUTOFF (pulled full out).
Ignition Switch -- OFF.
Master Switch -- OFF.
Control Lock -- INSTALL.
Fuel Selector Valve -- LEFT or RIGHT to prevent cross feeding.

Why can't you turn off the engine of GA aircraft like a car? Why is mixture pulled out before turning the ignition switch off?


texts: What are the concerns and consequences of an overweight landing?

texts:
If a 777 ER has to immediately land after takeoff on a planned 14,594 km trip (in the case of a fire, e.g.), the landing will be executed with a very heavy aircraft.

What are the major concerns of doing such a landing?
What will, on average, be the consequences of this overweight landing?


texts:
How does an airline select Captains for a new but different airplanes (ie, Boeing vs Airbus) that they just added to their fleet?

As an example, Delta has purchased many new Airbus A220. Since it is a new airplane and no one has any experience with it, do the pilots train the same for this new airplane and then based on their seniority one becomes Captain and the other a FO...or...they train for their respective position from the start?


texts: Is there any other category of aircraft in the FAA regulations besides 'Ultralight' that does not require pilot licensure?

texts:
I am asking to clear up contention on my related question that was put 'on hold' by the moderators.  To my knowledge, there is no other category of aircraft besides 'Ultralight' as defined in CFR 14 part 103, that doesn't require any kind of pilot's license.  The 'experimental' category requires a recreational pilot license.

The problem with the 'Ultralight' category is that in practice it ends up being discriminatory against heavier potential users.


texts: What are the mandatory elements of an ICAO flightplan?

texts:
I need to write a software parser for ICAO flightplans, and in particular I need to parse FPL messages.

What are the mandatory elements included in a flightplan document? For example the image below illustrates a typical flightplan form:

Also the above form contains special sequences such as <=. What is the signification of this sequence? Does it correspond to a newline in the generated flightplan text format?

A corresponding textual representation of a flightplan is also shown below:

(FPL-REU974-IS
-B77L/H-SDE1E2E3GFHIJ4J5M1RWXYZ/LB1D1
-LFPG1845
-N0490F310 OKASI UL612 MILPA UM730 TOP UL50 ELB UL12 VELAD UM728 NERAR UP3
RCA/N0489F350 UR611 TIKAT UG300 MAV UM665G ITLOX UM665 UVESO/N0486F370 DCT DENLI
UR780 MIDRI UR780G UVENA
-FMEE1036 FIMP
-PBN/A1D1L1S1 NAV/RNP10 DOF/121114 REG/FOLRA EET/LSAS0039 LFFF0039 LIMM0048 LIRR0111
LMMM0218 HLLL0237 HECC0343 HSSS0425 HAAA0545 HKNA0700 HCSM0701 FSSS0745 FMMM0900
SEL/CGFR ORGN/RUKOUU PER/C SRC/RQP RMK/ADSB ACARS EQUIPPED TCAS EQUIPPED)

So basically I need to write a program capable of parsing the previous textual format and validating it against any errors and or missing elements.


texts: When were commercial pilots first allowed to use glasses?

texts:
Currently, pilots with defective (but correctable) vision are allowed to pilot airliners if they have at least two pairs of their corrective lenses (typically glasses) with them on board.

Was there a specific moment in time when this was first allowed by law and regulations (prior to which persons with defective vision would have been prohibited from piloting an aircraft, even with corrective lenses)? Or has flying with corrective lenses been allowed since the earliest moments of airliners' history?


texts: Why "Throttle...Open 1/2 travel" on engine troubleshoot checklist?

texts:
Why do some engine troubleshoot checklists (on small single engine piston aircraft) call for throttle to only be open 1/2 travel? I suspect it has something to do with modern fuel injected engines, but haven't found anything explaining why half throttle, instead of full throttle.
Below is an example, however, I saw at least one other checklist online for another single engine piston (non-Cessna) that had similar "1/2 open" throttle language.


texts: What energy density is required for the batteries in order to make an all-electric analogue of the Cessna 150 or similar plane?

texts:
I think I have some general understanding that at the present moment even with the best possible batteries, a 2 seater training aircraft (like the C-150) would be very impractical. I'm not even talking about electric analogs of the Piper Seneca, let alone airliners. At the same time, compared to piston engines, electric engines are less heavy for their output and far more efficient (I think around 90+ %). Pipistrel claims that Siemens has a 85kW engine which is only 14 kg. I also like the idea that electric engines offer us some flexibility in the energy distribution.

What sort of progress do we need in terms of energy density of current batteries, to make a 2-4 seater aircraft real and equivalent in terms of range and performance to its piston analogues? Also, will it be cheaper to charge as opposed to the cost of liquid fuel? (Assuming the electric engine is similar to a piston one in terms of power.)


texts:
I'm working on a research project looking at Mode 3A/C replies and have noticed some pulse patterns that look very similar which I suspect are Mode 2 replies.  They appear to differ by just one pulse.

I'd like to extend my decoder to decode these as well but I'm struggling to find out how Mode 2 pulses are encoded.  I know that mode 3A/C is encoded using the Gilham code but that excludes the extra pulse that I am seeing.

Is there a publically available document which explains how Mode 2 pulses are encoded ?  I've search high and low and haven't found one yet.


texts:
I visisited Tirana, Albania the first week in August. Outside a shopping mall called "TEG" there was an old jet fighter on display. I can't recognise what make and model this is. Can anybody here help me?

PS: I'm sorry about the poor qualities of the pictures, but there was hard to find an angle with free sight and it was far darker than it appears on the pictures.


texts: What does mean 'GS' in RNAV (GPS) Chart?

texts:
Hello.

I have a question about 'GS' in my RNAV(GPS) Approach Chart.

Usually, (Including PAPI, VASI whatever...) Normal Glide Descent Angle means 3.00 degree.

but some 'GS' says 3.07, 3.04, 3.09 even 7.75 in KSBS airport. (Picture above)

In this case, What does mean 'GS' exact ?

As far as I know, it's 'GS' means draw an imaginary line extend from Touch-Down Foot marker (1,000ft marker) to FAF for Non-Precision Approach.
(Even do I Step-Down Approach ? I also wonder.)

but someone says, it's a line extend from 1,000ft marker to VDP,

and another one says, it's a Normal Descent Rate when PAPI indicates 2white-2red. (Exact Center-line of PAPI Glide Slope. I know approximately 0.4 of marginal has exist on PAPI for 2White-2Red (2.81-3.19)

If the last one's word is true, an airport have a 7.75 GS, like a KSBS Airport, then the PAPI of KSBS airport indicates 2white-2red when I follow the 7.75 GS ?

Waiting for your answers. Thank you.

BEST


texts: MH370 Curved Track / Arc to southwest...Isn't this also affected by the Earth's motion?

texts: How does the Earth's eastward motion figure into the tracks proposed by Inmarsat data etc?


texts: I have bad eyesight, can I still be a commercial pilot in Malaysia?

texts: So, I have really bad eyesight (short-sighted): without my glasses, I can't read text unless it's near. So can I be a commercial pilot?


texts: What is the name of the previous Air Traffic Management System (ATMS) of Hong Kong International Airport?

texts:
Hi I really need help for the question.
The current ATMS for Hong Kong International Airport is the AutoTrac III, but does anyone know what is Hong Kong's Previous ATMS?


texts: Where can I find Radar Weather Reports (RAREPs)? Are they still used? They are not anywhere on the aviationweather.gov website.


texts: How do flight procedure designers decide when to assign an altitude constraint to a waypoint?

texts:
I am studying procedure design manuals (TERPS, PBN 8260.58A manual, ICAO PANS-OPS 8168 manual etc.) and I haven't found any guidelines concerning altitude constraints that can be imposed on a waypoint.

Take, for example, JFK's DEEZ FIVE departure. CESID has an "AT or ABOVE 2500" altitude constraint. Is there a reason that an altitude constraint was imposed on CESID, rather than on e.g. SKORR or YNKEE?

Another example, as far as STARs are concerned, is SEA's HAWKZ SEVEN. There is a Minimum Enroute Altitude for each leg, which is more than enough both for obstacle clearance and for communication. Why did the designers decide to an "At or ABOVE FL220" at PTERA? And why at PTERA and not e.g. at KRIEG, KNGDM or WRUSL?

Can someone point me in the right direction?


texts: Saw it on a 747 freighter nose door, see it again on an F16's M61A1 gun assembly.  How do you design with a flexible shaft? In what situation do you use it to replace a bunch of rigid shafts and gears? Does it provide the strict angular synchronization of normal rigid driveshafts? Or is the synchronization only approximate, and can only be used in situations like either the 747 nose door or M61A1 gun-to-drum drive where there is only a requirement for a rough 1-1 translation of motion and power and no real demand to perfectly synchronize? Can you guarantee that if there is a constant speed revolution in one side you would get a constant speed revolution in another?


texts: During night flying, which color lens for a flashlight is most beneficial?

texts:
I went on a night flight tonight after not flying for a few months.  I didn't have any monochrome lights, so I actually just covered a flashlight of mine with red athletic tape (which acted as a filter really well).

I know that using monochrome is the most important thing about preserving night vision - but does it particularly matter, while flying, which color I use?


texts: What are the differences between battens and ribs?


texts: Why is the DC10/MD11 center engine placed where it is?

texts:
While reading this question about trijets I started wondering why the center engine in the DC10 and MD11 where placed where they are. Most trijets have the center engine at the very back of the fuselage with the intake in front of the vertical stabilizer. The DC10/MD11 engine is placed above the fuselage at the bottom of the vertical stab.

I'm wondering if there is some advantage to that. Does placing the engine there create an appreciable pitch down moment? And how would that relate to the pitch up moment of the underwing engines? Are there any other aircraft that have this configuration?


texts: On a recent long-haul flight I sat by the windows and was dreaming away staring into infinity out of the window. Then a thought came up, in Asia sleeping busses are very common. This made me think, why are there no dedicated sleeper planes? Especially for the long-haul 10 to 13 hours this would be ideal.


texts: How to tell the difference between METAR and SPECI reports?

texts:
I am trying to use METAR data from AviationWeather.gov to programmatically collect hourly rainfall data.  This Wiki says that the first field in the report should be "type" - either METAR or SPECI.  METARs are sent every hour, SPECIs are sent sporadically under certain conditions.  The problem is that the AviationWeather.gov reports are missing that first field, so I can't tell the difference between METAR and SPECI reports.  I care because I can only get reliable cumulative Rainfall data from the METAR reports.

What am I missing?


texts: Is V(L/D)max equivalent to best glide speed regardless of weight, engine, height, etc.?

texts:
I've read Carson's paper on V(L/D)max, and while theoretically interesting, it does not seem to me to be useful in actually finding the V(L/D)max of an arbitrary aircraft, as it assumes knowledge of total parasite area (f) which can only really be calculated experimentally (and is very hard to calculate at that).

Another paper, by Russ Erb, claims that optimal glide speed, in the emergency section of the Pilot's Handbook for an aircraft, is equal to V(L/D)max for that aircraft.  This sounds wrong intuitively as it does not seem to take into account weight, air pressure, height, or other such variables.  As a math major, I am certainly suspicious of people who say "I'll spare you the derivations."

For an aircraft with an engine, such as a Cessna or a Bonanza, is best glide speed roughly equal to V(L/D)max?

I was told by an experienced pilot that

  Vldmax at weight G = Vldmax at weight L * ( weight G / weight L )^0.5

This would seem to contradict the claim that V(L/D)max = best glide speed, as best glide speed (according to the Bonanza Operating Handbook, as an example), is constant.


texts: What can trigger the ELT on GA aircraft?

texts: Does the Emergency Locator Transmitter (ELT) on smaller aircraft activate automatically in case of an accident? If so, what triggers it? Is it a certain amount of G's that triggers it or are there other parameters taken into account?


texts:
Couldn't you just generate lift with a long body? Maybe a little broader than a normal plane.

As a design enhancement, we would need  a heavier bottom, so the plane doesn't flips to a side.


texts: What is the clearance between a fan blade and the nacelle?

texts: What is the distance between the tip of a fan blade and the inside of the nacelle for a turbofan like the Rolls Royce Trent 900? Does this distance change significantly during cruise due to thermal expansion?


texts: Can the lift fans used on a F-35 be driven by a turboshaft engine instead of the jet engine? If yes, which one?

texts:
This is for a sci-fi story I'm writing, so the answer doesn't have to be perfect, just close as possible.

Can the lift fans on a F-35 be driven by a turboshaft instead of the jet engine If yes, which one? The jet engine that drives the lift fans in a F-35 is called Pratt & Whitney F135  engine. The engine dumps 20,000 shaft horsepower onto  shaft that spins the fans. But i need a way to do this with a turbine, not jet engine with thrust coming from the rear.

I'm assuming that it takes a certain amount of shp (shaft horsepower) to spin the lift fans at the correct rpm.  The fictional vtol is to have 4 lift fans driven by four turbine with little heat signature to avoid infrared.


texts: Does holding an MEI entitle you to instruct in ASEL/ASES as well?

texts: Suppose someone earned a commercial pilot certificate in both ASEL and AMEL as well as only a  Multi Engine Instructor license.  Contingent upon both the MEI being valid and a valid Class II or better medical certificate, does the MEI allow this person to exercise the privilege of flight instruction in a single engine aircraft as well?


texts: How does a G1000 equipped with a GDC 74 calculate IAS from dynamic pressure?

texts:
How exactly does a G1000 system equipped with a GDC 74 air data computer calculate the indicated airspeed that is displayed on the PFD from difference between the total and static pressure (i.e. dynamic pressure) measured from the pitot-static system?

The reason I ask is because I want to reverse the calculation and convert KIAS back to dynamic pressure, i.e. $ q $ as defined below:

$$ q = \frac{\rho u^2}{2} $$

My objective is to calculate dynamic pressure from the KIAS value that is logged to the data logs written to the top SD card by the MFD. The problem is that there are multiple ways to perform this calculation -- i.e. does the G1000 display an indicated airspeed that is uncorrected for instrument and position error (IAS, in the traditional sense) or corrected for instrument and position error (CAS)?


texts: Could supersonic transport make a comeback?

texts:
When the Concorde was retired from service, reasons given included:

It was expensive to operate; it burned a lot of fuel and had high maintenance costs, resulting in high ticket prices
Could only operate on overseas routes where the sonic boom it created could go essentially unnoticed
It had a very limited market because of the above

But the Concorde was built with 1960s technology and aeronautical science. Modern aero engines are more fuel efficient, modern materials and manufacturing methods could potentially reduce maintenance costs, and there is today about 50 years of additional aeronautical science available.

So my question is this:

Is it possible to design a 200-300 seat airliner having performance comparable to Concorde (Mach 2+ at 50,000 ft or so), without creating a noticeable or objectionable sonic boom at ground level, and operating economics at least close to that of a typical subsonic airliner?

I have read similar questions ([one] and [two]) which explore the reasons Concorde was retired, but the discussions are framed around Concorde itself - an aircraft developed in the 1960s and never updated, or the abandoned Boeing 2707. None appear to acknowledge that at least four decades of scientific and technological progress has occurred since these aircraft were in development, and how that may or may not alter the feasibility of an SST service flying an all-new design. They also don't address the question of  whether new advances allow for large aircraft to fly supersonic without creating a noticeable or objectionable ground-level sonic boom.


texts: How is roll control achieved for the space ship two?

texts:
When looking at scaled composite 339 space ship two I fail to see control surfaces on the trailing edge of the wing. For me, it seems that the only moving surface on the wing is the feathering mechanism and that control surfaces are all located on the tail.

My question is: when not in space, how is roll control achieved? does it use horizontal stabilizer in an asymmetric way? Is there a control surface I fail to see?


texts: Is NOAA GFS winds aloft data available for applications?

texts: Where can I find the NOAA's winds aloft data in a form that I can use in an application? I plan to develop a software able to calculate the flight path of a lighter than air aircraft or drone using windspeed data from the NOAA Global Forecast System.


texts: How much does it cost to ground a B737 max aircraft for an airline?

texts:
What are the cost items for which an operator with such an aircraft in the fleet incurs per aircraft because of the grounding of the Boeing 737 max aircrafts and how much is the average cost incurred?

Is there any possibility of claiming the losses by the airline companies from the Boeing company?


texts: How do aircraft carriers treat foreign Flight Information Regions?

texts:
Aircraft carriers have the right to be anywhere as long as they stick to international waters. But as soon as a plane leaves the deck, that's somebody's FIR.

Granted they can fly low, or even know where the radars are pointed. But that's not good for exercises and other missions. Do they coordinate, ask permission, pay a certain fee, or just simply show up. What about clandestine missions?

I've also seen before on Jeppesen en-route charts rectangular areas marked as air refueling corridors, if my memory serves me well, such example was near Malta. Same question, how does that work?

(wikimedia.org)


texts:
What model of aircraft is this?
So, what type of airplane is it?


texts: What are the advantages of dual counter-rotating rotors vs coaxial rotors?

texts: It just seems to me, as though, dual counter-rotating rotors are a much better solution (Chinook) than coaxial and that the center of gravity is offset to allow useful loads to be spread out. Even though that the airframe needs to be longer, does this give more stability on the whole airframe and if so, would engine failure allow for proper auto rotation? I am thinking of small two-four person model for this question.


texts: Why can the A320 VAPP be decreased down to VLS?

texts:
I read in the Airbus A320 FCTM (p349), normal procedures descent section:

  The flight crew can insert a lower VAPP in the MCDU PERF APPR, down to
  VLS, if landing is performed without A/THR, without wind and no ice
  accretion.

You have no margin against a stall condition. Why is that possible to decrease VAPP till VLS?


texts: How can the Airbus A319 accommodate 156 passengers with overwing emergency exits?

texts:
This official image from the Aircraft characteristics airport and maintenance planning document for the A319 advertises the A319 as accommodating 156 passengers in a high density layout, this is also the figure in other Airbus documentation.

What I would like to know is how emergency exists is accommodated for? In the image it shows a row of seats at the exits, but I was under the impression that there is not allowed to be seats in line with the emergency exits? Can this variant thus only accommodate 150 passengers (156 - 2*3)?

My question is also valid for the A320.

Then I would also like to know, is there a policy for the amount of lavatories on board the aircraft, or is that simply a choice made by the airline? Are there for example airlines that have only one or even none lavatories on board models only used for short hauls?

Thank you for any help.


texts: Why is pitch measured with respect to the horizon and not the ground?

texts:
Why is the pitch measured with respect to the horizon and not the ground? How different are the angles between the ground and the horizon? Would it be possible to fly with an attitude indicator that indicated pitch with respect to ground rather than horizon? What does it mean when you have a 0 degree pitch with respect to the horizon? What, exactly, are you flying towards in that case?

I've always had a hard time understanding this. Thanks for your time.


texts: How does exceeding the critical Mach number of an aircraft affect its operation?

texts: If an aircraft exceeds its critical Mach number, does it affect the way the aircraft is handled? Are there any significant changes to performance or the safety of the aircraft when above this speed? What actually happens to the aircraft in the first place?


texts: After a crash, does the information stored on flight recorders have expiration dates?

texts:
After the recent announcement of the recovery of the flight recorders of AirAsia flight were recovered, I was wondering if black boxes deteriorate after a set amount of time.

As of now, nothing of the plane MH370 has been recovered, including either of the flight recorders. In another downed flight in the past, it took over two years for the for the black boxes to be recovered from the ocean, and even then the information in the black boxes were intact.

So do these black boxes ever expire? Or do they always keep the information intact throughout the years?


texts: Use of a leased/rented aircraft for business use and flown by a company employee

texts:
I believe this is allowed under 91.501 but not sure what the definition of "operated by the company" is.

A pilot with ATP,MEL,MEI is employed by the company as its corporate pilot and paid a salary.

The pilot finds a twin engine aircraft owned by another company/individual that is not used in any commercial operation. A per hour dry rate has been establish for this aircraft.

The purpose of the flights is to fly company employees to meeting sites at multiple company locations.

Can the company pay the dry rate plus fuel for use of this aircraft?

Can the pilot operate this aircraft legally under part 91 based on compensation as a salaried employee?


texts: What are the legal requirements for me to purchase an airplane that I will provide instruction in?

texts:
I'm planning on getting my CFI certificate and I would like to purchase a Cessna 172 to rent to students and provide instruction in.

What are the legal requirements for me to do so?  Are there specific things I need to do beyond 100 hour inspections?

What is the best way to set something like that up to provide personal liability protection?


texts: Can private flights between the US and Canada avoid using a port of entry?

texts: I'm considering getting back into flying private after a 15 year absence. I'm a dual US/Canadian passport holder. I'd like to fly between homes on Nantucket, MA and rural Nova Scotia regularly. Is there any type of permit that would provide an exemption from landing at a port of entry every time?


texts: How long after takeoff for a Boeing 747-400 to reach cruise speed?

texts:
Assume it is fully loaded (pasengers and cargo) and optimal conditions, almost no wind, etc etc...

How long after takeoff does the plane reaches cruise speed?

If he goes in a straight like on the axis of the airport strip (i.e. makes no turns), how far will have it traveled when it reaches cruise speed?


texts: I'd like for this question's answers to be a references of the mnemonic devices pilots can use to assist with memorization of the equipment required by the FAA for flight in powered civil aircraft. What are the common mnemonic devices used to remember equipment required by 14 CFR 91.205?


texts: What altitude restrictions are there in Class C airspace?

texts: So if I'm flying into a Class C airspace, I call approach and I establish radio contact and tell them I want to land, then I enter the airspace.  If I'm still talking to approach and haven't been handed to tower yet, and they tell me to make (say) left traffic for Runway 15, does that give me permission to descend to TPA?  When do I need to maintain a specific altitude in Class C and when can I descend at my discretion?  And more broadly, if ATC doesn't give me any altitude restrictions in the Class C, can I fly at whatever (safe) altitude I want to as I come in for the landing?


texts:
I've heard that some seaplane bases have IFR approaches, but what about landing at sea?

If you flew out into international airspace, could you land at sea and then taxi back into US waters without being subject to US regulations? You wouldn't have to know where the "runway" is because it's everywhere.

(FYI, I'm a SEL pilot, so I'm not considering actually trying this!)


texts:
In level flight all forces must be in balance,that mean center of overall pressure(lift) is in line with C.G.

Disturbance comes  in such way that shift C.P. back.

Is this glider stable?
If I use aircraft stability definition,glider is not stable ,because neutral point is in front of C.G.
(for me glider is  stable,because lift in reality act in CP,so lift make counter clock wise torque about C.G., this plane will put  nose down.better to consider pitch moments for every AoA with corresponding  position of center of pressure..)
I dont understand why proffesor draw lift at A.C., if lift act at C.P. ?


texts: Partial ownership: are there any pitfalls to owning the plane through a shell company?

texts:
I'm currently saving money for a plane and training, and the expectations are that I won't have the money for full ownership of much else north of a Cessna 150.  I'm investigating partial ownership instead, and I've read that forming a company/partnership to own the plane is better than each member of the group just pitching in out of pocket.

Are there any drawbacks to using this method for plane ownership?


texts: Why don't we fly helicopters with yokes?

texts:
Both yokes and sticks are common in fixed wing aircrafts, with yokes on mainly passenger-carrying aircrafts and sticks mainly on gliders, aerobatic aircrafts and fighter jets.

However I have never seen a helicopter with a yoke-style flight control. Why?


texts: What is a "round-robin flight", in layman's terms?

texts:
I'm struggling to find a sufficient explanation of a round-robin flight, as it pertains to ATC.

Can someone explain, in layman's terms, what it is and the lifecycle of a round-robin flight? Graphic analogies are welcome.


texts: What is the maximum altitude allowed to fly a model plane/copter in Germany?

texts: What is the maximum altitude I'm allowed to fly a model plane or 'copter in Germany?


texts: Why don't contra-rotating propeller configurations with more than two propellers exist?

texts:
I wasn't able to find a single example of more than two propellers stacked axially in a contra-rotating configuration. There is a huge number of contra-rotating propeller setups, but it is always a combination of two propellers on the same shaft, not four or six.

Why isn't a piston engine used to run more than two standard propellers on a single shaft? Hasn't it been tried (or tested at least) in 100+ years of aviation history?

(This question isn't about turbofans/turbojets, but I also couldn't find anything for ducted fans: two props on a single axis is a maximum.)

Blade-solidity is explained here:
Contra-rotating props explained here:

An increase in a number of blades does seem to reduce the efficiency, whereas an increase in propellers on an axis seems to increase the efficiency.


texts: What should I do to become a pilot for skydivers, in France?

texts:
What are the steps needed to become a pilot that can transport skydivers?
I'm more specifically interested in the situation in Europe, France.

I would expect lessons / certifications, then more certification to accept passengers, then more certifications to be allowed to carry skydivers and let them jump. Also, medical examination, books, insurance, fees...

How much would it cost?
I'm more interested in the money amount spent usually observed than the theoretical price. I have a day job so I won't be able to easily spend all days of the week at the airport.

How long should I expect until I'm certificated?

Then, how often should I fly to stay current.
Obviously, there is the issue of practicing enough to be safe and the legal requirements to be allowed to fly with passengers.

I also expect to be required to be certificated with a specific level for the skydiving. Bonus points if you can answer that too.

I have seen this question about how much it cost to learn to fly, but it is less specific than my case. Still, many interesting points in its answers.


texts: Do Red Bull Air Race aircraft make use of nitrous oxide injection?

texts: Microsoft Flight Simulator X contains Red Bull Air Race missions where the player flies an Extra 300S through a race course and makes use of Nitrous Oxide injection for the engine.  While I have heard of NO injection for automobile engines, I have never encountered an aviation engine which made use of this.  Can anybody verify if RBAR teams make use of this?


texts: What kind of cameras are onboard high altitude UAVs that aid in its control?

texts:
I ask this question in the context of people flying their drones much higher than the usual hobby planes. Satellite based GPS navigated Autopilots using photogrammetry and/ or military drones.

What kind of cameras do first-person-view (FPV) pilots use and mount onboard to control the plane, and not for any sensors to collect data/ perform other tasks?


texts: How does an eILS improve throughput (for the A380)?

texts:
While researching where Heathrow's MLS approachs had gone, the only thing I could find is a topic on Heathrow's new eILS (enhanced ILS). As of the topic's date (Aug 2015) it seems eILS is only available in Heathrow and Zurich (at least for Europe).

While researching what eILS is (was not easy), I found this IATA presentation from 2017 that discusses it. It mentions the following:

  Ability to handle multiple A380s in Wide Area of the DLSA (currently only 1) and retain ILS usage, as no DLSA.

And it shows a diagram that I don't really understand:

I tried to search for ILS DLSA (Dynamic Localiser Sensitive Area), but I couldn't find anything. So, how does eILS do its thing?


texts: About F-35 hover/ roll posts responsiveness

texts:
how responsive is the f35 in hover. especially in the roll axis.
What do think of the roll posts? is it a good concept?


texts: Is it possible to ping ACARS repeatedly and track an aircraft?

texts:
This is a followup to What data does ACARS send back to base? Can it be used to track a plane?

I had asked this as a part of the earlier question, but it seems to be a large enough issue to be separate (plus no answers covered this aspect).

All electronic communication systems have low level diagnostic and channel check packages (commands). By pinging, I mean to send a system specific query message, and estimate the response time at base station or first receiver. Repeat the procedure multiple times, and calculate the response time differences. (Assumption) If the response time is decreasing, then the aircraft is moving towards the receiver, if it is increasing, then the aircraft would be moving away. Couple the time difference obtained from multiple responses, with the location of the receivers (which may be satellites or ground stations). Then, approximate the plane heading, location or speed, with reference to the receiver, and then with reference to the ground.

Would a process like this be possible with a high speed aircraft's ACARS? Are there any aspects specific to an aircraft that would make this impractical?


texts: Who logs Pilot-in-Command time with all automation, autopilot, auto throttle, FMS, Autoland doing the flying?

texts: Who gets to log PIC, if the First Officer programs the FMS and turns on the autopilot at 1000FT AGL while the Captain calls the checklist?


texts: Would it be possible to use a magnetron beneath glider plane to generate its own thermals?

texts:
Would it be feasible to install a series of magnetrons or something else on the underside of a gliders fuselage and wings in order to heat the air beneath the glider and ultimately cause the glider to obtain high altitude flight or obtain flight when thermals are not available? If hot air rises would you theoretically be able to artificially heat the air beneath a glider in order to achieve high altitude flight?

I was watching videos about gliders and I noticed that thermal air pockets are often required to achieve altitude gain. I'm a dumb guy so excuse me if this is a ridiculously dumb question.


texts: How is RVSM approval obtained for a properly equipped airplane?

texts: If an airplane is already equipped for RVSM flight, how do we obtain a Letter of Authorization (LOA) for RVSM in order to actually fly in RVSM airspace?


texts: What are the advantages of the angled flight deck layout used by some aircraft carriers?

texts:
I've been flying aircraft carrier approaches in a flight simulator lately and noticed that the carrier has an interesting layout. I have an image below where the landing runway is in red and the takeoff runway is in blue.

I can understand the takeoff runway - taking off into the wind with the catapult so that you can get enough air flowing to take off. The part that confuses me is the position of the landing runway. It is at a slight angle to the direction of the carrier's motion, meaning that when I fly the approach I have to aim to the right of the carrier and let it move underneath me. It seems to me as though this would just complicate an already difficult procedure, particularly in rough weather conditions.

Why not just take off and land in the same direction? As far as I am aware the aircraft only take off forward of the jet blast shields i.e. at the tail of the blue arrow. This would leave plenty of room on the carrier for landing. The only time I can think this would be a problem would be when a pilot needs to abort the landing and quickly take off again when there is another jet waiting to take off ahead of him, though this would assume that aircraft were taking off at the same time as others were landing (I have no idea if this actually happens).

It would be great if someone could shed some light onto why aircraft carriers have this layout - I'm not a pilot, just been playing around in simulator.


texts: Do I need a digital or analog scanner to listen to Air Traffic Control?

texts: I'd like to buy a scanner to listen to Air Traffic Control (e.g. Tower, Approach, etc.). It would be used mostly at either Washington National [DCA], Dulles [IAD], or Baltimore [BWI]. Would I need a digital or analog scanner to hear these transmissions? Thanks!


texts: On a 777 what would happen if the aft pressurization switch was accidentally left closed?

texts: The Boeing 777 has fore and aft pressurisation switches (see example here). If the aft switch was forgotten on takeoff, could this cause a loss of cabin pressurisation when the aircraft reaches altitude?


texts: Did Airbus add an audible alert when the autopilot partially disengage after the crash of Aeroflot Flight 593?

texts:
The major reason that lead Aeroflot Flight 593 to crash was the partial disengagement of the of autopilot (by the pilot's kid who was in the cockpit) which could have been avoided if the pilots were more familiar with the Airbus 310-100 or there was an audible alert.

Do new Airbus aircrafts have an audible alert in such cases now? were the old ones some how altered to implement this?


texts: Material alternatives for aircraft leading edge

texts: Are there any material alternatives for the aluminium used on the aircraft leading edge? By alternatives, I mean composite alternatives.


texts: Could atmospheric effects cause a PA-30 to break up?

texts:
About a week ago, a Piper PA-30 crashed into a residential area just a few miles from where I live. An engine was found to have landed a 0.24 nm from the impact site. Sadly, the pilot of the aircraft was killed. Thankfully, however, in spite of the crash occurring in a crowded subdivision, nobody on the ground was injured.

Now, to the heart of my query:

The NTSB preliminary report indicated an in-flight breakup of the plane. There was not an active thunderstorm in the area, but with 30 minutes or so a small cell had developed (source: me, I do live nearby). Are smaller aircraft subject to atmospheric effects that could cause an in-flight breakup? If so, what sort of atmospheric conditions, assuming a skilled pilot who wouldn't purposefully fly into known bad conditions, would be necessary to cause such catastrophic damage to a small craft like a PA-30?


texts: How do electric carbon monoxide detectors work?

texts: How does the electric carbon monoxide detector in cabin or cockpit on aircraft work?


texts: In general, how do aircraft handle differently in inverted flight versus in upright flight?

texts:
Inverted flight is flight with a roll angle between 90° and 270° (although it classically referred specifically to flight with a roll angle of 180° - i.e., upside-down).  In what ways, in general, does aircraft handling in inverted flight differ from aircraft handling in upright (non-inverted) flight?

Partially inspired by reading about the crash of Alaska Airlines Flight 261, including how the pilots apparently tried (albeit unsuccessfully) to recover their airplane from its final dive by rolling it inverted.


texts: What are the correct fixes for the MAX's pitch control systems?

texts:
At this point, the ramifications of faulty data input from only one sensor into the MCAS system of the 737-MAX are well understood, having allegedly led to 346 deaths, losses of almost 10B USD for Boeing, losses of around another 1B USD for American and Southwest, skepticism about the FAA's oversight ability, and even a potential hit to overall U.S. GDP.

That's pretty bad. Even in today's business culture where many mistakes are whitewashed, explained away or "taken care" of by a few executive firings, it's still reasonable to conclude that had it known what was going to happen, the manufacturer Quality Control would have done anything in its power to identify and correct the issue before the planes first shipped.
Indeed, the concept (in hindsight) should have never left the drawing board.

Solutions could be as simple as releasing the software patch they claim is currently under test,  through programming not accepting data from only one sensor (not as an option), and better pilot training and education.

It could also be fixed by more organic solutions, such as :  adding several more AOA sensors, lengthening the fuselage, repositioning the engines (setting them a bit wider), and/or longer landing gear (see Constellation, Concorde, XB-70).

What would have to be done to the plane's design to make its aerodynamic handling equivalent or better than the 737 NG series (or any other modern airliner), without need of a late-stage corrective system?


texts: How are foreign militaries regulated in the USA?

texts:
I believe the US military is not officially subject to the FARs, but what about foreign military aviation?  What about aviation activities of the various National Guard outfits?

Example...the Belgium air force operating a squadron of C-130's during a training exercise held in the USA.


texts: Why does directional stability decrease at supersonic speeds?

texts: As an aircraft accelerates through the transonic region from full subsonic to to full supersonic flow its directional or yaw stability decreases. What causes this reduction?


texts: Are there any supersonic aircraft with strictly mechanical controls?

texts:
Are there or is it possible at all to create a supersonic aircraft with strictly mechanical (human powered without boosters) controls?

I know there was an attempt: Bede BD-10 but it never reached supersonic speed.

Have there been successful planes/designs that implemented it?


texts: How did aircraft flying in formation use flares to communicate with each other?

texts:
The image shown in the question Which aircraft had such a luxurious-looking navigator's station? (also below) shows a flare gun with several flares.

A comment below the question says:

  On the bonus question: flares were often used for communication between planes, sometime even when all planes in the formation had radio (to the point that new flare systems had to be designed for high altitude pressurized bombers at the end of WWII). Given the number of cartridges right under the flare gun, I think it is indeed for communication and not just for distress signaling, so you would probably want it readily available.

How common was it for this to be used, and how effective was it, especially during the day? When would it be used, and what would the flare indicate or communicate?

cropped and sharpened from https://i.stack.imgur.com/K0cO2.jpg used in here.

 Source.


texts: Why did this commercial flight fly in circles while far from the destination?

texts:
I was on the flight CX635 from Hong Kong to Singapore today, and I noticed the plane turning in a circle reminiscent of the holding pattern that planes often enter when they are queuing up to land.

However, this time I saw this flight pattern on the in-flight tracker while it was still in level flight, and once again when it was descending. When I got home, I saw that the pattern was also recorded on FlightRadar24.

Why did the pilot fly two circles in the middle of the ocean off the east coast of West Malaysia? I did not observe any obvious severe weather patterns, and the clouds were generally sparse (2 oktas or so) when it was doing the first roundabout, and there were no visible indicators of significant severe weather activity.


texts: What is the meaning of HOT-1, HOT-2, CAM, etc., in cockpit voice recorder transcripts?

texts: When reading the the written down recordings of CVR like here, for instance, it is common to see abbreviations like HOT-1, HOT-2 or CAM. I guess that CVR records multiple channels and the codes indicate the microphone that is believed to be closest to the source of the sound. But what exactly these abbreviations mean? Which others are possible?


texts: How do you choose CAT II vs. CATIII ILS?

texts:
When should we use CAT II or III during landing in bad weather? What we have in our country the standard shows 800m and RVR of 550 m for the ILS, which category procedure should be used if the visibility below or above?

On the other hand nothing tells us if it is CAT II or CAT III inside the charts except at the large airports.

And regarding the DH during the CAT III is it always 50 RA ?


texts: Are there references for the different maneuver configurations?

texts:
Since it's helpful to have specifics, lets use a 1978 Cessna 172RG as the reference (it's what I'm most interested in knowing about anyway).

Is there resources that would have the following information (for example, I know you would enter each maneuver differently).

  Maneuver: Rectangular Course
  MP: 15"
  RPM: 2200
  Gear: Down
  Airspeed: 108 Knots

I'm looking for a reference for all private and commercial flight training maneuvers that would have specifics on how to enter the maneuver that would allow the maneuver to be completed without excess airspeed (or not enough). I'm not looking for how to complete the maneuver (the AFH has this information), but how to enter the manuever. Does this exist as a general reference, or is it so specific to each airplane that it couldn't exist in a general form?


texts: Does avionics type matter when training for PPL?

texts:
Soon I want to start training for my PPL (VFR) and I'm currently looking at two flight schools in my area. At one of the two their whole training fleet is equipped with G1000 avionics, while the other also has aircraft with "old school" steam gauges.

My reasoning is that it's better to first learn it the old way, and then upgrade to glass, since it seems much easier than the other way around.

Is this reasoning sound, or does it actually not matter that much when training for PPL? To further clarify: I want to get my PPL for recreational flying, not for commercial use.


texts: What are good resources for learning more about communications?

texts: As title says, which book/web site/etc.. are available for learning proper communication (for Private Pilot License)?


texts: What techniques professional pilots use to keep their piloting skills sharp when not flying for an extended period?

texts:
I don't get to fly as often as I'd like. I know that simulators are good for brushing up on technique, learning new systems, etc.

Are there techniques that pros use (commercial or military) to stay sharp about things when they aren't able to actually fly? Specifically things that I would do not in a simulator, but say I have a couple months where I can't fly, but have an hour commute, or 30 minutes per day that I could do something flying-related to stay sharp.

I realize there is no substitute for actual flying, but I always feel a little rusty (mostly I just feel a little behind the airplane) when I haven't flown for a month or two. Are there things that other pilots do that I could learn to do in my down time that would mitigate this?


texts: Does the payload of an ICBM or regular airplane bomber explode if the ICBM or bomber is shot down?

texts: As the top says, does the payload of an ICBM or regular airplane bomber (please excuse my ignorance) explode if the ICBM or bomber is shot down? So, say a defense laser in space (yes, I know; this is hypothetical for a setting, but) disables an ICBM in mid-flight, would the bomb detonate as well? If I recall correctly, even regular bombs shouldn't explode if the bomber explodes, that is, the bombs are meant to go off exactly when the bombardiers wish them to go off. Thanks.


texts: What is the air crash featured in Queen's Innuendo official video?

texts:
There's a short cameo of a total destruction of a plane in Queen's Innuendo official video (2:11).

Here's the video itself:

And here is a screenshot of the most important frame:

Is anyone able to identify this particular air crash and the airplane involved?


texts:
Does the FAA have any regulations governing the design of a turbine engine FCU? I'm being questioned about an older Beechcraft PT6A FCU - in particular, how can I guarantee that when the power condition lever is at the shutoff/cutoff position, no fuel is moving to the combustor...? Any help would be appreciated... Thanks!

Edit - for those needing clarification:

Does the FAA have any regulations governing the design of a turbine engine FCU?

Simply as stated, does the FAA regulate how a turbine engine FCU can be designed - pressure allowances, flow volumes, etc.

I'm being questioned about an older Beechcraft PT6A FCU - in particular, how can I guarantee that when the power condition lever is at the shutoff/cutoff position, no fuel is moving to the combustor...?

As stated, I'm being asked to prove that when the power condition lever in the cockpit is moved to the shutoff/cutoff (pick one term) position, fuel will not flow into the combustor. Tying into my first question, does the FAA regulate that a turbine FCU MUST absolutely cut off all fuel moving to the combustor, or is that just left to the designer to ensure...?

Hope that clarifies everything. Not sure how much more detailed I can get without specific and possibly pointed questions.


texts: What would be the minimum number of engines required to climb in a 747?

texts:
There was a really good Air Crash Investigation by Nat Geo which showed the British Airways Speedbird 9 issue where volcanic ash swept over all four engines and through the air vents inside the cabin. As a result, all engines stopped working.

After around fifty attempts to restart the engines, engine four roared back to life. Although this did bring good news to all onboard, one engine would still not have given them enough power to clear the mountains that were in their path around Jakarta. Due to this, the Captain turned back to sea.

Nat Geo Flight 9. All engines stopped.

I don't think National Geographic would be super accurate but this looks like one engine could have cleared this mountain.

Anyway, this got me thinking.

A 747 can fly on one engine but can't climb? This does make sense, one engine can make a 747 fly for longer but it cannot climb with just one. What then would be the minimum number of engines required for the jet to clear the mountains? Two?


texts: Why does a T-tail produce a pitch-down moment in sideslip?

texts: Here is something which I did not find in any book, but confirmed in several wind tunnel and flight tests: A T-tail causes a strong nose-down moment in sideslip. This can even be observed in a potential flow analysis, so no fancy viscous effects should be required for an explanation. But I have never understood why it happens. I would even have an explanation for a pitch-up, but the pitch-down really has me puzzled. Does someone here know more?


texts: Does deploying flap change the aspect ratio of the wing?

texts: Specifically when a Plain flap is defleted the geometry of the wing will be altered (Camber is increased). Does this have any effect on aspect ratio? What's the connection between Camber and aspect ratio?


texts: What flights were significantly affected by insects hitting the fuselage?

texts:
Related
How do insects decrease aircraft performance?
This questions made me think was these effects actually noticeable in an any flights- maybe the pilots had to big changes to their flight management or did they reach emergency conditions?


texts: How are these Airbus A350s flying in formation without being affected by wake turbulence?

texts:
The first photo in this article appears to depict three Airbus A350s flying closely in tandem at approximately the same altitude.

I thought that a large jetliner would leave a trail of wake turbulence behind it that would be unsafe for several minutes.  Is there something special about the Airbus A350 that makes this formation possible?  Am I misinterpreting the photo?

The V formation in the second photo seems much more reasonable.


texts: What adds more weight to a twinjet? Tail-engines or wing-engines?

texts:
Let's say we have a large commercial jet, with exactly 2 engines, capable of holding at least 200 passengers.

It could be a traditional jet like the Boeing 777, where both engines are in the wing. Or it could be like the MD-90 with both engines at the tail.

My question is, which configuration adds more weight? With engines on wings, we must add pylons and strengthen the wing to resist bending, especially when on the ground. With engines at the tail, we must add weight to strengthen the T-tail. There might be some extra fuselage weight at the back for holding up the engines, but I'm not sure.

There may be other weight additions that I don't know about. Ultimately I want to know which config requires more weight.

Note: I'm not asking which is best. Best would require more than one factor. This question is only asking about one factor, weight.


texts: What is the gross weight limit for a Light Sport Aircraft?

texts: In the US, I see a lot of LSAs stating their take-off or gross weight limit as 1320lbs.  Can some of these planes have a higher physical limit and that 1320lbs is just more a category limit?


texts: How is Maximum Take Off Weight determined?

texts: How would a test pilot determine the MTOW of an aircraft. Does the manufacturer predict this value?


texts: Who operates delivery flights for commercial airlines?

texts: Seeing an A220 flying to Atlanta for delivery to Delta made me wonder: Which crew operates a delivery flight? The manufacturer’s pilots? Or the airline’s crew?


texts: Can a transonic airfoil have two shock waves?

texts:
I am currently running CFD cases on a transonic airfoil at Mach 0.75 and performing an angle-of-attack sweep to evaluate its performance. When I reached the angle of attack of 4.5 degrees (which I appreciate is very high for transonic flight, but tested nonetheless), a dual shock was formed on the suction side. Is this physically possible?

I understand how the suction-side flow may reaccelerate after a shock with favourable pressure gradient and possibly exceed sonic again, leading to a second shock, but wouldn't it just produce a single, stronger shock downstream?

I attached the two flowfields, colored by Mach number, with the first image representing the angle of attack of 4.5 and the second at 3.5 degrees.

Following jayS answer, I plotted the Cp for the two airfoils seen above, for comparison to the chart found.


texts: A document said that the optimum CG position is from 13% MAC to 33% MAC. I'd like to know what that means, and what would this look like on an actual plane.


texts: Where is the landing distance for seaplanes specified?

texts: I need to know, is there a specified distance for the landing areas of seaplanes? In airports, we have generally distances are defined according to the flight requirements. I need to know whether there are certain distances defined or just making the landing area by guessing?


texts: What dialogue would a crop duster typically have with ATC?

texts:
By Stefan Krause, Germany (Own work) [FAL], via Wikimedia Commons

What is the exact dialogue a crop duster pilot will have, if any, with ATC on a routine flight?


texts: Where is the spanwise flow? How does the span wise flow point the air towards the wingtip?

texts:
If you search Google for span wise flow, the first result under the pictures tab is a image of a wing with the span wise flow at the trailing edge:

(Source)

If you look at some other photos you notice others pictures that show to span wise flow at the leading edge:

(Source)

Is the flow at the leading or trailing edge?

At first I though the flow must be at the trailing edge because this would cause the airflow to point more and more towards the tip of the wing. After a little thought I realized that the air(span wise flow) should be flowing along the leading edge because that is where the air splits up in the first place.

So basically I am asking if the span wise flow is flowing along the trailing or leading edge of the wing.

How would this air cause the airflow to gradually point towards the wingtip?


texts: Is it OK to use foam for the ribs of an ultralight's wing?

texts: I have seen several YouTube videos of ultralights and even HPAs (Human Powered Aircraft) that use foam as the ribs  of their wings. Are ribs not supposed to be made of rigid, strong, woody and light material i.e pine,balsa etc.?


texts: Why is an approach that relies on both LOC and PAPI not considered a precision approach?

texts:
I am an aviation layman. I am reading about PAPI lighting system and it seems like it provides vertical guidance, just like the glideslope component of an ILS.

Coupled with a LOC, both vertical and lateral guidance are available to the pilot.

Why isn't such an approach considered a precision approach?

Thank you.


texts: Why is ARP (Airfield Reference Point) needed?

texts: An airport reference point is the centre point of an airport, located at the geometric centre of all the usable runways. The ARP is computed as a weighted average of the end of runway coordinates.


texts: Thought experiment: can an aircraft that is dropped from the sky get into gliding?

texts:
Here's a totally hypothetical question that came up in a discussion with friends:

If a commercial aircraft (say, an Airbus A320) was "dropped" from a typical cruising altitude (say, 35,000ft) with a current ground speed of zero and all engines off, would it be possible to get it into gliding by putting the nose down, and how far could it go?

The much more practical question "how far can an aircraft glide" is already answered (e.g.,
How far can airplanes glide?), but it would be great if somebody could participate in this thought experiment with no engines and no initial speed.


texts: If a commercial airliner enters into a spin at high altitude, is it possible to recover?

texts:
Often flying I have this fear, that something will snap, and the plane will start plunging to the ground in a spin.

My question is, once a passenger aircraft (e.g. an A320) goes into a spin, can the pilots recover it, stabilize it and make it glide, or is it too late?

A similar question was asked before, but I am looking specifically for answers regarding large passenger aircraft.


texts: What would happen if the sole pilot dies while flying an aircraft?

texts:
An aircraft is flying in cruise flight on a long distance flight. The autopilot is turned off. The only occupant of the aircraft is the pilot.

Suddenly that pilot dies, what will happen?


texts: What are the driving factors for performing a steep approach

texts:
What are the factors a pilot needs to consider before preparing for the steep approach?

How is steep approach combined with auto land feature.


texts: What is the thrust balance between compressor and exhaust nozzle for a turbojet engine?

texts:
I had this question asked in university and the teacher was unable to provide more than a theoretical estimate. The ratio I was given was 15/85.

Obviously in the case of a turbofan this ratio increases.

Is there any professional pilot or engineer able to tell even on a real example, what is the ratio of thrust distribution between compressor and jet for a known reactive jet engine, turboprop or turbofan?

I believe that helicopter turboprops produce no measurable thrust in the jet. Anyone?


texts: To what degree do airline ops specs preclude hand flying?

texts:
I retired in 1999. I'm curious to what degree typical airline ops specs now discourage or prohibit doing what I used to do as a matter of course insofar as hand flying.

For example, I usually hand flew the aircraft until leveling at the first cruise altitude (FL290 or FL310 on fully loaded 747-100/200 aircraft). For the step climbs as fuel was burnt, I nearly always disengaged the autopilot and did the climb manually. At the top of descent I clicked the autopilot off, and I flew approaches manually.

Many of my fellow crew members thought it odd that I did so much hand flying, but as I would explain when asked, I didn't get to the 747 until I was 50 and didn't get to its left seat until a couple of years later, and I wasn't about to forego any of the fun.

None of the hand flying I did was prohibited by our ops specs of the time. My question is: to what degree, if any, do current ops specs discourage or prohibit the hand flying I did?


texts: How did aircraft in WW2 navigate to the carrier?

texts: How did aircraft in WW2 navigate to the carrier after their mission? I was thinking of something like a beacon installed in the carrier but wouldn't it reveal the location of the carrier itself?


texts: Is it legal to build your own plane and fly it?

texts:
Is it legal to build and fly your own airplane? This essentially leads to two central questions: Will the FAA even let you build and fly your own airplane?, and Will there need to be inspections and testing records to certify it as flightworthy and legal before being able to fly it?
Say I built my own plane, a large plane. 3 Propellers powering the plane. Amphibious, can land and take off on a runway or on the water. It's red, if this makes any real difference. And it is built to support 2 people and is supposed to be able to fly for up to 1 week without refueling. That being said, if the plane crashes it'll cause quite some damage. And to fly for 1 week supporting 2 people and quite a lot of cargo in the form of food and other essentials, the airplane is loaded with fuel.
If I know the plane floats on the water, could I fly it in an unpopulated area in short testing runs, or is that considered illegal? This also brings the question, Is there is a limit to how much fuel a plane can legally carry in a single flight? Any help would be much appreciated.


texts: Does a turbojet aircraft restriction on a SID or STAR also apply to turbofan aircraft?

texts: Just wondering since I've never seen turbofan aircraft mentioned on SID or STAR charts, and many airliners are turbofan nowadays.


texts: Are the IMU velocities equivalent to the GPS ground velocity, except for the coordinate reference system?

texts: If the velocities measured by the IMU in the body-fixed reference frame are converted into earth fixed frame, are they equivalent to the ground velocity measured using the GPS?


texts: Statistically, are planes with advanced autopilot functionality less likely to be involved in fatal crashes? Answer only with actual statistics, not your personal opinion.


texts: What are the protocols of flying over conflict areas?

texts:
Apparently Malaysia Airlines Flight 17 used a general airway over the east of Ukraine, which currently is 'in conflict'.

What are the 'normal' procedures regarding (not) flying over conflict areas? Who is responsible for an up-to-date risk assessment? Who advises? Who makes the (final) decision?


texts: Do captains and first officers always fly together or are they mixed?

texts: I was wondering if the same captain and first officers always fly together for some time as some sort of a team or are they mixed around in every flight? I suppose if you have one plane that is the case but what happens in huge airlines such as emirates? Wouldn't it also be a drawback always flying with someone that you do not actually know?


texts: How does a lean die-out occur in a turbine engine?

texts:
Essentially a lean die-out occurs at higher altitudes with low engine speed, and low fuel pressure, which results in a weak flame. So an overly lean mixture exists.

With these conditions, how would this exist? Typically at higher altitudes you're assuming there's less air, and with a lower engine speed, you'd get less ram air going into the compressors.


texts:
(Source)

Is that a Ram Air Turbine (RAT) on the port side below the wing? Why is it already deployed and spinning during takeoff?

This answer mentions a minimum airspeed at which RAT can be deployed.


texts: Why use different airfoils on the same wing of an aircraft?

texts:
Why different airfoils are used in different portions of the same wing of an aircraft, for example Boeing 737 wing?

Boeing Commercial Airplane Company model 737 airfoils' dat files from here:
http://m-selig.ae.illinois.edu/ads/coord_database.html

BOEING 737 ROOT AIRFOIL (b737a-il),
BOEING 737 MIDSPAN AIRFOIL (b737b-il),
BOEING 737 MIDSPAN AIRFOIL (b737c-il) and
BOEING 737 OUTBOARD AIRFOIL (b737d-il)


texts: Why would the USAF have no support for autolanding?

texts:
One thing I noticed when reading through the KC-10 flight manual (see page 184 for the specific reference) is that the KC-10 lacks support for Category III operations, unlike its civil DC-10 brethren.  What was the purpose behind the USAF asking MDC to remove capability from a military airplane?

Furthermore, military ILS systems in the US are qualified to CAT II at best, even in areas where air carrier airports are well-qualified for CAT IIIb minima.  For instance, Joint Base Lewis-McChord only has a CAT II approach to RWY 34 whereas nearby Seattle-Tacoma Int'l has CAT IIIb approaches to 300' RVR on all three of its primary instrument runways.  Considering that I seriously doubt the USAF would somehow be buying ILS equipment inferior to what's available in the civil market -- is there some other reason they don't provide any low-visibility capability better than the CAT II minima of 100' DH and 1/4 mile visibility, as the published PAR minima in the A/FD are no better, either?

Update: KADW RWY 19R has a CAT IIIa approach, good to 700' RVR.  This seems to be the only military CAT III procedure published, though.  Perhaps the VIP airlift aircraft (E4, etal) have autoland support, even though the normal military heavies don't?


texts: Can coaxial rotors be mounted on a piston engine like the Lycoming O-320?

texts: What are the drawbacks of this compared to coaxial configuration with a turboshaft engine?


texts:
I am interested in the process of using maritime patrol aircraft in an antisubmarine role. I hope there is some general answer, because I have no idea what such missions look like.

How long can such a mission be and how big an area can it cover?
What techniques are used during such missions?


texts: Under what conditions can a pilot log simulated instrument time?

texts:
Can a pilot log simulated instrument time with these conditions and what regs would justify this:

VMC
Safety pilot on board
View limited device
VFR-only aircraft
Unapproved instrument navigation devices (ie. handheld NAV/COM)
Location USA

Say the pilot had a copy of Foreflight and a handheld NAV/COM with ILS capability. Aircraft is has typical VFR 91.205 equipment.


texts:
I was looking at the FCOM of the 787, and I came across an interesting thing. There is an HUD takeoff selection on the SID selection page. It got me to wonder, how does the HUD track the runway from so far away?

Is it related to ILS?


texts: How can I determine takeoff and landing from an ADS-B feed?

texts:
An ADS-B feed consists of a series of latitude, longitude and altitude points, without any "start" or "end" markings as such.

Using this data, which can contain arbitrary gaps and errors, what's the most reliable way to determine when an aircraft has landed or taken off at an airport?

Update: I'm looking at preprocessed feeds in VRS's AircraftList format, which on closer inspection has a boolean "Gnd" field.  (Note that there's no guarantee that any but the most basic data fields will actually be available in practice.)


texts: What is an out-of-trim condition and how is it detected?

texts:
I am reviewing autopilot requirements which mention that whenever an aircraft's altitude changes as a result of air disturbance or an out of trim condition, the inertial sensors will detect this change and an error signal is developed and fed to the relevant control channel, amplified, and applied to the servo actuator so that flight control surface can  be moved.
My question is what is out-of-trim condition? Is it something related to setting trim for constant speed?


texts: With radio not working, why it is more important to stay away from exactly class D airspace?

texts:
The instructions how to land when the radio is no longer working state as the first item "stay away from the class D airspace".

Why is the class D specifically mentioned in these instructions? How it could be that A, B which "has the most stringent rules" and C are less a problem?


texts: How should I deal with a cable break at low level during a glider winch launch?

texts: What should I do when rope breaks at 220-360 ft [75-120m] when there is not sufficient runway to land ahead and not sufficient altitude to make a return manuover and land with the wind direction?


texts: Is a radio call required when vacating an altitude after being given a discretionary descent?

texts:
When operating a flight under these conditions:

In the USA
Under the FAA jurisdiction
Given a descent with pilot's discretion by controller
Operating on an IFR flight plan

Is a radio call required when vacating the altitude that was occupied when given the discretionary descent?


texts: Why do new jet engines cost billions to design?

texts:
This question might come off as crude because it involves people's salaries, but I do not understand why new designs of large turbofans cost many billions of dollars to design. For example, the Pratt & Whitney geared turbofan apparently cost 10 billion USD.

Why? Last I checked, most scientists and engineers do not make millionaire salaries. I think it's more around 100 to 250k tops. Even if you had 100 of them working for 10 years on it, that would be 250M, or a quarter of a billion dollars. Instead, jet engine designs seem to cost multi-billions.

I don't understand. If it's just designing a jet engine, then raw materials cannot possibly be a major factor even if it's something like titanium or composites. How many prototypes could you possibly need? I mean I hope it's not all trial and error.

The other thing is computer software, which I thought would make things easier and cheaper to design. Granted you cannot just input the desired thrust and press a button, but surely there is decent fluid dynamic software out there that can help you design something much easier and faster than before.

So what makes it so expensive? Is there some super costly certification process? Or do you somehow need more than 100 engineers collaborating? 1,000? 10,000? If so, why? Cannot imagine that.

Maybe someone can explain the general process of jet engine design in the first place because I'm sure that would be helpful. They way I imagine it, you just go through stage by stage and try to get each blade shape and diameter right.

Or maybe I have some misunderstanding and the 10 billion includes the costs to put up the factory?


texts:
This question makes me wonder what happens at -1G.
When the load factor of an aircraft increases above 1, the stall speed increases. As the load factor comes closer to 0, stall speed decreases and becomes "infinitely" low (basically 0 kts) as an aircraft can not stall at 0G. But what happens at a negative load factor?
For example, during inverted flight the airfoil is still producing lift when the angle of attack is negative (enough).  Thus the stall speed should change and as the efficiency of a inverted wing is (almost definitely) not as high, I am assuming that the stall speed decreases.
But is a negative G maneuver necessarily to be done in inverted flight? No!
As a glider pilot,  I can refer to negative Gs during winch launches, or rather when they fail. You often practice cable fails, where your instructor disconnects you from the winch. To maintain speed and prevent a stall you push the nose down, ideally flying a small Zero-G parabola (as this will prevent a stall). But what if you push even more? Where is the stall speed going to be at?


texts: What are calibrated airspeed (CAS) and equivalent airspeed (EAS) used for? When would a pilot need to know these?


texts: How to calculate variable pitch propeller parameters?

texts:
I'm carrying out a project on Variable Pitch Propellers for UAVs and especially self-adjusting or Passive Variable Pitch Propellers that change pitch due to aerodynamic forces and Pitching Moments.

At the moment I'm working on a single element (sectional airfoil) using blade element theory for three different stages of the aircraft: Take-off (with a given high RPM,e.g 2000), Cruise (medium RPM,e.g 1000) and landing (low RPM e.g 500) and corresponding free stream velocities 0 , 80, 20 m/s respectively.

However while I'm trying to calculate first Lift and Drag and then Pitching Moments, I realized that there are unknown factors needed for the calculations such as lift and drag coefficients as well as Angle of Attack on that sectional blade element.

The purpose is to use at first a symmetric aerofoil with no camber and I was wondering whether I have to use a commercial aerofoil such as NACA and if so, how to get the Cl and Cd from this aerofoil.

My questions are:

How to calculate the angle of attack or pitch angle while I know their subtraction?
Do I need to give some values for a new parameter that will help to find  these calculations or RPM, Vinf, and r of the propeller is enough?
What about the chord length; do I need to give a random value there?

I am sorry if some of the questions are silly but I'm coming from a different background and I'm fresh in the aerodynamic field.


texts: Can a someone with just a PPL log PIC time on a non-transport commercial flight?

texts: I have a job that requires me to travel on a small company plane with a company "commercial"pilot. I only have my PPL. If I am certified in the type of aircraft may the pilot allow me to fly "solely manipulate the controls" of the aircraft, while he clearly remains the PIC and responsible for the flight? If I am rated in the aircraft could I log those hours?


texts: On coaxial helicopters, how exactly does the yaw mechanism work?

texts:
This question asks how coaxial helicopters achieve yaw. The accepted answer correctly states that this is done by increasing pitch on one rotor while decreasing pitch on the other rotor, which leaves lift the same and creates a yawing moment.

The post became active again on 20 July, when @Andy Ewen asked how the mechanism works exactly:

  ..a lot of the answers are stating the obvious but fail to explain HOW. Yes a torque differential between the rotors will effect a yaw but the real question is how is this achieved?

The post was deleted and not entered by OP as a separate question, hence this question. How is this achieved, exactly?


texts: Do non-US citizens still have to get an additional TSA check?

texts:
I'm familiar with the rules requiring all non-US citizens to acquire TSA clearance, but as of 2016 the rules have been changed and it seems that everybody has their background checked by the TSA as part of the student pilot certificate application process.

Does this mean that non-US citizens no longer have to go through the separate background check, or will they now be checked twice by the TSA?


texts: Why is the tail group of virtually every airplane swept instead of straight?

texts:
Even low performance airplanes like ultralights have their tail group (vertical and horizontal stabilizer with rudder and elevator) swept backwards knowing fully well that a straight tail group will produce more force than a swept tail group of the same area. Is the sweeping of an airplane's tail group simply aesthetics or is there some aerodynamic advantage involved?

The reason why I'm asking is because I'm trying to design and build an ultralight and was wondering if I can just build a straight rectangular tail group as seen below (for the sake of simplicity).


texts: Where can I find a collection of maximum range at maximum payload values for all aircraft types?

texts:
The scope of my Master Thesis is the development of an assignment algorithm of aircraft types to routes with a given distance. As part of violation checks I'm validating the possible range of the AC type against the route distances.

As defined per payload-range diagram the max range of an aircraft type is not a static value but depends on the amount of payload desired. For a more realistic approach I'm looking for values of the max range at maximum payload of every aircraft type defined in ICAO Doc 8643.

However this value is not very easy to find out. Does anyone have an idea where to find a list of all (or at least all major aircraft types) max ranges at max payload of all aircraft types given in ICAO Doc 8643 grouped by the ICAO Designators (e.g. A332, B773, etc.)


texts: How would a new "clean sheet" General Aviation piston engine with all the latest technology differ from existing Continental/Lycoming types?

texts:
My understanding is that current GA piston engines from Continental and Lycoming are based on a design from the 1960's. There have been many evolutionary improvements, but only within the limitations of those 1960's designs. They are large displacement (~1.5L/cylinder), run at RPMs in the mid 2000s range so that they can spin the prop at optimal rates without using a gearbox, and they are air cooled to save the weight and complexity of a liquid cooling system.

What would a completely new, designed from the ground up GA piston engine look like today? Factoring the massive improvements that have been made in all sorts of engines over the years in non-aviation applications- for autos, trains, boats, generators, etc.

Would they still operate at such low RPMs? Yes reliability and durability are still major concerns, but manufacturing tolerances are so many times smaller now then they were in the 1960s (possibly allowing for reliable operation at higher RPMs), and they are now mounting fixed gearboxes to commercial airliner turbine engines so adding a fixed gearbox to a GA piston engine should be trivial.

Would they still be air cooled? Yes it can still save weight, but possibly at the cost of extra cooling drag, and definitely at the cost of much more finicky operation that requires the pilot to carefully monitor engine temps throughout their flight cycle.

Would they still be in a flat engine arrangement (flat 4, flat 6, etc.)? I would imagine so, I can't imagine an alternate piston engine arrangement with the smoothness, packaging, and scalability advantages of the flat architecture. Straight engines get too long, and V engines require many more changes to scale the number of pistons up or down.

Would they still fly on spark-ignited gasoline-type fuel, or could compression ignition based on jet fuel produce the power density and reliability required? I realize that the single largest factor in this area might be the simple availability (or lack thereof) of fuels, but I am talking about purely from an engineering perspective. Suppose we are talking about North America where both Avgas and Jet A are widely available, what would be the superior fuel for flying GA piston engines?

What other differences might there be that I haven't considered?


texts: What is the physical meaning of circulation found in Kutta condition?

texts:
The Kutta–Joukowski theorem is applicable for 2D lift calculation as soon as the Kutta condition is verified. When this is the case, there is a circulation $\small \Gamma$ around the airfoil. My question is related to this circulation:

What is the physical meaning of the circulation $\small \Gamma$, often represented like this (example 1, example 2, example 3):

(Own work)

I'm interested in a simple explanation of the circulation (is air moving around the airfoil? for dummies) and how does this circulation relate to a view of the airflow in a wind tunnel, where there is no apparent air flowing clockwise around the airfoil:

Source: Youtube

The rest of this post is a presentation of the circulation theory which motivates my question, and as I understand it, but is not part of the question.

The Kutta condition is linked to stagnation points, the points where air tubes separate to flow on a given side of the airfoil, and where they join again behind the airfoil. The Kutta condition stipulates the latter point coincides with the airfoil trailing edge:

  Wikipedia: A body with a sharp trailing edge which is moving through a fluid will
  create about itself a circulation of sufficient strength to hold the
  rear stagnation point at the trailing edge.

(Own work)

According to theory, when the airfoil moves through air, the circulation moves the rear stagnation point to the trailing edge, and then maintains it at this position. When at this position, the circulation is finite and can be used to compute lift with Kutta–Joukowski theorem:

  Wikipedia: The theorem relates the lift generated by an airfoil
  to the speed of the airfoil through the fluid, the density of the
  fluid and the circulation around the airfoil. [...] The lift per unit
  span $L^{\prime}$ of the airfoil is given by:

  $$L^{\prime} = −\rho_{\infty} V_{\infty} \Gamma$$

  where $\small \rho_{\infty}$ and $\small V_{\infty}$ are the fluid
  density and the fluid velocity far upstream of the airfoil, and and
  $\small \Gamma$ is the circulation defined as the line integral

  $$\Gamma = \oint _{C}V \cdot d \mathbf {s}$$

  around a closed contour $C$ enclosing the airfoil and followed in the
  positive (anti-clockwise) direction.


texts: What is the difference between a shock wave and an expansion wave?

texts:
Studying high speed aerodynamics I have found a question asking for what happens to static temperature for an airflow passing through an expansion wave.
The correct answer states that it decreases- the opposite of that on a shock wave.
What is the difference between these two waves that makes them contraries?


texts: Should I avoid testing unnecessary equipment?

texts:
Suppose you are on a day VFR flight and you are testing your aircraft lights. If you discover that the bulb for one of your nav lights is blown, then you can turn the switch off and tape it off, placard it as inop, and fly anyway. However, if you don’t placard it, my understanding is that you are not legal to fly, even if it is day VFR and you leave the switch off.

My question: should you avoid testing unnecessary equipment? Presumably if you did not test the nav lights during your preflight (not intending to use them) then you never knew they were broken, therefore you didn’t need to turn off and placard as inop. What is best-practice here? My question is specifically about nav lights, but I am also interested in other optional equipment (eg an autopilot).

(This is in the USA as a Part 91 flight.)


texts: What is the procedure to obtain an FAA ATP while in the United States for a holder of a CPL from Pakistan?

texts: I hold a CPL from Pakistan and currently fly an A320. I have accumulated over 4000 flight hours. If I visit the United States, what is the procedure to obtain a FAA ATP certificate?


texts: Is there any situation during flight where adverse yaw (yaw due to roll) is desirable?


texts: Why is the aiming point distance shorter in the US vs. Europe for long runways?

texts:
In essence, if you compare EGLL and KJFK (but it works for other airports too) you would see that US airports generally adhere to the rule of 1000 ft in distance between threshold and aiming point base. In Europe there usually is an additional (2nd) pair of TDZ zone markings which brings an additional 150 m to a total of 450 m between threshold and aiming point.

What is the source of this diversification and does it change how a pilot would handle final approach in two different settings? Lower flare/harder touchdowns in US?

For simplicity let’s assume we are comparing long (i.e., 3 km or more) runways only.

EGLL example: please notice that even at EGLL there is 420 m at 3 directions but 27R is 470 m.

KJFK example:


texts: Is the Auxiliary Power Unit used after landing when ground power is available?

texts: Assuming the airport provides ground power at the gate, will the Auxiliary Power Unit (APU) be started and used after landing? If not, I guess the engines will only be shut down when the Ground Power Unit (GPU) is connected. In this case, how do pilots know that the ground power is connected, so that they can shut down the engines?


texts: Do airline pilots have to wear face masks in the cockpit because of COVID?

texts: Do the flight crew with a commercial airline have to wear a face mask while on the flight deck, as both crew are in close proximity to each other and in a tight confined area? If not, why not?


texts: What is the expiration period for a 3rd class medical certificate?

texts: I got my 3rd Class Medical for a Private Pilot certificate in May 2013 at the age of 39.  I'm now 41.  Does the 60 month rule apply to my certificate or do I need to retest under the 24 month rule for over 40 year olds?


texts: How is drone (UAS) traffic regulated in the US?

texts:
Does the FAA regulate drones at this time?
Maybe they regulate only a certain class / size of UAV / UAS?

Is drone regulation to the level that traffic is managed through ATC?


texts: How are VFR / GAAP approach points selected?

texts:
This is kind of an Australia based question.

How are VFR approach points selected and why they are where they are? Also what challenges will pilots face from the GAAP (General Aviation Airport Procedures) approach points to the VFR approach points transition?


texts: Do any airplanes really have this piece Tom Cruise is hanging onto in this movie?

texts:
The piece Tom Cruise is holding onto on this moving plane seems useless as a component, maybe even inductive of drag. Is this a real airplane component, or just a film prop?

I don't know the model of the airplane; I'm hoping maybe the shape is recognizable to some of you, or maybe it's even a "no-brainer".


texts: How to interpret the published altitudes for each of US STAR procedures?

texts:
I have been studying the STAR procedures, as published by FAA, and I am trying to understand the way that the altitudes are defined for each fix/route. Take, for example, CAMRN4 of JFK.

I see the MEA (Minimum En-route Altitude) of the segment from SEA ISLE to BOTON. Then, no altitude restrictions are applied except when reaching HOGGS, where there is an expected altitude of FL180. The next waypoint with a defined expected altitude is CAMRN, with an expected altitude of 11000ft.

What happens in the intermediate segments (HOGGS --> PANZE --> KARRS...) in terms of altitude? When along a controlled arrival, for example in this specific STAR (CAMRN4), how is the altitude controlled between waypoints when nothing is explicitly stated on the procedure diagram?

The main reason I am asking is because I have been trying to understand Arrival/Departure Procedures and I see that altitude information is often sparse or even completely lacking from some of the diagrams.


texts:
Here are a few thoughts:

'Real' accidents happen much too seldom to be of any real measure, and they would have to be compensated for the number of passenger kilometers as well to be objective. Large airlines may have be involved in more accidents, but they have more aircraft. Many airlines low down on the reports had accidents many years ago.
Avherald and the like may be good sources but emphasize that they don't report on all accidents.
Different jurisdictions have different reporting requirements.

What is a fair and unbiased method of measuring airline safety?


texts: How is fuel removed from a light aircraft if required for weight and balance?

texts:
With small, light aircraft, weight is always a consideration. Say you had a four-place single engine aircraft that you wanted to take yourself and three of your (non-FAA-standard weight) friends, but also at the time you get to the aircraft, you discover the tanks have been topped up.

Is there a standard way (or best practice) for removing fuel from the tank so you could carry all your intended passengers (provided you don't actually need all the fuel to get to your destination) and stay within the gross weight limit.


texts: What is the definition of mountainous area?

texts:
MEA, MORA, grid MORA, and MOCA for a non-mountainous area gives 1,000 ft clearance from the highest obstacle, and in mountainous area gives 2,000 ft clearance from the highest obstacle.

But what is the exact definition of a mountainous area?

I have also heard that MOCAs have a different clearance calculation for the mountainous area depending on the terrain/obstacle elevation, (3000 ft - 5000 ft gets 1500 ft clearance) and (above 5000 ft gets 2000 ft clearance) can someone clarify this.


texts: What is the explanation for the different lines in the payload/range diagram for the Airbus A320?

texts:
In the A320-200's 'AIRCRAFT CHARACTERISTICS AIRPORT AND MAINTENANCE PLANNING' document. It presents the A320's PL/R capabilities as:

Firstly, I would like to know: What are the 3 different MTOW's listed? Is it for different seating layouts? eg 'high density' vs 'business + economy' or what? Note that 73.5(78) tonnes is the MTOW listed on Airbus's website, seen here, but they don't clearly indicate what the figure in brackets indicates.

Secondly, does the payload axis include passengers as well as cargo? If so, if the maximum amount of passengers is listed as 180, how much additional cargo can the aircraft carry, both in the cargo hold and overhead luggage trays? i.e. what model does the airlines/airframers use to estimate the weight of 180 passengers?


texts: What is the actual air speed over and under a wing due to Bernoulli's Principle?

texts:
Bernoulli's Principle states that as a fluid speed increases, its pressure decreases, and vice versa.  Air flowing over the wing of an aircraft flows faster than its neighboring air flowing under the wing.

But how much faster?  Using the cruise conditions listed for a Boeing 747-400 – airspeed Mach 0.85 (567 mph, 493 knots, 912 km/h) flying at 35,000 ft – what are the corresponding maximum and minimum speeds of the airflow over the wing?

For the purposes of the calculation, assume standard atmospheric conditions for an EAS of 273 knots.

In general:

How much does this depend on the shape of the airfoil (or: does this translate to general aviation as well)?
Does changing the angle of attack (without stalling) affect the airspeed/pressure differential?  If so, by how much?
Typically, where on the wing (inboard to outboard) is the most Bernoulli-derived lift generated (i.e. due to airspeed/pressure differential)?  Or does this vary greatly with wing design?
Where on the airfoil (leading edge to trailing edge) is the region of highest and lowest pressures (and thus, the slowest- and fastest-moving air)?


texts: Why do some nations allow the usage of hand held devices and some not throughout the landing till the take off

texts:
After going through this site I am still not clear as to why do some nations do not allow the use of hand held device's especially  cell phones for making calls or texting but for gaming or reading during take off or landing or throughout the flight.

although the difference lies in network usage but still the device is ON and still may cause disturbance to the onboard equipment like navigation or communication. Then what's the point in allowing for gaming or reading throughout the flight.

I have seen some reports that claim they don't cause disturbance and some say they do.


texts: What is this turbine engine panel that opens on landing?

texts: Tonight I flew from Munich to Dortmund on an A319 and I happened to sit just above the wings and turbine on the right side. Upon landing, the turbine opened a window or panel which exposed some grid like structure inside it and just a few seconds later, after touchdown, closed it again. Could someone explain to me what that is, how it is called and what its purpose is?


texts: Do small helicopters like the R44 require an FAA type rating?

texts:
From what I read in 14 CFR 61.31 it never mentions type rating requirements for rotorcraft or helicopters. I Googled online but most of the results showed up for Australia, Canada and the UK.

I am starting to believe that the US does not require a pilot to have a type rating for a Robinson R22 or R44 helicopter.

Am I correct that unless the FAA has made a type certificate for that helicopter it does not require a type rating? Would it just require a checkout from wherever you are going to rent?


texts: What is the difference between the Maximum Glide and Minimum Sink ratios?

texts:
In this comment a brief explanation is made of the differences between Max Glide Ratio and Min Sink Ratio:

  Sink rate is how much altitude you lose over time, for example, how many feet per second. So minimum sink is the lowest sink rate you can get. Glide ratio is how much distance you can travel per given loss of altitude, for example, how many feet per feet. So max glide ratio is the shallowest angle you can glide at.

However, I don't understand how the lowest sink rate you can get isn't the same as the shallowest angle you can glide at. If I can design wing A to sink at only 1 foot per minute, wouldn't that automatically get me a longer glide ratio from altitude X than wing B that sinks at 2 feet per minute?