29 votes
Accepted

How can best glide speed be lower than best rate of climb speed?

The best glide speed is the speed where tangent line from the origin (zero horizontal and vertical speed) touches power curve (for unpowered airplane). Best rate of the climb is the highest point of ...
Martin's user avatar
  • 2,766
25 votes
Accepted

What is "Bird Strike Speed"?

Aircraft structures are required to withstand the structural damage caused by birdstrike. According to 14 CFR 25.571 - Damage - tolerance and fatigue evaluation of structure: (e)Damage-tolerance (...
aeroalias's user avatar
  • 100k
19 votes
Accepted

What if you have a double-engine failure after V1 but before VR?

The Airbus A320 FCTM (Flight Crew Training Manual) does not describe any procedure for rejecting a takeoff after reaching V1: The decision to reject the takeoff is the responsibility of the Captain ...
Bianfable's user avatar
  • 55.9k
16 votes
Accepted

What are the landing stall speeds of a Cessna 172?

Short answer At low speed, near the stall, 40 KIAS (the low end of the white arc) and 48 KCAS (Vs0 in the POH) refer to the same actual speed. While there is a limited divergence (0 to 2%) between ...
mins's user avatar
  • 73k
15 votes
Accepted

How can V1 and VR (rotate) speeds be calculated?

There is no general equation/function that you can use to calculate V1/Vr... the manufacturer test out the aircraft's performance during certification, and you then compare your current aircraft and ...
RAC's user avatar
  • 4,616
15 votes

Has the "Foote takeoff" technique really existed, and how did it work?

At the time of the Comet disasters, Vr did not exist. The standard takeoff technique was what was used on all previous airplanes - line up, release the brakes, apply full power (derated thrust did not ...
RAC's user avatar
  • 4,616
15 votes
Accepted

How can an aircraft’s maximum design operating speed be greater than its never-exceed speed?

Maximum design operating speed means "we calculated the aircraft will break apart at that speed". It's obviously higher than the never-exceed speed, which means "you can safely operate the aircraft up ...
Rainer P.'s user avatar
  • 2,920
14 votes

Why is ditching speed higher than stalling speed?

As far as I'm aware - and maybe a seaplane pilot could give a better answer - one of the big issues with ditching is judging your height above the water. If you stall it in, you might get it wrong and ...
Pondlife's user avatar
  • 71.7k
14 votes

Why don't Transport Category aircraft have a listed Vy?

Large commercial jets operate within a much wider range of weights than most GA aircraft do, and since Vy varies with weight, it wouldn't make sense to publish "a" single Vy speed for them. The crew ...
Ralph J's user avatar
  • 51.4k
13 votes
Accepted

When does the overspeed alarm goes off in a plane?

The overspeed goes off when either the indicated airspeed exceeds that limit or the mach speed exceeds the mach limit. At least that's how it worked on 747-100/200 aircraft. The 350 knot figure for ...
Terry's user avatar
  • 39.1k
13 votes
Accepted

Why would one want to slow to V2 following an engine failure during takeoff?

Simply put, V2 is the speed that guarantees the best angle of climb on one engine. Any slower or faster increases the risk of hitting an obstacle. Drag There are 2 main categories of drag - induced ...
Ben's user avatar
  • 14.3k
12 votes
Accepted

Why is ditching speed higher than stalling speed?

This is somewhat restated and overlaps the other postings. Here are my thoughts on this: The ditching speed is to provide a safe approach speed. Depending upon the seas, you may not have the ability ...
mongo's user avatar
  • 17.7k
12 votes

How can an aircraft’s maximum design operating speed be greater than its never-exceed speed?

VDO is the maximum speed, demonstrated in testing, that the structure is designed to handle (usually for flutter). VNE is an operating limitation for the pilot to observe that includes a bit of ...
John K's user avatar
  • 131k
9 votes
Accepted

Why is flutter a function of true, not indicated, airspeed?

Flutter happens when structural and aerodynamic eigenfrequencies converge. Aerodynamic eigenfrequencies depend on the time the air molecules take to transverse an aerodynamic surface.
Peter Kämpf's user avatar
9 votes

Why is manoeuvring speed higher in utility category?

There are three factors: Va speed, weight, and CG limit. Va is connected to the weight limit, not to the CG limit. If you look at a typical V/G diagram, you'll notice that Va is defined by the ...
rbp's user avatar
  • 16.8k
9 votes

Why is the takeoff decision point based only on speed and not time or distance?

Some operations, including the USAF, use an acceleration check speed at a given distance (usually 1,000-2,000'). Data is derived from normal acceleration data gathered during performance testing. ...
ANDY-S's user avatar
  • 430
9 votes

Do manufactures list the maximum speed of an aircraft based on its theoretical maximum speed or dive speed?

The 365 knots listed in that brochure is (as noted in the text) the maximum cruise speed. That is the maximum speed at which the aircraft can be expected to operate under normal circumstances in level ...
60levelchange's user avatar
9 votes
Accepted

Do manufactures list the maximum speed of an aircraft based on its theoretical maximum speed or dive speed?

The maximum cruise speed from the brochure is a True Airspeed value and is based on the highest TAS achieved with the engines operating at the maximum cruise power rating specified by the engine ...
John K's user avatar
  • 131k
9 votes

Why would I want to lower the stall speed?

Don't I want to have a higher stall speed so I could be far from stalling? Unfortunately this is incorrect. Aerodynamic stalls happen when an aircraft’s airspeed is at or below the aircraft’s stall ...
Dean F.'s user avatar
  • 16.5k
9 votes
Accepted

When is Vmo/Mmo applicable?

The limitation is always the lower one of the two, meaning your actual IAS must be below Vmo and your actual Mach must be below Mmo. Let us consider this case: you accelerate all the way to Vmo and ...
Bianfable's user avatar
  • 55.9k
8 votes

Does MMO (limiting Mach number) assume any maneuvering limits?

The problem is that in a deliberately entered spiral dive it is very difficult to keep things in check. In an idle descent, pitch is your only speed control (well... really, in the end, pitch is your ...
John K's user avatar
  • 131k
8 votes

Is there an aircraft that can go supersonic at sea level without using afterburner?

According to Wikipedia, the BAC TSR-2 was capable of supercruise (no reheat) at Mach 1.1 at 200 feet (~60 m) altitude. The TSR-2 first flew in 1964. The English Electric Lightning had demonstrated ...
Zeiss Ikon's user avatar
  • 17.1k
8 votes
Accepted

What does it mean to move a single flight control to its full deflection?

Yes, that is correct. Moving any control surface until you hit the stops is considered "full deflection". For the purpose of maneuvering speed, this is the speed at which any single control surface ...
Ron Beyer's user avatar
  • 36.2k
8 votes

How does an inoperative Anti-Skid affect V speeds?

When you say it affects V speeds, I assume you mean V1 (and possibly VR), but not V2. V1 is usually calculated from the balanced field length, which is where accelerate-stop-distance and accelerate-go-...
Bianfable's user avatar
  • 55.9k
7 votes

Why is ditching speed higher than stalling speed?

I tried to put this in as a comment to @Pondlife's answer, but ran out of room, thus this answer is an amplification of what he said. He is correct. Judging height above the water is a challenge, ...
Terry's user avatar
  • 39.1k

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