Questions tagged [v-speeds]

Questions on the critical speeds of an aircraft guiding elements such as rotation, climb, and maneuvering.

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7
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2answers
551 views

How does an inoperative Anti-Skid affect V speeds?

I am trying to figure out why is it that when you have an inoperative anti-skid system, the calculated V Speeds are lower? I'm trying to see this from a performance perspective, could this be due to ...
9
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1answer
254 views

When was the concept of V1 introduced?

When was V1 speed first introduced? Was it the result of a particular accident or series of accidents?
2
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2answers
131 views

What is the takeoff decision speed (V1) for a Gulfstream G500?

Can someone tell me what is the decision speed (V1) of the Gulfstream G500? Is it 200kt as shown in this picture?
1
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2answers
167 views

What forward airspeed produces maximum rate-of-climb in helicopters?

Lift in a helicopter increases with airspeed (from zero IAS up to some Vmax). But in contrast to fixed-wing aircraft a helicopter can generate lift at zero airspeed. Is there a formula for the ...
0
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1answer
137 views

Why does Vmca decrease with increasing altitude?

A question from a mock MEP class rating test: Many thanks for your help.
0
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0answers
101 views

What are the VMO and Vd of a Boeing 757-200?

I'm doing an university project on the B757-200 and I need some data. I can't find anywhere the VMO and VD. Is there somebody that can give me these information or at least a book where to find them?
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2answers
187 views

Where does an FMS wind information comes from to calculate V approach?

To calculate the V approach the FMS is using a wind either taken by the ADIRS or inserted on APPR PERF page. At first I will say that it takes the wind inserted by the crew, but I am not completed ...
9
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2answers
3k views

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

According to this AAIB report on a June 2009 mid-air collision between an RAF Grob Tutor and a glider, the Tutor’s maximum design operating speed (VDO) is greater than its never-exceed speed (VNE): (...
3
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3answers
457 views

What is physics explanation for minimum sink rate airspeed?

I did some research on Minimum Sink Rate, and saw much information defining it, (such as it is the speed at which the aircraft will remain in the air for the longest time, etc.) and how it is ...
8
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4answers
965 views

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

I was looking up V-speeds for C172. I don't have easy access to an official copy of the POH, but online I found: $V_y$, best rate of climb speed (at sea level): 76 KIAS (p22) $V_{glide}$, maximum ...
0
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1answer
98 views

Space Catapault Model [closed]

A secretive space catapault is said to be in progress. For the sake of mathematical simplicity, assume the launch vehicle is one kilogram point-mass and to be placed in geosynchronous orbit. What ...
11
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3answers
2k views

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

Reading The Crash Detectives: Investigating the World's Most Mysterious Air Disasters by Christine Negron, I came across the following description, in relation to some early de Havilland Comet ...
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1answer
155 views

What is the procedure for a fast landing that is too slow for go-around? [closed]

Say an aircraft (A320 or similar) on landing, hits the tarmac way too fast and on a short runway, less than V2 but around V1 or slightly over. This could happen if a pilot had recently moved from ...
4
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1answer
106 views

Is there a V speed for the point an aircraft starts an ascent at 0 angle of attack?

Some aircraft with an angle of incidence or cambered airfoils are capable of climb without any angle of attack, Is there a V speed for the speed at which an aircraft starts a positive climb?
3
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0answers
96 views

What were the typical rotation and landing speeds of the X-29?

Looking online through all the available literature, I could not find the typical rotation ($V_r$), landing or even stall speed of the experimental forward swept wing X-29 aircraft. I'm curious to ...
1
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1answer
260 views

Exceeding VLO and by how much is too much?

Piper Seminole (PA-44-180) VLO (max gear retraction speed) is 109 KIAS. I've heard that manufacturer published limitations are significantly lower than actual structural and system limitations. What ...
7
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2answers
1k views

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

It is the speed below which you can move a single flight control one time, to its full deflection, for one axis of airplane rotation only This is part of the explanation of maneuvering speed. What ...
5
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2answers
1k views

What is the most fuel efficient climb speed for a C172 SP?

Assuming ISA, sea level, no wind, max gross weight, what speed would be most fuel efficient per 1,000 ft of climb? Alternatively, if that converges to the most fuel efficient cruise speed, when there'...
4
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2answers
360 views

Are there any aircraft where minimum-V1 is limited by Vmcg?

V1, unlike all the other Vspeeds, is not rigidly determined by the laws of physics, the aircraft’s specific abilities, and the conditions of the particular takeoff being attempted,1 but is, rather, ...
6
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1answer
644 views

Where does the factor 1.3 for Vapp come from?

The approach speed Vapp is usually given as 1.3 * Vs0, or 1.3 times the stall speed in landing configuration. Why 1.3? What created a consensus of 1.3 * Vs0 as the generally accepted textbook ...
3
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1answer
174 views

Are there reference speeds like V1, Vr or V2 for a touch and go procedure?

Are there any reference speeds like V1, Vr and V2 on a touch and go procedure? During takeoff, these are used to mark certain states of the takeoff, including the speed at which the aircraft starts ...
3
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2answers
242 views

Do modern aircraft automatically manage the deceleration to Vref?

Typically in most aircraft, the pilot manually reduces the speed gradually until reaching the landing zone/flare zone. Modern aircraft have FMC. Does the FMC automatically manage the speed gradually ...
2
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3answers
156 views

How are V speeds spoken?

How are V speeds spoken? --Research for my novel. Is it the V and the number or letter notation or is there something more to it? The Wikipedia Page on V Speeds does not delve into the subject ...
5
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1answer
299 views

Why not separate out the two definitions of V-1 into two separate Vspeeds?

V1, officially the takeoff decision speed, has, somewhat infamously, two separate definitions: It is defined as the minimum speed at which, if one engine fails, the pilots can press to liftoff and ...
0
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2answers
2k views

What is the difference between Vno and Va [duplicate]

What is the difference between the maximum structural cruising speed (Vno) and the manuevering speed (Va)? Can you also please explain how these speeds are calculated? I do understand that Va is set ...
5
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2answers
908 views

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

Reading about the crash of American Airlines Flight 191, the proximate cause of the final loss of control was the pilots' reduction of the aircraft's airspeed to V2, in compliance with the published ...
0
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1answer
11k views

What's the difference of Vs from Vs0 or Vs1?

Vs: Stall speed or minimum steady flight speed for which the aircraft is still controllable Vs0: Stall speed or minimum flight speed in landing configuration. Vs1: Stall speed or minimum ...
1
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1answer
299 views

Why isn't Vy equal to Vmd?

$V_{md}$ is the speed where the rate of sink is the lowest. So if you add full power, it should be the speed with greatest rate of climb, namely $V_y$. But we also know $V_{md}<V_{bg}$ according ...
2
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4answers
1k views

Why is best angle/rate of climb indicated in airspeed?

I understand the difference between best angle of climb $V_{x}$ and best rate of climb $V_{y}$. When I take off I would aim to maintain one speed or another depending on what I want. But I don't ...
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1answer
1k views

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

Is there an aircraft that can go supersonic at sea level without using afterburner? Quick look through the "supercruise" capable aircraft might be helpful in narrowing down the possibilities, though I ...
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3answers
2k views

Definition of “Rotation Speed” vs “Lift Off Speed” vs “Fly Off Speed”

Is rotation speed and lift-off speed ever used interchangeably? (AMENDED Question) Is lift off speed and fly off speed the same? (See supplemental info below) I thought I clearly understood the ...
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3answers
4k views

For what is VMCL the minimum control speed?

I would like to ask which of these options is correct: VMCL is the minimum control speed for: A) approach in go-around configuration B) approach in landing configuration C) go-around in ...
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3answers
1k views

What determines the maximum speeds for a particular aircraft?

Aircraft have three different maximum airspeeds: VMO (maximum operating speed) - the maximum speed that the aircraft is allowed to reach during normal operations. VNE (never exceed speed) - the speed ...
0
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1answer
436 views

What is the best glide speed for the DC-3 with 2 engines out?

What is the best glide speed for the DC-3 with 2 engines out? I realize we may consider best speed for ground distance traveled or best for duration - and that weight can be a factor. I can't find ...
-2
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1answer
928 views

What is the stalling speed of a Cessna 172SP at an altitude of 2000 feet?

What is the stalling speed of the Cessna 172SP if the temperature is +11 degrees Celsius, the power is off, the CG is at the forward limit, the flaps are at 0 degrees and the altitude is 2000 feet?
7
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2answers
821 views

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

This answer to a question about emergency descents notes: [Y]ou can accelerate descents by banking the aircraft into a turn. This allows you to increase angle of attack, thus increasing drag to ...
3
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2answers
588 views

Why is V1 based only on using brakes?

V1 is the speed that an aircraft may abort a takeoff so long as the airspeed is below it, or is committed to flight if it is over that speed. V1 calculations are based only on the brakes (not sure ...
1
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1answer
157 views

Is it a common airline practice to base T/O speeds on the actual T/O weight when an assumed temp thrust is used?

Let's say the current outside air temp is 15 C and you have decided to use 50 C as the today's assumed temperature for your takeoff. In this case, use of the T/O weight the assumed temp thrust ...
11
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2answers
18k views

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

I want to learn about how can the V1 and VR (rotate) speeds be calculated for take off. And which factors are affecting this calculation? Basically it may depends on the aircraft weight, runway ...
2
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1answer
153 views

What is the name of centre of mass speed of an aircraft?

I have a list of positions (X [NM], Y[NM], Z[NM]) of an aircraft. Every coordinate is given every 1 second. I calculate the speed [knots] between two consecutive coordinates in the following way: $...
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2answers
1k views

Why should a Piper Seneca not take off after an engine failure below 100MPH?

In the Seneca (PA34-200) AFM, in the ENGINE FAILURE DURING TAKEOFF section, it is noted that if engine failures occurs during takeoff ground roll and 100 MPH has not been attained, the pilot must ...
4
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1answer
220 views

Is it possible to determine a rotation speed (Vr) using other known V-Speeds?

Is it possible to come up with a good estimate of rotation speed using other known V-Speeds? For example: if I know a plane has a Vs @ 55kt. and a ...
3
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2answers
2k views

What makes V1 one or two knots less than Vr on this performance table?

(B738 AFM, 0-2000 feet elevation, up to 27°C) Example of V1 and Vr differences. The table shows that the V1 speeds are invariably one or two knots lower than their matching Vr speeds. Given that V1 ...
2
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1answer
812 views

Is reducing V1 a viable option for pilots when the ASDA is shorter than the ASDR?

Let's say you were planning to ferry some passengers and cargo in a jet but after some calculations found out the ASDR (Accelerate-Stop Distance Required) was greater than ASDA (Accelerate-Stop ...
18
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2answers
2k views

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

The go/no go decision on takeoff for airliners is calculated as a V1 speed. The question is, why is there no time or distance for V1 calculated. In other words, if we don't reach V1 in X seconds or by ...
5
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2answers
2k views

Is there something like a table of aircraft required runway lengths?

I'm looking for a chart showing the minimum length a runway can be for various aircraft to land and take off. Does something like this exist?
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2answers
369 views

How should these translated takeoff and climb settings be interpreted?

I am having difficulties understanding this transcript. It is originally not in English, so I was wondering if anyone could help me to make sense of this and also help me with the correct wording in ...
14
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1answer
3k views

What is “Bird Strike Speed”?

I read through the reference speeds of the Hawker 850XP and I stumbled upon the "Bird Strike Speed". It is specified as "280 KIAS up to 8000 ft". What does that speed mean?
0
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2answers
2k views

What is “50 ft obstacle climbing speed”?

Vy and Vx make sense to me. They are used for fastest height gain at a given time and biggest angle of climb. But what is the purpose of that speed (it's from DA20 POH)? It's only 3 kts faster than Vx....
12
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3answers
2k views

Why is ditching speed higher than stalling speed?

I was looking for a checklist for the Cessna 182 and I stumbled upon this one. When I looked at the speed-table, I found an interesting entry. It says "Ditching" with a speed of 65 KIAS: Everything I ...