Questions tagged [aircraft-performance]

Aircraft performance covers areas such as the amount of runway required to takeoff or land and how fast an airplane can climb or descend.

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1answer
3k views

How can an airplane descend faster than a free-falling roll of toilet paper?

Watching this video, I was wondering, does the Toilet paper have this much lift, because I think the descent speed of the Airplane is not that much? I don't think that a parachute-plane can catch up ...
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2answers
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Is it possible to have V1 greater then Vr?

According to wikipedia, decision speed ($V_1$) is computed taking into account the runway length (and other parameters). If an aircraft uses a long runway (one listed here), there may be enough runway ...
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7answers
36k views

Why do most single propellers have a clockwise rotation?

Why do most single propellers have a clockwise rotation (seen from the pilot's point of view)? There are though multi-engine planes that have each propeller rotating different directions, but in the ...
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3answers
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Why would a Su-25, which has more power and is much lighter than an A-10, only fly half as high?

On the web, on several sites, the A-10 is listed with a ceiling of 14 km, the Su-25 with 7 km, although there is data that puts the height for the Su-25 at 10 km. Nevertheless, why would the Su-25 ...
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3answers
740 views

How do pitch attitude, airspeed and sink rate come into play in a rapid descent or a dive?

So, I have a hypothetical aircraft that needs to get from FL350 to 10,000' as quickly as possible. What is the difference in sink rate between a 'standard' airliner rapid descent (idle thrust, ...
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6answers
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What is the minimum stopping distance for a 747-400?

Im looking at purchasing disused 747-400: The aircraft will be stripped of all seats and other non essential items. The aircraft will be then flown to my property in Victoria, Australia and perform ...
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2answers
242 views

How are performance variables accounted for when testing solar-powered aircraft?

With so many factors that could affect performance (wind, visibility range (amount of light), angle of the sun, etc.), how do they accurately test solar aircraft flight time? Any tips for doing my own ...
10
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2answers
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How can I calculate the fuel consumption of an Airbus 320-200 at various loads?

I want to know: What is the fuel consumption of an Airbus A320-200 - 180 Seats, at 100% load factor for a distance of 2000 km? What is the fuel consumption of an Airbus A320-200 - 180 Seats, at 80% ...
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2answers
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Are there certification requirements for an emergency descent?

In case of emergency, an aircraft may have to descend very quickly. Is there some performance (L/D ratio with full spoilers, descent rate, ...) to be proven in the certification process for such ...
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5answers
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Is a winglet better than an equal span extension?

Is there indisputable evidence that a winglet improves performance over an equal span extension? Please note: I am only interested in L/D improvements. Winglets do improve roll performance, that is ...
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3answers
547 views

How can I take 360° panoramic pictures in an aircraft or helicopter? [closed]

I would like to receive some answer or advice on how to create 360 panorama images. My plan is to use Cessna or Helicopter.
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1answer
844 views

Radius of Turn Query [closed]

I am making a project related to flight paths. If we are given two points in space (lat,long) and the flight headings(angles) that the flight should attain at that points. By using the radius of ...
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4answers
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Why is the fatality rate in the Diamond DA40 so remarkably lower than the SR20/22?

I assume it has a lot to do with the stall characteristics, but with the SR20/22 having a combined 1.6/100,000 Fatal rate and the DA40 having .35/100,000 Fatal, it seems like a very stark difference. ...
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2answers
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Why were the specifications of the Pipistrel Panthera downgraded?

I'm curious if this was a failure of the simulations or a result of the engine swap they did at the last moment. Originally, they said they could cruise at 200kts @ 10g/h fully loaded. Now its down to ...
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1answer
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How is the climb gradient calculated?

I was part of a discussion about the differences between all engine climb gradients and one engine inoperative (OEI) climb gradients, and a colleague suggested that climb gradient can be calculated as ...
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5answers
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Is it possible for an SU-25 to fly high enough to shoot down a Boeing 777?

A common theory from pro-Russian netizens surrounding the MH-17 tragedy is that it was a Ukrainian SU-25 ground attack fighter plane which shot down the civilian airliner. However, MH-17 was flying at ...
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4answers
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What is the maximum safe bank angle of a 747?

This question arose during the comments of another question, linked for the curious: What does it take to turn a 747 around 180 degrees? Because the discussion was interesting, (and to avoid ...
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1answer
950 views

What is the upper altitude limit for propeller driven aircraft? [duplicate]

Is it possible to fly 100 kilometers with a propeller driven aircraft? and if not what is the limit of a propeller driven aircraft?
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3answers
16k views

What is the minimum turning radius of an SR-71?

What is the minimum turning radius of an SR-71 at Mach 3.2 and an altitude of 80,000 feet? I have heard that if an SR-71 were to cross the Pacific coast over San Francisco and pull a hard turn to ...
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1answer
4k views

Why is the minimum runway length non-linear in relation to the landing weight?

The graph below shows the landing runway length requirements for a Boeing 747-8. (taken from the Boeing 747-8 Airplane Characteristics for Airport Planning) Considering the fact that the kinetic ...
7
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1answer
959 views

What is the most carbon-efficient way to take off in a passenger plane?

Consider two possible flight paths for a jet passenger plane; the first is a slow climb, held low over 20 or so miles to avoid other flight paths, the second a more rapid climb over 10 miles to the ...
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Why are planes slower at higher altitudes?

On many flight simulators, I have noticed that planes tends to get slower with increasing altitude. For example, I can reach 1100 knots just above the sea level in Google Earth flight simulator(F16), ...
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1answer
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How could MH370 fly west to Straits of Malacca within time frame without being seen on Radar? [closed]

Malaysia originally claimed they saw MH370 on military radar climb to 45,000ft (in excess of its service ceiling) then drop 40,000ft (12,000m/6.47nm) within 60 seconds. Prior to May 2014 Malaysia ...
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3answers
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How high can propeller airplanes fly?

Is there a maximum height a propeller airplane could fly? Some lower bounds for maximum flying altitude: 12,000m (39,370ft): Antonow An-70, produced 1994 12,310m (40,387ft): Lockheed Martin C-130J ...
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In a 777, what would happen if the auto-pilot and the altitude hold failed at the same time?

I know nothing about a Boeing 777 flight controls. In general, I know that the speed of an aircraft is controlled by the throttle on the center console. I have never heard of an automatic speed ...
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3answers
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What is the ferry range of an A380?

The Wikipedia entry for the A380 gives the maximum range at design load as 15,700 km. The equivalent entry for a Boeing 747-400 gives around 14,000 km but distances of 18,000 km have been performed in ...
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3answers
5k views

Why is managing CG (centre of gravity) important?

Why do people have to worry about CG? Is it primarily due to fuel penalty, or take-off and landing performance, or is it mostly just to keep the aircraft from tipping over during loading and unloading,...
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10answers
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Why 1st and 2nd class but not fast or slow airplanes?

Why do airlines separate passengers into 1st and 2nd class but do not offer fast or slow connections? Isn't the biggest cost the kerosene? And isn't the cost directly proportional to speed?
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1answer
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How does altitude affect the speed of sound?

I read once that the speed of sound decreases as altitude increases. I wonder if that's true and, if so, are the pressure waves made at high altitude lesser than the ones at low altitude because of ...
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3answers
3k views

What is the fastest airplane?

There are many airplanes that claim to be the fastest piston, private jet, airliner, but what is the all time fastest airplane? How fast does it travel?
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2answers
4k views

Is the maximum lift-drag ratio found at minimum drag?

Figure 10-5 of the FAA's Pilot's Handbook of Aeronautical Knowledge shows: I didn't think $L/D_{MAX}$ coincided with $D_{MIN}$. Is this Figure accurate?
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1answer
532 views

Why are the power and drag curves called polars?

See Wikipedia:Drag polar and Wikipedia:Polar curve (aviation) for example. These curves are not on a polar coordinate system. Why are they called polars?
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1answer
901 views

How can I get the velocity-power curve for a particular aircraft?

The answer for How does wind affect the airspeed that I should fly for maximum range in an airplane? refers to a velocity/power-required curve. As far as I can tell, this curve can't be deduced from ...
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4answers
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How does wind affect the airspeed that I should fly for maximum range in an airplane?

I have heard that wind affects the actual airspeed that I should fly for maximum range in an aircraft. I understand that wind will not affect the airspeed that I should fly if I am looking for ...
17
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2answers
8k views

How is minimum runway length related to V1?

1) Is $V_1$ used to determine minimum runway length? How is $V_1$ calculated? 2) If it is used to determine the minimum runway length, and for example we have a runway of 8000 ft and my airplane's ...
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1answer
191 views

Which maneuvering speeds are included in the TCDS?

I've been looking at the data found in various type certificate data sheets and found something that is a bit ambiguous. In reading a TCDS (like this one, for example) in the "airspeed limits" section ...
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7answers
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Why are older airplanes still in use?

It is normal to see older planes (20+ years) quite frequently. In fact, a few months ago I saw a plane over 50 years old (not in a museum but on a runway, about to take off). Comparing to cars, there ...
18
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1answer
70k views

How are take-off segments defined?

From take-off performance calculations I remember that the take-off and initial climb was expressed in a number of segments. Each segment had its own performance requirements. I presume they are ...
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4answers
35k views

What do winglets do to increase aircraft performance?

It seems like a lot of the newer airliners have winglets or wing fences. How do they improve aircraft performance?
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2answers
990 views

Does a quadcopter have flight modes beyond traditional aircraft?

Quadcopters, by virtue of software-piloting rather than human-piloting, are capable of new modes of flight. I've seen one in which the machine maintains altitude despite the loss of two rotors by ...
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2answers
1k views

Is it possible and effective to perform a forward slip in a large commercial jet?

I'm wondering if it's possible to forward slip a large commercial aircraft, like the A320 or even B777, and if so: is effective or useful, since most small aircraft which I gather do it have no ...
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2answers
701 views

How much drag do the gear doors create during retraction?

It's been said that if you retract the gear at a critical moment that performance will actually be worse than if you left the gear down. However, is this really true, and just how long is the ...
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4answers
2k views

What is an optimum engine-out bank angle?

I've heard three methods you should use in a multi-engine aircraft when engine-out, each recommending a different amount of bank: Wings level, hold aileron to maintain roll and correct using rudder. ...
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2answers
3k views

What dictates the prop RPM used during cruise?

I've seen on numerous different constant-speed propeller aircraft and different pilots using different RPMs during the cruise phase on a propeller aircraft. What dictates the RPM used during normal ...
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4answers
43k views

Does temperature affect takeoff performance?

A few days ago, a Copa flight from Porto Alegre to Panama was delayed from noon until 12:30 AM. The company explained that the high temperature (about 40 degrees Celsius) would require a longer runway ...
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4answers
29k views

How does the mounting location of a jet engine affect aircraft performance?

Different jet airplanes mount the engines in different ways. For example: Under the wing To the fuselage How does the engine location affect aircraft performance? Is one better than the other?
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During a takeoff emergency, is it safer to abort or continue the takeoff if either can be done within the available runway?

In a multi-engine airplane, if an engine failure occurs at the exact moment that a decision needs to be made to reject or continue the takeoff, and there is plenty of runway available to do either, ...
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2answers
7k views

Why/How does a “Powerflow” exhaust increase horsepower?

I've seen airplanes (typically Cessna 172s) with a "Powerflow" exhaust system and then claim to get several more horsepower, resulting in faster cruise speeds. How does a Powerflow exhaust work, and ...
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3answers
4k views

How do I determine the best altitude to fly for fuel economy?

If you fly low, air is dense so you can get more thrust from your engines, but you get more drag. On the other hand if you fly higher you have less drag but the output of engine decreases as well. So ...
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4answers
3k views

How does flight duration affect the hourly fuel consumption in heavy aircraft?

A 15 hour flight across the Pacific obviously requires more fuel than a 7.5-hour transatlantic flight. How significant is the hourly fuel consumption increase due to the additional fuel carried at ...