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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8
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1answer
531 views

Why is 51,000 ft a common service ceiling for business jets?

According to this article on aerospace-technology.com, many of the larger business jets seem to have a service ceiling of 51,000 feet. Other sources verify this trend. What is the reason for this, if ...
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2answers
3k views

What are the most powerful airplanes that ever flew?

This question What are the least powerful airplanes that ever flew? made me wonder what the most powerful manned airplanes are that ever flew. There are two sensible categories, I suppose: Most ...
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3answers
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Could an airliner be as efficient lower and slower?

Could an airliner ever be as efficient at 15 or so meters using ground effect as it is at 50,000 km even if it has to go slower and be shaped differently?
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5answers
406 views

How efficient would an airliner be if it did not have to carry its own fuel?

Hypothetically, if all the fuel was supplied externally or pulled from the atmosphere to where the plane had never to carry any fuel on board, how much more efficient would an airliner be? The plane ...
3
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1answer
65 views

Can I use any reference area for lift and drag coefficient?

I know that for rockets they often use the circular cross-section S_reference for the drag prediction: drag = rho/2 v^2 * c_D * S_reference For aircrafts they use the chord length of a wing as ...
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2answers
148 views

What is the method to find the resonance frequency of a PowerFlow exhaust?

I asked a related question about PowerFlow Exhaust systems, which produced another question for me: How do they go about finding the resonance frequency so they know how long to make the exhaust pipe? ...
2
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4answers
4k views

Would a 50 mph aircraft holding a ground pattern in a 20 mph cross wind risk stalling by abruptly rolling away from a crosswind?

This is another play on the "down wind turn myth". We all know a plane flying in a "uniformly moving airmass" is not affected by wind direction and speed. But a plane following a ground track must ...
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3answers
356 views

How can I calculate the maximum range of an aircraft descending with power (not gliding)?

Let's assume I have an aircraft, for which the thrust is not enough to keep the altitude. So over time I will lose some altitude. But it will still go further then it would without having an engine (...
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3answers
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If the Concorde had an engine fail at cruise altitude, would they enter the coffin corner?

I know the coffin corner is only meant for subsonic aircraft, but if the Concorde is just cruising at Mach 1 and had an engine failure and also lost that afterburner, would it enter a coffin corner ...
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2answers
2k views

Why does a higher load factor increase stall speed?

I think that’s self explanatory, why does load factor (G) affect stall speed? Why does load factor result reaching the critical angle of attack at higher airspeed?
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6answers
9k views

What is the commercial passenger aircraft top speed record?

Aircraft manufacturers claim that commercial passenger aircrafts cruise at the speed of 400-500 knots. But, is the top speed of a commercial passenger aircraft recorded (while in air)? If so, what is ...
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0answers
184 views

Do modern aircraft still have PCMCIA?

Do modern aircraft still have PCMCIA for engine monitoring?
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1answer
204 views

If the modern airliner was redesigned from scratch, would it look functionally different? [duplicate]

If the modern airliner (Boeing/Airbus) was redesigned from scratch today without any need for "backward compatibility", would it look functionally different from the current design? And if so, what ...
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0answers
547 views

What is the stall speed of the Antonov An-225?

Under certain circumstances - maximum gross weight, unaccelerated 1G flight, clean configuration (landing gear up and flaps)? Indicated airspeed (KIAS) of course.
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1answer
194 views

What is the physical-based/theoretical reason why supersonic area ruling works?

Supersonic area ruling is used to reduce the drag rise that occurs as aircraft pass through the transonic regime. While it has been validated experimentally, what is the theoretical/physics-based ...
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2answers
4k views

Which aircraft can fly at FL600 or above?

I would like to know some examples of aircraft (specific models) which can fly at FL600 or higher. I am interested in aircraft which can or could fly at that altitude on a regular basis (service ...
4
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1answer
86 views

Constant turn radius with Δ airspeed and bank

Can someone explain how speed impacts rate of turn and and degree of bank required? I'm trying to understand this practice problem but can't get the concept: Say you have 2 vehicles travelling at ...
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2answers
8k views

In WW2 aircraft, where were gun cameras mounted, and did they suffer performance penalties?

During WW2, some aircraft had gun cameras that activated whenever the guns fired, so that people on the ground could evaluate performance and help with kill ratios and other statistics. These were ...
1
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1answer
171 views

Is there a rule of thumb for aircraft design? [duplicate]

I'm wondering how to best scratch build an rc aircraft and what rough proportions the aircraft should be in. I'm aware of the fineness ratio that determines the width to length ratio of a cross ...
2
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1answer
155 views

What would the point to point range of the current Virgin Galactic Spaceship 2 launch system be?

Many people have suggested that the next step for Virgin Galactic after single point "space tourism" flights begin would be passenger suborbital flights, providing travel times many times faster than ...
3
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2answers
179 views

Why do airfoils in an airplane's wings have different shape and size along its span?

Why wings of an airplane consist of different shape and size of airfoil. What will happen if the thickness of wing are same throughout the wing?
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1answer
414 views

Do the F-16's leading edge flaps lock up at +2° when the aircraft as a whole is supersonic, or when the airflow over its wings is supersonic?

My question is: do the leading edge flaps lock upright when the aircraft as a whole is supersonic, or when airflow over wings of the aircraft is supersonic?
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5answers
741 views

What factors influence the maximum speed of an airship?

I'm interested in learning about the physics of airships; in particular, how you determine an airships maximum speed. For example, the Hindenburg topped out at about 80 mph. The ship itself weighed ...
36
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1answer
7k views

Do the Mt. Everest rescue helicopters have modified engines to operate at high altitudes?

There are so many climbers on Mt. Everest today that there is now a helicopter rescue service there. They operate rescue up to 21,000 + ft. Because this is essentially stationary service it seems that ...
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2answers
1k views

Why does the stick force per-g test require it to be harder for pilots to pull back on the yoke instead of easier?

What happens when it’s easier to pull back banked at such steep angles, wouldn’t it be a good thing that a pilot can maintain his altitude easier than harde?
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1answer
172 views

How would a pilot stabilize the aircraft after a dual engine failure?

Since there would be no more thrust, they would have to exchange energy by losing altitude to keep forward speed. But what happens towards the end, when you have to reduce your V/S to something like -...
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0answers
209 views

How efficient would it be to have a plane with the cockpit in the back?

Would it be efficient to have a passenger planes cockpit move to the back of the plane, rather than the front? What I have in mind is cameras on the fuselage and nosecone that connects to the cockpit ...
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1answer
231 views

Why can’t aircraft use GPS to generate the IAS, instead of using pitot tubes? [duplicate]

I’m mostly asking after reading about Aeroperu Flight 603, which was caused by a piece of tape blocking the sensor. Is there any other way to gather IAS or is this the best way to do it?
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3answers
764 views

What is the relationship between centre of gravity, centre of pressure and pitch?

Ok so I've got a couple of questions regarding CG, CP and pitch 1) When the aircraft is taking off, is the tail down force required to pitch up the aircraft high? Because the aircraft always has a ...
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3answers
1k views

What effect does wing loading (high and low) have on aircraft performance?

I've read that stalling speed is partly determined by wing loading. Correct me of I'm wrong - "Aircraft with high loading have more weight relative to their wing area hence the stall speed is ...
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3answers
277 views

If the pilots used the brakes upon landing, would the force essentially slam the front wheel down?

So if the pilots braked immediately, with only the back wheels down, and nose wheel still up, would the force from braking cause the front wheel to come slamming down?
4
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1answer
385 views

What are L/D ratio of famous WWII fighters?

I'm looking for L/D ratio of old warbirds. I'm particularly interested by the P-51D, the Supermarine Spitfire Mk.VII and the Mitsubishi A6M3 Zero, but I'm also quite curious about other warbirds that ...
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5answers
9k views

Is it possible to stall a plane so badly that the nose refuses to go down due to lack of airspeed?

So basically, a stall from a high AoA to the point that the entire plane just falls with the rear end pointing straight down? Because if wind is no longer passing over the wings, then this includes ...
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0answers
60 views

What are the differences between a compressor wash on wing vs on test bed

I work in an aircraft engine overhaul facility and I’m trying to understand the process of compressor washing engines on Wing compared to washing them in a test bed. What process steps are different ...
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3answers
212 views

Is the point of “groundspeed” in aircraft just to have a second reference of speed but two totally different measurements of speed? [duplicate]

From not understanding groundspeed will always be significantly higher than airspeed, unless the plane is pitching up and down. Is the ground speed just there for pilots to look at and say “okay we ...
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1answer
138 views

Does the F-16's neutral stability also extend to the negative-G flight regime?

If an F-16 pilot pushes the stick forward hard enough to send the aircraft into negative-G flight, does the jet tend to accentuate the new flightpath, requiring the pilot to counter that, or not?
4
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2answers
270 views

If, one day, we have an electric airplane, will it be easier to control than a fuelled airplane?

Elon Musk said that Tesla will make battery which can last for million miles. So probably in the next few years there will be a (small) airplane powered by an electric motor rather than by fuel. If ...
2
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1answer
588 views

What's the maximum range an A350-900 can reach at TOW of 250,606 kg and full payload?

When the TOW (takeoff weight) of an A350-900 is 250,606 kg (because of runway length limitation), with maximum payload, what is the maximum range it can reach using the chart above? It is easy to ...
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3answers
609 views

How does the engine wash improve engine performance?

According to maintenance manual, we usually carry out engine wash (CFM56) with pure water as scheduled task. Pure water is injected into the engine from the LP compressor inlet while the engine is ...
4
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1answer
8k views

What fomula use for calculating pressure altitude?

I'm having some trouble making my calculations of pressure altitude match those in apps and text books. I'm using the formula from Wikipedia: (29.92 - altimeter setting) * 1000 + airport elevation ...
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1answer
152 views

Can pressurized aircraft be flown without pressurizing

Are there any pressurized aircraft models which can also be flown without pressurizing the cabin? For example, if there were a short ferry flight, or a flight where the aircraft never got high enough ...
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1answer
214 views

Flying a twin engine aircraft with 2-axis control

I believe a twin engine aircraft, with 2-axis control (i.e. Rudder and Elevator), under normal circumstances is flyable. But is it safe at all? If one of the engine dies, will the rudder alone be ...
4
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2answers
626 views

What is the impact of thermal Anti-Ice on descent performance?

I am just another one of the passionate flight simmers trying to understand more about Anti-ice system mechanics. I am talking about the Boeing 737-800 here if it makes a difference. What bothers me ...
3
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2answers
169 views

What is the maximum (unloaded) range of the Beluga XL?

Airbus states that the range of the Beluga XL is 4000 km at maximum payload. Does anyone have a figure (or estimate) for it's maximum range with no payload?
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1answer
158 views

Can accelerations be used to calculate load factors?

Can I use the z accelerations to calculate the load factor in that axis? Please explain how or why not.
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3answers
744 views

How do flaps help an aircraft take off at a lower speed, yet cause drag at the same time?

Wouldn’t the drag caused by the flaps just decrease the acceleration, so, although they can lift off at a lower speed, wouldn’t it be faster to just use no flaps and rotate at the higher speed that is ...
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1answer
273 views

What's the difference between hover power and maximum continuous power?

What's the difference between hover power and maximum continuous power? Is a pilot clear to fly when its hover power is more than maximum continuous power calculated by table?
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4answers
646 views

What makes airplanes pitch up during landing?

So what exactly pitches the plane upward with the rear end down? Do flaps help lower the nose when deployed 80%-100% down with such low speeds?
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4answers
360 views

How much of an airplane's forward energy is lost to lift?

An airplane needs to move forward to generate lift, and because energy isn't created from nothing, all the kinetic energy of lift comes in the form of drag, where air (air resistance) turns forward ...
42
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6answers
15k views

Do airplanes need brakes in the air?

A few days ago I flew on a Boeing 737-900ER. Luckily I was sitting just beside the left wing, seat 26B. I observed that the spoilers were activated (opened) just after the pilot spoke on the Passenger ...

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