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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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4
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1answer
48 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
7k 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 ...
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1answer
99 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
101 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 ...
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0answers
20 views

Are there any repository of load and trim sheets? [closed]

Does there exist any repository of load and trim sheets? I am looking to study aircraft performances and wish to look into load and trim sheets of active aircrafts in service. Does Airlines treat ...
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2answers
108 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
228 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?
8
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5answers
419 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 ...
34
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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 ...
4
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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
155 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
193 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
207 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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0answers
40 views

Types of wings aircrafts use [duplicate]

Now I know that aircrafts can use swept back wings. But I want know why sometimes they don't use the wings mentioned below: 1) Rectangular wings 2) Trapezoidal wings 3) Delta wings 4) Forward Swept ...
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3answers
165 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
242 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 ...
2
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3answers
254 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?
3
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1answer
217 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 ...
19
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6answers
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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 ...
3
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0answers
49 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
186 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
113 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
239 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
178 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
351 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 ...
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0answers
33 views

Where can I find data comparing coefficient of lift (and drag) curves for any airfoil with and without flaps deployed

I'm doing my masters thesis on a FISHBAC wing so I'm hoping to find coefficient of lift and drag curves for any airfoil with and without (any type of) flaps deployed (and preferably leading edge ...
2
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1answer
158 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
110 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
98 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
276 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
139 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
53 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
317 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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0answers
79 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
207 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
218 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 ...
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6answers
14k 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 ...
2
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1answer
104 views

What is the range difference between LEAP and PW1000 powered A320 and A321 NEOs?

Mounted on the same aircraft, PW 1000G and CFM LEAP are two very different engines, with different performances, that should have an impact on range. And we know range is a very important aircraft ...
2
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0answers
83 views

How can I approach analyzing the basic performance characteristics of an unknown aircraft?

I am working on a project for one of my classes. My group and I have been given information on an unknown aircraft, and we must find the max velocity, max R/C, max range, and max endurance of the ...
2
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1answer
82 views

Why does lift curve slope increase when Fowler Flaps are deployed?

Below is an image for a Fowler Flap: Notice that as the flap is deployed, both the camber and the area increase. This change in wing shape modifies the lift curve as follows: (source: Development of ...
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1answer
198 views

Why do pilots wait for a positive rate to put the gear up, When V1 means “commit to takeoff”?

To explain further, V1 means they cannot stop in time if anything happens. Therefore they must commit to taking off. So why wait for a positive rate? Shouldn’t it be retracted as soon as they see a ...
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3answers
466 views

What is an airliner pilot's first go-to if he or she doesn’t have a positive climb rate immediately after take off?

Assuming a typical transport-class aircraft, what would the pilot do if the aircraft does not have a positive rate of climb immediately after takeoff? Would the pilot just lower the nose to pick up ...
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1answer
125 views

How can a runaway trim become so difficult to fight when all a pilot has to do, is “grasp and hold?” [closed]

and how can you even tell the pilots did “grasp and hold” during an investigation? Is it determined based off what they say?
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1answer
82 views

Is there a relationship between transonic buffet magnitude and altitude?

Transonic buffet happens at mach 0.95. The correlated true airspeed varies with altitude. Does the transonic buffet magnitude also vary with altitude, and if so, how?
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1answer
86 views

External Batteries [closed]

As a part of a project for a class we were tasked with trying to cut emissions/energy waste of airplanes. Now we've realized that running the apu on the ground at the gate and taxiing is a serious ...
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1answer
142 views

Do aircraft need special modifications for polar routes?

Does an aircraft need special modification for polar routes?
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1answer
178 views

Where and when would a 737-700 be taking off at an altitude of 19 kft?

Another question triggered by reading the 737 technical site; according to this section of the page on the 737's pressurisation system, the 737-700 comes with an option that allows it to safely take ...
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1answer
116 views

Why does IAS decrease with lower air density if power is constant?

TAS increases with less dense air, which is intuitive. What I don't understand is why IAS decreases. This is assuming sub-transonic speeds where compressibility effects are negligible. To phrase ...
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2answers
197 views

What is the explanation of this airfoil phenomenon? Why the air from below the leading edge's tip deflected up?

I have difficulties to understand this air phenomenon, why the air from below the leading edge's tip (from below the horizontal line) is deflected up and not just follow the bottom wing's surface? ...
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0answers
173 views

If an fighter jet that it have twin rudders, in use the angle of deployment it is not identical. Which is more deflected and why?

If an aircraft have two vertical tails then pilot push in the rudder pedal the rudders will not be deployed at the same angle.It is used throughout the all envelope of flight or is it possible only ...