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Questions tagged [aircraft-design]

Questions about the different choices that aircraft designers (typically aerospace engineers) make in order to create an aircraft.

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1answer
127 views

What percentage or airplanes have engines [on hold]

I heard that some airplanes don't have engines. how many airplanes in the world have engines?
4
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1answer
94 views

Can roll be controlled through elevators in a fixed-wing aircraft? [duplicate]

In fixed-wing aircraft, roll is typically controlled through ailerons. But I am wondering if roll could also be controlled through split, independently controllable left/right elevators?
3
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3answers
209 views

Do large non-pressurized metal planes have a maximum fatigue cycle?

For example the DC3. The way I understand it, the only thing that "ages" the airframes of DC3 is the landing/takeoff cycles and the accompanied periodic force loading/unloading. Do planes such as this ...
1
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1answer
79 views

What changes are needed for a piston-prop aircraft to withstand saltwater environment?

I'm interested in WW2-era piston-prop aircraft. I want to know what changes are needed to make the aircraft withstand saltwater corrosion. Presumably these are different and more expensive than the ...
-1
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0answers
45 views

Aircraft thrust [on hold]

Suppose i have made light aircraft. And it has total weight of 200 kg with person and the maximum thrust given by propeller is 45 kg will it fly or not. If it cannot fly then how much thrust we need ...
0
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0answers
52 views

Fuel De-aerating Tank?

I know turbine engines (bearings) are cooled by oil jets and that when oil is scavenged from the bearings it is more of a mist than a liquid, hence the need for various types of de-aerating this mist ...
0
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1answer
27 views

What to be considered in designing airplane tail (vertical and horizontal stabilizer, elevators and rudder)? [on hold]

I would like to make a small amateur triplane with it maximum weight approximately 400 kgs with maximum speed 100 knots (180 kph). I have read many discussions about how to calculate the wing ...
1
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0answers
49 views

Why does the Comet's horizontal stabilizer have so much dihedral?

The Comet's horizontal tail has a noticeably extreme amount of dihedral compared to that of, say, a 707: (Image by MilborneOne at Wikimedia Commons.) Note how the Comet's tail has about twice as ...
0
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4answers
121 views

Why some WWII fighters still have fabric/wood control surfaces?

I've heard people say that the reason US in WWII preferred designs with fabric control surfaces with either a metal or plywood frame is they can sustain some small arms fire without disintegrating. Is ...
10
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3answers
327 views

Do fighter jets have deicing in their wings?

If there is such thing as deicing for fighters? If so, is bleed air or electric heating preferred? I could not imagine that a $50MLN fighter jet would not be able to get the ice off its wings.
1
vote
4answers
177 views

How is vertical speed managed in Airliners? [duplicate]

When an Airplane starts to take off, the Horizontal velocity would generate it the necessary lift, and then Airplane pitches up to further increase the lift. As the Airplane is climbing up, the net ...
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2answers
179 views

Boeing 737-MAX Control System Design Flaw? [on hold]

I’m concerned about Boeing aircraft safety design flaws because it is so disturbing to see so many lives lost in aircraft accidents. I’ve attempted to contact Boeing about this. But officially they ...
3
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2answers
242 views

Can an Airbus A380 or Boeing B747 fly with only 2 engines?

If during cruising with full load, these two kinds of airplane got two of their engines failure: With one engines fails in each side (so, only one engine works every side). With 2 engines fail in one ...
2
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1answer
274 views

What is the purpose of this item next to the cockpit window on the B737?

Hello does anybody know what the purpose of this odd looking shape is
3
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3answers
331 views

Is the MD-11's third engine slightly nose up?

From my visual inspection, the third engine (the engine on the horizontal stabilizer) is slightly "nose up", especially compared to the engines on the wing. That means, the front part of the engine is ...
0
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1answer
41 views

Difference between FMCF and AIMS on B777?

What is the Difference between Flight Management Computing Function and Airplane Information Management System on B777?
0
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1answer
119 views

Where can I find complete aircraft blueprints for the purpose of study?

Where can I find aircraft blueprints for the purpose of study? I find that I learn a lot more when I am able to get the big picture of a machine that is used in real life (for example, to understand ...
1
vote
1answer
188 views

Boeing 737-MAX stabilizer control

Various websites have stated that during the 737-MAX crash in Indonesia, the pilots could not pitch up because of a faulty AOA sensor pitching plane down. Stabilizer has a rear fulcrum and front jack ...
4
votes
2answers
145 views

Why the Antonov AN-225 has negative dihedral wings combined with a positive dihedral horizontal stabilizer?

I know the reason why it has negative dihedral wings, but I do not really know why it is combined with a positive dihedral horizontal stabilzer, which are the benefits this configuration provides?
10
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5answers
3k views

Why didn't Boeing or Douglas make a jet airliner before the British DH Comet?

I was looking at the history of commercial aircraft and was wondering why UK-based De Havilland was the first to produce a jet powered airliner (the DH 106 Comet) when the US had a much bigger civil ...
4
votes
2answers
344 views

What is this unusual leading edge flap on a B737-200?

On this video of Air North's gravel runway-equipped B737-200, there's what appears to be a small leading-edge flap (Krueger flap?) inboard of the engine. Refer to the screen shot below. What is this?...
0
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1answer
57 views

Where should the support points be for testing a model wing in a wind tunnel?

When testing a certain wing profile inside a wind tunnel where should the model, small scale wing be supported? Should the support be under the center of mass of the wing or under the aerodynamic ...
2
votes
4answers
196 views

Why are the leading edges of wings not always made as 'sharp' as possible?

Why is an airplane's wing (the leading edge) not made as sharp as possible to break the air, in the same way that a ship's hull is made sharp to easily break the water? This is unlike Concorde's nose ...
0
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2answers
78 views

Would a sharper leading edge increase lift and reduce drag at lower speeds?

A recent scratch built glider kept turning to the right even after painstaking efforts to match the wings perfectly. Extensive addition of fin area to the tail failed to correct it. Closer ...
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1answer
44 views

contra rotating propeller incidence angles of first and second prop with different spin diameters? [on hold]

Do contra rotating propeller incidence angles of first and second prop with different spin diameters affect positive or negative thrust an speed of the a/c?
0
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0answers
34 views

How could I measure frontal area based on a technical drawing?

I want to compare frontal surface areas of two airplanes, and I have their digital technical drawings and wingspan data. What program could I use to obtain the surface area using this data? Esentially ...
0
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2answers
109 views

In an airplane wing, which one is primary, and which one is secondary

I got this device detail of a wing. Those parts are: 1: wingtip fence, one of the wingtip device beside winglet. 2 & 3: aileron. 4: flap track. 5 & 6: slat. 7 & 8: flap. 9 & 10: ...
0
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1answer
46 views

How do we derive Lift Coefficient of an airplane's wing?

In many references I read that lift coefficient ($C_l$) is a product of wind tunnel test. But many times I read the formula to calculate the coefficient of lift. From the lift equation, $$L=\frac{1}{2}...
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0answers
42 views

How many variations are there of the Avro Lancaster?

How many different variations of the Avro Lancaster are there?
2
votes
2answers
79 views

How do endplates reduce induced drag?

I have heard the explanation which states that the endplates reduce the tip vortex formation thereby reducing induced drag. From what I understand induced drag is the backwards component of the total ...
3
votes
3answers
303 views

Why did narrowbody jetliners take so long to switch over to high-bypass engines?

High-bypass turbofans were introduced into the airliner market around 1970, when the first widebody jetliners were released (the 747 was first, followed in rapid succession by the DC-10, L-1011, and ...
1
vote
1answer
60 views

What was the Airfoil of Handley Page P.115?

This extreme sweptback delta was built to test the Concorde wing at low speeds, sources say it had a biconv 6% airfoil, but I failed in finding data about it.
16
votes
3answers
6k views

Why has the 777x been designed with folding wingtips?

I recently visited the Boeing factory outside Seattle, WA and noted in the distance a new 777x being built with, what looked like very large wingtips. However, on closer inspection they're not - the ...
11
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4answers
2k views

Why isn't there a single best airfoil for subsonic flight?

Why does airfoil used by modern subsonic aircraft (this is true for transonic airliners too) vary from plane to plane? Haven't we figured out a single best airfoil shape, with the highest lift to ...
7
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4answers
434 views

Why do cargo aircraft still have floors?

Even with dedicated cargo aircraft built as cargo aircraft (rather than converted from a passenger-carrying configuration), the cabin is virtually always still divided into an upper and a lower lobe (...
1
vote
1answer
51 views

What is the wing span in aspect ratio's calculation?

We all know that the aspect ratio of an airplane is calculate as: $$AR=\frac{b^2}{S}$$ Where: $AR=$ Aspect ratio $B=$ Wingspan $S=$ Wing's area In an airplane, wing span is the distance from tip ...
0
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4answers
164 views

How does Bernoulli's principle contribute in lifting airplane?

I have searched if any explanation that bind Bernoulli's principle in lifting airplane. There is one here which receive many appreciations, but still did not answer the question. So far, it was taught,...
1
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2answers
70 views

Since speed is related to dynamic pressure, then why is static pressure used instead of dynamic pressure in ASI to measure speed?

Since speed is related to dynamic pressure, then why is static pressure used instead of dynamic pressure in ASI to measure speed? Why is dynamic (or pitot) pressure not sufficient?
0
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3answers
135 views

What makes an airplane can take off very short?

I watch STOL pilot champs Zenith CH701 here. The engine power are: 130HP, 80HP, 120, and 100HP respectively. Amazing. As per my observation, the third airplane take off shorter than it length. It uses ...
0
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0answers
13 views

What is a typical Cd0 value for single-slotted flaps?

I've been having trouble finding any source for what a typical value would be for single-slotted flaps. I haven't been able to find any information within Anderson's Aircraft Performance and Design or ...
2
votes
1answer
101 views

What would be the power requirements and performance of an Scroggs type of Delta with 250 cm span?

Roy Scroggs, a tailor, patented in 1917, US1250033, and in 1932 US1848578, a Delta Wing plan form machine 'Flying Dart', flight tested with an OX-5 engine, they say ...
1
vote
3answers
127 views

How does a pilot maintain stability for an unbalance loaded airplane?

Consider Cessna 172 which has 4 seats, including the pilot, with the seat configuration as the picture below. Say the airplane has no passenger, only the pilot him/her self. I am not sure where it ...
0
votes
2answers
164 views

Who designed and built Rans S-7 airplane?

I read in the Washington Times, that a man named Swingle, who has no knowledge and experience in aircraft design, built one which he called a bush airplane. But I read in Wikipedia, that the RANS S-7 ...
52
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8answers
21k views

Why are fuel tanks located in wings?

Passenger aircraft have fuel tanks in the wings. Why? What are the advantages and disadvantages of this location ? examples of disadvantages I would suspect: added weight increases the structural ...
0
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4answers
160 views

How does scaling of UAV size impact range?

Lets say you have two autonomous small aircraft, one with a wingspan of 200 cm and one with 400 cm. Both have the same general design. They are both optimized for travel distance on one full tank (gas ...
0
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0answers
39 views

How to determine the bulge of an airfoil?

In calculation or designing, how to determine the airfoil bulge (thickness)? What is the guideline or consideration in designing airplane's wing? We all know that the bulge (the ticker in the airfoil) ...
0
votes
1answer
132 views

What is the exact purpose of the string attached between front fuselage & the tail section of the transport aircraft's? [duplicate]

]2 228]3]3 Usually I got to notice a string attached between front fuselage to rear tail section of the transport aircraft's, what exactly might be the purpose or function of it? But comparatively, I ...
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1answer
185 views

Why is the nose cone of Russian fighters pointing slightly down? [duplicate]

Let's take SU-30 as an example: The nose cone is clearly pointing a bit downwards with respect to the level of the engines and wings. Why is this? How can this kind of a banana even fly properly? ...
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1answer
148 views

What is the best aircraft engine to be used on small aircraft? [closed]

I intend to build small aircraft as I explained here. But I am quite confuse to chose the BEST engine to be used. My requirement is range from 60HP to 100HP. BEST in here is considering the price, the ...
0
votes
1answer
197 views

Why does Germany is not so advance in aircraft development? [closed]

I tried to see what countries are the most advance in developing aircraft. I found that Germany is not so advanced (CMMIW). Indeed, there is Dornier there beside has share in AirBus. I don't know ...