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
83 views

Why is the aviation industry taking so long to move away from the tube with wings model? [duplicate]

The industry is spending billions on maximising fuel efficiency and reducing other costs associated with the tube-with-wings model. When will novel designs like semi-dirigible and lifting body arrive, ...
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2answers
77 views

Does a RC aircraft require suspension in landing gears?

we engineering students are preparing for a particular competition with dimensions of 170 in. (length + breadth + width) for that competition we require landing gear but for that are we supposed to ...
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5answers
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Do aircraft cabins have suspension?

On cars, we have 'shock absorber' suspension that decouples the passengers and loads from the road vibrations, bumps etc. On planes do we have any form of suspension that decouples the passengers &...
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35 views

Are there design guidelines for sizing vent/surge tanks?

Could someone explain the sizing process of Vent/ Surge tank of Aircraft fuel system? I understand the Vent tank is to collect fuel overflow from the main fuel tanks. The reason could be due to Fuel ...
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0answers
66 views

Could a tail rotor serve as a spin breaker for winged aircraft?

It seems that yaw, more than pitch or roll, creates the greatest wing asymmetry in a spin. If the spin progresses to the point where it cannot be broken, some aircraft are equipped with parachutes to ...
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2answers
306 views

Could a BV-347 be upgraded by extending the wings?

The CH-47 Model 347, also referenced as BV-347, was a helicopter that utilized a wing for forward flight and to carry external payloads. Could the wings be extended and engines on the rear rotor ...
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2answers
174 views

When are more engines better than not on a plane?

A model of this airplane was used to carry a space shuttle. In this picture below the airplane had a few extra engines added since then. How is the number of engines decided on an airplane? Why not ...
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2answers
5k views

Why does the Antonov AN-225 not have any winglets?

Winglets provide a lift boost that would be useful to a plane of this size. But the An-255 does not have any winglets. Why is it so?
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0answers
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I want to write a computer program to design a light aircraft: how would I test the validity of its results? [closed]

Raymer's spreadsheet is one way to do design an aircraft. https://vdocuments.mx/raymer-simplified-aircraft-design-spreadsheet.html There is also this interesting presentation here: https://www....
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3answers
204 views

Is it better to have the engines center or apart on a plane?

Are there any advantages or disadvantages to having the engines closer or farther to the center of the plane? How is the ideal engine spacing determined length or span wise for performance? Related: ...
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1answer
32 views

What is the best or most popular way to reduce wing tip vortices on an ultralight operating at 600-800k Re?

What is the best or most popular way to reduce wing tip vortices on an ultralight triplane, operating at 600-800k Re with fibreglass wings ,10 ft wingspan, gap of 2 chord, chord of 2 ft, 0 stagger? ...
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1answer
80 views

What would be the advantages and drawbacks of a single-propeller tiltrotor?

When looking at existing tiltrotors, most of the designs use two propellers, sometimes four. helicopters (and light planes), on the other hand, generally use only one propeller. Have there ever been ...
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4answers
334 views

Why are overwing engines so rare?

This comment to a question about underwing vs rear-mounted engines notes the existence of a rarely used third option: overwing engines. There seems to be very few planes using those. What are the ...
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3answers
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Why do most airliners have underwing engines, while business jets have rear-mounted engines?

Why have modern airliners converged on a configuration with two or occasionally four underwing engines, while modern business jets have converged on a configuration with two or occasionally three rear-...
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2answers
166 views

Can cold thrusters/roll posts be used to control/stabilize an aircraft (like a satellite)?

Aircraft use control surfaces to control their motion/direction. Would it be a good idea (i.e., more efficient, less weight, better responsiveness, less drag, etc.) to use thrusters/roll posts to ...
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3answers
514 views

Would a Chinook helicopter fly better with contra-rotating along with counter-rotating propellers?

Would a Chinook perform better or have any advantage with dual contra-rotating propellers over a Chinook with just normal counter-rotating propellers?
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3answers
294 views

How does the A350 variable camber system decrease drag?

Just curious how the A350 reduces drag/fuel burn by extending the flaps ever so slightly during cruise. Everything I've read about extending flaps says that extending them pushes the centre of ...
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2answers
6k views

Which are more efficient in putting out wildfires: planes or helicopters?

A lake is near where both helicopter and plane can access the water and fire. Which aircraft (if you had access to only one) is more efficient in putting out wildfires? Which aircraft is preferred to ...
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1answer
68 views

Does empennage height above the main wing matter [closed]

Am still in my preliminary design, am already wondering as to how high above the wing should the empennage (tip of vertical stab) be?
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1answer
161 views

Was the F4F-1 Wildcat ever built?

The original design for the F4F Wildcat was as a biplane, but with the -2 model, it was redesigned as a monoplane. I am wondering if the -1 model was ever actually built, or did it remain as a ...
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5answers
2k views

If I were to build a J3 cub twice the size of the original using the same CG would it fly?

How big of an engine would I need, if the original is 65hp? What would be the weight of the up-scaled plane? Simply twice the weight? What would be the stall speed? How fast would it go? 75mph? Is ...
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3answers
231 views

Does fly-by-wire permit smaller tail fins (area and thickness) for jetliners?

To prevent an XY problem, here's the context: A striking feature of the 777 is how small and thin its tail fin is compared to the 747. When I asked about this many, many years ago, someone told me ...
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1answer
129 views

How did Airbus A380 overcome corrosion issue in which aluminium wiring used? [duplicate]

The corrosion of aluminium is generally recognized to be a major problem. What new technologies or technics might be used in aluminium wiring to get away from the corrosion issue?.
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1answer
128 views

Would this modified tire work to prespin an aircraft tire? [duplicate]

In order to decrease that initial hit of the tire spinning up to ground speed on the runway, could adding a blades or shape into the tire rim of a commercial plane save on tires by prespinning the ...
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1answer
282 views

Why do some helicopters have wheels instead of skids?

I have noticed that Black Hawk helicopters have tires, but I have not seen one take off like a plane. When would a helicopter need to use a running take off or landing? When is it determined ...
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5answers
15k views

Why were the first airplanes “backwards”?

In the question Is the location of an aircraft spoiler really that vital? the accepted answer states "Surfaces behind the CoG act as stabilisers, keeping the nose pointing forward. An aeroplane has ...
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1answer
81 views

What does the “test result indicator” indicate on a cockpit voice recorder?

I am really curious as to what the “green/red” strip of led indicate and the numbers below it. Having read around the web, i speculated that it could be an audio quality rating scale. Would help alot ...
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1answer
2k views

Is the location of an aircraft spoiler really that vital?

I was wondering that spoilers in most of the aircraft are always placed aft (towards the tail) the CG location. Why aren't they placed ahead of the wings or near the nose of the aircraft? The same is ...
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0answers
60 views

Definition of Critical Part in type certification process

first time here :) I'm part of the team at Flytrex (flytrex.com) and we're working with the Aircraft Certification Office to certify one of the first UAS systems (drones) under new initiative to ...
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1answer
1k views

Why does the A-4 Skyhawk sit nose-up when on ground?

The rear of the plane is nearer to the ground, while the front part of the plane is away from the ground (see image below). Other planes are more flat. I think it was for high AoA but these planes ...
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2answers
135 views

Eviation Alice Powerplant Placement

I saw an article from the BBC about the Eviation Alice this morning that left me puzzled. The design is a tail wheel tri-motor with the power plants located in a pusher configuration at the wing tips ...
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1answer
345 views

Did the Douglas SBD Dauntless have a second set of controls?

In the book Never Call me a Hero, the author mentions that there were controls in the rear seat of the Douglas SBD Dauntless. However, I don't recall ever hearing this before, though I know the TBD ...
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11answers
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Would a two-seat light fixed-wing aircaft with a landing speed of 20 knots and a top speed of 180 knots be technically possible?

Watching helicopters come in to land, on occasion, I have noticed that they approach with a forward speed of a few knots, never land straight down. If there is sufficient landing space, would it be ...
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1answer
63 views

Does the canard config have radically different controls than classic config?

Classic configuration is something like the A320: wings in the middle, horizontal stabilizers at the tail. Canard configuration is something like the Beechcraft Starship: wings at the back and ...
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1answer
143 views

Does the DC-3 passenger airliner have slats?

The DC-3 is a very popular and widely used aircraft, yet has low speed tip stalling risks due to the design of its wing, which at the time of its development represented the leading edge in drag ...
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1answer
221 views

Why only the outboard (“low speed”) aileron drops when there is no hydraulic pressure on the 747-8?

As the title says, why only the outboard ("low speed") aileron drops when there is no hydraulic pressure on the 748? (Full resolution)
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1answer
70 views

What is the effect of aileron deflection on the centre of pressure?

Deflecting an aileron will increase or decrease the camber of the outer wing where the aileron is attached. I learnt on this platform that centre of pressure (c.p.) moves fore and aft with aileron ...
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3answers
212 views

Could wing tilting be a mechanism for VTOL and high angle of attack for jetliners? [closed]

My question is about turbofan airliners, could an airplane tilt its wings 90 degrees so that the fuselage horizontal axis is perpendicular to the longitudinal axis of the turbo fan. This way an ...
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1answer
147 views

Is there an easy way to determine where a part goes on an airplane?

In order to classify parts for export I need to determine where our parts go on the plane. (Engine or structural/body) Specifically looking at the canister, heat shield assy and lock support for the ...
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2answers
262 views

How much lift does the wing attach fitting actually carry?

How do I calculate the lift force that the the bolt that join the wings to the fuselage of a strutted or braced airplane carry? I know in a cantilever airplane,the bolts have to carry all of the lift ...
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4answers
189 views

How to determine the compressive force in the spars of a strutted wing?

How does one calculate the compressive force that the inner section of a strutted or braced wing (from the strut attach point to the wing root) experiences? I know how to calculate the tension in the ...
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2answers
1k views

The Mig 21 and the Mirage III have been criticized for lack of range, is this a limitation of the wing configuration?

Mig 21 Range: 1,470 km (910 mi; 790 nmi) at 10,000 m (32,800 ft) with 2 × K-13A missiles and 800 l (180 imp gal; 210 US gal) (Wikipeda) J-7 Combat radius: 850 km (459 nmi, 528 mi) (air superiority, ...
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3answers
297 views

Why are Vertical tails generally tapered?

I'm just intrigued to know why the vertical tail of a majority of aircraft is tapered? Is it due to aerodynamics, structural design or due to some instrumentation or multiple other reasons?
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1answer
116 views

How is paint embrittlement countered in high altitude aircraft?

There are cases of aircraft that are not designed for high altitudes that can still fly there and as a result the paint on these aircraft "falls off". Although most aircraft have paint that is chosen ...
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1answer
56 views

Propeller effect on the L/D of an aircraft (Pusher Propeller configuration)

I recently performed an aerodynamic analysis of a fixed-wing UAV with a pusher propeller configuration. I found out that the L/D reduced by about 15% when compared to the body alone without propeller. ...
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3answers
216 views

Constellation nosewheel angle

Why are the nosewheels on the Constellation canted in a few degrees ? Is it to ensure both tyres have ground contact during tight ground turns ? I've observed that on the A320 during tight turns that ...
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3answers
358 views

Why don't solar powered aircraft use wings with more surface area

I was looking at some solar aviation projects, and I noticed they appear to follow the designs of a glider. The Helios drone above is basically a flying wing with a high aspect ratio. And the solar ...
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1answer
128 views

Why was the An-225 built when the VM-T Atlant already did the job?

The Soviet Buran program decided to use a carrier aircraft to move their orbiter and Energia tanks similarly to the American Shuttle Carrier Aircraft. However, the Soviet Union built two types to do ...
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2answers
183 views

Where can i find aircraft blueprints for study purpose? [closed]

I'm a 3D artist and i want to start my new project. I'm going to create an exact model of the Embraer 190 aircraft. I need this for my graduation project at the university (I chose such a project, ...
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0answers
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Aerodynamic Pressure Loads in FEA of Lifting Surfaces - Query

Let me give a brief summary of the process involved in the FEA of lifting surfaces with the wing as an example: 1. The wing is modelled as a hollow surface body in Ansys, meaning only the exterior ...