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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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3answers
175 views

Can a Stewart Platform be used instead of a swash-plate assembly in a helicopter? What are the pros and cons? [closed]

https://en.wikipedia.org/wiki/Stewart_platform Also, are there any helicopters in service that use this mechanism? I was thinking along the lines of using it instead of the part of the swashplate ...
3
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1answer
374 views

How does wing bending relief of an a340 compared to an a330 allow it to carry 30t more fuel in a center section of nearly identical wings?

From this question this reference in ymb1's answer states that the a340 and a330 have nearly identical wings. Because of bending relief from the weight of its outboard engines, the bending moment ...
2
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2answers
251 views

Why is it necessary for pilots to have trim controls on fly-by-wire aircraft?

On Airbus family airliners why is it necessary for the pilots to have the facility to trim when there is no aerodynamic feedback through the flight controls?
-1
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1answer
190 views

How to reduce cosmic radiation in commercial aviation? [duplicate]

There have been some (somewhat limited) studies that show (certain) cancer risks increase with flying hours: The risk for all cancers, malignant melanoma, prostate cancer, basal cell carcinoma of ...
1
vote
2answers
187 views

Is it possible to build a honeycombed vacuum balloon? [closed]

Is it possible to build a vacuum balloon with a near perfect void that can lift heavy objects and doesn't collapse and buckle under the atmosphere? I expect perhaps a honeycombed or lorimerlite ...
3
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5answers
333 views

Is wing sweep needed on supersonic aircraft?

Area rule states that bodies with the same crossectional area distribution have the same drag. Does that mean I could use a straight wing on mach 1.2 aircraft with performance as high as sweep winged ...
12
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4answers
3k views

What is the aerodynamic motivation behind vortex generators?

An airplane's wing creates lift efficiently when the airflow is parallel to the chord of the wing. Vortex generators twist the airstream on the wing surface. Doesn't this kind of twisted airflow ...
3
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3answers
670 views

What are the disadvantages of having vortex generators?

I know the advantages of vortex generators (VGs): lower stall speed, lower landing and takeoff speed according to www.stolspeed.com. So what are the major reasons most GA planes and low speed ...
0
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1answer
106 views

Twist optimization for a low speed aircraft

I'm currently designing an aircraft with the following specifications- s=1.8m^2, AR=7-8, trapezoidal planform with a taper ratio of about 0.45, a load of 25KGs and a cruising speed of 13-15m/s. I'm ...
4
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1answer
187 views

How did Airbus fit 6,340 gallons more fuel into the A359?

Bloomberg posted an article that says, among other things, the A350 ULR variant increases range by utilizing "additional space already available in the existing tanks to carry an extra 6,340 gallons ...
28
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4answers
4k views

In the early days of flight, were there any cockpit control schemes other than the modern one?

Back in the early days, what kind of control schemes were invented for aircraft, other than the modern one? (pedals to yaw, yoke to pitch and roll). I'm only interested in control schemes that can be ...
3
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3answers
247 views

In a pusher configuration with turboprop(s), how is the superhot exhaust avoided?

I actually looked around for turboprops in a pusher configuration, and so far I only found one: P180 Avanti. You can see the propellers are behind the turbine, and in fact it looks like two exhaust ...
2
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3answers
251 views

How does the wraparound wing design reduce drag?

How does the wraparound wing in this AOPA article reduce drag? One would think all that extra leading edge and surface area would make it worse. One more link also. The Parsifal Project has ...
3
votes
1answer
163 views

Why autogyros use pusher-, whereas, piston-engined planes use puller-configuration?

I found that most modern gyrocopters use a pusher-configuration, whereas, most piston-engined planes use puller-configuration. Since the pusher-configuration has major disadvantages, are there ...
4
votes
1answer
336 views

Could Mach 1.4 be a better design point for SST?

There's been a number of recent proposals for design work on low-supersonic bizjets that would cruise at Mach 1.1-1.6, the common theme being avoiding a sonic boom. I'm wondering if this range of ...
0
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0answers
35 views

If elliptical lift distribution is considered in every case, does the induced velocity change based on the shape of the wing?

Shapes like rectangular, curved, trapezoidal etc. Here I mean rectangular or curved when viewed from the top. The sectional airfoil shape is the same in each case.
0
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1answer
219 views

Spanwise flow and wingtip vortices in forward-swept wings

One of the benefits of forward-swept wing is that spanwise flow direction is from tip to root. However, in this answer an X-29 has quite significant sweep angle, at which drawbacks such as ...
2
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1answer
1k views

How to select the most efficient airfoil for low speed flight?

What airfoil (or family) has the highest $C_L/C_D$ ratio at speeds in the $50\:km/h$ range. The use case would be an ultralight with a max speed of $50\:km/h$
3
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4answers
395 views

Why aren't there aircraft with forward-mounted vertical stabilizers? [duplicate]

Many aircraft have the horizontal stabilizers mounted in front of the main wings (this is called a canard configuration); however, to the best of my knowledge, there don't seem to be any aircraft with ...
0
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2answers
595 views

Could two GE9x engines power a 747? [duplicate]

These new GE9x engines are huge and extremely powerful, but could two of them power a B747–8? It is possible for some engines to power the original 741s but I am mainly interested in the B748.
0
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2answers
150 views

Why do we not have autonomous helicopters? [closed]

We see a lot of fixed wing autonomous UAVs. What is preventing this in the case of helicopters? I know the helicopter flight dynamics are complicated. But what exactly is the complication in this ...
3
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1answer
159 views

What is a compounding wing and how does it increase helicopter performance?

The US Army is developing a list of enhancements for the next generation Apache attack helicopter. Among them this was mentioned: Topping the list of major changes is re-engining with the 3,000-shp ...
2
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2answers
226 views

Would it have been feasible to install 'conformal fuel tanks' on the Mercure?

The Dassault Mercure was a short-range twin-jet airliner. It was canceled with sales not reaching the breakeven point. Other similar jetliners like the Boeing 737 had a more convenient longer range. ...
0
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5answers
361 views

Why wing ribs have diagonal struts

Why do ribs have diagonal struts,why not vertical as seen in airfoils of Citabria airplane?
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0answers
138 views

Why don't helicopter rotors use curved blades? Curved from the top view. [duplicate]

I'm studying blade element analysis and I tried applying it to curved rectangular blades instead of straight ones. It doesn't really show any significant changes in the inflow ratio computation. Why ...
6
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2answers
631 views

How does the fuselage handle the different loads?

I have been trying to find out how the loads experienced by a fuselage are transferred between structural members (bulkheads, formers, frame assemblies, skin, longerons, stringers). I understand that ...
2
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2answers
315 views

Would the Concorde have been better off using a tailed delta wing?

In one of the answers to this question about the Concorde's lack of high-lift devices on its wings, it was pointed out that the Concorde, using a tailless delta wing, wouldn't have been able to use ...
2
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2answers
373 views

Why are there so many aircraft designs which look generally profoundly similar?

The F-86, mig-15, Dassault Ouragan The b-1 and tu-160 Concorde, tu-144, 2707 The low wing and T tail with two engines at the back. (CRJ, dc9) The 'standard' shape with the mid aircraft wings, and ...
9
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3answers
947 views

Why did Concorde not have horizontal stabilizers?

The Concorde did not have horizontal stabilizers or elevators. As a result, the pilots have to move fuel around the aircraft to trim it up or down, as sluggish and hazardous move. Why did the design ...
1
vote
2answers
108 views

What are technical and aerodynamical limitations to blown wings main propulsion?

Why wouldn't some blown flap or blown wing device (suppressing propeller or fan or jet exhaust from aircraft design) produce sufficient thrust needed for takeoff and cruise flight, opposed to "only" ...
6
votes
1answer
351 views

Is there any way to reduce the noise and vibration in a C-130 Hercules?

We are using C-130 B and E Models with T-56 A-15 engines and Hamilton Sundstrand 54H60-91/117 propellers. A lot of vibration and resonance are felt on these military version aircraft even after using ...
2
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1answer
498 views

What is the structural significance of 'dimples' on the fuselage of a Boeing 747?

I recently watched the following video: In the video there is a mention that there are 'dimples' visible on the fuselage of a Boeing 747, when it is on the ground. It ...
5
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2answers
992 views

What material is used for the floor panels in the main cabin for Boeing 747-400?

Just conducting some research into materials used in construction for Boeing 747-400 and Douglas DC-3. I just found out that in a DC-3 the floor panels in the main cabin and companionway are of ...
28
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3answers
11k views

Can cameras and LCD screens replace cabin windows?

Windows in aircraft create a weakness to the structure, that is why they are very small. I'm not asking about installing them in the cockpit, which would create safety pitfalls, but could the windows ...
5
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1answer
257 views

Why do aerobatic aircraft have separate tanks instead of a single acrotank?

I've been reading about fuel tanks in aerobatic planes such as the Extra 330, Edge 540, XA41 and I don't really understand why in the Extra 330 there are separated center tanks and an acrotank instead ...
6
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2answers
484 views

What are the limitations to adding wings with engines to a helicopter?

I've probably seen this in science fiction and cartoons but never in real life. Rotor wing aircraft (helicopters) have numerous advantages over their fixed wing counterparts, and vice versa. For ...
11
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6answers
2k views

Has there been an aircraft with multiple type of engines? [duplicate]

Has there ever been an aircraft that can fly using at least two different type of engines? For example, a piston engine and a turbine engine, or a piston engine and a electric motor. To clarify the ...
3
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2answers
167 views

Would an Area-Ruled fuselage improve MiG-15 and MiG-17 performance?

The top speed range of these Mig 15-17 airplanes is in the close trans-sonic region, but when first drawings came, Area Rule was unknown. Even if owning a jet fighter is not exactly 'Maintaining pilot'...
0
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2answers
114 views

What are the methods of reducing vortex? [closed]

I have tried reading the notes on the wing tip, but didn't understand well. How will the vortex be reduced on the wing tip.
0
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1answer
372 views

How does angle of incidence affect an aircraft's stability?

How does angle of incidence affect an aircraft's stability? I've tried searching the web for the simplest answer that makes sense but so far I've come up with nothing as yet. I know it sounds simple, ...
3
votes
3answers
280 views

Is it possible to build a flight-capable aircraft powered by compressed gas?

I pray this isn't a physics SE question. A star engine can be considered "gas operated". So what if we power a star engine with unleashed, formerly compressed gas instead of... actual gas/aero-...
2
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1answer
1k views

How to calculate required thrust for take-off knowing gross weight and L/D?

I know that many variables play into the required thrust for a take-off and for climb. Most of those specs boil down to a targeted gross weight, wing loading and L/D ratio. Intended flying speed range ...
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1answer
113 views

How much speed is required to achieve lift on something that weighs 1000lbs? [closed]

I was wondering how much speed would be needed to get an object that weighs about 1000 pounds to generate enough lift to get off the ground and achieve flight?
3
votes
2answers
276 views

Why is the F-117A the only plane to use the fully faceted design? [duplicate]

One of the keys to the stealth capability was its faceted design. The concept is that curved surfaces have a larger radar cross-section. The idea of making all surfaces flat to reflect radar away from ...
2
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1answer
666 views

How I determine numerically the roll rate of an aircraft?

I'm a Spanish student of aerospace engineering and I'm doing my final bachelor work that consists in designing an unlimited aerobatic plane, and I wonder if it is possible to calculate an ...
4
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0answers
102 views

Could airliners have cameras to let the pilots see the engines and wings? [duplicate]

Why can't jet airliners have a camera installed on the fuselage and a monitor in the cockpit so that pilots can see engines and wings which are normally behind them and hidden from view? Something ...
3
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2answers
155 views

Is there any “copyright” for aircraft's design between different manufacturer?

Are there any regulations for the copyright of aircraft's model design between competitors in the aircraft industries? Basically is there a regulation for avoid that one company just steals the ...
18
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3answers
3k views

Why do many light aircraft have a trim tab on one side of the elevator only?

Most light GA aircraft, like this C172, have pitch trim tabs on one side of the elevator only. Why not on both? Doesn't the asymmetry add inefficiency in the form of a slight rolling moment?
8
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2answers
463 views

How do the flight decks work in unison on the Stratolaunch?

This article implies that the Stratolaunch has two flight decks. How are the dual flight decks arranged on the Stratolaunch aircraft? I'm curious if things are fly by wire or if there are separate ...
3
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4answers
1k views

How can I find the optimum chord wing length for this wing?

This Aviation SE forum looks the perfect place to ask this question: people here usually make maths the root of most solutions and I think this may solve my aerodynamic optimization problem! I am ...