Questions tagged [aircraft-design]

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

Filter by
Sorted by
Tagged with
4
votes
1answer
173 views

Are there any Navions on floats?

I have a friend that is considering putting his Navion on floats. A huge challenge. I recall having seen a photo of a Navion on floats, an old black and white photo, but I can no longer find it. If we ...
2
votes
1answer
156 views

Why does the European MALE RPAS UAV use twin engines?

I don't know why the European MALE RPS UAV designers chose to use twin engines? I know two engines are expensive but add safety... Does choice is to obtain mass flow @ Medium altitude(low air ...
2
votes
4answers
184 views

What is the effect of the Load Factor on wing Structures?

I am quite confused with the definition of Load factor and how it applies to the wing structures of an aircraft. For example, you have an Aircraft being subjected to a Load Factor of 2 and whose ...
4
votes
2answers
231 views

How do modern turboprops avoid slow spool up of early jets?

I was reading about modern crop dusters that are blessed with 600 or more horsepower turboprops and have seen them do amazingly effortless high angle of bank turns near the ground. It seems that a ...
31
votes
2answers
8k views

Has a commercial or military jet bi-plane ever been manufactured?

Are there any, or have there ever been any commercial/military jet bi-planes? What would be some of the major advantages vs disadvantages if one was built? Electric radio controlled ducted fan model. ...
2
votes
1answer
354 views

Why the need for the MCAS on the Boeing 737 Max 8?

Was there a problem with stalling on 737 jets before the 737 Max, if not then why is MCAS needed on the 737 Max 8.If it was a problem why did Boeing wait so long.
4
votes
1answer
214 views

What happened to the Fokker 100 revival project?

What happened to the Fokker 100 revival project by NG Aircraft? They wanted to build a better Fokker 100 called the Fokker 120NG/Fokker 130 in 2010-2014 which originally should be completed this year....
22
votes
5answers
9k views

Why was the Spitfire's elliptical wing almost uncopied by other aircraft of World War 2?

The Spitfire was one of the most successful designs of its day, with flying qualities of a similar standard to the other best designs of the era. In its decade of production from 1936 it grew bigger, ...
1
vote
2answers
298 views

Why was the Electra uniquely vulnerable to whirl-mode flutter?

The Lockheed L-188 Electra, notoriously, suffered from early problems with whirl-mode flutter, which caused two Electras to break apart in flight in 1959 and 1960, forcing an expensive redesign of the ...
0
votes
1answer
170 views

What are the STOL features on the Pilatus PC-6 Porter?

What's so special about the Pilatus PC-6 Porter that makes it a world-leading STOL aircraft? How do its features work?
0
votes
0answers
66 views

Is Engine up thrustline actually desirable for “speed stable” designs?

The much maligned Max 8 and the Buckeye Navy trainer. What could they have in common? Both would want static stability (trimmable speed stable approach) for landings. Both would want maximum fuel ...
2
votes
1answer
152 views

What is the input range of common fly-by-wire controls?

What's the range that typical fly-by-wire controls (let's take A320 and B777 as examples) allow inputs in? The A320 controls in the y-axis of the side stick (forward/backward axis) the g load - what'...
0
votes
1answer
200 views

Which helicopter can auto rotate the farthest? [closed]

Could the rotors be modified to perform better at auto rotating and maybe less at powered performance?
28
votes
2answers
10k views

What helicopter has the most rotor blades?

I have seen 2 rotor blades up to many and wonder when does having more rotor blades become less efficient? What helicopter has the most rotor blades? Related: Why don't helicopters prefer shorter ...
3
votes
2answers
2k views

Why complex landing gears are used instead of simple, reliable and light weight muscle wire or shape memory alloys?

Muscle wires actuators are really simple, have a high power density and are reliable. Landing gears on other hand are used only twice per flight while taking off and landing (if everything goes well ...
2
votes
3answers
222 views

For length in aircraft design, and in weight and balance manuals, what measurement unit does Airbus use?

What length measurement unit does Airbus use for aircraft design and in their weight and balance manuals? Meters or centimeters? Possibly they use both like Boeing does for, say, feet plus inches for ...
6
votes
1answer
177 views

Do any aircraft possess washed-in wing characteristics?

I have been teaching ground school at my local Canadian Air Cadets. When I was teaching about the wing twist of an aircraft, I was asked if any aircraft possess washin characteristics (vs washout). ...
35
votes
9answers
13k views

Why are there no cargo aircraft with “flying wing” design?

From that I have seen so far, the "flying wing" design (like the one of B-2 Spirit and Northrop YB-49) has superior performance but also a few notable problems that make it difficult to use for ...
0
votes
3answers
2k views

Could the Boeing 757 replace the Boeing 737 Max 8/9/10? [closed]

The "Baby Boeing" 737 started life in the 1960s with roughly half the thrust and around 60% of the weight as the 757. In stages the 737 grew into a capacity squarely in the range of the 757. ...
6
votes
4answers
586 views

Why is alcoholic gasoline such a showstopper for aviation?

One of the main reasons the common avgas grades are still full of 3-plumba-3,3-diethylpentane is the incompatibility of many aircraft fuel systems with the oxygenates (primarily ethanol, with some ...
0
votes
4answers
294 views

Does an rc plane tail also have airfoil or is it just flat material? [closed]

I've chosen an airfoil for the wing, now i'm confused weather i should do the same for tail or just attach a flat piece of wood as tail. I'm going for conventional tail design. This is my first ever ...
-1
votes
2answers
180 views

How are aircraft brakes applied? [duplicate]

I read somewhere that when both rudder paddles are pushed simultaneously it produces a braking effect. Is this true? If yes, please provide a detailed description of the above mentioned system.
2
votes
1answer
107 views

Could placing a fan jet further in front and closer to the wing create undesired pitch motion from its exhaust?

So far in discussion of the Max 8 people have mentioned CFM LEAP cowling size and 737 tail design as possible factors in the need to develop a MCAS system to control tendency to pitch up at high AOA. ...
46
votes
3answers
4k views

What is the offset in a seaplane's hull?

I noticed there is a little offset in a seaplane's hull (highlighted in the following picture). I suppose this is useful as it exists in all the seaplanes I know. It appears to be neither a ...
4
votes
1answer
151 views

Do aircraft engineers take into consideration engine placement to avoid ground strikes in a cross-wind landing?

On a multi-engine airplane with wing-mounted engines, do aircraft designers have a standard way of ensuring that the banked landings associated with cross-wind's do not cause a prop or engine-housing ...
8
votes
5answers
6k views

Has there ever been an airliner design involving reducing generator load by installing solar panels? [duplicate]

Has there ever been a trial/project/design, in which solar panels were incorporated in the design of a commerical airliner (e.g. on the wings), with the aim to reduce fuel consumption by lowering the ...
1
vote
2answers
70 views

How does Mass affect rate of turn?

After seeing effect of speed and bank angle on rate of turn, how would one mathematicly calculate the effect of changing mass. For example, in a 30 degree turn at 100 knots, how would the rate of ...
3
votes
1answer
198 views

Can airlines choose whether or not to enable MCAS on their fleets, and if so, have US airlines chosen to do so?

I've been told that, although all 737 Max aircraft are equipped with MCAS, the system can be deactivated by the individual airline. I've also heard that US airlines never activated MCAS in their 737 ...
0
votes
1answer
105 views

Airfoil- concave top and bottom [closed]

I remember building a radio controlled model in the early 90s with concave wing ribs/surfaces top and bottom...both sides of the wing were undercambered... It was a very great flying model...60" ...
2
votes
2answers
129 views

Can I use the load factor to estimate the lift?

If I have a fixed aircraft as the baseline, then I am not sure the specific flight condition, can I use the load factor to estimate the lift on the wing?
3
votes
3answers
460 views

Why aren’t there any lifting-canard airliners?

A lifting-canard aircraft, such as the Long-EZ, is an aircraft with the main wing at the back end of the fuselage and a pair of small, highly-loaded canards attached to the forward fuselage; the ...
16
votes
2answers
4k views

For airliners, what prevents wing strikes on landing in bad weather?

For any low-wing aircraft, particularly the MD-80 or some of the private jets, CRJ's, the wings appear about 5ft or less above the ground. It seems that just few degrees of roll before touchdown would ...
6
votes
4answers
2k views

Are taller landing gear bad for aircraft, particulary large airliners?

Buiding larger engines for larger aircraft as opposed to smaller but many engines has proved to result in more fuel efficiency. Having established one of the main drawbacks or impediments to building ...
0
votes
0answers
41 views

Bird strikes and engine protection [duplicate]

I am just wondering why the creators of aircraft cannot come up with some sort of high utility screens to mitigate bird.srikes. Thank you!
3
votes
3answers
176 views

Is there a general approach for designing a Trimmable Horizontal Stabilizer?

What is the general design flow when designing a Trimmable Horizontal Stabilizer (THS) and the attached elevator? I assume you would dimension the max. positive/negative deflections of the THS to ...
5
votes
2answers
469 views

How are forward and aft CG limits calculated?

I have been tasked to create a POH for my aero engineering coursework and part of this task is to create the CG envelope for the theoretical 65 passenger aircraft. I have figured out weight, moment ...
-3
votes
1answer
634 views

Boeing Dreamliner MCAS [closed]

If it was not known that Boeing had new software in the Boeing 737 Max, do we know whether this same software is not in the 787-9?
-1
votes
2answers
128 views

How to deal with larger and larger engines [closed]

What are possible solutions, if aircraft manufacturers can't fit ever larger turbofans onto the standard low-wing passenger jet configuration? Below, we see a 737 with large turbofans. If a new ...
1
vote
2answers
264 views

Why are fuel pump switches separate?

Since engines are run only when the fuel pumps are on and vice versa , why are there separate switches for this? Why can't it be automated ?
6
votes
1answer
276 views

Could the S.H.I.E.L.D. C-17 actually have a sensible center of gravity?

In a question about whether tail surfaces add to lift, I thought of a fictional example where the tail surface very much adds to lift: The Agents of S.H.I.E.L.D C-17, highly modified and super-engined....
-1
votes
1answer
688 views

What is a shroud (in aviation terms or engineering terms)?

Please can someone explain what a shroud is and give examples of types of shrouds and their uses on aircraft?
15
votes
5answers
6k views

Why do passenger jet manufacturers design their planes with stall prevention systems?

I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall ...
4
votes
1answer
1k views

Is there less vertical space for an engine under the wing of a 737 Max than for an A320neo?

The source of this question is the understanding that the LEAP-1B couldn't fit under the wing of a 737 without changing its longitudinal position. But this wasn't the case with the design of the LEAP-...
0
votes
1answer
382 views

Why is Boeing being blamed for the recent 737 Max crashes? [closed]

Boeing has received more than 5,000 orders for the aircraft, it has delivered 350 so far and only 2 of them have crashed. That's not a very high crash rate. The FAA, until just a day ago, was very ...
9
votes
3answers
442 views

Is it common for automated control systems to use non-redundant sensors?

While reading an article about the Lion Air Crash with a Boing 737 Max 8, I was very surprised by the following paragraph: In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from ...
3
votes
3answers
173 views

Load factor and how does velocity affect it?

An aircraft initially flying level with a velocity of 130 m/s pulls into: a turn of radius 300m at constant altitude (i.e. a horizontal circle) with constant velocity; a loop (i.e. a ...
5
votes
3answers
588 views

Could a C-130 Hercules be built using WW2 technology?

I'm looking at this as a "time traveller carrying only designs in his head" scenario. Obviously turboprop engines are out of the question, but how close in capability would it be possible to get a C-...
-4
votes
3answers
248 views

Why Buy A C182/172 Instead Of An C180/170? [closed]

So a thought came to my mind which covers not only Cessna planes but all others. The Taildraggers need a little bit less runway becayse AOA on takeoff is good and that AOA eliminates the need of ...
21
votes
4answers
8k views

Why are special aircraft used for the carriers in the United States Navy?

Why are aircraft such as the legacy F-14 and now the F/A-18 used by the US Navy carriers? It seems to me that developing a new aircraft from the ground up is very expensive. Is it not possible to ...
1
vote
2answers
152 views

How to determine angle of bank caused by shift in centre of gravity in an aircraft?

I’m trying to figure out the angle of a bank caused by a shift in the centre of gravity of an aircraft. How should I do this? What avenues should I go down to calculate this? I know that the plane ...