Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

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
11
votes
4answers
8k views

Why don't planes have a reverse propeller as air brakes?

When I first heard the word air brakes it came to me that maybe the engine start rotating in the opposite direction for that, but since that's not possible, why can't we have an extra engine for air ...
20
votes
1answer
2k views

What is the purpose of the three cylinders under the engines of the Junkers 52?

They're mounted underneath each engines on the JU-52. I saw them up close at the museum. Each one consists of bundled half-inch pipes running through the whole length, open at both ends.
6
votes
2answers
5k views

What are the properties of the wing (airfoil symmetry, angle of incidence) of an aerobatic aircraft?

On an aerobatic aircraft, such as an Sbach342, what type of airfoil does it have and what angle of incidence does it have in relation to the fuselage?
9
votes
1answer
1k views

Minix wingtip vortices mitigation - How does it work?

I stumbled upon this article: Minix wing tip device promises 6% gain in fuel efficiency for airliners. Such an economy is appealing and I must confess the design is "sexy". Could someone expand a ...
14
votes
1answer
2k views

Why simple paper planes fly better than most “realistic” paper plane models?

Just a A4 paper sheet folded into a plane seems to fly decently. But a model of actual (big) plane made out of paper is only good at falling... What is different for paper planes? Are there "modern ...
21
votes
3answers
5k views

Why is the use of tail-down force so common?

Why is the use of tail-down force so prevalent in aircraft design? Why not use canards to avoid induced drag?
10
votes
2answers
626 views

What considerations drove the choice of the Solar Impulse engines configuration?

Solar Impulse makes me think of a motorglider due to its aspect ratio. The Upward cranked tips wing configuration along with the engines configuration particularly draw my attention: The 2 innermost ...
11
votes
2answers
2k views

Why is dual crossfeeding prohibited on DA42?

Diamond 42 AFM says: The fuel crossfeed function can be tested simultaneously with both engines. Proper function can be tested by running the engines for approx. 30 seconds with CROSSFEED ...
39
votes
2answers
13k views

Why are the pitot tubes on supersonic combat aircraft so long?

I've noticed that on combat aircraft the forward (nose-mounted) pitot tube is usually very long, on the order of half a meter to well over a meter on some aircraft. Why are they so long? Surely the ...
27
votes
7answers
6k views

At what speeds can an airplane land?

I have read people's stories that they landed their small planes (e.g. C172) on bigger airports. They strongly recommended landing at a higher speed and without flaps as the runways are quite long, ...
14
votes
2answers
9k views

What is the “area rule”?

The "area rule" states that the supersonic drag on an aircraft is related to the total area on part of the aircraft. What is the exact definition of the rule? Why does this happen?
19
votes
2answers
5k views

Does the Predator drone's design make a tail strike more likely on takeoff and landing?

I was reading an article about drones and happened to glance at an included 3-view of the General Atomics Predator series UAV. The inverted-V tail appears to leave, at most, around 6" of clearance to ...
15
votes
2answers
6k views

Does a prone position for the pilot minimize g-force effects?

Knowing that the Wright Flyer was the first successful heavier-than-air powered aircraft, I'm fascinated by its operation requiring a prone position. Searching further, I was surprised to find out ...
43
votes
2answers
24k views

What is this flange on the engine?

Flying home from the Denver ComiCon, on a 737, I saw an angled flange on the engine. Could you describe its purpose? Photos by CGCampbell licensed CC0
6
votes
1answer
2k views

What regulatory load cases drive the structural design of aircraft?

What I am looking for here is a sort of a list gathering the manoeuvres and/or load cases imposed by regulation that lead to the sizing of a part of an aircraft. For instance, vertical gust load is ...
9
votes
1answer
2k views

Is there a real risk of ingesting FOD into jet engines when using thrust reversers?

In the discussion of Why doesn't the A380 use its outboard thrust reversers, one of the reasons given was that engines 1 and 4 would be at great risk of ingesting debris. It was pointed out that the ...
17
votes
5answers
14k views

What are good books to learn basic aerodynamics in plane design? [closed]

Well, since this stack is in beta, I thought I'd take a wack at asking a book question to see how it fits in this particular community (of if it even fits to begin with). I'm very curious about how ...
-2
votes
1answer
967 views

Supersonic Fuselage design [closed]

What should be the ratio of the fuselage and wings in a maximum dimension limited condition supersonic delta wing aircraft? Also can anybody explain clearly the "supersonic area rule" or "Whitcomb ...
40
votes
7answers
31k views

Why are airplanes riveted and not screwed?

Replacing airframe panels and inspecting hard-to-reach parts would be easier with screws, I presume. So why are rivets used?
4
votes
1answer
7k views

How to find the location of the Aerodynamic centre?

Everywhere I look I'm only able to find information about airfoils. How do I find out the location of the Aerodynamic centre of an arbitrary aircraft irrespective of its type or shape?
34
votes
9answers
25k views

Why does An-225 have anhedral wings though it is a cargo aircraft?

What are the rationale behind this anhedral high mounted wing configuration? Is that usual for very large carge aircraft?
20
votes
5answers
14k views

What aircraft has the highest suggested landing speed?

Just out of vague curiosity, what aircraft has the highest recommended landing speed for an earth bound (atmospheric) craft? And, btw, when I say "landing" I define it as thus: Controlled Powered (...
7
votes
2answers
2k views

Would a vertical stabilizer that extends both above and below the centerline be benefit or hindrance?

Ignoring for a moment potential schematic difficulties in creating an aircraft that can land and take-off without threatening a downward vertical stabilizer, would a vertical stabilizer that extends ...
22
votes
2answers
5k views

What was the first aircraft that could fly inverted?

I'm taking a guess and assuming the Wright Flyer was incapable of flying upside down. I'm just guessing it probably lacked the power... ;) So what was the first plane that could fly inverted for a ...
6
votes
1answer
2k views

Why can not two modes coincide perfectly for some cases in Flutter phenomena?

I have a question about flutter phenomena. As you know, flutter occurs when two modes (for example, first mode and second mode) coincide (that is, after a specific velocity, the frequencies of two ...
13
votes
2answers
4k views

Do aircraft engine intakes require air filters?

I see helicopters which have air filters in their engine intakes, but jet fighters and commercial turbojet airliners don't seem to have any filters in their air intakes. Isn't it true that even tiny ...
5
votes
2answers
816 views

What exactly is the afterbody of an aircraft?

In my understanding the afterbody is everything trailing behind the nose of the craft excluding the wings and fuselage, and will thus include the empanage. What exaclty is meant by the afterbody?
13
votes
1answer
2k views

How does an engine failure affect the flight of an airplane?

I'm not even close to an aviation enthusiast, but after watching some videos I found I have a deep misunderstanding on how airplanes work. . I've seen many cases where one of the engines fail and ...
41
votes
3answers
15k views

Why does supersonic flight detach airflow from a wing?

I've read in several answers to questions that when a wing passes the speed of sound the airflow will become detached from the craft towards the rear quarter of the wing (thus making things like ...
18
votes
2answers
18k views

How does chord length affect wing design?

In comments on the answer to a question about transonic speeds and control surfaces I came across this comment and I'm having a hard time understanding it. If you increase the chord, lift goes up ...
5
votes
1answer
8k views

What is the chord of a wing?

In the answer to this question the author mentions the chord of a wing. What exactly is that, and how is it used in wing design?
17
votes
2answers
4k views

What control issues did the X-1 have to overcome to achieve supersonic flight?

In Chuck Yeager's autobiography, he went into a little bit of detail as to why the X-1 was able to break the sound barrier safely where as the P-51D he flew during WWII could not have safely broken ...
16
votes
3answers
24k views

Why are delta wings not commonly used in commercial airliners?

Delta wings are most commonly seen on military aircraft. I understand that delta wings are ideal for supersonic flight, and provide high maneuverability. Having high maneuverability and speed are ...
16
votes
4answers
3k views

Why are swept wings better for breaking the sound barrier?

I'm told that swept wings perform better when an aircraft is trying to break the sound barrier. I was wondering why that would be?
4
votes
1answer
1k views

How can you find the best altitude for range or speed?

How can you select best cruise altitude (altitude for best range velocity) and maximum speed altitude? The specific case is a turboprop aircraft of gross weight 8000 lb.
21
votes
4answers
16k views

How does a large cargo plane like the C-130 Hercules take off and land in such a short distance?

So I was at an air show and saw a C-130J Super Hercules showcasing its capabilities. The take-off distance it covered was amazingly short (I guess equal to fighter jets), even though it uses ...
12
votes
1answer
1k views

What is the low resistance design path in an aircraft to withstand a lightning strike?

I know in a building we have lightning rods that conduct a lightning strike into the earth, but for an aircarft there is no ground to 'ground' so I assume the lightning enters and passes through the ...
6
votes
1answer
1k views

What is this extension/device on top of the wing of this ultralight?

This a shot of the Aero Synergie Papango ultralight, the succesor of the Aero Synergie J300 Joker. The wings are more elaborate compared to its predecessor's and include on their top two additional ...
69
votes
2answers
26k views

Why are aircraft tires not pre-spun prior to landing to preserve them?

Why has someone not designed a landing wheel with a fin or fins on it so that the air will start the wheels turning before the wheels touch the ground? Wouldn't that preserve the tires longer from ...
-7
votes
1answer
7k views

Can your intestines be sucked out by a commercial aircraft's toilet? [closed]

Say for example you have a complete seal (unlikely) between yourself and the toilet. Is the amount of suction possible to pull one's intestines (or insides) out and into the toilet? I think (probably ...
19
votes
3answers
5k views

How is the pressure difference in passenger plane toilets generated?

The toilets on passenger planes flush with an impressive amount of force - Is the negative pressure inside the tanks generated by a pump or are the tanks connected to the outside air pressure? ...
19
votes
2answers
34k views

What are cowl flaps?

What are cowl flaps and what are they used for? It seems I have only heard of them in connection with old planes, are they peculiar to radial engines?
5
votes
1answer
1k views

Is the ATR empennage configuration considered a T-tail or a cruciform tail?

How is the ATR 42/72 empennage considered? Is it a T-Tail or a cruciform tail? From the image the elevators are placed quite high on the tail that they can be considered as a T-Tail but is it so? ...
8
votes
3answers
3k views

How is a wing designed to be stall or spin proof?

Yeah, it sounds like two questions, but I suspect the answers are very closely linked (or maybe even have the same answer.) I was told in this question that trainer planes are often designed to be ...
19
votes
6answers
14k views

Do box-wings suffer from induced drag the same way as normal wings?

Most wings suffer from induced drag due to a pressure difference above and below the wing causing air to sneak around the tip, forming a vortex. There are various methods to minimize these effects, ...
15
votes
6answers
5k views

Why are older airplanes still in use?

It is normal to see older planes (20+ years) quite frequently. In fact, a few months ago I saw a plane over 50 years old (not in a museum but on a runway, about to take off). Comparing to cars, there ...
13
votes
4answers
2k views

Is an “atmospheric geostationary satellite” feasible with current technology?

Meaning by "atmospheric geostationary satellite" a vehicle capable of hovering 30 km above Earth surface, hence insde atmosphere, for unlimited time, making use of air propellers, solar panels and ...
15
votes
4answers
2k views

Why don't both black boxes hold the same data?

As I understand, there are two black boxes on-board an aircraft. One black box, the Cockpit Voice Recorder holds the cockpit conversations and the other, the Flight Data Recorder holds essential ...
14
votes
5answers
3k views

How do larger aircraft compensate for reduced visibility from the cockpit, e.g. less visibility of the rear of the aircraft?

In smaller planes, pilots has apparently great visibility in front, on the sides and a good portion of the rear of the plane. But as the plane's size is increased, the visibility is also reduced. One ...
46
votes
11answers
83k views

Why are push-propellers so rare, yet they are still around?

Jet engines are by their very nature push-engines, however, most propeller airplanes use pull-engines. Is there an inherent advantage to using pull-propellers except for the increased airflow over the ...