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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2answers
32 views

Does an airfoil drag coefficient takes parasite drag into account?

Im trying to understand why does L/D MAX, (the top of the polar curve that computes CL & CD ratio for any airfoil) is also the lowest point of the total drag curve. Im guessing the reason is that ...
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0answers
46 views

Where can I find ultralight aircraft designs? [closed]

Can somebody share to me where can I get I design sample of ultralight aircraft? I want to start a first ultralight aircraft industry in my country, Tanzania. I have design mine but I want to compare ...
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0answers
32 views

Is it possible for a higher aspect ratio wing to have increased drag compared to a lower aspect ratio wing of the same area?

Since increasing aspect ratio while maintaining wing area decreases chord, one can expect Reynolds number to decrease. Are there cases in which the resulting increased coefficient of friction would ...
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4answers
9k views

Why do aircraft with turboprop engine have black painted anti-icing system?

Everyday as I watch aircraft with turboprop engines, a question pops up: Why do aircraft with turboprop engines have black painted anti-icing system? For instance:
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0answers
28 views

How to determine placement forward of firewall to give desired Center of Gravity? [closed]

Can somebody tell me how you calculate the correct placement forward of the firewall for an engine installation in an ultralight to end up with the correct Center of Gravity?
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3answers
107 views

How does downwash affect angle of attack?

Many aerodynamics textbooks, as well as many answers on here and similar websites claim that the downwash downstream of a wing induces a net angle of attack that is lower than just looking at flow ...
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0answers
85 views

Aviation Bus comparison: interference, reliability, flexibility and security [closed]

Which of these two bus standards provides more reliability, flexibility and is more secure: MIL STD 1553 RS-485
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2answers
98 views

How would a fighter be changed from having static stability to having relaxed stability?

A good portion of aircraft, especially those designed before the 1970's, possessed static stability. However, modern fighters (and some airliners) have been build with relaxed static stability. This ...
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2answers
3k views

Why are longer wings with foldable wingtips used on the B777X instead of lighter ones with original size?

The new Boeing 777X has longer wings to improve efficiency, but has to adopt foldable wingtips to "fit" into all original airports that host its predecessor. Tendentially, longer wings would ...
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1answer
3k views

What is this strut in biplane rigging, attached only to wires, not bearing any load?

A few biplanes like the Stearman have a strut parallel to the fuselage, halfway along the rigging's landing wires and flying wires, not fastened to the airframe, not bearing any obvious load. One on ...
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2answers
228 views

If pilot use rudder to roll the aircraft at high AOA in the F4 Phantom then one aileron from one wing and one spoiler from other will be deflected?

I have heard that the F4 Phantom pilots can make barrel rolls at lower speed /higher AOA. They use only rudder deflection and keep the stick column centered (left /right wise)-only pull onto the belly ...
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3answers
277 views

Does the F-4 Phantom use (have) differential horizontal tail deflection?

Is differential horizontal tail deflection used to roll the aircraft around the longitudinal axis along with the ailerons / spoilers and a bit of rudder?
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1answer
102 views

Why couldn't the CRJ100/200 be equipped with triple-string autoland?

The gold standard for zero-visibility ILS approaches and landings is a triple-string autoland system, where the signals from the localiser and glideslope beams and the aircraft's radioaltimeter ...
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1answer
166 views

Can I fly this six motor drone? [closed]

My body weight; 70kg, Drone weight; 50kg, Props length 0.7m, 6 motors (2hp each), Total weight 120kg, Total horsepower 12, Each motor runs 3000rpm, Please can I fly it. Thanks!!! drawing of the drone
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0answers
80 views

Make a 3 engine turboprop electric or steam hybrid aircraft?

Was thinking about this, have a 2 engine regular turboprop with a third electric engine for extra performance (imagine a DC3 like the Conroy Tri-Turbo-Three). The 3rd electric engine would be run from ...
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2answers
189 views

How to know the material of key-top?

Posted it here originally. There are keys (push buttons) on the front panel of an avionics device that fits inside the aircraft cockpit. I need to know the material of which those key-tops are made ...
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2answers
88 views

Does dihedral improve roll stability in gusty conditions?

Against roll instability, should I add more dihedral/a high wing? I'm trying to build an RC plane that can handle windy conditions. For that I want extraordinary aerodynamic stability. For ...
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3answers
174 views

Pros and cons of a thin cambered wing?

What are the pros and cons of a thin cambered wing? Does a thin cambered wing suffer from a flow separation bubble on the lower side, at cruising speed/low AoA? Very roundy leading edge, can air ...
13
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5answers
5k views

Why are the guns on the AC-130 not mounted on the underside of the aircraft?

Why must the guns of the AC-130 be on the side forcing the plane to circle the target. Would it not be more practical to have the guns underneath the plane shooting downwards?
3
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3answers
315 views

Why don't aircraft owners put vortex generators on the top of their flaps to extend single flap lift creation past 40 degrees?

Why don't ultralight/LSA aircraft owners put vortex generators (VGs) on the top of their flaps? I understand that the maximum flap angle for a single lift creating flap is 40°, but 80° with a double ...
1
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1answer
148 views

What is an augmentor wing?

What is an augmentor wing in the context of STOL aircrafts? and is it still used today? This seems to be a term that I can only find in NASA aerodynamics (specifically powered-lift) research papers in ...
6
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2answers
356 views

The wing has a pressure gradient along the AB direction, is there a pressure gradient along the CD direction?

The wing has a pressure gradient along the AB direction, is there a pressure gradient along the CD direction?
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0answers
158 views

During WWII, what did internal bomb bays and turret layout look like on flying boats?

I am writing an alternate WWII story, and I was wondering if you fine fellows on this site could help me. I am trying to make a fantasy bomber version of the USN Boeing C-98 Clipper, AKA the Boeing ...
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2answers
224 views

What is the reason why dihedrals are used when building a plane? [duplicate]

How does dihedral affect flight characteristics of a plane? I know it increases stability, however is it the only reason why it is implemented? If so, aren’t there more effective methods to stabilize ...
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1answer
257 views

What are the differences between battens and ribs?

What are the differences between battens and ribs?
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0answers
127 views

Can a modern airliner handle turbulence forces of +5/-3G?

In the BOAC Flight 911 accident the 707 likely experienced around positive 5G and negative 2-3G. The wings of the 707 were only about as 50% as flexible as the wings of airliners today. How would a ...
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6answers
234 views

Does angular momentum contributes in lifting a helicopter? [closed]

I want to know whether it is possible to make a helicopter with blades that rotate counter-clockwise (CCW) seen from below. I have difficulty understanding the angular momentum in this situation. As ...
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4answers
4k views

Are there any aircraft that either fold or employ folding in their design (such as with origami)?

I became curious about origami and its application to aeroplanes and was wondering if there were aircraft that either fold and/or employ folding in their design in interesting ways. Let's limit this ...
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3answers
236 views

Why do many aircraft have both all-moving tailplanes and elevators?

Many aircraft - particularly large commercial airliners - have both an all-moving tailplane (horizontal stabiliser) and elevators. (They also have a small third moving element on the trailing edge of ...
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2answers
166 views

Is it possible to Fly Aircrafts on Mars?

I have been fascinated with the thought of flying all kind Aircrafts on Mars. To begin, I don't know much about the fundamental things or requistes for flying. Is it possible with the the things we ...
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0answers
42 views

What is the engine shell temperature?

What are the highest temperature locations in the outer shell on an aircraft engine? Particularly, modern turbofans like the Trent 900 for example. I'm interested in the temperature constraints of ...
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2answers
105 views

Can winglets be used to compensate the high induced drag created by a low aspect ratio wing?

I have read in some articles that the major advantage of having a high aspect ratio (AR) wing is to reduce the induced drag. If winglets main job is also to reduce the induced drag, how much drag does ...
3
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4answers
221 views

Why did wings start to be made with aluminium skin instead of fabric?

Why did engineers start designing planes with aluminium skin on the wings instead of fabric covering? While the force of lift acts on the skin, to my knowledge it is not subject to high stresses
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2answers
224 views

Why does the NASA X-57 need a “gust control system”?

Why are NASA's engineers concerned about gusts affecting the X-57? I understand that NASA is recommending automatic torque based prop speed control to be used in flight but also in gusty conditions. ...
2
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0answers
181 views

Has any pilot successfully flown through a hurricane with a single-engine prop plane?

Has any pilot successfully flown or could a pilot crab through a hurricane using a plane such as a Cessna or bi-plane? Would acrobatic planes work better because of their nimble agility and high power-...
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1answer
82 views

Is Ducted fan or Propeller better to maximize forward speed of RC aircraft with a given power?

I'm designing an RC aircraft of which the final goal is a crazy top speed. I'll be 3D printing and sanding / finishing the air frame surfaces to reduce drag. In order to achieve maximum top speed, ...
7
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7answers
3k views

Why don't bypass ducts in jet engines narrow down the flow to accelerate it?

Since decreasing the flow area increases flow velocity, why don't turbofan bypass ducts narrow down to produce more thrust?
23
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2answers
11k views

Why is the A380's fuselage designed with a flat bottom?

I want to know if there is some explanation for why the A380 bottom is flat instead of the oval shape, just near the wings.
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2answers
2k views

Is it feasible to add an aftermarket hydrofoil to a light aircraft?

Could long, aftermarket hydrofoils be added to the water-skids of a plane (like this Cessna with pontoons or smaller) Cessna 208 Caravan not designed to have a hydro foil, to increase its ability to ...
2
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1answer
153 views

Are there all terrain landing gears for planes?

Is there a landing gear set up that will allow a single engine plane (also, allowing for tundra tires than what is not available for current water skids) to land on rough grass and water? The wheels ...
2
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0answers
35 views

How much does the design, implementation, test and certification of a Passenger-to-Freighter Conversion cost?

This question answers how much it costs to convert a given aircraft from passenger to freighter once the STC is approved by the FAA. How much does it cost to obtain the STC in the first place? If this ...
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2answers
156 views

How has afterburner design changed since its inception?

I came across a NACA summary paper on the past 5 years of afterburner development and started reading cause it seemed interesting. However, a couple of pages in I scrolled back up and realized that it ...
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2answers
141 views

What are different components of an engine pylon?

What are the different structural components that are inside the fairing of engine pylon and what are the functions of each part? The pylons for each aircraft are made of Ti-64 alloys, can they be ...
32
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3answers
13k views

Why are commercial aircraft windows typically oval instead of circular?

Pretty much what the title says. Surely a circular window would allow more window area while not compromising on strength? Some planes(Gulfstream jets) do have circular windows. Is there a reason for ...
2
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4answers
164 views

Will it be more efficient if airplanes flap like birds? [duplicate]

Many airplanes have parts that are designed to mimic some features of animals. I have also read that birds are incredibly more efficient than most of the airplanes we see today. I wonder, will the ...
2
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1answer
48 views

What is the mathematical relationship between Specific Excess Power and an aircraft's acceleration at a given point on an E-M diagram?

If an aircraft is on the x-axis of an E-M diagram plot (zero turn rate) where the Specific Excess Energy (Ps) = 800, we understand this to mean that the aircraft has the potential to either ...
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1answer
73 views

What safety precautions are taken for an airline prototype test flight?

Regarding the software, the equipment and the personnel. Can the crew jump out of the plane with parachutes or is it a bad idea? Additionally, if you would compare the safety of today and the 1970/80s ...
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1answer
75 views

Which among the two contributes most of the lift, the upper or lower surface of the airfoil? [duplicate]

I see some explanations that lift is due to the suction of low pressure on the top surface of the wing and deflecting down of airflow on the bottom which results to upward force lift. I wonder, which ...
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2answers
112 views

How far away should the vertical stabilizer be from the leading edge of the main wings?

I am wondering what the advantages and disadvantages are of placing the vertical tail nearer to, or farther from, the main wing. For instance, when the vertical tail is just behind the wing, do the ...
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0answers
42 views

How to correct dynamic stability of UAV fuselages?

I was trying to design a fuselage model of UAV with considering lift coefficient (CL), after this I analyzed stability of both wing on fuselage. First I did the individual analysis for wing and ...

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