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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3
votes
2answers
175 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 ...
8
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1answer
380 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 ...
13
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11answers
2k views

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 ...
0
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1answer
69 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 ...
2
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1answer
144 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 ...
4
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1answer
269 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)
1
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1answer
82 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 ...
2
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3answers
222 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 ...
0
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1answer
149 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 ...
2
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2answers
314 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 ...
2
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4answers
222 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 ...
6
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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, ...
4
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3answers
341 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?
5
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1answer
125 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 ...
1
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1answer
65 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. ...
7
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3answers
244 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 ...
6
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3answers
377 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 ...
8
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1answer
364 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 ...
0
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2answers
192 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, ...
1
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1answer
50 views

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 ...
3
votes
2answers
139 views

What are the scale effects of GA wing tip airfoils?

[ update: I am adopting an improved description provided by Peter Kämpf: "...only looking at the airfoils in isolation..." ] The goal of this question is to determine if wing tip airfoil scale plays ...
7
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2answers
262 views

Why would banking be a problem for passengers on the Flying-V aircraft?

In this article, the author raises doubts about the viability of this aircraft: Sadly for the Flying-V, it will probably fail like the blended wing body designs we've seen down the years. It's ...
8
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1answer
767 views

How is a Flying-V more efficient than current fuselage-over-wing designs?

It's claimed the plane will use 20% less fuel than the Airbus A350-900 while carrying a similar number of passengers -- the Flying-V will seat 314, while the Airbus A350 seats between 300 and 350. The ...
1
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1answer
94 views

What was the decrease in approach speed of the KFIR over the Mirage 5 due to the canards?

The Mirage III approached at 170 knots according to the Dassault. The Mirage NG and the KFIR C2 as well as the Swiss Mirage 5s added canards to the design, what was the decrease in approach speed due ...
-1
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2answers
180 views

Can an airliner be landed with only the auto pilot or remotely?

In this question: How autonomous are commercial passenger airliners? explains how automated the auto-pilot system can be. Could a pilot or more work the controls of the auto pilot that does not have ...
-2
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2answers
138 views

Would a long pole help stablize a jet pack?

Jet packs are classically worn like a book-bag on the back. Would it be more stable if the exhaust ports were separated? Would the jet pack be easier to control if the turbines were at the ends of a ...
2
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0answers
120 views

Why are the boundary layer suction holes placed far forward from the engine?

Edit: I know that the suction holes reduce the boundary layer; I am wondering if there is a reason why they are placed far ahead of the engine’s intake. My thinking is that the long duct past the ...
3
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3answers
120 views

Sensitivity of aircraft stability with respect to the CG location

I am working on the design of an aircraft (2 m long, wingspan = 3 m). The platform is longitudinally stable but it is very sensitive to the variation in CG location. For example, 1) CG_location = 100 ...
3
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3answers
198 views

How can I fix the stalling of an RC plane after the addition of floats?

I'm modifying a RC plane into a bi-plane with floats and it keeps stalling. I don't have a bigger battery or better motor to add so how do I fix this? This is the biggest challenge I've ever faced.
1
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0answers
39 views

Looking for Polars for Liebeck LI74 with a Cl of 4.8!

Looking for Polars for Liebeck LI74 with a Cl of 4.8!! Does anyone have any info on this foil?
7
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1answer
390 views

Why do early airliners have “backward slope” windows

Does anyone know why many 1930's airliners in the US have cockpit windows that slope down and rearward, the opposite of what you might expect? Consider the Boeing 247: https://www.flickr.com/photos/...
1
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2answers
221 views

Why don’t double-bubble fuselages cause severe fatigue problems?

In response to my previous two questions about fatigue issues, or the lack thereof, generated by the cusps in double-bubble-fuselaged aircraft (Stratocruiser, DC-9-80), I received a number of answers ...
16
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2answers
893 views

Why does the F-15 have a swept-back trailing edge at its wing tips?

The F-15's wing has an curious feature: a swept-back trailing edge near the wingtips, along with an unswept inboard portion of the wing. (Modified from https://en.wikipedia.org/wiki/...
5
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2answers
353 views

Why do the inlet cones on an SR-71 retract at higher speeds while the one on a MiG-21 extends at higher speeds?

As shown by this illustration in the SR-71 flight manual, its inlet cones (spikes) retract as its speed increases: (source) Meanwhile, the Wikipedia page for the MiG-21 describes the opposite ...
0
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1answer
102 views

What are the pros and cons of a straight wing plane? [duplicate]

I need this asap for my folio... Much appreciated. I'm doing a research section on my folio and I need to know the pros and cons for a straight wing in general. Everywhere I've searched doesn't seem ...
3
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2answers
784 views

Would this be a dangerous impeller to use for a drone?

I am considering using a 3D printer to make unconventional impellers for a custom-made drone that I am planning to build. I am concerned that these plastic impellers may explode if their motors' RPMs ...
3
votes
1answer
133 views

Is there a Risk of Tail Tipping during Push-back of a passenger aircraft?

I remember that there were countless incidents occurred in which the aircraft sits on the tail as the aircraft was heavily loaded at the back of the cargo and/or cabin compartments or the cargo ...
2
votes
1answer
323 views

Does a no-touch policy really work?

In Boeing 787 and Airbus 350 aircrafts, more than half of the aircraft body is made of composite material. The composite structure of the fuselage does not indicate the damage when the body is ...
9
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2answers
177 views

If a Boeing 707 hits turbulence that registers as +5 G on the FDR, would the 787 experience lower G forces due to the flexibility of their wings?

A 707 being a much older plane with relatively stiff wings compared to the 787. What percentage would the g forces be reduced on a 787 given its wing flex? And yes, I mean if the 707 and 787 were ...
18
votes
2answers
2k views

Why is the S-duct intake on the Tu-154 uniquely oblong?

Is there an advantage to the oval/elliptical shape of the Tu-154's S-duct intake? It appears to be taller and an overall different shape than the side-mounted cowlings. This doesn't appear to be a ...
-5
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2answers
307 views

Is this a video of severe turbulence for an Airbus A320? (video) [closed]

I remember reading that in 1966, a 707 encountered turbulence and the wings and tail were torn off (BOAC 911). Is this video at all comparable? Is the A320 more robust than the 707?
11
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4answers
5k views

Do high-wing aircraft represent more difficult engineering challenges than low-wing aircraft?

Generally, it's easier to make things strong in compression than in tension. In a low-wing plane, the weight of the aircraft is on top of the wing; in a high-wing aircraft, it hangs from it. It ...
5
votes
3answers
361 views

Are there any current projects/plans for a VTOL passenger airliner?

I was very surprised to see there's a seemingly underway project for a VTOL "business aircraft" that seats a few people. http://xtiaircraft.com , https://www.startengine.com/xti-aircraft They ...
2
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2answers
165 views

Will creating a strong back pressure within a ducted propeller enable an aircraft to attain a higher altitude?

I would like to know if creating a strong back pressure within a propeller duct will enable an aircraft to attain a higher altitude. Please reference the conceptual drawing below. This is showing a ...
3
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4answers
309 views

Limitations of bird flight as an aircraft design

What is it that stops man from duplicating Bird Flight as Engineering? After all, birds do not require separate propullsion! They use the same wings for propulsion and navigation. My question ...
0
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1answer
223 views

Are there surveillance cameras in aircraft cargo bays?

I've heard that there are cameras on the fuselage and wings of some passenger aircraft. Is there a similar surveillance system in-built at the cargo bay/compartment of a passenger aircraft? During ...
1
vote
1answer
55 views

In the US, is there much variation among the various ARTC Centers as to where a SVFR clearance may be granted?

In the US, is there much variation among the practices followed by the various ARTC Centers and Approach Control facilities as to where a Special VFR clearance may be granted?
29
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6answers
4k views

Would an 8% reduction in drag outweigh the weight addition from this custom CFD-tested winglet?

I'm writing an essay at school about why there is so much variation in winglet design. I am analysing all the primary types of winglets used today in the aviation industry. I'm constructing them in ...
3
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1answer
48 views

How does Mach number of Jet engine vary with respect to Compression Ratio?

How does the performance of jet engine vary with Compression ratio. What are the variables that affect the Mach number of Jet engine.
7
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1answer
295 views

Why do Russian jets make a squealing sound?

Why do the engines noise from the Russian and Soviet jet create a squealing sound which is very distinct which most of the western jets don't have? Which part of the engine creates the noise, and why ...