90

The Gossamer Albatross is a human-powered plane with a top speed of 29 km/h (18mph). It was used to cross the English Channel and seems to meet the criteria of the question.


61

The Antonov AN-2 has no stall speed quoted in the operating manual and can fly under full control at about 30 mph. Thus if the headwind is sufficiently large the aircraft will move backwards with respect to the ground.


45

The Harrier, Yak-38, Yak-141, XV-15, and V-22 are all fixed wing aircraft. All can hover in mid air, controlled. So they are in controlled flight at 0 velocity. At least the Harrier can even be in controlled flight flying backwards, so with negative velocity. The others may as well, I don't know.


31

Much like water, exposing fuel to below freezing temperatures does not instantly make it freeze. It takes some amount of time, and as long as the fuel is not exposed to below freezing temperatures long enough to make it freeze, it won't be a problem. How much time? That depends on a number of factors like: Type of fuel Jet A (common in the US) has a ...


31

At the critical mach number, some part of the aircraft (usually the wing) will have air flowing over it at a speed in excess of mach 1. If the aircraft is not meant to fly at transonic or supersonic speeds, shock waves will flow over the wing. This can either cause the wing to stall, the control surfaces to become unresponsive, or the plane to go into the ...


28

The reason is both historical and operational. The first mass produced helicopter was the Sikorsky R-4. It had a single collective located between the two pilot seats, so by necessity, the person on the right would control the cyclic with their right hand, and the person on the left would control the cyclic with their left (because their right is needed on ...


25

For the GA fleet, there is some historical precedent operating here. Years ago, engines were much less reliable than they are today. Dragging it in generally means that you cannot glide it in if you have a complete power failure. This translates to saying in the event of an engine failure, you are landing off airport with limited selection of landing ...


24

It's a holdover from the old days when microphone technology wasn't as advanced. The military adopted "dynamic microphones" as the standard, which were less noisy than the alternative "carbon microphones." Carbon microphones required a DC bias voltage to operate, and the dynamic ones did not. Fast forward to current airplane microphones, which are ...


22

The wings of the Boeing 787 are so flexible because its carbon fiber material can be stretched more, and the high aspect ratio of 11 will magnify this effect. In flight the consequences are: Less shaking due to gusts, because the wing will dampen load changes more effectively. Delayed aileron response, because the lift change due to aileron deflection will ...


21

It's a hard-point called an "engine pylon". And yes, some designs use specific points designed to fail if there is excessive force, allowing the engine to separate from the aircraft without ripping the entire wing apart which would obviously be a catastrophic event. It has happened on a few occasions. The above image is from the Wikipedia page on the ...


21

This is less of a "big -vs- small" question, and more of a "single-engine -vs- multi-engine" question. So, to answer your question with another question: What would happen if an engine were to fail during the approach in each case? In a single-engine aircraft you want to always be in a position to land if the engine fails, so you don't want to get too ...


21

now, if you're looking at modern, more commonly used transportation, powered paragliding would probably take the cake. CC BY 3.0, https://en.wikipedia.org/w/index.php?curid=13110495 Powered paragliders usually fly between 15 and 50 mph (25 and 72 km/h) at altitudes from 'foot-dragging on the water' up to 24,000+ ft (5400 m) https://en.wikipedia.org/...


18

If you are including historical aircraft, the Wright Flyer averaged 10 fps (approx 6.8 mph or 11 kph) over it's first 120 foot flight in 1903. Reference: https://airandspace.si.edu/exhibitions/wright-brothers/online/fly/1903/triumph.cfm


17

I think most people would say the answer is no. Consider the dictionary.com definition as it relates to Aeronautics: 9. Aeronautics . a. one of a pair of airfoils attached transversely to the fuselage of an aircraft and providing lift. b. both airfoils, taken collectively. The wings are the big airfoils which are responsible for generating most of ...


16

You are right, the trailing edge does not need to point down. Take symmetric airfoils - here the trailing edge runs parallel to the airfoil chord. Or take reflex airfoils (like the HQ 34 of the SB-13 tailless glider): Here the trailing edge is indeed pointing upwards, and still this aircraft flies. But to create lift with as little drag as possible, it ...


15

I actually have a lot of experience in the shipboard systems that you are talking about. First, the gyro's do not keep the boat upright, they counter the rolling effect of waves but they cannot completely remove them. Gyro's of all designs work on the principle of conservation of angular momentum. That means that a spinning object will tend to impart a ...


14

I cannot answer all your questions, but maybe point you to some facts to come closer to an answer. Most important is the thickness of your parallelepiped - more than a few percent will just increase drag, without benefiting performance. It should be as thin as structurally possible. There are lots of model airplanes using flat plates for lift. The most ...


14

Building it just for very slow speed does not look practical (if you really need this, use helicopter). Some old planes may be slower, but they do not use the newest technologies and may not be built for slow flight anyway. Some patrol, agricultural planes may benefit from slow flying, but we need something more extreme. I expect such aircraft to be some ...


14

Gossamer Condor, the first human powered airplane capable of basic maneuvered flight. When it finally won the Kremer prize for a 1 mile figure 8 course it did that course in 7 minutes and 22 seconds. The later Gossamer Albatross that crossed the English Channel had to be faster. This assumes that the question criteria was AIRSPEED (not groundspeed) for a ...


13

For military transport aircraft: Wings further off the ground will mean that the engines will also be further off the ground, reducing the risk of foreign object damage. You can move vehicles under the wing, and taxi across smaller taxiways. The fuselage can be closer to ground, facilitating transport. No wing spar crossing the cargo floor. Reasons why ...


13

Rather obviously, both of these situations are far from likely to occur. As a result, the following is just idle (but hopefully informed!) speculation — I don't recommend experiments! I'm going to be a little bit cheeky in answering this question -- you've asked if it's possible for “a fixed wing aircraft to [...] get the engines up to speed and fly off.” ...


13

The Ruppert Archaeoptrix Electro (Wikipedia, official website) apparently has a stall speed of 30 km/h (19 mph / 16 kn), and I think that makes it a candidate for the current "slowest" fixed wing aircraft. It is a relatively new glider that can be foot launched, but there are also wheeled and motorless configurations, and it can also be launched by towing. ...


12

There are a few things to consider for a good aerobatic airfoil. The transition between attached and separated airflow has a big influence for spins or snap rolls, and a good aerobatic airfoil needs only a small change in AoA (angle of attack) to fully transition between the two. To achieve this, it helps to shape the forward part similar to an ellipse (a ...


12

Helicopters use more fuel than airplanes (considering everything else being equal). When helicopters are traveling slow, they need more energy to hold their weight. When traveling fast (according to their standards), the rotor drag is very high. This is the primary reason they need more power. More Power = More Fuel. Conventional aircraft have much less ...


12

Quick answer: The rotary wing is moving at different speeds over the radius, and on the left and right side in forward flight, and since there can be only one optimum speed, most of the rotor is working at less than optimum speeds, lowering the lift-to-drag ratio overall. The slim rotor blade needs a reflex airfoil, an airfoil with low pitching moment, ...


12

Is a propeller a wing? Maybe. It depends on how pedantic you feel like being about your definitions. A propeller is certainly an airfoil (usually several of them - each blade is an airfoil, and you can have one blade, two, three, four, or more attached to a hub). A wing is also an airfoil. Aerodynamically a wing and a propeller function the same way: Air ...


12

Generally, a slight nose-up attitude gives the best performance. This allows the fuselage to create some lift without producing too much drag, thus filling the drop in the spanwise lift distribution created by the interruption of the wing by the fuselage. However, in passenger aircraft this will make the job of attendants much harder because their trolleys ...


11

You should check out planes with custer wings. https://en.wikipedia.org/wiki/Custer_CCW-5 It was claimed that the aircraft could fly under control at 11 mph (18 km/h) and that it could take off with a 1,500 lb (680 kg) load at 70% power in 90 ft (28 m).


10

Yes - they are still considered fixed wing aircraft. Just because they have variable-sweep sections doesn't change what type of aircraft they are; their aerodynamics, behavior, and performance characteristics are still squarely in the 'fixed wing' category.


10

In case of an engine failure, the fixed wing pilots natural reaction is to push forward to lower the nose, then look for the correct glide airspeed. A helicopter pilot in most engine failures should pull back (although not agressively) to load the disc and restore, or increase rotor RPM. Maintaining rotor RPM is the only way to get to the ground safely so ...


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