98

Air-to-Air guided missiles are little airplanes. If there are only fins at the tail, it's a ballistic rocket, basically a fin stabilized artillery shell accelerated by a rocket motor instead of an explosion in a pipe. On missile like AMRAAM, Sidewinder, or Sparrow, the vanes are wings and the missile is a rocket powered aircraft that can climb, descend and ...


78

The small wings make it fly like a brick. Without the wings it would fly like a stone. Seriously, you are taking the expression too literally. The Space Shuttle is landing like a glider plane with a (not so good) glide ratio of about 4.5:1 (see What was the Space Shuttle's glide ratio?). No brick would be able to achieve that. Designing the Space ...


72

Yes it is correct that helicopters use more fuel when hovering: the engine needs to apply more power to overcome drag. Here is a graph of the engine power required for different airspeeds, from J. Gordon Leishman, Principles Of Helicopter Aerodynamics: The line for total power goes down between 0 - 70 kts with increasing airspeed, this is caused by the line ...


71

Stall was an unfortunate choice of words for an engine that suddenly quits since the aerodynamic stall in aviation means something very different and isn't related to the aircraft engine at all1. To a non-pilot, an aerodynamic stall can best be described as the situation where there is not enough air flowing over the wings to create the amount of lift ...


64

Living Wing The Super Hornet has a living wing, that is to say, the shape of the wing is constantly in motion throughout every regime of flight. Trailing edge flaps, leading edge flaps, stabs, rudders, and ailerons all move in concert to give the pilot the greatest control during particular phases of flight. This is evident by the use of the flaps switch. ...


60

Air Transat Flight 236 experienced a complete power loss over the Atlantic Ocean in 2001. Yes, all passengers and crew survived after the aircraft glided 75 miles to a runway on the Azores islands. Even in the event of the loss of all engines, an aircraft can keep its critical electrical systems running thanks to the ram air turbine which allows the crew to ...


60

The wing shape in the F4U Corsair is called the inverted gull wing. The main reasons for use of this is the large propeller used in the aircraft. The Corsair design was in response to the US Navy RFP (Request for Proposal) in 1938, which mandated the following things: It should have maximum attainable speed The stall speed should be 70 mph Minimum range of ...


60

Special mention for Raúl Pateras Pescara de Castelluccio (good article) who was fond of lots and lots of rotor blades, settling on sixteen for most of his designs, although his Model 3 had twenty. Pescara's helicopters may look a little comical (and dangerous!) but they are an important part of early helicopter evolution, pioneers in the first fully ...


59

It depends. As always. If thrust is high enough, why not? Knife edge flight is a regular part of aerobatic performances, and the fuselage is producing almost* all the needed lift. This requires Enough speed, A low ratio of aircraft mass to fuselage side area, and Enough rudder deflection to trim the aircraft in a sufficiently high sidelip angle. For ...


57

Is it practically possible to do that? Is it okay in terms of weight, CG? Bikes (depending on make and model) are not all that heavy and in this picture they are more or less center mass and would most likely fall in the CG range. aerodynamics Again this depends on the bikes and the placement but with proper care you could be ok. Admittedly a bit ...


55

A deep stall or a super stall is a condition where the wake of the wing impinges on the tail surface and renders it almost ineffective. The wing is fully stalled, so the airflow on its upper surface separates right after the leading edge, which produces a wide wake of decelerated, turbulent air. Consequently, the dynamic pressure at the tail surface is much ...


55

The torque in a helicopter is generated by the engine driving the main rotor in one direction, which causes the fuselage to spin in the other direction. The tail rotor shaft is horizontally mounted and hence creates it own 'lift' to provide anti-torque. The pitch of the tail rotor gives directional control. Common ways to design a helicopter without a tail ...


55

A climbing aircraft needs less aerodynamic lift than in horizontal flight, not more. Now I have your attention, I hope. The reason is quite simple: Lift equals weight, and just because the pilot choses a different flight path angle, the weight of the aircraft does not change. The total of all lifting forces must still balance the weight, but in climb you ...


55

An 'aerodynamic force' (just one force...) appears when a body is immersed in a fluid stream. By convention, two components are chosen, one of them parallel to the stream direction, called 'drag', and the other one, perpendicular to that 'drag' is termed 'lift'.


54

It depends on exactly how you define "lift" and "weight". You might say intuitively that lift is all the forces acting on the aircraft in the upward direction, like this: In this case, lift must equal weight, otherwise the aircraft would be accelerating. That is, it's rate of climb would be changing. But it's more usual to define lift this way: Here, lift ...


54

1) Airspeed, 2) Forward motion, 3) Size constraints. Just to begin with. Household fan blades are extremely slow, so they need more chord to push a meaningful amount of air. Aircraft propellers approach the speed of sound at their tips, and low drag is critical. All things equal, more span and less chord is more efficient. Reducing the airspeed for props ...


51

First of all, a missile is operating at a much higher dynamic pressure than the airplane. After all, it has to catch up with it to do its job. Since dynamic pressure scales with the square of airspeed, the wings of a missile twice as fast as the target would need only a quarter of the wing area to produce the same forces. Secondly, the missile uses its ...


50

Anhedral wings will induce roll instability and improve roll maneuverability. In a large/heavy airplane with a high-wing configuration there is usually excess roll stability, so this type of wings can be pretty common. Both the high wing configuration and wing sweep contribute a negative sideslip-induced rolling moment, and anhedral is necessary to limit ...


49

Mass doesn't affect the maximum distance, only the maximum endurance. For example, image two identical planes A and B: A weights 50kg less than B. Assuming no wind (horizontal / vertical) and speed of best glide, both gliders will land at the exact same spot. The lighter airplane A however will arrive later than B, as the speed of best glide is less than ...


49

Short answer: Increasing fuel prices would have driven down the most economical speed, but advances in aerodynamics have compensated for that and the maximum cruise Mach number is still at Mach 0.85. But there is a much simpler reason why this Mach 0.85 number seems so immutable. Please note that we are talking about the maximum cruise Mach number; all ...


48

Here is what I think you need to come to your own conclusion. First I will give a very general overview over lift creation, and then I will look at three wings: An unmodified wing This wing plus a winglet This wing plus the winglet, but this time folded down into the plane of the wing. For each I will plot the lift and bending moment distribution. I will ...


48

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a modified 747 that has an 5.5 m x 4.1 m door that is opened during flight for the installed in infrared telescope. But the door is usually closed during takeoff and landing. But according to this story there are emergency procedures to land with an open door and it had to do so once, when it ...


47

Some do (or have in the past) but very high altitudes present their own issues. Historically the Concorde cruised anywhere from FL550 to FL600 and was actually allowed to climb and descend at its discretion up there since they were well clear of any traffic. However the increase in pressure differential on the airframe as well as supersonic flight meant the ...


46

Ex US Navy pilot here. I flew the S-3 Viking, which refueled via the probe/drogue method, as opposed to the USAF flying boom method. I can confirm that the receiving plane is below the wake turbulence of the tanker, maybe by 8–10 feet. Although, even if you should ride up into the wake, the sensation is perhaps not as violent as you might think....


46

On the other hand, fuselage on an airliner is most of time bullet shaped. No, it is not. A “bullet shape” has a flat end, which is where most of the drag is generated (at subsonic speeds). But that shape is never used on flying vehicles except on rockets where the end is occupied by the rocket engines. Instead, airliners always have a tapered “boat” tail, ...


46

It's partly inherent in the way things scale. If you double the length of the model, then the wing area (length times width) increases by a factor of 4, but the weight and volume (length times width times height) will increase by a factor of 8 ... so doubling the size means halving the weight-to-lift ratio. In the most extreme cases, a tiny model will blow ...


45

The wing planform (which is the shape and layout of wing) for each aircraft is mainly based on the aerodynamic requirements. There are other considerations like stealth, controllability etc. The basic terminology in the wing geometry is given in the figure below. Source: grc.nasa.gov Most of the wing platforms in use (or have been used) fall under one of ...


45

They only change one, because that one is a new engine that is being tested. If you are testing a new engine you change 1 at first so if it fails you have 3 others. If you change all 4 and there is a systematic defect in the design, now you have 0 good engines instead of 3. You will also see that the test engine isn't always one suitable for a 747. ...


44

The simplest explanation is the "hand out of the window" one: Hold your hand out of the window while in a moving car and hold your hand at an angle. It gets pushed upwards. Your hand represents the wing of an airplane. The plane's engine simply makes sure the "hand" keeps moving forward against the force of the wind. Even a 4-year old understands the ...


44

The aircraft is the Boeing E-4B Advanced Airborne Command Post 'Nightwatch', which serves as the survivable mobile command post for the US National Command Authority. The aircraft are based on the same Boeing 747s as the VC-25s used by US President. There are four identical aircraft performing this function in the US. The "bulge" on the top is a radome ...


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