29
At uncontrolled airports, there is rarely enough traffic for signals to be needed, and pilots should (though are not required to) communicate with each other on CTAF—an option that cars do not have.
In the air, if you're close enough to see a turn signal, you are way too close and need to immediately follow the collision avoidance procedure.
More generally, ...
27
There are a few which do (none of them in production, though) and the reason is the added weight and restrictions in varying nozzle geometry for best efficiency.
The tail arrangement of the F-4 is the result of its heritage. Early McDonnell jets all had the fuselage extended past the engine exhaust in order to shift the engine mass forward, near the wings, ...
21
Keep in mind that not all sailplanes are designed for extremely light weight. Decreasing the weight also decreases the minimum sink rate, but doesn't help the still-air glide ratio, and actually hurts the glide ratio against a headwind.
Even in sailplanes that are designed for very light weight, designers have sometimes thought it worthwhile to employ a ...
18
I think the points raised in other answers are good, but they miss the essential difference. Cars choose from a discrete set of options, but planes do not.
When you indicate left when driving you are communicating to other traffic that either you are taking the next left turn, or that you're changing lanes (depending on context). In some situations the exact ...
12
The heat-seeking missiles of the time when the F-4 entered service were fairly limited compared to newer designs, and had to be targeted at an angle where they had a good view of the tailpipe of an aircraft. This changed somewhere around the late 70s when all-aspect missiles were introduced, allowing aircraft to be targeted from other angles as well.
I've ...
9
The radio-controlled model sailplane that recently exceeded 540 mph while dynamic soaring has to be a contender. Minimum speed in this flight (immediately after launch) may have been as low as 10 mph, which probably could have been sustained by staying on the front side of the ridge.
Link to You Tube video--
Though any plane ...
8
No. The empennage on the F-4 was never laid out in that manner to shield against IR guided missiles tracking it not could the design aid in doing so. Like the increased dihedral or the outboard sections of the wing the severe anhedral angle of the tailplane is more or less a cheap patch for poor aerodynamic design. The 23° anhedral to the tailplanes were ...
8
Aircraft have radios with which to communicate their intent. Cars do not. Pilots should be utilizing these radios even at uncontrolled airfields. A good mantra to have is that there are no uncontrolled airfields. Just pilot-controlled airfields. I will communicate my intent on the Common Traffic Advisory Frequency before entering the movement area of any ...
8
The highest range of speeds will basically match up with a list of highest top speeds... take ~200 knots off of the top speed of the SR-71, and you probably have your answer. Or if the question is for currently flying jets, unless your #1 and #2 have top speeds so close that the delta in their landing speeds is greater than the delta in their max speeds, #1 ...
8
The simple answer is there isn't the space. The problem with nose cargo doors is the cockpit. The cargo door must be high enough on the aircraft to line up with the main cargo hold to be useful. On larger aircraft designed with this in mind from the start, (747, C-5, An-124, An-225) the cockpit is placed in a location above the main deck so that the cockpit ...
7
CG Fore/Aft Location
The further forward the main wheels are in front of the CG, the greater the propensity for ground looping.
Main wheel separation
The closer together the main wheels, the greater the propensity for ground looping.
Main wheel Toe-in and Toe-out
The following text and images come from the book "Landing Gear Design For Light Aircraft&...
6
The Space Shuttle (or "Space Transportation System (STS)") reportedly re-entered the atmosphere from low Earth orbit at about 17,500 mph, and touched down as low as 214 mph, for a ratio of 81.77.
https://www.nasa.gov/mission_pages/shuttle/launch/landing101.html
6
Using AoA as reference gives a simple way to maintain a safe stall margin. If approach speed was used as reference, there would have been multiple speeds to memorize, as the weight is not the same from mission to mission.
Remember, wings basically always stall a certain AoA, not certain speed. Specifying a AoA to maintain, the weight of the plane is ...
6
Silly comments aside, "fat" wings, ones with greater camber, were all the rage 100 years ago when designers found they could eliminate draggy external bracing by building cantilever wings. Hugo Junkers was one of these pioneers.
Wind tunnel testing also showed increased camber not only increased lifting efficiency, but also, combined with large, ...
4
Yes, sweep makes a wing heavier and less efficient. But making the airfoil of a straight wing thinner runs into diminishing returns and also will drive up mass.
Since a thin wing needs to create the same lift as a thicker one, only the local speed increase from thickness can be tackled by making the airfoil thinner. The speed increase necessary for lift ...
4
Correct that changes to one performance parameter will affect others, but it isn't totally clear what you are asking.
If you are in the pattern at 11 deg AOA and level flight you are in equilibrium. 11 deg AOA correlates to a certain airspeed at a given weight.
That airspeed will vary depending in weight, and the correct indicated airspeed must be for each ...
3
A member of the Century Series, the F-102 was the USAF's first operational supersonic interceptor and delta-wing fighter. (Wikipedia: Convair F-102 Delta Dagger)
Its innovative "coke bottle" fuselage design to lower the drag at the wing root was critical in achieving supersonic flight.
Me at Saigon with my F102
3
The actual answer is straightforward. The F-15 wing was originally just a swept wing with a given taper ratio which resulted in a slightly swept trailing edge. The inboard portion was straightened just to simplify the flap. Because the flap hinge was now perpendicular to the fuselage the end of the flap was effectively sealed against the "booms" ...
2
Airplanes don't coordinate visually because they can't
The other answers are correct, but they seem all to miss out an important point: airplanes do barely see each other! Because (and in contrast to e.g. cars):
they can be anywhere in 3D, not just 2D on specific streets
they are incredibly fast (think of at least 2x the speed on the highway)
they are ...
2
Gliders spend a lot of time circling, entering thermals dodging others while ridge flying and generally performing manoeuvres designed to terrify most power pilots. Henry Ford remarked 'there is no substitute for litres'. For a glider pilot 'there is no substitute for span'. Mine is a titchy 15 meters. And even that represents a very large moment of inertia ...
2
I have two keychains both with pieces of fuselage from Virgin Atlantic 747-400's. One is 1.6mm thick and the other is 2.8mm thick!
2
Pressurized aircraft such as LearJets are designed to maintain sea level pressure up to a certain altitude, say 28,000 feet. Above that altitude, the cabin pressure begins to fall so that at 43,000 feet in this example, the cabin pressure is about 5,000 feet of altitude. However, air ambulances can tell the tower what altitude they will fly so that they ...
2
As other answers already note, the major attraction of geodetic framing was to provide a lighter and stronger structure than internal framing, with the not inconsiderable bonus of leaving much more internal space for fuel and payload. The geodetic frame could directly carry a fabric skin in a streamlined shape, instead of requiring the addition of (heavy) ...
2
Addressing only why gliders, even with only one main wheel, rarely ground loop.
Point by point:
No toe-in/-out.
No camber.
Tailwheel only, and often landing on grass.
Low CG. The wheel's axle may be almost as high as the CG.
Mass concentrated very close to the CG, especially if still carrying ballast.
Large wingspan and lightweight wings make it easier to ...
2
The downwash is about as high as wide, and angled only by a few degrees (more at slow speed). So the longitudinal distance needs to be many times longer than the wing span to make the wings independent.
And it would still be less efficient than increasing the span:
If you double the span, you will decrease induced drag four times.
If you half the lift, you ...
2
Since both the lift curve slope and the effective angle of attack are reduced by the cosine of the sweep angle at quarter chord, the lift coefficient of a swept wing at the same geometric angle of attack is reduced by the square of the cosine of the sweep angle.
Also, the pressure distribution over chord differs between straight and swept wings, especially ...
2
With all the connections between the cockpit and the rest of the aircraft, a modification which makes the cockpit swivel out of the way is way too complicated. In cases where a conventional airframe needed wide open access to its cargo hold, the tail would be made removable. The Junkers 52/1m would be one example, and the Conroy CL-44 "Skymonster" ...
1
Other than the answer of there isn't space, you would need to cut open the airframe. When 747 passenger planes are converted into freighters they don't have a nose door. There is obviously space but cutting up the airframe would make legally getting it in the air again virtually impossible.
1
Root bending isn't an issue for braced structures using wires or struts. The root fitting is just a pin joint on most wire and strut braced aircraft, and even if there is a one piece beam going across, like some hang gliders, it's not under significant bending, except at the point where the wires/struts attach outboard.
Root bending only matters on ...
1
One area where geodesic airframes have seen a recent resurgence, is 3-d-printed model airplanes.
I've seen an example where the fuselage and wings and tail surfaces were all of open geodesic construction, similar to the well-known Vickers "Wellington". The model was covered by a heat-shrunk plastic film such as Monokote.
Here's a website featuring ...
Only top voted, non community-wiki answers of a minimum length are eligible
