时间：2011-03-11 23:13来源：蓝天飞行翻译 作者：admin 点击：次
|
The flapping hinge permits the rotor blades to flap up or down to equalize the lift, or rotor thrust, between the advancing-blade half and the retreating-blade half of the rotor disk. flaps (airplane control surfaces). Auxiliary controls built into the wings of an airplane. Flaps can be extended, or lowered, to change the airfoil shape of the wing to increase both its lift and drag. When the flaps are fully extended, the drag is increased so the airplane can descend at a steep angle without building up excessive airspeed. Partially lowering the flaps increases the lift so the airplane can fly at a slower airspeed. See plain flap, split flap, slotted flap, Fowler flap, and triple-slotted flap. flare (aircraft flight maneuver). The last flight maneuver made by an airplane in a successful landing. The airplane is slowed down in preparation for landing, and it descends along a gradually sloping flight path that brings it to the end of the runway. When the airplane is over the end of the runway, just a few feet above the surface, the pilot flares by gently pulling back on the control wheel. Flaring increases the angle of attack and allows the airplane to settle onto the runway with the slowest forward speed and the least vertical speed. Flaring is sometimes called rounding out. flare (aircraft safety equipment). A safety device that was at one time carried in most airplanes that flew at night. A flare is a magnesium candle supported by a small parachute. If it was necessary for an airplane to make an emergency landing at night, the pilot released a flare, and as it left the airplane, it automatically ignited. The burning magnesium made a bright light that allowed the pilot to see the ground and make a reasonably safe landing. The parachute lowered the flare slowly enough that it was completely burned out before it reached the ground. flare (rigid fluid lines). A cone-shaped expansion on the end of a piece of rigid fluid line tubing. The fitting to which the flared tubing attaches has a cone-shaped end that exactly mates with the flare, and when the tubing nut is tightened onto the fitting, the flare and the flare cone form a fluid-tight seal. Tubing used in automotive fluid lines is flared at an angle of 45°, and tubing used in aircraft fluid lines is flared at an angle of 37°. flareless fitting (fluid lines). A type of fitting used on a fluid line that forms its seal without being flared. Flareless fittings use a compression sleeve around the end of the tube. The sleeve fits into a recess in the fitting, and when the nut is tightened, the sleeve is forced tightly between the tube and the fitting, making a fluid-tight seal. flashback (welding problem). A problem in oxy-gas welding in which the flame burns back into the mixing chamber of the torch. A clogged or overheated tip can cause the flame to disappear from the tip and burn back into the mixing chamber. A flashback is always accompanied by a shrill hissing or squealing, and the flame does not reappear at the tip as it does with a backfire. Flashback is extremely dangerous, and if the fuel gas, the acetylene or hydrogen, is not turned off at the regulator, the fire can burn back through the hose and cause an explosion. |
