It was well known that such an arrangement led to an aerodynamically inefficient rear wing, as it was in the downwash of the forward wing, so Albessard gave the inner panel of the latter a symmetric section set at 0?camber changing devices.
42.
He said the downwash problem made it doubtful that Marines would be able to perform " fast-roping, " another standard operation in which Marines slide down ropes from the aircraft's belly as it hovers 20 or 30 feet in the air.
43.
However, the aerofoil, by creating lift also creates downwash ( also see induced drag ), which alters the direction of the incoming flow by adding to it a component parallel to the'ideal'lift ( labelled V ind on the aerofoil diagram ).
44.
Helicopters generate downwash, so the air has to come from somewhere, seems to me having a bridge deck just over the rotor would seriously disrupt the aerodynamics-lifting the'copter as it ate away the air above it and causing it to hit the bridge deck above.
45.
Since the tail is operating in the flowfield of the wing, changes in the wing incidence cause changes in the downwash, but there is a delay for the change in wing flowfield to affect the tail lift, this is represented as a moment proportional to the rate of change of incidence:
46.
In single rotor helicopters, the vortex ring state can be corrected by moving the cyclic control in any direction, so as to get out of the column of air created by the rotor downwash, which controls the pitch angle of the rotor blade, slightly pitching nose down, and establishing forward flight.
47.
In contrast, birds flying in a stream immediately one behind another do not have wingtip coherence in their flight pattern and their flapping is out of phase, as compared to birds flying in V patterns, so as to avoid the detrimental effects of the downwash due to the leading bird's flight.
48.
The tailplane was increased in area, split into two separate surfaces, and moved down from the top of the vertical fin to the lower rear fuselage in order to avoid the downwash effects from the high-set wing at high F-104S was to be used to withstand the aerodynamic heating of flight at higher Mach numbers.
49.
Because the trailing edge of the front wing was close to the leading edge of the rear wing, the front wing's downwash would accelerate the air over the rear wing and cause it to gain lift more quickly than the front wing, resulting in an ever increasing nose pitch-down and flight directly into the ground.
50.
There are a few classical cases where this favourable response was not achieved, notably some early T-tail jet aircraft . In the event of a very high angle of attack, the horizontal stabilizer became immersed in downwash from the wing and fuselage, causing excessive download on the stabilizer, increasing the angle of attack still further.
