"QDurham" wrote in message
...
| Dan Ford wrote in part:
| See my question to Gord about ground effect. Is it really there, as a
cushion,
| or is that a myth?
|
| Probably a reality, but I don't recall noticing it in teh exercise
mentioned.
| Did have a friend who lost an engine in a P2V about half way to Hawaii.
| Officially, too heavy to stay airborne, dump enough fuel to be light
enough to
| stay airborne, and one hasn't enough fuel to reach land. Double bind.
| (It has ben suggested that is why Lindbergh elected a single engine plane.
| With the engines available, if he had two and lost one -- splash. If he
had
| one and lost one -- splash. But the chances of losing an engine in a
single
| engine plane are half those of a twin.)
| They went down to zero altitude --ground effect max -- went through plane
with
| bolt cutters dumping everything dumpable. They spent about 4 hours with
one
| mill feathered and the other operating beyond all redlines. Arriving at
| Barbers Point (?) there was no "letting down" to a landing. They simply
| lowered the gear onto the runway. Whew!
|
| Quent
|
|


Another example would be the Singapore Airlines 747-400 that had the tail
strike at Auckland a year ago. Pilot and 1st officer screwed up on
the load sheet (long story) and fed the numbers into the computer 100 tonnes
short.


As the plane was racing towards the end of the runway and still not taking
off, the pilot hauled back further on the stick - without advancing the
throttles. Tail drags for 400m while the plane accelerates _very_
slowly.

Eventually they lift off just before the end of the concrete - at something
like 168 knots, which for that configuration, was 3-5 knots under their
stall speed. Such is the value of ground effect.


On another note ....

Helos also come with 2 max hovering altitudes - in ground effect and out of
ground effect.



Cheers


Dave Kearton