Just some comments for you to ponder...
>There was a -real- near-accident several years ago when a pilot of a
>commercial flight saved his aircraft by executing either a barrel
>roll or a vertical (Immelman?) loop. It was smaller than a 747, but
>I remember being impressed at the capabilities of the plane.
Don't know of this specific incident.
There is a big difference in these two maneuvers.
A barrel roll, is a loop and a roll combined. Not a snap roll mind you,
just a regular roll. It is a low G maneuver. You are basically
corkscrewing through the air.
An Immelman is initiated the same as a loop, however, at the top, you
right the aircraft trading speed for altitude. Usually it is a higher G
maneuver than a barrell roll.
>I also saw a news report from the Paris Air Show. Showed some
>commercial jets nearly standing on their tails as they took off.
>Impressive!
Aircraft are certified to have normal performance at gross weight
(includes passengers, cargo, fuel, etc.). There is a safety margin built
in as well.
When you consider a 747 holds about 500 folks. Using a simple 300 pounds
per passenger (passenger themselves, their lugguage, dinner, water
ration, etc.) that is roughly 75 tons of passenger weight.
Without full fuel, passengers, and cargo, these planes weigh much less,
which is why they can do these types of maneuvers at airshows.
>I think I recall an anecdote that the test pilot of the
>747 barrel- rolled the prototype in front of a bunch of
>airline or company execs at a demo.
I know of a 747sp version that did a roll and a loop.
>This brings to mind a news story I read a few months
>ago. Seems that a disgruntled (and I mean *really*
>disgruntled) FedEx employee stowed away on one of
>their cargo jets, and appeared in mid-flight to attack
>the pilot and co-pilot with a screwdriver. The pilot
>disabled him by flying the plane *upside down*, throwing
>him to the roof. I can only imagine one of those huge
>cargo jets being thrown completely over on its back,
>I had no idea they could even do that.
Actually, the co-pilot initiated a negative push over maneuver.
It all has to do with G loading of the aircraft.
It is possible while flying right side up to push you to the ceiling,
likewise it is possible to be upside down and be forced into your seat.
BTW, for those that have seen Apollo 13, the low gravity shots were
filmed during negative G push overs. In this case, the negative push
over was in tune with gravity, so the actors levitated during filming.
If the pilot's had wanted to, they could have initiated a bit more push
over and planted the actors on the ceiling. Ouch, that would hurt -- it
does, believe me! ;-)
Sushi
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