| From: | WILLIAM FRIERSON <will1am@*****.ASU.EDU> |
|---|---|
| Subject: | Re: Banshee Bird Strikes |
| Date: | Thu, 8 Jun 1995 03:21:28 -0700 |
>William you are both right and wrong. A vectored thrust aircraft does fly
>aerodynamically at higher airspeeds. They have to since all of their thrust
>is being vectored aft to drive the plane, but you are correct at lower
>airspeeds the nozzles are aimed more downward to allow the thrust to carry
>the weight of the airplane. So when the computers sensed the new airspeed
>after the barrier they would merely readjust the nozzles to keep the plane
>flying, but the poor pilot(s) may have suffered a bit by the unexpected
>change in flight profile.
Looking at the illustration of the Banshee shows that there are two stub
wings at the rear of the vehicle. But they don't look large enough to
provide enough lift to keep the vehicle aloft. The nozzles are slanted
aft, but not even close to horizontal. You are right when you talk about
aircraft like the Av-8b Harrier and the Yak-36 Forger, both of which
transition to forward flight, with lift being generated by actual wings.
The Banshees down't look like they can trnasition to full flight at all.
Quite frankly, I think the whole idea is a bit off. Harriers can't take
off vertically with a full load of ordinance, and when they do, they burn
a _lot_ of fuel, shortening their mission radius and time in the air.
The idea of vectored thrust vehicles is very prevalent in Cyberpunk (RTG),
but I haven't seen any real world parallels (except the "Flying Bedstead"
test vehicle that led to the Harrier). The supposed advantages of no
rotors are that they can land in urban environments without worrying about
rotor strikes. This "advantage" is heavily outweighed by range, payload and
fuel considerations. Not to mention you'd have to worry about the landing
surface being smooth and/or FOD (Foreign Object Damage) if you landed on
a dirty lot.
Now tilt-rotors, on the other hand, are a great improvement over the basic
helicopter, improving speed, range and payload over helicopters. I'm pretty
surprised that there haven't been more orders for the Osprey and smaller
variants (though there is a special operations variant on order for the Air
Force).
>Bird strikes are an all to common occurance in (military) aviation. I've had
>several and have not lost an airplane yet. BUT I've never taken a bird
>directly on the windscreen or down an intake. So you are quite right, a
>heavily armored (for an airplane) aircraft would not be affected by even a
>large bird. Unless the bird hit squarely on the front windscreen with the
>plane moving at hight speed (even "bullet proof" glass shatters and the
>support frames give way under that stress), or the bird goes down the engine
>intake. I'm sure the engines in 205X are better than todays and could
>probably continue to produce thrust, but that bird would certainly reduce the
>amount of thrust that engine could produce. And take it from me pilots do
>not hang around with a bad engine!
Yeah, but again, looking at the illustration shows _no_ windscreen that
could be hit bu a bird. And the intakes are spread out and pretty small.
They would have to be armored and filtered to avoid FOD, especially since
they are supposed to operate at low and very low altitudes. I don't think
a bird would be able to fit into an intake. And ones that were small
enough, would be chewed up by the turbines (hopefully). Unfortunately,
FASA doesn't really delve into very deep detail about the vehicles (weight,
engine type and performance, etc.).
BTW, I finally grabbed the book and checked out the rules about barriers.
There is a test, per p. 97 (blast vs. barriers) to see which goes down
first. It would be a test of the barrier rating, plus another half (1.5
x Barrier rating) vs the body of the vehicle + half of armor rating, in
the Banshee's case 18 Body + 9 (18 x .5) for a total of 27. Even a
force 10 barrier is probably going to go down before the Banshee does.
I see it as slowing the Banshee down, like driving a tank through a wall
of a building (and a tank _can_ do that). Now, if the Banshee were more
like a jet fighter or Harrier, I'd say that the barrier would hold and
the pilot would be in a world of hurt as his light vehicle slammed into
a wall, crumpling it and causing a rapid decelleration to 0 mph. Followed
by a rapid descent into terrain. :)
Later
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William Frierson Internet: WILL1AM@*****.asu.edu
