June 27th, 2002, 07:51 PM
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Corporal
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Join Date: Jan 2001
Location: Newport News, VA
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Re: Battlestar Galactica II (No Joke)
[quote]Originally posted by Baron Munchausen:
quote: Originally posted by Krakenup:
Quote:
It's not a big difference, it's a HUGE difference. For example, an F-16 can perform a 9-G turn (until the pilot blacks out) using aerodynamic forces. Its thrust-weight ratio, however, is generally less than one so its acceleration using just the engine is less than 1 G.
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Well, I know that both the F-15 and the F-16 can fly straight up for a considerable distance. I clearly recall that the F-15 can reach 50,000 feet faster than the Apollo moon rockets could. Is the difference really all attributable to the very slow vertical lift-off of the Apollo rockets? I'd have thought that the F-15 and F-16 would have a better thrust-weight ratio than "slightly" more than 1-1. They are suppose to be able to make a start down the runway & then flip the thing into vertical before they would have reached horizontal take-off speed. It depends on what they are carrying. The F-15 Streak Eagle that set the time-to-climb records was stripped. It didn't even have any paint. They had to paint it to keep it from corroding before they put it in a museum. Your standard F-15 has a weight empty of 28-30K and two engines with about 25K thrust each. With a full load of fuel and weapons, they can gross out at up to 70K. Similarly, the F-16 has one 25K engine with a weight empty of 19K and a gross weight of up to 35K. Also, the thrust drops significantly with altitude. So the thrust-weight ratio varies, but it is usually less than one at combat conditions.
A lightly loaded F-15 or F-16 can go straight up at low altitudes, but they can't go up many thousand feet before they start slowing down. The Streak Eagle stayed on the deck to build up speed before it started climbing and then used all the aerodynamic lift it could get.
At altitude, you can use aerodynamic lift to get the aircraft pointed up at speed. The aircraft then zooms to an altitude that it cannot sustain. It's like throwing a ball. It keeps gaining altitude until it runs out of vertical velocity, and then it comes back down. There is no aircraft today with an air-breathing propulsion system that can stand on its tail at high altitude without falling like a rock.
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