Hello guys and gals, sorry for asking such a stupid question but here it goes, can someone please explain to me what the thrust to weight ratio is? what the numbers mean, like the F-15C has a 1:3? and i also see some of them like, 1:3:1, whats the 3rd number for? and how do u figure out the ratio? thanks alot people.adam

bumpadam

Hi Adam,A thrust to weight ratio is, simply, The amount of thrust an aircraft produces divided by the weight of the aircraft. For example, say you have an airplane with an engine that produces 1000 lbs. of thrust and the airplane itself weighs 3000 lbs. This aircraft whould have a thrust-to-weight ratio of 1:3 (1000/3000). The ratio gives you an idea of the performance of the aircraft. An airplane with a thrust/weight of 1:1 would be able to hover like a harrier jet; an airplane with say a 1.2:1 ratio produces more thrust than it weighs and it would actually be able to accelerate in a vertical climb. Hope this helps.Marc

Quite so. I suspect the F-15 has a ratio of close to 1:1 (http://www.globalsecurity.org/military/systems/aircraft/f-15-specs.htm) with 2x 25,000 lbs thrust and max. TO weight of 68,000 lbs giving a ratio of 0.74:1.00 (C/D models.) Clean, this ratio would no doubt be much closer to parity, as the early F-15s achieved several records.Alastair