2 ms·
I’m absolutely ignorant on the topic of aircraft propulsion, but I’d always assumed that the diminishing mass of fuel that one was carrying around with oneself
by qubex 7y ago
I’m absolutely ignorant on the topic of aircraft propulsion, but I’d always assumed that the diminishing mass of fuel that one was carrying around with oneself as the flight progresses is a key advantage that electric-propulsion aircraft can never hope to replicate (short of dropping battery packs with parachutes as they become exhausted of charge).
Am I absolutely wrong or is it not actually much of a factor?
- AdrianB1 7y agoYou are right in the way you are thinking, but you don't have the full information: in a 600 kg plane the fuel is 100kg. The mass reduction does not make such a big impact, especially as you rarely top the tanks (you can carry more luggage or a heavier pilot & passenger) and you never empty it (30 minute reserve is usually raised to 1 hour reserve), so you have a 10% variation of the total mass of the plane on regular flights: no significant impact. On the other side, large planes carry a lot more fuel as a percentage of the total mass, it really matters to them.
- Filligree 7y agoI hope to hear actual pilots chiming in, but from first principles: It shouldn't be a large factor. Drag is independent of mass, and while lifting the fuel to cruising altitude takes energy, most of the flight should ideally be cruising. The rocket equation doesn't apply; that's for an entirely different regime.
- skykooler 7y agoWhile drag is "independent" of mass, the lift required to maintain level flight is affected by weight, and drag is affected by lift. A heavier airplane will absolutely require more power to cruise.