Forum: General F-35 Forum

The F-35 was designed from the ground up with one engine, yes. But that doesn't mean it's locked into a single-engine propulsion system or flight control system. If you used a pod of matched engines then you could use techniques to streamline maintenance procedures. You really are more concerned with airframe downtime than the downtime for the pair of engines. The next concern is whether the said cost of this strategy outweighs the benefit. Over glacial water you might prefer the higher operating expense.

Only one word: Supercruise. The laws of physics don't change. A larger diameter turbine can't supercruise as well as two smaller diameter turbines with equivalent airflow. The single, larger diameter engine will, all else being equal, have more thrust and lower specific fuel consumption. But it will Mach stall sooner.

However, two engines means twice as many moving parts, and twice as many opportunities for mistakes and failures. Plus twice the maintenance and more fuel costs. And it offers less than twice the chance of saving the plane or pilot. Many things that can take out one engine, can take out two. Many a failing engine manages to, itself, take out the second engine. And many things that can take out an engine can take out other critical parts of the plane, or even outright kill the pilot anyway. Closely spaced engines have little more damage tolerance than one engine. Widely spaced engines have a less than benign one-engine failure mode. Two engines, basically, is a very costly way to provide far less than two times the reliability of one engine. For the same lifecycle cost, you could realistically design, manufacture, and maintain one engine with about the same safety factor as two lesser engines. It'll give you better range, and lower fuel costs too. It just won't supercruise as well.

Now, if pulse detonation engines become viable, you can have one supercruise engine with few moving parts, and multiple redundant thrust elements. An F-35 with a pulse detonation engine the size of the F-135 would be an amazing F/A-XX.

That doesn't sound right. Isn't it the bypass ratio that determines the effective top speed, not the radius?

Look, its one thing to develope a single engined fighter out of the twin engined F-5 (presto! F-20 Tigershark!) But to turn the -35 into a twin..... Modular construction aside, it'll be easier and cheaper just to develope an entirely new platform. Fusealage will be different, wings will be different, intakes will be different, weapons bays will be different... All you'll have as comman will be the cocpit section.

This has to be misinformation, plain and simple. There's not going to be ANY cost benefit to this versus an all new fighter.

If they want a twin LO aircraft, making a carrier suitable F-22 variant would make far, far more sense. Doesn't even need to be a swing wing "NATF" like was proposed in 88 or 89....

To clarify what I was saying when I first brought that up. I am not advocating F/A-XX be an F-35 with a second engine shoved in it. What I am saying is I would reuse everything I can from the F-35. I would basically port over the engines, weapons bay, cockpit and avionics and put a new wrapper around it. My main concern with F/A-XX would be keeping cost down as much as possible and not overreaching. There would still be development cost there but they would be concentrated in airframe shaping and new flight control software.

A stretched body using the F-35C wings should do wonders. Too bad they cannot use pods for a pair of engines to make removal relatively lightning fast. Treat the design like a NASCAR racer, pitstop time to minimum and maximum time spent out on the track. ...

TEG is gonna p!ss himself laughing if he reads this thread.

With the risk of going way off-topic. Isn't the F/A-18 a two-engined derivative of the YF-17 of some sort?

The advantages of multiple engines is that you leave room to recover after failure.