It will climb (and slow down), but again, it's the thrust that's producing the climb, and this is an extreme example that isn't illustrative. Fighter jets produ

It will climb (and slow down), but again, it's the thrust that's producing the climb, and this is an extreme example that isn't illustrative. Fighter jets produce enormous thrust for their weight with many having thrust-to-weight ratios greater than one. If they weren't air-breathing, they could literally fly into space. A normal airplane, even if it weren't air-breathing, couldn't do that. Depending on the configuration an F-16 has a T/W a little under 1.1, while a transport category aircraft (an airliner) will have a T/W somewhere between 0.20 and 0.35. Totally different performance characteristics.