The F-35 program was in the news again last week, and is coming under fire. I expect it will become discussed with greater frequency as plans to reduce military forces and spending continue to unfold.Let's start by noting that F-35 is concurrent development of 3 versions. Only the B model is a VSTOL, i.e. "jumper". The A and C model are conventional take-off and landing. The difference is that the C has a larger wing and therefore more endurance and payload.
Air superiority is an essential component in US strategy. We and others are banking on the F35 with no updated F15's, 16's, or 18's underway to fill any gap created by delays and potential cancellations in the F-35 program. Is it smart to bank exclusively on expensive stealth craft?
The essential fact is that most of the planned production is already A and C model with the B-version, aimed at USMC support being a very small number. If you were to handicap the programs to bet on which will survive, the odds are longest against the very complex B model remaining in the mix.
Regarding single engine vs two engine, I'm one of the folks that have tried combat both ways. I never had an engine failure in 23 years of fast jet flying, so reliability doesn't rank very high in my worry list for normal ops. In combat flying, where engine loss is the result of enemy action, I never saw an instance in which a two-engine jet took a hit that cost an engine and survived on the remaining engine. The usual scenario is that destruction of one engine would lead to destruction of the second as various components came apart.
Updates to the teen-jets have been continual since adoption. A Block 50 Viper C-model may be a single-engine F-16, but it is considerably different than an A-model or even a Block 25 C-model. Upgrading those systems further would be a stop-gap and waste of funds in the long term, particularly after the research and development investment already sunk costs in F-22 and F-35.
The Raptor is the undeniable air superiority asset and should fill the high/low mix role which the Eagle did so well. The -35 is the Viper replacement with vastly upgraded systems and still retains a respectable self-defense capability against enemy air. Remember at all times that we operate as integrated weapons systems, not as single aircraft. Total situational awareness is provided by the integrated package.
Stealth is a major capability. Reduction of signature to allow first detection of enemy assets is a force multiplier. It is not an exclusive, but it is a necessity.