It was a long time ago, but I think that the aircraft was recommended not to be flown unless operationally necessary (before the accident). Read back, TPs were not flying it. I will state with 100% certainty that Jon was unhappy to take this aircraft and felt their was no choice. Why 100%? He said so in plain language.
This is why the Seal theory breaks down, even if the Mk2 had walters kit fitted (it didnt), they would have used the Mk1 if it had become serviceable. Those poor seals would have had a wasted journey in their nuclear powered hover cars. Luckily the Starship Enterprise would have beamed them and their cars back to base and they could have continued plotting to rule the universe with Darth Vader.