sharpend wrote:
The VC10 has gone supersonic, though in error. Crossing the Pond at speed with the Flt Eng off the flt deck, then passing thro a front resulted sometimes in a big change in temperature which resulted in s big speed jump. Though the mach warning horn would have sounded, unless of course a naughty man had pulled the cb.
Oh really? That could only happen if someone was trying to maintain a constant TAS and failed to notice a change in OAT of around -57 deg C! Frankly I smell BS, I'm afraid! Try doing the IMN / IAS / OAT calcs, mate! What I suspect happened was that no-one was monitoring the IAS and the change in OAT across a front increased engine thrust, which caused the aircraft to accelerate, tripping the high speed warning horns...and probably the odd surge or few!
During Full Air Tests, I was authorised to take the VC10K2/3/4 up to (IIRC) M0.925. The airflow noise and buffeting, as well as the nose down pitch change at high IMN and the general handling, indicated to me that anything faster would have been
very risky. The VC10 C Mk1 was cleaner, but even so I very much doubt that any RAF pilot ever went supersonic in a VC10!