ETPS reckoned that the C-130 would be a good lead-in trainer for the wretched Jetstream.... It was an UTTER piece of crap with dreadful control harmony - light and unresponsive in roll, heavy and sensitive in pitch. Abysmal, absurdly overcomplicated engine and propeller systems, a primitive autopilot which wasn't even integrated with the flight director, nosewheel steering which was almost impossibly stiff in cold weather, every method of generating electricity bar the Van de Graaf generator and Wimshurst machine and a very noisy flight deck! If you tried to land it in the approved manner, it would drop out of the sky when the 'power levers' were set to idle, due to the loss of lift over the part of the wing influenced by the large diameter propellers. Of course they wouldn't idle simultaneously, so the plummet to earth would be accompanied by an unpredictable wing drop. Top tip was to flare the wretched device with some power still applied and only to select idle once it was on the RW. The METS QFIs expected ridiculously long-winded crew briefs - one that I recall was "Co-pilot, you are to restrain the flight fine pitch mechanical lock lever!" Why? Lest it rise up and smite thee? 'Off / start / run' was too much for the RAF, the approved starting sequence was an exercise in futility with various coloured lights and indications accompanied by crew incantations and finger gestures as the infernal Asatzous slowly shook and shuddered their way up to ground idle. The heavy RAF radios also gave it an aft CG, which reduced the marginal pitch stability even further.... At least the RN's Heron Flight Jetstream T3s were fully sorted, with much better Garrett engines.
Engines, I think you were referring to the bomb door tank? There was an option to use both the BDT and a bomb bay tank for loooong range ferries, but the bomb bay tank wasn't often fitted, IIRC.
The Gyron Junior was a pretty dreadful engine. Bad enough in the Buccaneer S1, but even worse in the Bristol 188 as the engines were also fitted with reheat - giving a max endurance of around 25 minutes.
But the Buccaneer S2 and all sub variants was an excellent airframe indeed. A pig to fly below 300 KIAS, but utterly superb at 301+ KIAS. Had it been properly upgraded with Tornado-level avionics and a new cockpit, it would have been amazing.
Yes, sorry - my mistake concerning the Javelin. It was indeed at low level when use of reheat would cause the thing to decelerate due to inadequate fuel pump delivery pressure.