The Nimrod could drop survival equipment - and even the Hercules could drop stuff off the ramp if any survivors are still alive by the time it has plodded its way to the scene.
The VC10K cannot drop any survival equipment and is totally useless as an 'SAR' asset except to relay messages and, assuming the Mk17 HDU actually works at low speed, refuel a C-130.
Still had the front one though?
Or even the emergeny chute, then you could watch everything you chucked out hitting the wing
And how do you propose to open the cargo door from the inside?
The pointless escape chutes were removed years ago and were never een fitted to the VC10K4.