Why USN pilots prefer VC-10 to a KC-135 by FFP aged 6 and three quarters.
Assuming that the jet isn't MPRS (and I'm not sure how many are....)
The KC-135 is primarily a boom aircraft, but can be adapted to refuelling probe equipped aircraft by the use of a BDA (Boom Drogue Adapter) This 10ft length of hose has a drogue attached to the end. This must be set up on the ground (there is no way of attaching the BDA in flight).
When the receiver makes contact, the hose must then be bent into 2 ninety degree angles to enable fuel flow. This, coupled with the offset position of the receiver and lack of visual cue's make it harder for the receiver.
Why the USN prefer VC-10's to a KC-10
2 Wing hoses make it a quicker process for the USN. Can refuel Maverick and Iceman (although when they had F-14's the wingtip clearance was a little too close for comfort) at the same time, as oppposed to cycling through the centreline on the KC-10. The 10 will be primarily boom refuelling in the AOR, so it's a bit of a pain to bring up the boom, trail the centreline, reel response check it (up until recently
) then start the refuel. VC-10 is configured ready to go, so it's easy if your looking for a tanker at short notice.
Beags is right concerning the flexibility reason, but then how flexible (and how much individual thought do you allow the pilots) do the USAF need to be with 59 KC-10's and 540 odd 135's ?