Originally Posted by
Whinging Tinny
Ships are not stable platforms and in constant motion, hence the need to lower the aircraft to the deck to change an engine as well as the height issue. Everything must be secured to the deck to prevent movement issues. Also on certain occasions, the 'goal post kit' (engine removal guidance tools) were used to facillitate the removal and installation of the ECU in poor conditions.
A RAF GR3 had an engine change down South using this method.
It certainly got interesting when the ship's bridge was asked to steer a steady course for an hour or so whilst the engine was hoisted up or lowered down and during the evolution they decided to heel the ship over and go zigzagging around the oceans.
As people who have changed out Harrier engines know, there is not a lot of room between the engine and airframe and it's more than easy to get your hands trapped.
All good fun though and a great way to annoy the fishheads below when lashing everything down or storm lashing aircraft/equipment during normal ops.
Lowering the aircraft nose to lift the wing and remove the engine was nothing to do with stability, it was to do with getting the aircraft in the rigging position, and thus the wing and engine coming out of the aircraft straight. In the RAF we would "EITHER" retract the nose leg and drop the aircraft nose low, or remove just the nose wheel, but still drop the aircraft nose low. It was possible to use the same hoist to remove the ECU & Wing, but this meant moving the hoist point around, so we "RARELY" used the same hoist for both operations. With a well versed crew, we could get an engine change with all the associated work done in two 8 hour shifts, the biggest hassle was the tie down runs with associated hot air leak checks - then it was over to the two wing master race to air test the machine, complete with perf hovers if we could - if we were in the field or somewhere else, we could enter a lim for "no limiting hovers" which basically meant you could hover the machine if there was an escape route available (Runway) but to a field pad or similar, then no!