Ah back in '79 we were told to put a 1500 kg electric forklift into ATL.98 Carvair ZK-NWA. The load sheet said if we ever managed the feat of getting it up to the sill the floor beams could not carry the weight anyway. Kept telling the marketing manager but he knew nothing about planes and the first guy to refuse was summarily sacked.
First we used a big Toyota landcruiser to try and drag it up an inclined ramp. Well half way up the clutch caught fire.
Plan 2. Use our own forklift to hoist it up to the side door. Gotta be nuts huh ?
We'll they started to lift it but thank fully it got up about two feet off the ground before the forlift performing the lift toppled over. Honestly what a buch of squareheads they had for management.