I never want to drop a trailer on its knees, touch wood I wont. Always try and hitch up same way every time then accidents shouldn’t happen.
Silver_Surfer:
When the fifth wheel is under the trailer but BEFORE the pin locks in, you should raise the axle suspension all the way up then reverse the rest of the way and engage the pin. This ensures the trailer legs are off the ground and all the weight of the trailer is on the fifth wheel giving you a meaty bang. Always put your dog clip in as sometimes the arm isn’t fully in even with the correct sounding bang and the little arm may not be all the way down.
Definatly, also handy when alot of weight on the legs too, makes it easier to wind up when nothings weighing them down…
But accidents happen, its experiance. I remember last year dropping a trailer off in the bay flued up to the hilt late on a friday afternoon in the pouring rain. Wind legs, pin etc… Pull away…ping ping ping Psssssssssss.
Buggerance thinks me… ripped all the suzies out 
- Proceeded to spend the next 20 mins changing all the leads…
Luckily, no one was around to witness it, and my embarrasement. Phew! - Although did have to explain why i needed a complete set of spares in one go 
always happens when your rushing
When I am under, I always lift the suspension even if its slid under normally, turn the radio down and listen for the clunk clink noise, once the suspension is as high as it will go, give it a tug. Once the legs are now wound up nice and easily, dump the air back to normal running, then put on the susies.
Dogmatix:
‘… I always lift the suspension even if its slid under normally … and listen for the clunk clink noise, once the suspension is as high as it will go, give it a tug … dump … back to normal …’
Pretty much the same, I use the ‘M1’ and ‘M2’ buttons on the DAF suspension pad, ie, I intially go in on max low until the fifth whell has disappeared, then give it max high upon which to complete the engagement: Why else is the facility to do that or the buttons there - other than to help scarper from a low bridge resting on the trailer roof, of course…
Also, despite being the crappiest bit of a hook-up & despite how dark/wet/early/late it is, I always grovel underneath to look-see that the ‘bar thing’ is in place.
The other advantage of lifting the suspension before backing under, is that it lifts the legs off the ground. This meand that if you aren’t perfectly in line it doesn’t drag the sideways causing damage to the feet. It also stops damage to the ground.