Cockpit-voice recordings indicate that the crew of the National Airlines Boeing 747-400 freighter which crashed in Afghanistan was concerned over the security of its heavy armoured vehicle load.

Transcripts of crew conversations in the hour before the accident, although given limited context, suggest a sense of unease about the restraints on the five MRAP vehicles.

The US National Transportation Safety Board transcripts show that the first officer informed the captain that one of the straps was “busted” and indicates that the load had moved.

Another crew member, a second captain, appears to respond jokingly to a remark that ties have loosened by stating: “What…do you think’s gonna happen when you…slam it on the runway and slam on the…brakes and don’t use reverse?”

The 747, which had been loaded with the MRAPs at Camp Bastion, had experienced brake overheating on landing at Bagram, which had resulted in the crew’s discussing cooling procedures.

While the second captain joked about “getting off” the aircraft and being “scared”, the first captain seemed more wary about the broken strap and the overall adequacy of the restraints for the vehicles.

“I hope…rather than just replacing that [strap], I hope he’s beefing the straps up more,” he says.

Some 15min later the captain asks the loadmaster, “How far did it move – a couple of inches?”, and when the loadmaster replies in the affirmative, the captain responds: “That’s…scary.”

“Those things are so…heavy you’d think…that they probably wouldn’t hardly move, no matter what,” he adds.

Loaders at Camp Bastion had been instructed by the loadmaster to tie down the two 18t MRAP vehicles with 26 straps and the three 12.5t vehicles with 24, says the NTSB in factual documentation detailing the 29 April 2013 crash. The straps were rated at 5,000lb (22,240N).

Investigators believe that the rearmost MRAP broke free as the 747 departed Bagram on a flight to Dubai. The aircraft subsequently pitched up and stalled. None of the seven occupants survived.

Source: Cirium Dashboard