Ops topics

Flying Safety, May, 2004

This edition is about cargo problems. They all come from HAPs submitted by the workers in the field. No major damages, but the potential for the loss of an aircraft or life was present. Be careful as you move the world, as Murphy may come along for the ride if you aren't careful.

Pallets Versus Cargo Floor

Mishap crew 1 (MC1) was loading palletized cargo on their C-5 and ATOC personnel presented them with a load plan, requiring the on-load of a 29,840 pound generator mounted on top of an airdrop platform train. MC1 had no experience loading airdrop platforms, but knew there was guidance in the Ops Group FCIF. After reviewing the FCIF, MC1 decided the cargo would not be secured in the logistics rails, but loaded "slightly off center provided the runners are kept on top of the rollers." MC1 followed the FCIF method 1--out of the rail system. The cargo was pushed into position without incident, and secured with chains to the cargo floor.

Normally, these airdrop platforms are situated in the center of the C-5 cargo compartment on top of rollers designed to accommodate the platforms. However, airdrop platforms can be configured to fit in the pallet logistics rail system. Airdrop platforms have longitudinal beams (feet) which support the platform. They do not have a flat-bottomed surface, as does the standard 3-463L pallet. Although standard rollers are capable of supporting airdrop platforms, there is potential that the platform feet could roll off standard rollers when not secured in the logistics rails or loaded on the airdrop platform rollers.

MC1 then flew the aircraft on the first leg of the journey. A second crew (MC2) accepted the airplane and cargo, did not detect any damage or questionable cargo configuration/placement and flew the aircraft to the cargo's destination. While attempting to download the airdrop platform using the cargo winch, MC2 heard popping sounds and stopped the winch operation. The aft inboard corner of the platform had shifted toward the cargo floor centerline and the platform feet were off the rollers. The shift overstressed many of the rollers, liberating them from their mounts. The platform feet were now in contact with the aircraft cargo floor. After reporting the incident, aerial port personnel and MC2 agreed they would not be able to offload the generator without inducing additional aircraft damage.

A third crew flew the mishap cargo back to home station where the cargo was safely unloaded. Lesson learned from this mishap? Airdrop platforms are designed for a specific purpose with airdrop rollers and should not be used to transport cargo outside the logistics rails while on top of the standard "small" rollers. We deliver a lot of cargo, but in this case we paid to have the cargo delivered and returned with a damaged aircraft. This caused a lot of headaches for a lot of people, and the cargo didn't get to where it was needed.

Shifty C-17 Pallets

Upon engine shutdown, following an overseas flight, the loadmaster (LM) at the forward LM station initiated power by pushing the sidewall panel switch and the electrical power switch both to "on." Simultaneously, with this action the LM heard a loud noise from the back of the aircraft and saw that his aerial delivery system (ADS) lock status panel indicated all the ADS locks had released, allowing the pallets to shift forward. The pallets did not shift forward enough to cause damage to the aircraft, but could have done so had it occurred in flight. Maintenance personnel determined that the intermittent power transfer that led to the release of the rails was caused by an electrical short in the LM panel. The faulty panel has been sent to depot for further inspection. Luckily this didn't happen in flight, and the aircraft wasn't damaged. Be ready for the unexpected, and ensure your cargo stays where you want it.

Leaky C-17

Three C-17s were each uploaded with three 3000-gallon bladders and one pump assembly module IAW tech data. The bladders were outfitted with a vent hose that ran along the floor, then connected to the aft cryogenic vent port to vent fumes. Supply filled each bladder with 2500 gallons of JP-8, and no leaks were observed. The aircraft then took off to deliver the fuel to thirsty customers. Fuel operators supervised the loading and noticed nothing unusual during the flight. However, at some time during the mission, fuel vented from the bladders through the cryogenic vent ports. Upon arrival, the fuel was pumped from the bladders of the mishap aircraft to the customer. When the aircraft crew chiefs conducted their post flight inspections, one of them found puddles of fuel (approximately 1-2 gallons) in the aft pod hydraulic pump access panel compartment. The crew chief then observed fuel leaking onto the main landing gear, and a ground emergency was declared.

Here we have a minor hardware problem that allowed fuel to leak into an aircraft and then onto the ground. Luckily, there was no fire or explosion, and all we had to do was clean up the fuel spill. The potential for disaster was there and we got lucky. Make sure when you are transporting hazardous cargo that everything is in proper condition, and we reduce the risk of carrying the stuff that will get you killed.