Dynamic International Airways Accident: A Maintenance Mishap
The pilots in the airplane following Dynamic International Airways flight 405 on the taxiway radioed a warning, “Hey, yeah, Dynamic, the left engine looks like it’s leaking, I don’t know, a lot of fuel. There is fluid leaking out of the left engine.”
Shortly thereafter, the leaking fuel caught fire on the B767. The airplane halted and the slides inflated for the 101 occupants to conduct an emergency evacuation while Ft. Lauderdale fire trucks rushed to the scene.
Flames engulfed the left side of the airplane and black clouds of billowing smoke erupted skyward. Some of the thick smoke wafted through the doors and into the stricken airplane, no doubt adding to the anxiety of passengers now crammed into the aisle shuffling towards the emergency exits.
All thoughts of the flight to Venezuela on the charter airline were forgotten in the press to get out. “I was terrified, so I started pushing people,” recalled passenger Daniela Magro.”
“It was a real scare,” said passenger Luis Campagna. “As we were getting out of the plane down the chute, the smoke was beginning to enter and the engine was in flames.”
After the accident, Dynamic issued a statement that said, in part, “Safety of our passengers and crew members is the first priority of Dynamic International Airways.”
Dynamic Airways, founded in 2009, is headquartered in Greensboro, N.C., and had begun charter flights in July between Ft. Lauderdale and Caracas.
After the fire was quenched, the airplane was towed off the taxiway and parked. The National Transportation Safety Board (NTSB) dispatched four investigators to the scene. On 3 November 2015 the NTSB issued a preliminary statement on the 29 October fire:
There is at least one other major issue that bears on this case. Fuel leaks to a screwed-on fitting do not suddenly appear. They manifest themselves in a slow, worsening leak beforehand. On the repeated trips to South America, did pilots notice a disparity in fuel consumption between the left and right engine? If they had no means of determining a disparate fuel consumption rate, was total fuel consumption greater than expected? If so, what was done about it, if anything?
The basic premise here is that anything loose will only get looser. Fittings for fuel line couplings do not get tighter, only looser without corrective maintenance action. As the saying goes, a coupling is only as good as the torque applied to it. In this case, the connective fitting may have been under-torqued — loose — for quite some time.Improperly connected fuel lines to engines have occurred before. The case of Canadian airline Air Transat flight 236 comes to mind. On a 2001 trans-Atlantic flight from Toronto to Lisbon, with 293 passengers and 13 crew aboard, the airplane exhausted all fuel and made a successful unpowered landing at Lajes airfield in the Azores — gliding some 65 miles to the landing.
Subsequent investigation by the Portuguese authorities — the Aviation Accidents Prevention and Investigation Department — found fuel had dribbled out a ruptured line, and that the flight crew was totally unaware of this leak. The #2 engine had been replaced before the flight, but without adequate clearance between the fuel line and an hydraulic line. Vibration in the inadequately-separated hydraulic line ruptured the fuel line. (For the full Portuguese report, see www.fss.aero/accident-reports/dvdfiles/PT/2001-08-24-PT.pdf)
Maintenance personnel had “force fit” the fuel and hydraulic lines where they run together in the engine pylon.
In the case of Dynamic Airways flight 405, the connection of the fuel line to the engine doubtless features a fitting that must be tightened to a certain tolerance, which requires a tool called a torque wrench to ensure that the fitting is neither under- nor over-tightened. Does the nut require periodic and measured adjustment? Was a torque wrench used, or just a plain old wrench? Was this maintenance performed on schedule, or had it been deferred until a more convenient opportunity?
For transport-category aircraft overall, the Dynamic Airways accident reveal a larger design issue. An airliner should not, ultimately, depend for safety on one connection that can vibrate free over a mere 240 hours of service since the airplane was pulled from storage.