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.

Photo taken from a passenger window in a following airliner

Photo taken from a passenger window in a following airliner

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.”

Not all emergency slides were used; the investigators will determine why

Not all emergency slides were used; the investigators will determine why

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:

  • “Examination of the left engine revealed no evidence of an engine [sic] uncontainment or other failure.”
  • “…[T]he main fuel supply coupling assembly had disconnected in the wing-to-engine strut above and behind the left engine. This coupling has been retained for further examination.”
  • The fuel connector is known as a 'wiggins coupling'

    The fuel connector is known as a ‘wiggins coupling’

  • “The lower inboard portion of the left wing, left engine cowling, and left fuselage center section sustained thermal damage. The fire did not penetrate the fuselage.” Note the NTSB’s use of dry, formulaic language to describe severe scorching, charring and blackening; note also the declaration that fire had not penetrated the fuselage while ignoring reports of smoke getting in to the passenger cabin
  • The maximum temperature in the wing fuel tank will be an indicator of how close true disaster was averted

    The maximum temperature in the wing fuel tank will be an indicator of how close true disaster was averted

  • “The NTSB is reviewing the airplane maintenance records … According to the aircraft records, the accident airplane was in dry storage for approximately 29 months until September 2015 when Dynamic International Airways leased the airplane. Dynamic International Airways has operated the airplane for about 240 hours under the present lease.” The airplane appears to have been a “boneyard bargain”; it had an astounding13 operators before being acquired by Dynamic. The airplane was nearly 30 years old. The integrity and thoroughness of the maintenance records — with so many operators — should be a major focus of investigation.
  • “An initial review of the airplane onboard logbook revealed there was no entry of maintenance action having been performed in the area of the fuel coupling prior to the accident flight while in [Ft. Lauderdale].” One of the areas of inquiry ought to be the maintenance requirements for an aircraft brought out of storage and engaged in active revenue service.
  • “Dynamic International Airways has issued a Fleet Campaign Directive to inspect the remainder of their aircraft to ensure proper installation of the fuel line coupling assemblies.” In other words, hasty action after a fire, not before. Again, the issue is post-storage inspection of the airplane, and any maintenance conducted. An item like the fuel coupling to the engine is critically important and requires a maintenance supervisor to inspect any work thereon and to sign maintenance paperwork attesting to the rigor and completeness of any action. Maintenance records on file at corporate headquarters should be thoroughly examined.
  • 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.