Plane & Pilot
Tuesday, December 16, 2008

Parachute Jump Operations

The risks go beyond just jumping out of an airplane

ntsb debrieferThis past September, the NTSB completed a special investigation on accidents involving aircraft used in parachute jumping.
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NTSB debriefer
PARACHUTIST SAFETY. As a result of its investigation, the NTSB urged the FAA to require that parachute jump operators use FAA-approved aircraft maintenance and inspection programs.
This past September, the NTSB completed a special investigation on accidents involving aircraft used in parachute jumping. The U.S. Parachute Association asserts that there are between 2.2 million and 3 million parachute jumps yearly in the United States. The NTSB doesn’t collect statistics on jumper injuries and fatalities unless they’re associated with an aircraft accident. According to the NTSB, since 1980, 172 people, mostly parachutists, have been killed in 32 accidents involving parachute operations.

The NTSB became interested in doing the special investigation after a twin-engine de Havilland DHC-6-100 crashed in Sullivan, Mo., on July 29, 2006. The pilot and five parachutists were killed, and the other two parachutists on board received serious injuries. The turboprop had just taken off when flames began shooting out of the right engine. It flew to just above treetop level, then entered a right turn and crashed.

Investigators found that compressor turbine blades in the right engine had fractured and that the engines were being operated beyond the manufacturer’s recommended TBO (this was legal because the airplane was being flown under Part 91). The NTSB suggested that the developing fractures might have been detected during an overhaul. It also noted that the onboard single-point restraints used by the parachutists to fulfill the seat-belt requirement weren’t as effective as other systems, and likely contributed to the number of injuries and fatalities. Additionally, the airplane’s seating configuration hadn’t been properly documented.

Investigators found that the propeller autofeather system was inoperative and suggested that if it had been working, it might have helped the pilot feather the right prop and, thus, maintain aircraft control. The NTSB concluded that the pilot didn’t maintain adequate airspeed after the engine problem developed.

In its report, the NTSB identified three recurring safety issues in parachute aircraft accidents: inadequate aircraft inspection and maintenance; inadequate FAA oversight/direct surveillance of parachute operations; and deficient pilot performance in basic airmanship. Parachutists may accept the risks associated with jumping out of planes, but they shouldn’t have to accept undue risks while riding inside them. Parachutists are entitled to, at a minimum, an airworthy airplane, an adequately trained pilot and enough FAA oversight to ensure the safety of the operation.

The NTSB found that engines on planes used for parachute operations are often subjected to more wear and tear than those used in other Part 91 operations. They’re exposed to brief cycles of idle, takeoff, climbing, descending and landing, and often aren’t shut down between flights. In a service letter, Continental noted that engines used in parachute operations may require more frequent overhauls than are provided for by published TBO numbers. Pratt & Whitney excluded its turbine engines used on parachute aircraft from participation in programs to extend TBOs.

The NTSB expressed concern that jump operators are allowed to fly under Part 91 while advertising their services to the public and carrying annual passenger loads into the millions. It was also troubled that pilots don’t have to undergo initial and recurrent training specific to parachute flight operations.

In its safety recommendation, the NTSB called on the FAA to require jump operators to develop and use FAA-approved aircraft maintenance and inspection programs that include compliance with engine manufacturers’ service recommendations (e.g., TBOs and component life limits). The NTSB says the FAA should work with the U.S. Parachute Association to assist operators in implementing effective inspection and maintenance quality assurance programs. It wants the FAA to require jump operators to institute periodic flight checks to determine pilot competence, and to develop pilot training programs that address weight-and-balance calculations, preflight inspections and emergency and jump procedures for each type of aircraft flown. The NTSB also says that the FAA should be conducting, at a minimum, periodic on-site inspections of maintenance and operations. It noted that the FAA advisory circular “Sport Parachute Jumping” was published in 1991, and hasn’t been updated since.


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