HEMS Crash Documents Reveal Varied, Complex Causes

 - January 20, 2009, 9:56 AM

Not surprisingly, there is no “magic bullet” solution to the spate of fatal helicopter emergency medical service (HEMS) crashes over the last two years. Rather, investigation documents, released by the NTSB late last week, reveal a complex mosaic of multi-level human and technology failures behind nine of these crashes in the past two years. Page upon page of interviews, transcripts and forms unveil myriad indirect and direct causes, including “helicopter shopping” by dispatchers–when one HEMS company rejected a flight, generally due to weather, they kept dialing until another operator accepted the flight. Other factors include pilots assigned, or voluntarily taking, excessive duty time; pilots flying into marginal weather or below safe performance envelopes; a pilot flying injured; and, in at least one case, a pilot with a vision restriction apparently flying without wearing his glasses. Organizational problems also loom large as at least contributory factors: morale problems; high personnel turnover; maintenance issues; old equipment; failure to install modern safety enhancements such as TCAS, TAWS and NVGs; and instrument-rated pilots flying IFR-equipped helicopters, but not being allowed to fly IFR under the terms of the operator’s Part 135 certificate.