NTSB Finds Pilot Error as Probable Cause of Maryland Helicopter Crash
The National Transportation Safety Board has determined that the probable cause of the Sept. 27, 2008, crash of a Maryland State Police (MSP) helicopter emergency medical services flight was the pilot's attempt to regain visual conditions by performing a rapid descent and his failure to arrest the descent at the minimum descent altitude during a non-precision approach.
On Sept. 27, an Aerospatiale (Eurocopter), call sign Trooper 2 (N92MD), registered to and operated by the MSP as a public medical evacuation (medevac) flight, impacted terrain in District Heights, Md., while on approach to Andrews Air Force Base (ADW). The pilot, one flight paramedic, one field provider, and one of two automobile accident patients being transported were killed. The other patient being transported survived with serious injuries from the helicopter accident and was taken to a local hospital.
NTSB found that the pilot failed to adhere to instrument approach procedures when he did not prevent the helicopter's descent at the MDA. The flight was cleared for an instrument landing system (ILS) approach. After the initial call to the ADW tower, the pilot reported that he could not capture the glideslope and was on a localizer approach. The controller responded that her ILS equipment status display was indicating no anomalies with the equipment. Post accident tests confirmed no anomalies with the instrument approach equipment and testing of the helicopter's navigation equipment did not find any deficiencies that would have precluded the pilot from capturing the glideslope.
Furthermore, NTSB concluded that although the descent rate and altitude information were readily available through cockpit instruments which the pilot had access to, he likely became preoccupied with looking for the ground, which he could not identify before impact because of the lack of external visual cues. Since there were no recorders on board the accident helicopter, NTSB could not determine why the pilot did not use other options available to conduct a safe landing in instrument conditions.
Several contributing factors to the cause of the accident, NTSB noted, were the pilot's limited recent instrument flight experience; the lack of adherence to effective risk management procedures by the Maryland State Police; the pilot's inadequate assessment of the weather, which led to his decision to accept the flight; the failure of the Potomac Consolidated Terminal Radar Approach Control (PCT) controller to provide the current Andrews Air Force Base weather observation to the pilot; and the increased workload on the pilot due to inadequate Federal Aviation Administration air traffic control handling by the Ronald Reagan National Airport Tower and PCT controllers.
As a result of this accident investigation, NTSB issued recommendations to the Federal Aviation Administration, the MSP, Prince George's County, and all public Helicopter Emergency Medical Service operators regarding pilot performance and training, air traffic control deficiencies, patient transport decisions, emergency response, and FAA oversight.
A summary of the findings of NTSB's report will be available at www.ntsb.gov/events/Boardmeeting.htm.