EMS crash underscores value of risk assessment

 - November 24, 2009, 6:26 AM

When a veteran EMS helicopter pilot, probably thinking he was running out of options, decided to dive under a cloud deck to look for the ground, he crashed his Maryland State Police (MSP) Eurocopter Dauphin into terrain about 3.2 miles north of Andrews Air Force Base (ADW), killing all on board except for one of the two teenage traffic accident victims being transported to a nearby hospital.

The NTSB has determined that the probable cause of the Sept. 27, 2008, accident 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 (MDA) during a nonprecision approach into ADW.

Contributing to the accident were the pilot’s limited recent instrument flight experience; the MSP’s lack of adherence to effective risk-management procedures; the pilot’s inadequate assessment of the weather, which led to his decision to accept the flight; the failure of the Potomac Tracon controller to provide the current ADW weather observation to the pilot; and the increased workload on the pilot due to inadequate FAA ATC handling by Ronald Reagan Washington National Airport tower and Potomac Tracon controllers.

The crash on the extended centerline of Runway 19R at Andrews killed the commercial pilot, one flight paramedic, one field EMS provider and one of the two accident victims. The other patient survived with serious injuries from the helicopter crash.

Night VMC prevailed for the departure from Waldorf, Md., but the MSP helicopter, callsign Trooper 2, encountered IMC en route to a hospital north of Andrews and diverted to the air force base. The MSP communications center in Baltimore was tracking the flight using GPS-generated location reports transmitted with an experimental ADS-B communications link.

The pilot’s expectation that he could descend below the cloud ceiling at an altitude above the MDA for the approach, his familiarity with Andrews, where Trooper 2 was based, and the reduction in workload a return to visual conditions would have provided are all factors that may have encouraged the pilot to deviate below the glideslope and attempt to “duck under” the cloud ceiling, according to the Board. 

The pilot had obtained a Duat at 18:51 that indicated ADW would be VFR until 0100 September 28. At about the time of the 23:58 crash, weather had deteriorated to four miles in mist, scattered clouds 200 feet, ceiling broken at 500 feet and temp/dew point 20 degrees C.

According to the Safety Board, the failure of the Potomac Tracon controller to provide the current Andrews weather information likely led the pilot to expect that he could descend below the cloud ceiling and establish visual contact with the ground.

In addition, the Board said the air traffic services provided by the DCA tower and Potomac Tracon controllers to the accident flight exhibited numerous procedural deficiencies, including unresponsiveness, inattention and poor radar vectoring. These deficiencies were a distraction to the pilot and increased his workload by requiring him to compensate for the poor services provided.

Mishandled ATC
Corky Smith, the NTSB investigator- in-charge of the accident, described it as an instance where “a pilot was vectored all over the place.” Investigators found that Potomac Tracon gave him an incorrect vector to the final approach at Andrews.
And when the pilot of Trooper 2 recognized that he was in difficulty and asked the ADW controller to give him an airport surveillance radar (ASR) approach, she replied that she could not because she was not current in the seldom-used procedure. But she later told investigators that if she had realized the pilot was in trouble and not just practicing an ASR, she would have given it to him.

Although the MSP comm center was tracking the flight, the duty officer lost situational awareness while the helicopter was in flight. “The lack of adherence to effective flight-tracking policies by [MSP comm center] personnel created an institutional mindset that allowed duty officers to assume that aircraft had landed safely when the [ADS-B] signal was lost; over time, safe landings were taken for granted,” the NTSB found.

Further hampering the efforts to find the crash site was the FAA’s inability to provide timely location data and the MSP troopers’ and comm center personnel’s lack of training and equipment to conduct a search involving GPS coordinates. Because of the confusion, one search area initially was along the Chesapeake Bay about 30 miles southeast of the automobile accident site and about 36 miles southeast of Andrews AFB.

Had it not been for the crew of Trooper 8, who had to abort an attempted aerial search in another MSP Dauphin, locating the accident site would likely have taken several more hours than it did, according to the NTSB. The Trooper 8 crew was led to the scene by the cries of the sole survivor and the smell of jet-A.

The pair used cellphones, a GPS and a last known position provided by the Andrews controller to pinpoint the crash site as a park about 3.2 miles north of Andrews on an extended centerline for Runway 19R.

Members of the Board were taken aback to learn that helicopter EMS operators do not perform written risk assessments. “I cannot fathom why any commercial operator would not perform a written risk assessment,” said NTSB chairman Deborah Hersman. “I’m disappointed that the FAA does not have a rule for commercial operators to perform a flight risk assessment.” Board member Robert Sumwalt added, “It’s just pen and paper; it’s not rocket science.”

Earlier, he said that if the Eurocopter Dauphin had been equipped with a helicopter terrain awareness and warning system and a written flight risk assessment was mandated, “this accident wouldn’t have happened.”

Before the accident, Sumwalt said, “We looked at the Maryland State Police as the gold standard. I hope this accident will serve as a wakeup call.”