Night Flight Through Cajon Pass Ends In Disaster

The NTSB has released its preliminary report on the December 10 crash of a Mercy Air Services Bell 412SP helicopter (file photo of type below) near the summit of Cajon Pass and Hesperia, CA that killed its pilot and two medical crewmembers.

The reports says the crew was repositioning the chopper after transporting an injured patient from Phelan, CA to Loma Linda. The flight departed Loma Linda University Medical Center at 17:42, with a planned destination of Southern California Logistics Airport in Victorville, CA.

Night visual meteorological conditions predominately prevailed along the route of flight, and a company VFR flight plan had been filed.

According to the report, the crew had traversed Cajon Pass near the accident site five times previously on the date of the accident. All other flights that day were conducted during the day.

Reported weather conditions from Victorville, 15 nm northeast of the accident site, were visibility 10 statute miles; a broken cloud layer at 3,800 feet, and an overcast cloud layer at 4,900; temperature 11 degrees Celsius; dew point 03 degrees Celsius. Weather conditions at Ontario International Airport, Ontario, California, 19 nm southwest of the accident site, were visibility 10 statute miles; a broken cloud layer at 3,800 feet, and an overcast cloud layer at 5,500; temperature 13 degrees Celsius; dew point 06 degrees Celsius.

The aircraft was equipped with a satellite tracking system reporting its location and other flight information to a ground base while in operation. Every 30 seconds the base equipment recorded the date, time, latitude, and longitude from the chopper's on-board system. Although the system was capable of also recording the transmitted altitude and airspeed, the company had not yet installed the required software upgrade.

The NTSB lead investigator reviewed the transmitted data finding the helicopter departed Loma Linda and flew towards the Cajon Pass in a northwest direction. The flight path tracked Interstate 15 northbound until it had almost reached the summit of the pass. At that point the chopper's track veered northeast while the Interstate turned toward the north. The last known position of Mercy Air 2 was recorded at 1755, and was 0.3 nautical miles northwest of the first identified impact point.

The San Bernardino County Fire Department dispatch center received numerous calls of an explosion and fire northeast of Interstate 15 in the area of Oak Hills around 18:00. Fire rescue personnel responding to the calls reported search efforts hampered by intermittent waves of fog blanketing the area.

Searchers eventually found the wreckage in mountainous terrain on a 45-degree slope between 4,000 to 4,300 feet MSL. The debris path emanated uphill on a 155-degree bearing from the first identified impact point at the base of the slope.

Examination of the maintenance and flight department records revealed no unresolved maintenance discrepancies with the helicopter prior to departure.

FMI: www.ntsb.gov