Accident Overview
An emergency medical services helicopter on a night flight with a 3-month-old patient aboard declared an emergency landing after reporting an onboard fire. The pilot transmitted that he was level at 3,000 feet and then stated his intention to make an emergency landing. Subsequent transmissions were unreadable, but approach control personnel interpreted them as references to a fire. A flight nurse then broadcast on the hospital frequency that the helicopter was on fire and going down. Radar and radio contact were lost shortly thereafter.
Crash Description
The helicopter crashed in a slight nose down, right bank attitude and was consumed by fire. The impact damage indicated that the helicopter struck the ground at a high vertical velocity with little or no forward movement. Both the engine and airframe were examined, and no preimpact part failures or malfunctions were found.
Modifications and Oxygen System
The helicopter had been modified for EMS operations under four supplemental type certificates. One modification included the installation of a high-pressure oxygen system. During the accident sequence, several oxygen lines failed due to impact or fire, creating a blow torch effect. Investigators noted that there was no provision for emergency shut-off of the oxygen supply at or near the cylinders. The source of the fire was not determined.