What happened
On April 4, 2005, at approximately 19:10 local time, an HB-350 helicopter, registration PP-EMT, operated by the Mato Grosso State Military Police Air Patrol Group (GRAER), departed on a night rescue mission. The crew, consisting of a pilot, co-pilot, an assistant, and a nurse, was responding to a road accident on the BR-364 highway.
While flying low over the highway near the Serra de São Vicente, the crew encountered severe weather conditions, including low ceilings and restricted visibility due to moist fog. The estimated ceiling was approximately 100ft. Attempting to return to base, the pilot initiated a 180-degree turn. During this maneuver, the aircraft was flying at an altitude of approximately 125ft, which was below the minimum safety altitude of 200ft required for night VFR operations. The helicopter struck the ground approximately 700 meters from the highway, resulting in three fatalities and one serious injury. The aircraft sustained heavy damage and was a total loss.
The investigation
CENIPA's investigation focused on the operational environment and the decision-making process of the crew. Investigators examined the crew's flight experience, noting that while the pilot was qualified for night VFR, the crew had limited experience in night rescue missions. The investigation also reviewed the pilots' duty hours, finding that the crew had been on duty for over 11 hours at the time of the accident, exceeding the limits established by Brazilian aeronautical law.
Technical analysis of the flight path suggested that the lack of visual references during the night turn, combined with the low altitude and the absence of IFR (Instrument Flight Rules) capability in both the crew and the aircraft, created a high risk of spatial disorientation. The investigation also noted that the organization lacked a designated Flight Safety Officer to oversee procedural corrections.
Findings
- Adverse weather conditions, specifically low visibility and a ceiling of approximately 100ft, significantly contributed to the accident.
- Improper judgment by the pilot, who continued the mission and descended below the 200ft minimum safety altitude for night VFR operations.
- High motivation to complete the rescue mission led the crew to delay the decision to return to base when weather conditions deteriorated.
- Potential fatigue due to a work shift exceeding 11 hours, which may have impaired the pilot's psychomotor performance and judgment.
- Lack of IFR capability, as neither the pilots nor the aircraft were certified for instrument flight, preventing a safe climb above the clouds.