What happened
At approximately 21:32Z, an LH 527, a four-engine aircraft, collided with the southern slope of the Serra dos Macacos mountains at an altitude of 2,045 feet. The aircraft was performing a departure from the Rio de Janeiro area and was in a right-hand climbing turn at the time of impact. The collision occurred at a speed of 296 KT (IAS), resulting in the destruction of the upper surface of the left wing and the lower part of the fuselage. The aircraft subsequently disintegrated over a distance of 800 meters.
Following takeoff, the crew received several instructions from the Tower and Approach controllers. While the first instruction regarding a change in altitude was implemented, the crew did not verify the specific details of the subsequent instruction. During the sequence of communications, the crew engaged in a consultation regarding a terminal chart, which caused a delay of approximately four minutes in the departure sequence. During this time, the traffic situation evolved, removing initial restrictions but also altering the intended flight path. The aircraft eventually struck the terrain after the crew failed to recognize the proximity of the mountains during a right-hand turn.
The investigation
The CENIPA investigation examined the communications between the aircraft and the air traffic controllers, the flight data recorder, and the voice recorder. The investigation established that the radar system at the Rio Approach was operating with a reduced number of scopes due to a technical failure, and there was a lack of coordination between the Approach and Tower controllers.
Investigators also reviewed the pilot's use of a terminal chart. It was determined that the pilot likely miscalculated his position due to a failure to account for the 19°W magnetic declination, leading to a false sense of security regarding the terrain clearance. Additionally, the investigation found that the Tower controller provided incomplete instructions and demonstrated limited proficiency in English, which contributed to the crew's misunderstanding of the required flight path.
Findings
- The Controller of the Departure position provided incomplete instructions that led the aircraft into a heading and altitude profile that resulted in the collision.
- The crew received incomplete departure instructions, specifically lacking the full details of the required procedure or altitude constraints.
- The pilot likely misinterpreted an instruction to increase speed as a total release of speed limits, resulting in the aircraft exceeding the 250 KT limit for terminal areas.
- The commander's consultation of a terminal chart likely provided a false sense of security because he failed to recognize the magnetic declination, leading him to believe the aircraft was further south than it actually was.
- The commander's limited experience in the area (this being only his third flight in the region) contributed to the failure to recognize the potential terrain hazard.
- There was a lack of coordination between the Approach and Tower controllers, and the Assistant Controller and Supervisor failed to provide necessary support to the Departure Controller during a period of high traffic.