Robinson R44 forced landing in Brasília lake due to weight and ground effect changes

Casualties unknown • BRASÍLIA, DF, BR

A Robinson R44 helicopter experienced a loss of control and forced landing in Lake Paranoá after attempting a takeoff from an unauthorized location while overweight.

What happened

On January 19, 2012, at approximately 21:30 UTC, a Robinson R44 helicopter, registration PP-MOF, was performing a private flight from Brasília International Airport (SBBR) toward Santa Genoveva (SBGO). After receiving authorization to overfly Lake Paranoá, the pilot landed at the Pier 21 Shopping Center parking lot, a location not designated as a helipad. After picking up three passengers, the pilot attempted a vertical takeoff with a rearward movement to avoid obstacles.

During the maneuver, the aircraft transitioned from a paved surface to an area over the water, which sat approximately two meters lower than the takeoff point. This transition caused a loss of altitude that the pilot could not recover, resulting in a forced landing into the edge of Lake Paranoá. The aircraft became partially submerged and sustained substantial damage, though the pilot and all three passengers emerged uninjured.

The investigation

CENIPA investigators examined the aircraft's performance capabilities and the pilot's operational decisions. The investigation focused on the weight and balance of the aircraft and the impact of the terrain transition on aerodynamic performance. The investigation established that the pilot did not perform the necessary takeoff performance calculations or weight estimations prior to departure. Furthermore, the investigation noted that the pilot did not inform Air Traffic Control of the intention to land at the shopping center parking lot.

Findings

  • The estimated weight of the aircraft at takeoff was 1131 kg, which exceeded the maximum gross weight of 1089 kg for operations within ground effect and the reduced limit of approximately 1020 kg for operations outside of ground effect.
  • The transition from a paved surface to a water surface reduced the effectiveness of the ground effect, increasing the power required for flight.
  • The pilot failed to account for the change in performance caused by the terrain drop and the loss of ground effect over water.
  • Overweight takeoff was the primary factor preventing the maintenance of altitude.
  • Contributing factors included poor flight planning, inadequate pilot judgment, flight indiscipline, and the pilot's limited flight experience.

Probable cause

The accident was caused by the aircraft operating above its maximum allowable weight during a transition from a paved surface to a water surface, which neutralized the ground effect and increased the power required for flight, leading to an unrecoverable loss of altitude.

Frequently asked questions

What happened in the 2012-01-19 aircraft accident near BRASÍLIA, DF, BR?

A Robinson R44 helicopter experienced a loss of control and forced landing in Lake Paranoá after attempting a takeoff from an unauthorized location while overweight.

What aircraft was involved and where did it happen?

The accident on 2012-01-19 involved a aircraft, registration PPMOF, at BRASÍLIA, DF, BR.

What was the probable cause of the accident?

The accident was caused by the aircraft operating above its maximum allowable weight during a transition from a paved surface to a water surface, which neutralized the ground effect and increased the power required for flight, leading to an unrecoverable loss of altitude.

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