4 fatalities

1984-08-25: Rockwell Grand Commander 690 (N9150N) — James P. Demetry — Little America, United States of America

Little America, United States of AmericaTakeoff (climb)

On August 25, 1984, a Rockwell Grand Commander 690 (registration N9150N) operated by James P. Demetry was involved in an aviation accident near Little America, United States of America during takeoff. 4 people were killed. Investigators recorded the probable cause as: The pilot continued flight into known adverse weather, including clouds, thunderstorms, turbulence, rain, low ceiling, and icing conditions, leading to loss of control, in-flight breakup, and collision with terrain. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781219229Data APIEditorial standards

About 10 minutes after takeoff, the pilot was cleared to FL190. ATC lost radar contact at 1030:39. Witnesses saw fire/explosion before impact. Wreckage scattered over 2 miles. All four occupants killed.

Summary of Events

Approximately 10 minutes after takeoff at 1005 mountain daylight time, the pilot was cleared to climb to flight level 190 (FL190), which was the last communication with air traffic control. At 1030:39, the controller attempted to contact the pilot to advise that radar contact had been lost and to recycle the transponder and squawk 6062. No response was received.

Witness Reports

Two witnesses reported seeing the aircraft just before it impacted the ground. They observed fire and/or an explosion prior to impact. One witness stated that the aircraft broke up after it descended below an estimated ceiling of 1,000 to 1,200 feet.

Weather Conditions

Weather reports indicated thunderstorms, turbulence, rain, and cloud tops up to 25,000 feet. Probable light to moderate icing conditions existed in clouds above the freezing level of 14,000 feet. The aircraft was equipped with weather radar.

Radar and Wreckage Analysis

Radar data showed that just before contact was lost, the aircraft's speed varied between 221 and 272 knots, heading varied from 072° to 014°, and vertical velocity varied from +300 to -2,400 feet per minute. Wreckage was scattered over an area of two miles. Examination revealed evidence of a catastrophic in-flight breakup due to overload, including positive overload of both wings.

Official Findings

The investigation identified the following occurrences and findings:

  • Occurrence #1: In-flight encounter with weather, involving clouds, thunderstorms, turbulence in clouds, rain, low ceiling, and icing conditions. The pilot continued flight into known adverse weather.
  • Occurrence #2: Loss of control in flight due to failure to maintain aircraft handling.
  • Occurrence #3: Airframe/component/system failure/malfunction during uncontrolled descent, including exceeding design stress limits of the aircraft, wing overload, and fuel system overload.
  • Occurrence #4: Fire during uncontrolled descent.
  • Occurrence #5: In-flight collision with terrain/water during uncontrolled descent.

Probable cause

The pilot continued flight into known adverse weather, including clouds, thunderstorms, turbulence, rain, low ceiling, and icing conditions, leading to loss of control, in-flight breakup, and collision with terrain.