Disorientation brings down Cirrus

Aircraft: Cirrus SR22. Injuries: 1 Minor. Location: Bennett, Colo. Aircraft damage: Substantial.

What reportedly happened: The pilot was practicing instrument approaches in night VFR conditions. He was in a right turn and had turned his head to the right to look at some instrumentation when he felt the airplane accelerate. He looked at his flight displays, which indicated he was in an extreme unusual attitude, possibly inverted.

He attempted to recover from the unusual attitude but realized that he had severe vertigo and spatial disorientation. He activated the airplane’s ballistic parachute recovery system. After the parachute deployed, the airplane hit the ground in a nose-low attitude, sustaining substantial damage. No pre-impact mechanical problems were discovered during the investigation.

The airplane was equipped with an Avidyne Entegra Primary Flight Display (PFD) and Multi-Function Displays (MFD). This equipment displays flight and navigational data to the pilot, and also records data regarding airplane pitch, roll, airspeed, altitude, heading, acceleration forces, GPS position, and engine data. The data downloaded from the displays showed that, just prior to the accident, the airplane went through a series of pitch and roll oscillations, with maximum pitch values of approximately 26° nose up, and 75° nose down. The airplane reached maximum roll values of approximately 83° right wing down, and 120° left wing down. The maximum indicated airspeed, which occurred just prior to the parachute deployment, was 190 knots. This data corroborates the pilot’s description of events.

FAA guidance indicates that if neither horizon nor surface references exist, the attitude of an airplane must be determined by artificial means from the flight instruments. However, during periods of low visibility and night conditions, the supporting senses sometimes conflict with what is seen; when this happens, a pilot is particularly vulnerable to disorientation.

Probable cause: The pilot’s failure to maintain control of the airplane during an instrument approach due to spatial disorientation.

NTSB Identification: CEN11LA164

This January 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Comments

  1. Guy Mangiamele says:

    Meg, there is no mention of the pilot’s experience level, ratings held or time in type. Was any of that available?

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