Unsafe Practices

On Feb. 25, 2004, the Transport Accident Investigation Commission (TAIC) of New Zealand issued its report of the CFIT crash of a Piper PA 31-350 Chieftain near Christchurch, just 2.5 miles on approach to the runway. The pilot and seven of the nine passengers were killed; the other two passengers were seriously injured. Among the safety issues identified: the desirability of TAWS (terrain avoidance warning systems, also known as enhanced ground proximity warning systems, or EGPWS) adoption.

The report notes: "The blunt object trauma from ... tree impacts probably caused fatal injuries to the occupants directly, rather than flailing or deceleration injuries while restrained within the cabin."

The TAIC urged the Director of Civil Aviation to monitor the development of TAWS with the view to requiring its installation in relevant aircraft. It should be noted that Honeywell produces a "baby EGPWS" specifically for installation at lower cost in light planes like the Piper. Unit cost is about $10,000. Many operators have installed it voluntarily in several thousands of airplanes, but it has not been mandated, anywhere, for piston-powered aircraft. One would think that if the flight is carrying paying passengers, at least a basic system would be required.

Also of interest in this report: the possibility of cell phone interference with the airplane's navigation systems. Herewith, details from the report:

"The call made from the pilot's cellphone to his home while the aircraft was on the ILS [instrument landing system] approach was not answered, but was connected to his voicemail instead. His partner listened to the first minute of it shortly afterwards, and heard only the steady noise of aircraft engines. She deleted the recording without listening further."

"The use of cellphones on board aircraft has been identified from numerous occurrence reports overseas as a cause of random interference to the proper functioning of aircraft avionics such as navigation equipment and autopilots. New Zealand Civil Aviation Rule part 91.7(a) stated:

No person may operate, nor may any operator or pilot-in-command of an aircraft allow the operation of any cellphone, or other portable electronic device that is designed to transmit electronic energy, on any aircraft while that aircraft is operating under IFR."

"The use of cellphones and computers permitted by the pilot on the flight had the potential to cause electronic interference to the aircraft's avionics, and was unsafe."

(The full TAIC report may be accessed at http://www.taic.org.nz/aviation/03-004.pdf)