Description

On 9 June 1995 a de Havilland DHC-8-100 collided with terrain some 16 km east of Palmerston North aerodrome while carrying out a daytime instrument approach. The airplane departed Auckland as scheduled Ansett New Zealand flight 703 to Palmerston North airport.

The aircraft was flown to join the 14 nm DME arc and thence turned right and intercepted the final approach track of 250°M to the Palmerston North VOR. The final approach track was intercepted at approximately 13 DME and 4700 feet. A few moments later the First Officer made a remark about the DME distance and altitude of the aircraft. Just at that moment the Captain said that the landing gear was not locked. He advised the First Officer to check the Quick Reference Handbook and stated “I’ll keep an eye on the aeroplane while you’re doing that.”

The First Officer carried out the checklist with some discrepancies and the Captain provided some advise. The GPWS/TAWS audio alarm sounded just as the First Officer completed the procedure. Few seconds later the aircraft collided with the ground. One crew member and three passengers lost their lives and two crew members and 12 passengers were seriously injured in the accident.

The Investigation

Several causal factors were identified by the investigation. They are divided in two sections.

Crew related:

• The Captain did not ensure the aircraft’s engine power was adjusted correctly for the aircraft to intercept and maintain the approach profile.
• The Captain’s lack of attention to, and/or mis-perception of, the aircraft’s altitude during the approach.
• The pilots’ diversion from the primary task of flying the aircraft and ensuring its safety, by their endeavours to correct an undercarriage malfunction.
• The Captain’s perseverance with his decision to attempt to get the undercarriage lowered without discontinuing the instrument approach in which he was engaged when the situation arose.
• The absence of a requirement for cross-monitoring of the aircraft’s altitude while executing the QRH “Alternate Gear Extension” procedure.
• The First Officer not executing the QRH procedure in the correct sequence, which distracted the Captain.

System related:

• The inadequate warning given by the GPWS.

A number of recommendations were issued. The addressees included the Chief Executive Officer of Ansett New Zealand, the Director of Civil Aviation New Zealand, Chief Executive of the Airways Corporation, Minister of Transport in Canada and the President of the New Zealand Air Line Pilots’ Association.

The recommendations focus on: adequate crew training and supervision, breaking of approach in the event of abnormality, CAA operators’ audit adequacy, introduction of Minimum Safe Altitude Warning (MSAW) functionality, provision of procedure to supply SAR services with any relevant radar information, changes in RTF used by approach controllers and finally “study to determine why the GPWS did not provide a greater degree of warning in the environment of the DHC-8 accident”

Related Articles

• Controlled Flight Into Terrain (CFIT)
• Cross-checking Process
• Terrain Awareness
• Situational Awareness (OGHFA BN)

Further Reading

• Report 95-011 of the Transport Accident Investigation Commission, New Zealand