False crash alarms worry Ministry

Press, 17 April 1980, Page 23

False crash alarms worry Ministry

By

LES BLOXHAM

,*< The increasing number f offalse alarms, trans.mitted by emergency locator beacons in light air- ,, craft and helicopters wor- . ries the Civil Aviation Dir vision of the Ministry of ? Transport. Eight transmissions j have been traced and ini' vestigated so far this 'month: all were proved to .be false. ? . The offending beacons ' had been either accidentally turned on or activated J by faulty circuits or vibra- ' tion, particularly where . helicopters were involved. , An emergency locator , beacon transmits an alterf nating tone oft a special "frequency. They are meant to be activated either automatically when an aircraft crashes, or manually In a forced landing. r Searching aircraft equipped with inS strumented direction-find-ers tune in on the signal •and ultimately pinpoint the position of the transmitter. Although effective only • on long-of-sight, the beacons can be picked up over exceptionally long

distances. A few weeks ago a signal from a helicopter forced down in a west Coast valley was monitored by an Air New Zealand DCS flying at 13,000 m over the Tasman about 350 km off Hokitika. Another beacon heard transmitting on Good Friday was eventually traced by a searching aircraft to a helicopter parked and abandoned in a paddock about 30km north of Invercargill. The pilot of the light aircraft who was asked by the Ministry to investigate, landed nearby, switched off the transmitter, and left a curt note for the helicopter pilot.

There was a similar incident south of Haast the next day. Occasionally false transmissions are triggered by mischievous fingers. The police at Murchison recently traced a signal to an aircraft parked on a farm: the beacon had been turned on by children. The Ministry adheres to a strict policy of checking all emergency signals, a costly business wherehelicopters have to be hired at $3OO an hour for a search, but a spokesman

for the Civil Aviation Division in Christchurch emphasised that it was better to be sure than sorry. Pilots responsible for false transmissions are not liable for prosecution; nOr do they have to contribute to the cost of a search. “I suppose we could choose to ignore an emergency signal if a check of flight plans revealed that no aircraft was missing, but this would undoubtedly lead to our missing a genuine emergency,” said the spokesman. “Some aircraft, helicopters in particular; frequently work In remote areas without a flight plan.” Part of the problem is that pilots cannot always readily tell whether their locator beacons have been inadvertantly bumped Into action. The Ministry last.week appealed by Notam (a priority notice to airman) to all pilots to make a check simply by tuning into the appropriate frequency (121.5 meg/hertz) on their aircraft radios. By so doing they could find the source of an emergency signal to be surprisingly close at hand.