Qantas 737 suffers altimeter fault similar to doomed THY aircraft
Qantas and the Australian Transport Safety Bureau said they will consult with and assist Dutch crash investigators after a QF 737-800 last week suffered a radio altimeter malfunction similar to the one that is suspected of causing the loss of a Turkish Airlines -800 on approach to Amsterdam on Feb. 25.
Qantas Flight 1020, an -800 operating from Hobart to Sydney on April 7, experienced the radio altimeter fault on approach. According to a QF spokesperson, the -800 was “at approximately 100 ft. when the captain’s radio altimeter indicated that the aircraft was at around 10 ft., about where the auto thrust activates full retard on the throttles.”
As in the THY crash, the captain’s altimeter was indicating a different set of data than the first officer’s. “Upon noticing the fault, the captain immediately disconnected from the auto thrust and manually flew the aircraft into Sydney,” the spokesperson said. “It is Qantas flight operations policy for pilots to guard the thrust levers and fly with hands on the levers when the aircraft is on auto, which ensures that should a fault with the thrust levers occur, the pilots are immediately able to fly manually.”
The carrier self-reported the incident to ATSB, which confirmed it will investigate due to the similarity of the fault to the assumed cause of the THY crash. The QF spokesman told ATWOnline that “there is no suggestion by the ATSB that Qantas or its pilots were at fault. This investigation is simply to assist European regulatory authorities.”
A preliminary investigation by the Dutch Safety Board revealed that the only fault discovered on the aircraft was in the captain’s radio altimeter, which suddenly changed from 1,950 ft. to read -8 ft. in altitude although the right-hand altimeter functioned correctly.
Source: ATW by Geoffrey Thomas