PC-12 Synthetic Vision Incident

[pelmet]

Honeywell Evaluates Synthetic Vision After PC-12 Incident

WASHINGTON—Honeywell Aerospace is investigating ways to make its synthetic vision systems “more robust” following a June 18 incident in Australia involving a medevac Pilatus PC-12 outfitted with the company’s Primus Apex integrated avionics suite.

The incident, described in an Australian Transport Safety Bureau (ATSB) final report, has broader implications in the aviation industry, as synthetic vision systems (SVS) have been growing in popularity—not only in general aviation and business aviation, but for future applications in the air transport sector.

In Australia, the two pilots and a flight nurse were departing Meekatharra on a dark (but moonlit) night on a medevac mission to Paraburdoo in Western Australia. Eighteen seconds after takeoff, when climbing through 250 ft. at an airspeed of 110 kt., the PC-12’s radar altimeter failed and wound down to zero, causing the SVS (which uses radar altimeter data along with runway and obstacle database information) on both pilots’ primary flight displays to show the virtual terrain rising “rapidly” upward.

Faced with the dominance of the visual scene from the SVS during a high-workload phase, the pilot reacted by pulling the yoke back and climbing steeply. The ATSB said no warnings or cautions were displayed regarding the failed radar altimeter, and the crew did not receive any oral alerts from the aircraft’s terrain awareness and warning system.

Both of the highly experienced pilots said they were aware of the Apex operating manual warnings that the SVS should not be used for primary controls inputs or navigation, but told investigators “The prominence of the synthetic vision display is such that it is difficult to ignore erroneous information and locate valid information,” the ATSB said.

The incident could reveal the need for enhanced failure-mode training when SVS is used on the primary flight display, particularly as the technology increasingly becomes standard avionics equipment on aircraft. For the air transport sector, all of the major manufacturers are considering the technology, which shows a 3-D virtual representation through the windscreen, as a means of preventing aircraft upsets.
In the Australian incident, the SVS itself nearly caused an upset, as pilots believed its imagery despite the backup attitude display showing contrary information. The situation was resolved when the pilot-not-flying looked outside and saw enough detail to determine the aircraft’s nose was too high, and alerted the pilot-flying. The ATSB said the SVS corrected itself as the aircraft climbed through 850 ft.

Honeywell issued a pilot advisory letter describing the event in August, and cautioned pilots to use SVS as a situational awareness aid only, and not for the “indication of attitude or altitude in lieu of the primary flight display indications for pitch, roll, yaw or altitude.”

The avionics maker said it is “investigating ways to make the synthetic vision system more robust against a similar failure,” with the focus of the investigation being to prevent the SVS display from “continuing to display the image when the data is incorrect but assessed as valid by the radar altimeter.”

http://aviationweek.com/connected-aeros ... 04a775afd4

[idratherbeflying]

Faced with the dominance of the visual scene from the SVS during a high-workload phase, the pilot reacted by pulling the yoke back and climbing steeply. The ATSB said no warnings or cautions were displayed regarding the failed radar altimeter, and the crew did not receive any oral alerts from the aircraft’s terrain awareness and warning system.

Oral not aural...what was the flight nurse doing??

[C-FABH]

Oral not aural...what was the flight nurse doing??

Orating