Indonesia’s National Safety Transportation Safety Committee (NTSC) suggests that poor visibility may have contributed to a landing accident involving a Wings Air ATR 72-600 on 25 December 2016.
The aircraft (PK-WGW) was operating flight WON1896 from Bandung to Semarang. As it was landing around 18:34 local time, the aircraft bounced three times. The crew tried to go around, but this was unsuccessful.
“The unrecovered bounce resulted in abnormal landing attitude with vertical acceleration up to 6g and collapsed the right main landing gear,” says the NTSC in its final report into the accident.
None of the 68 passengers or four crew onboard were injured, but the aircraft was a hull loss. The blades of the aircraft’s right-hand engine were broken off “about 26cm from the tip,” and the fuselage suffered “several dents and punctures.”
The final approach to runway 13 took place in night conditions and with light rain. The crew was also informed that the runway was wet. At 18:20, the crew asked the control tower to reduce the intensity of the runway lights. The intensity was reduced, and the pilot confirmed the amount of reduction was appropriate. Subsequently the aircraft touched down nosewheel first with a force of 6g, and commenced the three bounces, the second of which was as high as 14ft.
Analysis of the of the cockpit voice recorder indicates that the windshield wipers are not activated despite the light rain.
“The low-intensity of the runway light and the wet runway which reflected very little light might [have] affected the pilot depth perception and caused the pilot to perceive incorrectly that the aircraft was higher than the real condition,” says the report. “In addition, the absence of the windshield wiper activation might reduce the pilot visibility to the runway.”
This, says the NTSC, resulted in a late flare for landing.
“The excessive rate of descent on the first touchdown might have degraded the landing gear strength, followed by landing with vertical acceleration of 6g that was sustained solely by the right main landing gear.” This likely caused the right main landing gear’s failure.
The report gave no safety recommendations, but stated that its 2017 recommendation that Wings review bounce its recovery training had been followed.