A Ruili Airlines Boeing 737-800 (reg B-7866) made an emergency landing on the night of July 6 after the heating element in the left cockpit windscreen failed, causing it to crack.

The pilots conducted an accelerated descent, dropping around 18,000 feet within six minutes. There were no injuries to the 178 passengers and nine crew onboard.

According to the airline, flight DR6558 departed Xi’an (XIY) for Kunming (KMG) at 10:16 p.m. and the crew reported the malfunction of the heating element at 10:45 p.m. noting sparks and later cracks appearing on the windscreen. A Mode 3 transponder ‘7700’ code was also transmitted to declare an emergency. 

The aircraft diverted and landed at Chongqing (DAX) at 11:35 p.m. where the 178 passengers were transferred to another aircraft, which arrived at KMG at 6.01 a.m.

Investigations are currently underway. 

According to Aviation Week Fleet Data Services, the seven-year-old aircraft is leased from Industrial and Commercial Bank of China and is one of 20 737s that LCC Ruili operates. 

The July 6 incident was reminiscent of what happened during Sichuan Airlines flight 3U 8633 on May 14, 2018. In that incident the right windshield separated from the Airbus A319, resulting in an explosive decompression leading the first officer to be partially sucked out of the aircraft. The aircraft landed at Chengdu (CTU) safely 35 min. later with the first officer and a member of the cabin crew suffering some injuries. 

A Civil Aviation Administration of China investigation revealed that a damaged and corroded seal resulted in electrical arcing, causing a difference between temperature and pressure between the aircraft and the atmosphere that led to the windshield bursting out of the fuselage.