BA Boeing Co

By Jon Emont and Feliz Solomon 

The Sriwijaya Air jet that crashed into the Java Sea on Saturday didn't fly for nearly nine months last year, with air travel severely reduced because of the coronavirus pandemic, Indonesia's transportation ministry said.

The Boeing Co. 737-500 was inspected and declared airworthy before resuming flying operations, the ministry said.

The Indonesian carrier's aircraft carrying 62 people went down minutes after taking off from the country's capital, Jakarta. Divers and other crew are trying to retrieve the plane's black boxes--the flight-data and cockpit voice recorders that can help investigators piece together what caused the crash. Searchers have encountered a series of challenges, including sharp and bulky debris, and murky waters hampering visibility.

The plane had stopped operating in late March, weeks after Indonesia announced its first Covid-19 case, the transportation ministry said. The aircraft began flying again on Dec. 19, after clearing an inspection by the ministry's Air Transportation Directorate General, it said.

Its first flight after the long hiatus didn't carry passengers and was noncommercial, the ministry said. The plane began flying with passengers on Dec. 22, 2 1/2 weeks before the crash. The aircraft's certificate of airworthiness from the transport ministry is valid until Dec. 17, 2021, the ministry said.

The transportation ministry said it followed an airworthiness directive issued by the U.S. Federal Aviation Administration dated July 24 that required operators of some Boeing flight models, including the Boeing 737-500, to conduct an engine inspection before flying. On Dec. 2, a little more than a month before the crash, Indonesia's air inspector gave the plane an engine-corrosion check.

Sriwijaya Air Chief Executive Jefferson Irwin Jauwena said Tuesday that since March, Sriwijaya Air had undergone a security and safety audit under the Basic Aviation Risk Standard program, which is run by the Flight Safety Foundation in Alexandria, Va. The audits look at several aspects, including safety- and quality-system management, manual operations, licensing, and supervision of aircraft and spare parts, he said.

A spokeswoman for Sriwijaya Air didn't immediately respond to requests for comment on whether the plane's prolonged inactivity might have affected its flightworthiness and what maintenance was undertaken when the plane resumed flights in December. The airline said earlier that the plane was in good condition before the crash.

"It's important that the full records be made public, to show where it was serviced, when and by whom," said Shukor Yusof, founder of Malaysia-based aviation consulting firm firm Endau Analytics. "I'm not questioning the reliability of these documents, but it would be really good if we could see a full list, a full history of this aircraft."

Some experts around the world have raised concerns that the lower frequency of air travel during the pandemic could impact air safety. Chow Kok Wah, a Singapore-based aviation consultant, said planes that have been grounded for longer periods than usual require unique inspection protocols. Investigators might look for explanations in the aircraft's maintenance records, he said.

Viriya Singgih contributed to this article.

Write to Jon Emont at jonathan.emont@wsj.com and Feliz Solomon at feliz.solomon@wsj.com

(END) Dow Jones Newswires

January 12, 2021 04:34 ET (09:34 GMT)

Copyright (c) 2021 Dow Jones & Company, Inc.