40 years after JAL crash, U.S. has yet to fully explain the cause

ASAHI
August 12, 2025

Lights are arranged along the Kannagawa river in Ueno Village, Gunma Prefecture, on Aug. 11, where a Japan Airlines jumbo jet crashed in 1985 at the Osutaka Ridge. The lights form “8” and “12,” the date of the disaster. (Kotaro Ebara photo

When Japan Airlines Flight 123 suffered a loss of control, Hirotsugu Kawaguchi, a 52-year-old passenger on board, started jotting a note to his children: “I really want you to be good to one another and try your hardest together to help your Mum. I can’t tell you how terribly sorry I am. I know I’m not going to survive.”

His messy, shaky handwriting moves me deeply.

What caused the JAL crash on Aug. 12, 1985, that killed 520 people?

At the time, the Aircraft Accidents Investigation Commission concluded that a “faulty repair” had been done by Boeing Co. of the United States.

Specifically, when a part of the aircraft’s pressure bulkhead was replaced, Boeing’s technicians used two splice plates, instead of one continuous splice plate that was called for under normal procedures.

This reduced the bulkhead’s resistance to fatigue cracking, and actually caused it to fall apart.

Why, then, did the Boeing engineers deviate from their usual repair procedures? The answer to that, I believe, is the real cause of that accident.

However, Boeing rejected Japan’s demand to interview the engineers, and nothing has been explained to this day.

This year marks the 40th anniversary of the crash.

Just recently, Boeing updated its official website, where it says that the use of the two splice plates was “by instruction,” following the discovery that using and affixing one continuous plate as originally specified would be “more difficult (than using two plates).”

This information is reportedly quite new to Japan’s transport ministry, which means there must be many more things that the United States has not told Japan.

Who decided it was all right for Boeing to ignore the “correct” procedures? Couldn’t anyone have pointed out, at some point, how risky that was?

There is more information we need to know, and it’s still not too late.

“Big things have small beginnings,” goes an old saying. Put another way, a major catastrophe can be averted by correcting the first small error.

Finding out the truth behind the JAL crash will help us learn a lesson. And that must be exactly what the many people who lost their lives on Osutaka Ridge would want.