737NG cracks spread, new FAA guidelines due today

Four aircraft have been found with extended cracks beyond the initial “pickle fork” wing safety attachments.

As a result the FAA are to issue new guidelines on an area extending to eight of the frames in the wing, not just the original two.

Aircraft with 30,000 cycles are now to require extended checks. If others are found in the 22,600-29,999 cycle band then a far wider investigation is likely to follow.

“The cracks are common to the aft fastener hole joining the frame fitting outer chord and fail-safe strap at water line 199,” Boeing explained in a Sept. 30 operators’ message. “The frame fitting cracks are estimated to be 1-inch long from the aft edge of the fitting. The cracks in the failsafe strap are also extending from the aft edge, but the length is unknown because the cracks are hidden between the fitting and the skin/ [failsafe] strap“.

It’s just another bit of bad news for Boeing as the older airframes start to have issues that have come as something of a surprise.

The only good news is that Boeing seems to be heading towards getting certification of the MAX completed by Christmas and modifications to get the first ones flying by January.