Piper SB 1161

Last week I received a new Piper Service Bulletin, which seems to affect all
older (pre 1983) retractable gear PA-28s (Arrow), PA-32s (Lance/Saratoga),
PA-34s (Seneca), and PA-44s (Seminole). It calls for recurrent dye
penetrant inspections of a particular wing rib (one in each wing) where the
main gear side braces attach. On paper, the SB looks like the inspection
might be quite a job because it requires jacking the plane, removing the
gear side brace, and swinging the gear after reinstallation. However, if
done during annual it might not be such a big deal since the gear swinging
has to be done anyway. The inspections are "required" every 500 hours, but
the requirement can be curtailed by installing a "Service Kit" on the
affected rib. Installation of the kit is also a corrective repair if cracks
are observed, unless the cracks have propagated too far.
The SB can be viewed and downloaded at
http://www.newpiper.com/company/Publications/SB%201161%20Rib%20Assy%20Insp-Mod.pdf

Does anybody have any insights into the history and disposition of this SB?
Specifically, I am wondering:
How prevalent are the rib cracking problems that the SB addresses?
Is an Airworthiness Directive likely to follow?
About how many hours of labor will the recurrent inspection add to an
annual?
About how many hours of labor would be required to install the Piper
Service Kit (per wing)?

Any insights from other Piper owners and/or A&Ps would be appreciated.


-Elliott Drucker