Originally Posted by
dragon man
I believe there is not even a service bulletin issued yet so to me the question still remains valid.
Just because a SB hasn't been formally released doesn't mean it's not "out there". It's pretty much SOP to go out with a preliminary SB and have one or more operators 'try it' (frequently with airframer representatives assisting) to make sure it's correct and to incorporate any lessons learned into the final release.
Further, if a SB is going to be the subject of an AD, the release process once it's finalized takes much longer than for a routine S/B because the regulating authority has to review and approve everything. Routine SBs can be approved by a DER and the release takes a couple days - an AD'd SB approval takes weeks or months.
One of my biggest complaints about the process before I retired was that the greater the safety implications of a change, the longer it took to get it out to the field. The longest flow for a routine SB was actually drafting it up - once it was done I could review and sign it off and it was ready to release.
If it was safety related and I expected it to be AD'd (which safety related stuff nearly always was), then I needed to create a cert plan (~week), get it approved by the Boeing Regulatory Authority (~2 weeks), which then forwarded it to the FAA for approval (~2 weeks), then after confirmation the FAA had approved the cert plan, I could "recommend approve" the SB (big No-No to sign the recommend approve before you had an approved cert plan) - after which it went the same route (with the same flow times) as the cert plan. And of course if something got rejected anywhere along the line, it was back to square one and start over again (I once had a 'recommend approve' rejected because under the affected models it said "747-SP" where as the TCDS says "747SP", and a Cert Plan rejected for EGT as an undefined acronym
).