Previous owner of my TB20 also missed the opportunity to buy crankshaft at low price and consequently he agreed to lower the sales price for €20k.
I don’t think any pre-GT TBs had the crankshaft AD. Maybe some late-model pre-GTs had the affected engines?
Peter wrote:
I don’t think any pre-GT TBs had the crankshaft AD. Maybe some late-model pre-GTs had the affected engines?
Yes they did. Actually many of them because AD was related to crankshafts installed in different Lycoming engines produced after March 1997. So in total it was 141 TB20 and 35 TB21 that were affected with this AD. Out of these 141, I can’t say how many were pre-GT but I was one of the unfortunate ones. However, you might be right if out of these 176 aircrafts the majority was produced after year 2000.
According to Lycoming table in bulletin, almost 5.000 engines were affected plus few thousand crankshafts delivered for overhauling various engines.
Emir wrote:
Lycoming engines produced after March 1997. So in total it was 141 TB20 and 35 TB21 that were affected with this AD.
I don’t think it works like that: engine production is one thing, aircraft production a different one. For relatively low cost piston engines it is customary to buy them in batches at a reduced price then install them in the next six-twelve month’s worth of production (so much for JIT production)
Can you figure it out by sn, or is it not easy to know which engine sn’s went on which TB airframe sn’s?
As I noted at the end of here there is a debate around when the 12 years starts. One view is that it starts when the engine is shipped by Lyco, while another is when it is installed in the airframe, while another is when the CofA was issued.
The same issue also had an impact on the way Socata wrote up the dates in the airframe logbooks, relative to the longest permitted engine storage time for the specific preservation method…
Antonio wrote:
I don’t think it works like that: engine production is one thing, aircraft production a different one.
I know that, I don’t understand what’s wrong with my post – I derived the numbers from Lycoming table within SB which should be pretty much correct. The affected engines were produced from March 1997 onwards so affected aircrafts are produced from 1997 onwards. In general, 1997 engines were put into 1997/1998 aircrafts, 1998 in 1998/1999 and so on – my engine was 1999, installed in February 2000 and, according to CAA, 12 years expired in February 2012.
Antonio wrote:
Can you figure it out by sn, or is it not easy to know which engine sn’s went on which TB airframe sn’s?
It’s not easy but luckily TB20/21 have distinct engine types, so you can easily get the numbers from Lycoming SB. In mandatory SB (SB569A) Lycoming listed all affected engines (by serial numbers, to their best knowledge) and all affected crankshafts (by serial numbers).
