A friend just sent me this. Apparently just about all the fabric covered Piper aircraft are subject to this SB, which may become an AD.
Considering that quite a few Cubs and short-wing Pipers have somehow mysteriously become experimental, this may directly affect several "homebuilts" that used previously existing Piper parts during the "51%" owner build
The short version is that within 100 hours you must literally perform "the acid test" on the rudder to see if the main rudder spar was built out of 1025 steel or 4130 steel tube. If the rudder main spar tube is 1025 steel... the rudder is immediately not airworthy any more.
The SB says replace it with a rudder that is known to be made from 4130. You might be able to cut out the 1025 tube and weld in a new 4130 tube, although it doesn't say that in the SB.
Considering that quite a few Cubs and short-wing Pipers have somehow mysteriously become experimental, this may directly affect several "homebuilts" that used previously existing Piper parts during the "51%" owner build
The short version is that within 100 hours you must literally perform "the acid test" on the rudder to see if the main rudder spar was built out of 1025 steel or 4130 steel tube. If the rudder main spar tube is 1025 steel... the rudder is immediately not airworthy any more.
The SB says replace it with a rudder that is known to be made from 4130. You might be able to cut out the 1025 tube and weld in a new 4130 tube, although it doesn't say that in the SB.
