Lonewolf, I think Jimf671 was referring to the S92 AD asking operators to check the main gearbox mounting bolts. Here is the reason copied from the AD.
"The FAA received a report of a failure of a main transmission mounting bolt, detected during routine maintenance inspection. Undetected bolt failure could result in loss of support of the main transmission, and subsequent loss of control of the helicopter."
AKA: gearbox detaching from airframe with rotohead attached ... Same undesired result.
The oil filter studs were a totally different issue.
The main gearbox mounting feet with the "2 bolt redunanticy" were also responsible for several ADs. 2 bolts in a single foot is not really redundanticy, when the foot breaks off you just have 2 useless bolts in the frame rather then 1.
Last edited by Satcomm; 23rd May 2016 at 03:01.