What is all this talk about 1.5 threads showing, and pointless use of feeler gauges? The following is an extract from a MB Special Information Leaflet (SIL), issued in December 2013. It superseded a SIL issued in November 2011, which contained the same information exept the feeler guage check.
Maintenance Check of the Drogue Shackle connection to the Scissor Shackle (Refer to figures 1 & 3).
a) Ensure that the Seat has been made SAFE FOR MAINTENANCE.
b) Cut the No.8 parachute thread which passes through the Drogue Shackle and remove.
c) Ensure the first thread of the bolt is flush with the top face of the nut with just the dome protruding (as shown in figure 3b). If the nut is not correct as detailed, complete the procedure in item 2.2.
d) Lift the Scissor Shackle and ensure a 0.030" (or 0.75mm) feeler gauge can be inserted to contact the securing bolt as shown in figure 3b.
e) If the Drogue Shackle passes the gauge check and the first thread of the bolt is flush with the top face of the nut with just the dome protruding, install a new length of No.8 parachute thread to secure the Drogue Shackle in accordance with the relevant Technical Publication.
f) Complete all other necessary procedures detailed in the relevant Technical Publications to return the seat to operational use.
g) Record the satisfactory completion of this instruction on all relevant documentation
Why wasn't this information brought out by the SI or inquset? What steps have been taken to ensure this vital piece of information is reflected in the current maintenance procedures for ALL Mk10 seats.
DV