Originally Posted by Gerard C
As to Group 1 and 3 which are sister categories if the original windows are retained do we have to apply a film on them for circuit use? Or replace them by 4 mm Lexan units? Scrutineering may be different on this point, I thought it was for Grp2, 4 and 5.
Appendix K is simple, take Appendix VIII to Appendix K for Group 1 and 3 from Period E up to G1, at the top, it says "NO OTHER MODIFICATIONS AUTHORISED, therefore as nothing permits the replacement of original windows, no FAA type material for these. It must be original, safety glass and yes, addition of film is accepted as added safety.
If a ruling doesn't say "It is permitted", "may be used" or makes it an obligation by using "must" and/or "minimum requirement", then, it is not allowed.