Appendix 4 Examples of changes that may require full-scale fatigue testing

The following are examples of types of modifications that may require full-scale fatigue testing:

(1)passenger-to-freighter conversions (including addition of cargo doors);

(2)gross weight increases (e.g. increased operating weights, increased zero-fuel weights, increased landing weights, and increased maximum take-off weights);

(3)installation of fuselage cut-outs (e.g. passenger entry doors, emergency exit doors or crew escape hatches, fuselage access doors, and cabin window relocations);

(4)complete re-engine or pylon change;

(5)engine hush kits;

(6)wing modifications (e.g. installation of winglets, changes in flight-control settings such as flap droop, and change of wing trailing-edge structure);

(7)modified or replaced skin splice;

(8)any modification that affects three or more stiffening members (e.g. wing stringers and fuselage frames);

(9)a modification that results in operational-mission change, which significantly changes the original equipment manufacturer’s load/stress spectrum (e.g. extending the flight duration from 2 hours to 10 hours); and

(10)a modification that changes areas of the fuselage from being externally inspectable using visual means to being non-inspectable (e.g. installation of a large, external fuselage doubler that results in hiding details beneath it).

[Amdt 25/19]