Originally Posted by
Pilot DAR
I'm involved in STC approving a Human External Cargo dual hook system, which will use a Y harness, down line, and other harness and hardware parts. Any experienced thoughts would be appreciated....
Don't know if this will help... but about 10 years ago there was a change in FAA policy over external load systems that were used for Part 133 HEC ops. The issue was there was a change to the Part 27 certification requirements on external load equipment that a number of existing external systems no longer met which caused an upset in the HEC ops community. Several guidance documents were issued and I believe one of the options to continue HEC with these "non-certified systems" was to use a Belly-Band" or similar device as a back up. However, any future external load systems that were certified per 27.865 or 29.856 had to incorporate these new regulations which included lightning protection for the hook release mechanism. Unfortunately, I don't recall all the details but I've linked the ones I do remember below. If these links are in the right direction let me know and I'll see if I can find out more.
https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-27/subpart-D/subject-group-ECFRc1a5e0bbe2be31b/section-27.865
https://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/info/all_infos/media/2012/InFO12015.pdf
https://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all_safos/media/2018/SAFO18004.pdf
https://rgl.faa.gov/Regulatory_and_G...E/SW-18-15.pdf