Flammabiliity: Small Part Exemption (SPE)

[Onwing]

Dear all gents,

I am installing a NOT flammability-tested small part in cabin. I heard that there is an fire retardant Exemption depend on the size of part.

So what is the size limit for such Small Part Exemption (SPE)? And is there any issued paper or regulation can be of reference?

Sincerily wait for your guidance.

Onwing

 

[der8110]

One of the more abused rules. Logically, anything smaller than the specimen size (3x12") but practicality is by the name of the part as in Appendix F: "small parts (such as knobs, handles, rollers, fasteners, clips, grommets, rub strips, pulleys, and small electrical parts) that would not contribute significantly to the propagation of a fire".

There are exemptions as you suspect, but those are worked out individually with the certification authority and are therefore generally proprietary.

So why not just get samples that are specimen-sized and just test. Choosing fire retardant materials is nice but does not take the place of a test. A good predictor. The reason I don't do flammability is half the day is spent having to listen to clever new schemes of avoiding test.

 

[bf109g]

Trust me, in some cases the effort expended by engineers to justify not doing the test is more expensive than actually doing it.

But if you think you have a valid case for not doing one, it surely wouldn't hurt to present that to your certificating authorities.

 

[tbuelna]

Flammability of small parts in a cabin......

Just remember what happened to Grissom, White and Chaffee due, at least in-part, to small pieces of flammable velcro all over the inside of their Apollo 1 capsule.

Regards,
Terry