horizontal stabilizer anti-ice

huangyhg

horizontal stabilizer anti-ice
does anyone know if there is/was an faa requirement for thermal, mechanical, or other anti-ice system to be incorporated in the horizontal stabilizer leading edge on commercial aircraft? i haven't been able to find any mention in 2 days of web searching.
i worked on the md11 hs years ago in the mid 80's and there was a picolo tube tube system installed, but i can't recall if there was a specific far req at the time.
tia
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the faa has had several "advisory circulars" related to ice protection systems in existance for many years. they contain a lower level definition of requirements. in recent years, due to the atr72 accident near chicago, most of these documents have been rewritten, or superceded. that faa web site should also get you to a list of these acs. the faa is (or just has) changing part 25 to include a more specific rule for icing and ice protection systems.
in general far/jar 25 size aircraft do not have ice protection on horizontal stabilizers (the wing thickness & duration time in icing) allows the manufacturer's to get away with it.
other categories (inc far/jar 23) have some de-icing / anti icing.
the re-write of ac rules to allow for freezing drizzle will mean they will be forced to look at it again.
you might search for regulations on certification for flight into known icing conditions.
regards,
grant wittenborn
aerospace engineer