Liberator tail

[virgo]

Having just visited the excellent museum at Duxford, it was noticed on the Liberator tailplane and fin, rows of holes about 5mm diameter, 20 mm apart and about 100 mm behind the leading edges for the full span of the tail and running from top to bottom of the fin.
In the absence of any other evidence of ice protection (Pneumatic rubber boots, heater mats or liquid outlets) it was assumed that the holes were hot-air outlets for thermal anti-icing ? Is this assumption correct ? If so, where does the hot-air come from ?

Apparently the Liberator "Davies" wing was very prone to icing - why was this ?
Any help will be much appreciated.....................Thanks.

[Saab Dastard]

Virgo,

I'm pretty sure that all the production B-24 marks had pneumatic boots on wings, tailplane and fins, although I've read that some later models (late-J, and above) had exhaust-heated anti-ice, though I'd be amazed if that was piped to the tail surfaces!

The Duxford Liberator is a B-24M that was used for icing research, so perhaps those holes were for pressure measurement?

The B-24 wing was no more prone to icing than any other, but the effect on performance was much greater, due to the high aspect ratio laminar flow wing. So even small amounts of ice accretion dramatically increased drag and reduced lift - far more than with more conventional wings.

SD

[stevef]

The sizes and spacing suggest that the holes might be rivnuts for attaching pneumatic de-icer boots.
Rivet nut - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Rivet_nut)

[virgo]

SAAB......thanks. Interesting that the aircraft was used for icing research. Your suggestion could be the answer. (If any pruners have access to other B24s, any chance of checking them out ?)

Effect of icing on laminar flow wing also makes sense - did the P51 Mustang have the same sensitivity ?


Steve........thanks also, but the holes ain't rivnuts.