• Version
• 124 Downloads
• 962.12 KB File Size
• 1 File Count
• December 4, 2016 Create Date
• December 4, 2016 Last Updated

National Advisory Committee for Aeronautics, Technical Notes - Effects of Ice Formations on Airplane Performance in Level Cruising Flight

The lack of quantitative evidence of the deleterious effects
of ice formation on airplane components has restricted the evalua-
tion of the icing problem and has therefore tended to retard the
development and the adoption of new and improved ice-protection
systems. Although serious reductions in airplane performance have
often been experienced, possible errors in airspeed indications due
to ice on the pitot static tube made difficult an accurate evalua-
tion of the magnitude of the hazard; and the relative effects of
ice on the propeller compared with that on the remainder of the
airplane were not accurately. evaluated.

Several investigations have been made of the affects of pro-
peller icing (references 1 and 2), but very little research has -
been performed to determine quantitatively the effects of ice on
other components.

Results of wind-tunnel investigations using simulated ice
formations on propellers (reference 1) indicated a loss in pro-
peller efficiency of only 3 percent for level-flight operating
conditions. Propeller-whirl studies conducted by the Army Air
Forces, during which icing conditions were artificially created,
indicated negligible losses. In both cases the results were incon-
clusive because the quantities of ice simulated. or obtained were
smaller than formations frequently observed during flight in
natural icing conditions.

Preliminary flight investigations of propeller icing in
natural icing conditions (reference 2) indicated significant pro-
peller performance losses. These data were inGOnclusive because
they did not permit a distinction between the affects of propeller
ice and the effects of ice formations on other components of the
airplane.

An investigation was therefore undertaken to determine the
effects of ice fomations on propellers, wings, empennage, engine
cowlings, and miscellaneous Improtected components of the airplane.
Flight operations were conducted in the Great Lakes region by NACA
Cleveland laboratory personnel and over most of the United States
by the NASA Ames laboratory personnel under conditions of natural
icing during the winter of 194.647.