Page 18 - Volume 15 Number 8

with the exception of the Straight 100, have the left and right Fuel Vent Heat switches.
As the “Hot Five” become the “Hot Three” on 100s, here’s another interesting tidbit: They become the “Hot Four” on some A90 and B90 models because some of these airplanes have no Stall Warning Heat switch.
The actual stall warning vane (the movable piece) has always been heated. Whenever the battery switch comes on, the heat is there. For a while, that was the only heat associated with the stall transducer. But then
4 some concern arose about the stall warning becoming
17 8
inaccurate when ice accumulated on the metal plate behind the vane. Safeflight, the manufacturer of the system, began offering heating for this plate and Beech added that on the assembly line and added the Stall Warning Heat switch in the cockpit. The previous airplanes now had a mandatory kit available that added the plate’s heating element. However, rather than force the operator to run an additional wire from the wing to the cockpit and add a new switch on the subpanel, they tied this component into the Right Pitot Heat switch. (Realize that all earlier King Airs had the right pitot tube midway out on the wing, not on the nose.)
Due to the extensiveness of items to cover in this article, it will have two parts. Next month we will continue to discuss the ice protection systems King Airs have and the difference between the various models. KA
King Air expert Tom Clements has been flying and instructing in King Airs for over 46 years and is the author of “The King Air Book” and “The King Air Book II.” He is a Gold Seal CFI and has over 23,000 total hours with more than 15,000 in King Airs. For information on ordering his books, contact Tom direct at twcaz@msn.com. Tom is actively mentoring the instructors at King Air Academy in Phoenix.
If you have a question you’d like Tom to answer, please send it to Editor Kim Blonigen at editor@blonigen.net.
16 • KING AIR MAGAZINE
AUGUST 2021