Page 25 - May 2022

When changing from 30% to 100% flaps for landing, you may wish to do so in steps ... 60, 80, 100%. Instead of trimming forward (nose down) as they extend, stiff arm the control wheel to maintain the visual glide path and be patient. As the drag takes effect, airspeed will decrease and you will find yourself once again nicely trimmed. During this time do not rush to reduce power. The airspeed will very rapidly decay with full flaps if power is too low! The same torque that gave a stabilized ILS approach with 30% flaps will yield about the same descent angle with 100% flaps at landing speed.
Fuel Venting
Sometimes B100s (and E90s, F90s, A100s, 200-series and 300-series that have basically the same fuel system) have been known to vent an awful quantity of fuel onto an FBO’s ramp or hangar floor. There is a step pilots can take that almost guarantees this event will never happen.
When fuel is being transferred from the auxiliary tank to the main tank, it transfers at a rate greater than the rate at which the engine is burning the fuel. Consequently, the main tank overfills and builds up enough pressure that a relief valve should vent excess fuel from the main tank back into the aux tank. (Although it should do that, sometimes a portion of the excess is vented overboard!) When auxiliary fuel transfers to an already-full main tank, that main tank becomes pressurized or overstuffed with fuel. If ever there is a time when fuel venting will occur, this is it.
I suggest, therefore, that you delay turning on the Aux Transfer switches until leveling off at cruise altitude. Doing so will allow the main tanks to come down from their full condition and hence provide some room so that the aux fuel may now be accepted without causing an overstuffed condition.
When conducting wing-bending analyses, the designers assume that the main tanks will be full if the aux tanks contain fuel. That’s why the “Limitations” tells you to fill the auxes last and use them first. Nonetheless, taking out 100 or 200 pounds of fuel from the mains before transferring the auxes will not be enough to cause bending concerns unless perhaps you are loaded right up to the maximum zero fuel weight limit. In routine passenger-carrying operation that is very rarely the case.
The C100
Bet you have never heard of this King Air model, have you? In 1976, Beech decided to add enough power to the A100 to have it perform as well or better than the B100. They accomplished this by replacing the 680 SHP PT6A-28 engines with the 750 SHP PT6A-135 engines, the same engine that was to be used on the F90. Since this was such a simple change (so they thought!) Beech began building C100s before the experimental flight testing was completed. BF-1 was the first serial number and they built eight of them, through BF-8. Well, too
much of a tendency toward tail flutter was uncovered at the higher speeds these engines provided. Rather than take the time and effort and money to redesign and strengthen the tail assembly, the decision was made to shelve the idea and to convert the eight undelivered C100s back into A100s. If one looks closely inside the cowl of the last eight A100s, one will find a “BF” serial number alongside the “B” number!
Summary
Fewer members of the 100-series branch of the King Air family tree have been produced than any of the other branches. Even the latest 100-series model is now almost 40 years old. For those seeking the same large cabin of the 200 or 300 and yet for a price that is less than many used 90s, the 100-series has developed a devoted following. They are solid, pleasant-handling, fun, flying machines. KA
King Air expert Tom Clements has been flying and instructing in King Airs for over 50 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.
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KING AIR MAGAZINE • 23