Page 20 - Volume 13 Number 12

insult anyone’s intelligence. There is nothing worse than having a routine and relatively minor check turn into a major fiasco in a matter of seconds. I formed the habit of taking the pitot covers off and putting my cellphone and car keys on top of them. This ensures that I put them back on when I’m done and I don’t get distracted by my phone while focusing on the aircraft.
Stall Warning Heat: On King Air 200s, 300s and 350s, the stall warning vane only gets half heat on the ground because the squat switch cuts the heat in half to compensate for lack of airflow. On those models if the tab gets warm you are good to go. Stall warning heat on model 90s is different. Its stall warning heat systems vary almost from aircraft to aircraft. It requires maintenance manual research by aircraft serial number to ascertain what configuration your 90 has. I could write a small book on just that subject. Suffice it to say that
some 90s heat the vane all the time and others cycle the heat on and off. Allow ample time for heating in case yours is on a cycle, but don’t just go up and grab it. You could burn your fingerprints off! Especially if your stall warning heats continuously. If a couple of minutes have gone by and you haven’t blistered your fingers, add stall warning heat to your squawk list. And while you are at it, make a note for your shop to research what kind of stall warning system is in your 90.
Prop Heat: Although the prop heat boots are an external heat item, you are better off checking this in the air. The manual check done on the ground takes two people – one to turn the prop and feel the prop boots while the other is in the cockpit operating the system and monitoring the gauges. Although recommended by the maintenance manual, I’ve seen this test fall short on many occasions. I’ve written several articles on King Air prop heat and the problems with this test specifically. Two of those articles appeared earlier this year, in the February and April issues. Testing your prop heat in flight requires a clear understanding of the type of system installed in your King Air and keeping a keen eye on your prop amp gauge.
FCU heat: This is the least crucial of the external heat items. It’s a tube located inside the engine cowlings by the fuel control. In 200s and 300s, the FCU heat comes on when the condition levers are moved forward. In the 90 models, there is an FCU heat switch in the cockpit for each engine. If the FCU heating element isn’t working, there is still plenty of heat inside the cowling, even in freezing conditions, for that engine to operate normally. The only time a malfunction of FCU heat becomes an issue is in reverse or in an over­torque situation. FCU heat is checked at Phase Inspections.
battery off. It’s easy to overlook when you are poking around your aircraft and not following a pre­ flight or post­flight checklist. After years of waking at midnight and wondering if I left a battery switch on, I developed a habit to fix the problem. When working on a King Air with a dual bus system, I leave the beacon switch in the on position. The flashing beacon is a constant reminder that the battery is on. Try it yourself. As you get ready to leave the hangar and you look back at the aircraft on your way out the door, if that beacon is still going, you will happily turn your battery off and be thrilled you didn’t drain it dead. When I’m working on a King Air with a triple feed bus, I use the nav lights as my “battery reminder” since the beacon bus is not powered with the battery on.
Speaking of checklists, my late father­in­law was an absolute stickler for them. He wouldn’t get within 50 feet of his aircraft without a checklist in hand. Were he alive to read this article, he would have made his own checklist with all of the above items on it; he would have gone to the airport on a brisk morning to make sure his aircraft was winter ready; and he would have carried his handmade checklist throughout each activity. Safety was paramount with him and ‘checklist’ was his middle name. Before his passing he was honored by the AOPA as a 62­year member. Allow me to raise a glass to all owners and pilots, wishing you a multitude of safe hours flying your King Airs. KA
Dean Benedict is a certified A&P, AI with nearly 45 years’ experience in King Air maintenance. He’s the founder and former owner of Honest Air Inc.,
a “King Air maintenance boutique” (with some Dukes and Barons on the side). Now, with BeechMedic LLC, Dean consults with King Air owners and operators on all things King Air related: maintenance, troubleshooting, pre-buys, etc. He can be reached at dr.dean@beechmedic.com or (702)
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Battery Off: As a friendly
reminder, after checking all these
items, don’t forget to turn your 773-1800.
18 • KING AIR MAGAZINE
DECEMBER 2019