I just wrote about the cabin door in the February 2017 issue of this magazine, but I thought of a few more points I could make on this topic.
To summarize briefly where I left off: If a King Air has a cabin door squawk, nine times out of 10 it is going to be the door warning light on the annunciator panel coming on when the door is properly secured. The warning light is triggered by switches. All King Airs have two switches in the door frame and one switch in the door handle inspection light hole. Newer King Airs, plus many 300s and 350s, have two additional switches, one at each upper door hook. If one of these switches fails, you get that warning light. A bad switch is the most common reason for a door light when the door is closed and locked.
Obviously, if you get a light on the ground, you aren’t going to take off until you verify the door is properly closed and the light is extinguished. It could be that the door wasn’t properly latched, or it could be a bad switch. If everything looks good on the ground, but you get a cabin door light on the annunciator panel after you are airborne, the chances are your door is fine and you have a switch going bad somewhere in the system. This assumption is based on my experience with King Airs over the last 40-plus years.
Warning Light in Flight – What to Do
The POH addresses the subject as follows:
Illumination of Cabin Door Warning
Warning: Do not attempt to check the security of the cabin door. Remain as far from the door as possible with seat belts securely fastened until the airplane has landed.
- If the cabin door warning annunciator illuminates, depressurize cabin (consider altitude first) by activating cabin pressurization dump switch on pedestal.
- Do not attempt to check cabin door for security until cabin is depressurized and the airplane is on the ground.
- Check security of cabin door (on the ground) by lifting the cabin door step and checking position of arm and plunger. If unlocked position of arm is indicated, turn door handle toward locked position until arm and plunger are in position.
Furthermore, the placard next to the handle is pretty clear: “Do not attempt to check security of cabin door by moving door handle unless cabin is depressurized and aircraft is on the ground.”
What Not to Do
Should you get a cabin door warning light in flight, don’t touch that door handle! Many years ago, a pilot got a cabin door warning light during flight and his co-pilot left his seat to check the door. Apparently, he grabbed the handle to see if it was locked, but turned it the wrong way! Since the aircraft was pressurized, the door flew open and the co-pilot was sucked out of the aircraft. The pilot declared an emergency, made his descent and landed. Of course he assumed his co-pilot fell from altitude and was fatally injured. Imagine his surprise when he discovered the co-pilot had managed to grab hold of the door cable, held on for dear life, and lived! Astonishingly, he was not seriously injured (at least not physically). Reportedly, the biggest problem the emergency personnel had was helping the poor guy pry his fingers from around that door cable. They say 30 minutes went by before the guy could manage to let go. This is a true story! I was at BeechWest in Van Nuys when it happened and reports of the incident reverberated throughout the Beechcraft community. I’m guessing it was during the late ‘70s or early ‘80s. My recollection is that the pilot landed at San Luis Obispo, California. I have scoured the internet for mention of this incident and have come up dry, but I’m not making it up!
It just so happens that when a King Air cabin door comes open in flight, it stays at 90 degrees to the fuselage. It won’t flop all the way open as you might expect. This may have helped the co-pilot to hold on.
Is the Door Essential?
It comes as a surprise to most King Air owners, but your cabin door is not essential for flight. What I mean by this is that a King Air can take off, stay aloft and land safely with the door removed. Am I suggesting you do this? Of course not. But this speaks to the stability of the King Air in flight. Think of the number of King Airs that have been converted to jump planes.
I mention this because I’m still fuming over a pre-buy inspection done on a 300 that was brought to my attention by the seller of the aircraft. The shop chosen by the buyer had squawked a long list of things as airworthy items that weren’t the least bit. On the top of this list was “cracked Royalite panels on the cabin door interior surface.” Really? This makes my blood boil. Royalite is a lightweight fire-rated plastic used extensively in aircraft interiors. Some King Air doors have carpet in this area (on either side of the steps), and many have Royalite panels. This is part of the aircraft decor! It is totally cosmetic, and has nothing whatsoever to do with the airworthiness of the aircraft. Calling a crack in the Royalite (such as what’s shown in the photo on page 11) an airworthy item is only done by a shop hell-bent on gouging the seller and/or buyer in every way possible.
The tendency to turn a pre-buy inspection into a full-on restoration project has gotten out of hand. A pre-buy is supposed to give the buyer a clear picture of the condition of the aircraft so that he/she and the seller can come to an agreement on price and terms. It’s not supposed to take a 30-year-old aircraft and make it brand spanking new!
Airworthy items (actual safety-of-flight items) are typically addressed by the seller before the buyer takes possession, or the buyer pays a reduced price to the seller and has them addressed post-purchase. Either way, the shop doing the pre-buy inspection can’t sign off an aircraft with a known airworthiness issue. Sadly, unscrupulous shops hold buyers and sellers over a barrel by labeling every squawk, quirk and minuscule flaw as airworthy. Fortunately, a knowledgeable King Air mechanic can advise buyers and sellers on which squawks are truly airworthy and which are not.
With respect to King Airs, in particular, their resilience is one of their most desirable qualities. With proper maintenance, they’ll go on and on. May your King Air be no exception to this rule; and may no one touch the door handle in flight. Happy flying!
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