Photos by Clint Goff
Of the five senses that humans possess, which one is most important when flying? Which is the least important? I’d argue that taste is the least important, unless we are including the cookies at the Wilson FBO at the Chattanooga Metropolitan Airport (KCHA). That leaves sight, hearing, smell and touch.
Sight and touch seem to be the most important to our flight experience. If I were to suddenly go blind, I’d have a tough time safely finishing a flight. If I lost my sense of touch (although the passengers on my last landing might argue this already happened), I’d also have as difficult a time safely finishing the same flight. While smell can alert you to the presence of smoke or fumes in the cockpit, but (aside from that previously mentioned plate of cookies) smell is not something that’s directly related to flight safety.
But what about hearing? We don’t think about it much, but hearing is absolutely critical to the safety of flight. Your hearing is tested when you see your AME for a flight physical, so it is important to the FAA. I’ve had the batteries in my headset drain completely, leaving me temporarily unable to hear the radios, which impacted my ability to safely operate the airplane. And there are plenty of other sounds that we can control through our audio panel: the marker beacon, navigation radio signals, communication radios and intercom.
What sounds in the King Air can affect the safety of flight? Which ones can be muted or managed? There are a lot of sounds present that are not manageable by the audio panel and most of those sounds are important. Some are audible alarms and some are audible tones for simple awareness. Nevertheless, they exist and we should know about them and be ready to respond when they occur. Let’s break down some of the sounds, as they can truly impact flight safety.
Passenger in command?
Autopilot disconnect: Every autopilot installation should have an audible tone when the autopilot is disconnected. This tone should occur whether you turn OFF the autopilot or whether the autopilot disconnects without your command. It is critical for you to know whether the autopilot is engaged or not.
We have a saying in the aviation training world, “Either you fly the airplane or the autopilot flies the airplane, never neither and never both.” If the autopilot is ON and you manipulate the controls, then the pitch trim servo will activate to neutralize the forces you are applying. This can lead to an incredibly dangerous situation because of wild pitch excursions when you let go of the controls, which can lead to spatial disorientation. If the autopilot is ON, you should place your fingers on the controls (not a full grip) to monitor and be ready to take over the controls but allow the autopilot to do its job without intervention.
The other dangerous situation is when the autopilot turns OFF and the pilot does not notice. Then, the airplane is simply wandering through the sky. I’ve seen it many times in training and sadly also in the real world. When this happens, the airplane can end up in an incredibly dangerous flight regime, easily inducing spatial disorientation, a stall or exceeding aircraft limits.
I once trained a pilot who previously owned a Cirrus and moved up to a King Air. The push-to-talk (PTT) and the autopilot disconnect switches are inverted in those two airplanes. For the first 25 hours of training, the pilot inadvertently turned OFF the autopilot while trying to talk on the radios. He’d push the A/P disconnect button and miss the audible tone when the autopilot was disconnected. Confusion ensued, which was sometimes debilitating. It was a disaster, many times over.
The point? Learn what your autopilot disconnect sounds like. Garmin has a rather benign and short “ba-bum, ba-bum” when it disconnects. Other autopilots have a much louder and more obnoxious aural warning. Make sure you know the sound and have a hand on the controls when you hear it.
It can be muted?
Gear warning: This is a critical sound alert as indicated by the rather harsh word warning in the description. If your landing gear is not down and locked and you retard a power lever (either) or have the flaps deployed beyond the APCH setting, you will get an obnoxious gear warning aural alarm. There is a microswitch in the center pedestal on each PL, and if you pull back the PL(s) to activate the microswitches and the gear is not down and locked, you will activate the gear warning aural alarm. The same applies to the flaps. If you select the flap DOWN position and the gear is not down and locked, you’ll get the aural warning.
And, either sadly or gloriously depending on your perspective, in most King Air models, there is a way to mute the gear warning. I love this muting ability because I find myself pulling back the power levers often in flight and activating the aural warning. It is easy to push the mute button and proceed with the flight in silence. To make matters more mutable, in most 3XX models the GEAR WARN MUTE button is on the left engine PL, depressed by the thumb. Most 3XX pilots have migrated to the habit of holding the mute button when moving the PLs, ensuring this feature is never activated. They completely take this safety feature out of commission by the creation of a habit. Is this right or wrong?
I bet 95% of 3XX pilots hold their thumb on the mute button every time they move the PLs. As long as they don’t land gear up, then all is well that ends well. But one gear-up landing can cost north of a million dollars and cost you your career or insurability. If you have migrated to holding the mute button when moving the PLs, I’m going to challenge you to reconsider your operational practices. I’m not saying never push this button in advance, but maybe do it only if you have passengers you don’t want to annoy. Be cognizant of your safety systems and be mindful when muting them. Intentionality is the key.
You should be in the habit of landing your King Air with the flaps in the DOWN position. Remember, if the flaps are in the APCH position, the gear warning system is not activated. I can’t remember the last time I landed a King Air with less than DOWN flaps when not training for an emergency situation. Sure, it can be done, but why would you do it? All King Air models land nicely with DOWN flaps; it provides the most stall safety margin and there’s no real need to land with less flaps in a strong crosswind in a King Air (which has a robust crosswind margin). Make DOWN your flap setting for landing, even if it is only to activate the gear warning system. You cannot mute the GEAR WARN when the system is activated by the flaps, providing another reason to always use the DOWN flap position on landing.
To the buffet? Golden Corral, here we come!
Stall warning: This one is a passion of mine. When you hear the stall warning, you should push forward on the yoke. We used to teach pilots to practice stalls “to the buffet” and ignore the stall warning, but why? We want pilots to learn to hear the stall warning and respond with an appropriate action. The appropriate action is always to push forward on the yoke.
As a DPE, I see all sorts of wrong responses to the stall warning. The pilot might shove the PLs forward – a terrible idea because it adds a yaw, which can induce a spin. Sometimes the pilot might push the yoke forward and then instantly pull it back – creating a secondary stall. Or the pilot might simply ignore the stall warning. All those responses are wrong and show how poor the airmanship can be with some pilots. The correct response to a stall warning is to push forward on the yoke and ensure the stall does not occur.
Know what your stall warning sounds like. It is easy to remind yourself because you have a stall warning test switch in your cockpit. I bet this is the dustiest switch in your cockpit. Who tests the stall warning? Well, you should.
Igniter warble: I don’t know what to call this sound, but it is the annoying sound that happens when the igniters are firing and you activate the PTT switch. For this discussion, I’ll call it a warble. I don’t know why the igniters can be heard when transmitting, but they can be heard through the headset. This is mostly just an annoying sound, but it seems that pilots forget, wonder and get distracted. Next time you hear it, remember that it is in the background when you transmit, so everyone else hears it too.
Altitude alerter: This sound is not universal to every avionics system, but most have some sort of tone alerting you when you deviate 300 feet off your selected altitude. This can be annoying, but it can also be a lifesaver – or maybe a license-saver. When you have an altitude selected and exceed it by 300 feet from your altitude, this tone sounds off. If you listen and are reminded to look at your altimeter, you might make the appropriate control input to get back to altitude.
This feature might also alert you when 1,000 feet from a selected altitude. I usually say aloud “one to go” when passing within 1,000 feet of an assigned altitude. This callout was drilled into me over years of flying crewed aircraft to remind the entire crew that we were approaching our level-off altitude. When flying with one pilot, this alert can be a real help to keep you situationally aware if you listen for this tone and know what it means.
Anyone hypoxic?
Cabin altitude high: All King Air aircraft have a CABIN ALT amber caution light that illuminates when the cabin altitude exceeds between 10,000-10,500 feet and most also have an associated auditory tone. This sound can be muted because there are times when you might choose to fly with a cabin altitude above 10,000 feet. In the King Air 3XX/2XX with RVSM capability, the cabin altitude will be above 10,000 feet when the airplane is operated at FL350. In the King Air 90/100, the cabin altitude will be above 10,000 feet when flown at 25,000 feet. This is doable in all these airplanes, but you do want to be aware that the cabin altitude is high.
In the more modern King Air models, there is a secondary CABIN ALT HI red warning light, which presents on your caution/advisory/warning panel when your cabin exceeds 12,500 feet. Red lights should really get your attention and you should be responding to correct a cabin altitude above 12,500 feet. This aural warning can be muted too, so really look at the panel to see if you have an amber or red light. Amber says “consider me” while red says “do something now.”
The King Air cockpit can be noisy with so many aural warnings, noises and tones that are not controlled through the audio panel. The good King Air pilot will know what all of these tones sound like and what to do (or not do) when they are present. Know your King Air!