Missing the message in a noisy world
There sure is a lot of information out there these days. When it gets to be too much to process, we just call it the background noise of daily life.
Noise isn’t all bad if it gets your attention at the right time.
Alarm clocks, smoke detectors, and emergency vehicle sirens can be painful to hear, but they get the job done. The same can be said of systems on board airplanes that use “aural” warnings to alert the pilot to an imminent hazard, such as an approaching stall. Whether the system uses pneumatic or electronic technology, the dire wail it emits requires no interpretation.
Where cockpit life may get confusing is when there’s more than one aural warning system on the job. Add a little bit of complexity to that basic aircraft, such as retractable landing gear, and now there may be two aural warning systems to differentiate. Was that the stall horn, or the gear-up alarm that just activated? When you only have a second to decide, you are set up for what comes next.
And, what if one on-board system uses noise as a warning—but another on-board system, designed for pilot comfort, cancels out noise? Here, too, Old Man Distraction (OMD) may get you. OMD doesn’t succeed often, but when he does, he can make an awful mess of things. Two gear-up accidents from February 2011 show what he can accomplish.
On February 22, 2011, a pilot was flying an instrument approach at the North Bend, Oregon, airport in a twin-engine Piper PA-31-350. He broke out into visual conditions but did not use a prelanding checklist when entering the pattern, and he forgot to lower the landing gear despite a gear-up alert sounding in the cockpit, said a National Transportation Safety Board accident summary.
“During the landing flare, he heard the noise caused by the wing flaps and both propellers contacting the surface of the runway, and he added power and immediately executed a go-around. He then entered a closed pattern, lowered the landing gear and repositioned the flaps, before making an uneventful landing. He said during the approach he heard the gear warning horn sounding, but he thought it was the altitude alerting system.”
The NTSB determined the probable accident cause as “the pilot’s failure to lower the landing gear while on approach to landing. Contributing to the accident was the pilot’s failure to follow a written checklist during the approach portion of the flight.” Going around after striking both props was yet another “pilot’s failure.”
Five days later, in Brenham, Texas, it was partly a case of systems in conflict when a Beech Bonanza G35 landed gear-up with three aboard at the “busy nontowered airport,” according to an NTSB accident summary. All occupants were uninjured. There was an aural gear-up warning aboard, and it worked. But there was also a noise-cancelling system in the airplane—and now throw in the requisite distraction. The pilot “inadvertently forgot to extend the landing gear, partly because of the strong gusting headwind he experienced on final approach,” said the NTSB summary in recognition of the powerful nature of that distraction.
As with the case of the twin, the moment of realization was abrupt and, no doubt, agonizing. “His attention was directed toward making a smooth touchdown when he suddenly saw the propeller stop as it contacted the runway surface.”
That was the “what” of the event. Next came the answer to “How?”
“After the airplane came to a stop, the pilot removed his electronic noise canceling headphones and he then heard the landing gear warning horn, which was not wired into the audio interphone system,” the accident summary said.
The NTSB stated the probable accident cause simply as “the pilot’s failure to extend the landing gear during the approach, resulting in a gear-up landing.”
Any warning system may work as designed until it is forced to compete with another gizmo that either mimics or counteracts its effects.
Does that argue for fewer systems? Not likely, as technology does more and more of the flying. What it may advocate for, instead, is more specific warnings—or at least, in aircraft lacking voice alerts or words flashing on a screen, more practice working with—and therefore easily recognizing—the sounds produced by the systems that do exist. Maybe one of those warnings should be made to speak or flash in front of the pilot’s nose the words “Got the checklist?” That simple reminder could cut down a lot of noise.
Won’t happen to you? That’s excellent news. But anyone who has ever gotten up to answer the phone, only to realize that it was just ringing on the TV—and that it doesn’t even really sound like your own phone—knows that it doesn’t take much. Now put yourself in that Bonanza’s cockpit during a landing in tricky winds, or in that Piper Navajo after breaking out of the clouds with a runway out there.
Will you prevail?
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