A retired airline captain, Barry Schiff has been flying for 49 years.
After inching our way along the parallel taxiway behind a lengthy procession of early morning departures, we were finally cleared for takeoff on Runway 30L at St. Louis. I shoved the thrust levers about three-fourths forward and called for our flight engineer, John Dunne, to "trim throttles."
He further advanced the go-knobs and made fine adjustments until the three engines of our Lockheed L-1011 were producing the precise amount of takeoff thrust.
I noted that the center engine was running a little hot and asked John to pull back the power slightly.
"V1!"
Through the corner of my eye I could see that he was retarding the throttle much more than I would have expected.
"Rotate!"
I had the TriStar poised for flight on its hind legs when I noticed that John had pulled the throttle fully aft. The engine was developing full power and still running a little hot.
"Nothing I can do with it, Barry. We've lost control of Number Two." Dunne demonstrated by moving the throttle fore and aft with no power change of any kind.
"That's a new wrinkle," I replied as we began climbing toward our assigned altitude. The first officer (I cannot recall his name) said correctly that we would "have to treat it like an engine failure."
We advised ATC of our need to return to St. Louis as John pulled out the engine failure checklist. As soon as I turned off the start switch, which immediately deprived the engine of fuel, there was an uncomfortable jolt that called for an explanation to our passengers. Two hours later we were again en route to Los Angeles with the problem repaired.
Although this is an unusual event in jet operations, something similar happens every once in a while in a lightplane when a throttle jams and cannot be moved. If it freezes in the idle position or when developing insufficient power to maintain altitude, there is no option in a single other than to make a forced landing.
But how would you handle the situation if the throttle jams and engine control is lost while developing cruise power or greater? Descending, approaching, and landing safely with so much power would be difficult if not impossible. The only way to handle the problem would be to shut down the engine with the thought of cycling power on and off as needed later in the flight.
Such a procedure should not be difficult or dangerous as long as some advance thought is given to the problem.
Some might be surprised and amused to learn that this was the normal manner in which pioneer pilots flew behind rotary engines. (The propeller was attached to the engine, which spun, while the crankshaft remained stationary.) A pilot used a "burp" switch on his control stick to turn the ignition on and off. There was no in-between. It was either full power or none. This is because it was impossible for a carburetor (and, hence, a throttle) to operate while spinning rapidly.
Although a pilot with a jammed throttle also can vary power from full to none by cycling the magnetos on and off, it probably is better to use the mixture control instead. When the mags are turned off, the engine continues to inhale a fuel-air mixture that could contaminate and foul the spark plugs, which would delay restoration of power when needed. Using the mixture control is effective in modulating power on and off as long as the propeller is allowed to windmill, which it should do as long as airspeed is maintained at or above the best glide speed.
During 49 years of flying I have discovered that virtually anything that operates in an airplane has the potential to fail, items that we normally take for granted.
In 1958 I was flying a cattle buyer from Los Angeles to Salinas, California, in a North American Navion. It was a cold night, and my passenger, Harry Abdul (the father of entertainer Paula Abdul) asked if I would turn up the cabin heat. I slowly pulled out the knob and waited for warm air to flood the cockpit. But there was none. I pulled the knob all the way out. Nothing. There was to be no heat on that winter night. I should have known better, but we opted to continue even as the cabin became increasingly frigid (almost to the point of being hazardous).
Along similar lines, have you ever opened an air vent and found that you were later unable to close it? It happens.
On another occasion while flying a Beech Bonanza from Las Vegas to Albuquerque, I began to switch from the left fuel tank to the right. The valve was somewhat stiff, so I muscled it in the desired direction. This is when the handle broke off in my hand. Fortunately, there was a pair of pliers in the glove compartment that I could use to wrench the valve into position. To this day I never switch tanks in a single unless reasonably close to an airport.
There are so many gadgets in the modern cockpit that are extraordinarily reliable but, like all devices, have the potential to fail and create consequences you might not have considered. On the next rainy day, crawl into a cockpit and play "What if." Ask yourself what you would do if this control or that switch were to fail. It is an interesting exercise in preparedness.
Visit the author's Web site ( www.barryschiff.com).
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