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I Learned About Flying From That: Stuck Throttle Approach

A case of too much power.

Some events in flying aren’t covered by our instruction, the reading of popular or safety-specific magazines, or the emergency checklists. During these events, the pilot is left to his or her own devices, perhaps assisted by controllers and even passengers. But in the end, the pilot in command has the ultimate authority. I was presented with such an event in my Cessna P210 with a nonpilot by my side, and I learned a lot from that flight.

It was during the return trip one April from Grant County Regional Airport (GCD) in John Day, ­Oregon, where I hold a monthly clinic for some of my more distant cardiology patients, when I ran into trouble. The temperatures during the day had been about 40 degrees F with intermittent sleeting. After a typical departure and climb in the P210, I reached my assigned altitude of 14,000 feet in VFR conditions, where the OAT was well below freezing, typical for central and eastern Oregon in spring. Upon leveling off, I tried to retard the throttle to cruise power, but the throttle was stuck. Trying not to alarm my sole passenger, Karyn, one of our practice’s best nurses, I loosened the throttle friction control completely and tugged firmly several times. I thought about putting my right foot on the console for more leverage but decided that it wouldn’t be good for the airplane or for Karyn’s confidence in the pilot in whom she’d entrusted her life.

By dialing the prop speed down to 2,200 and leaning the mixture to lean of peak, I’d depowered the airplane to 190 knots TAS. Despite the headwind, we were going to be arriving in Bend (BDN) soon. I consulted the POH for what I knew wasn’t there, an emergency procedure for a stuck throttle. When I convinced myself that I hadn’t missed anything relevant in the POH, I decided to fess up with my passenger. First, I mentally formulated my plan and then interrupted Karyn, who was reading a book, oblivious of our situation. I calmly explained the status of our flight and then outlined my plan for descent, approach and landing, while trying to exhibit confidence that the outcome of the flight was not in doubt. Exhibiting the quiet strength and confidence that makes Karyn a great nurse for our office, Karyn replied “OK” and then resumed reading her book.

I notified the Seattle Center controller of our urgent situation and requested changing the destination to Redmond (RDM), where Runway 28 was longer than Bend’s and more aligned with the moderate surface winds. Center requested the requisite information (fuel, souls and emergency equipment on board) and then declared an emergency for me (they can do that?). Upon arriving in central Oregon, the clouds were scattered as forecast; this facilitated my plan for slowing the airplane and descending. I used my Precise Flight speedbrakes to slow the airplane to 160 knots indicated airspeed, below the maximum gear operating speed, then dropped the gear and put out 10 degrees of flaps. Taking advantage of the now clearing skies and the open spaces of central Oregon, I descended to 2,000 feet agl and was handed over to Redmond Tower.

My plan was to make a turboproplike power-on approach to the runway and then pull the mixture to ­cutoff once the mains touched the ­runway. Starting with a three-mile final approach, I again aggressively leaned the mixture and lowered the rpm, but was still flying at 120 knots, 50 percent higher than the usual 80-knot approach speed. At one mile from the threshold, I took one last-ditch tug on the throttle. Surprisingly, it moved freely. I canceled IFR and diverted to Bend, where the landing was unremarkable. Since temperatures were now well above freezing, the stuck throttle might have been due to frozen moisture on the cable assembly. My shop later replaced the throttle linkage for the gear-up warning as specified by a service bulletin, but the exact cause was never proved and there’s been no recurrence over the intervening two years.

I later met with my instructor to review my actions and try out my planned scenario on a simulator and in the airplane. As he predicted, getting the main gear to the runway surface was impossible with full climb power, despite 10 degrees of flaps, gear down, speedbrakes and engine depowered as described above. Once the nose was raised to flare, the 210 climbed immediately and briskly. We tried making approaches at 20 and 30 degrees of flaps (with miles-long final approach) but couldn’t get the airplane down to the threshold without exceeding the upper end of the white arc. Ultimately, we went back to the 10-degree flap approach and pulled the throttle to idle (to simulate idle cutoff) at the runway threshold. I was able to touch down before midway on the Redmond runway and stop well before the departure end. This strategy seems more manageable to me than pulling the mixture while in the pattern. Although most of us have practiced (simulated) power-off approaches to landing, I’d bet few of us have tried it starting at high cruise speeds.

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