Learn from This
This story was submitted to the Jan 2014 issue of the Short Wing Piper News by a member of the Club and a Technical Advisor, DAR. It could have easily ended very badly, I don't know where to start with an analysis!
A pilot’s Waterloo odyssey
By Frank P. Sperandeo III SWPC Past President
Sooner or later we will all have our own personal Waterloo experience. Napoleon had his, and I guess my time had come - in the cockpit of a PA- 20/22 Piper Pacer.
I believe everything we do, aviation wise, has an innate psychological con- sequence of our actions - especially in flight of an aircraft where safety is paramount. Add to this recipe some latent common sense and a pinch of engineering experimentation, and a pilot can solve most maintenance problems - not in my case on a May flight to an SWPC chapter meeting in Mexico, MO. Little did I know that my aviation/mechanical skills would be tested, but also psychological mettle.
Ratchet back to January, 2013, when I decided to catch up on some needed maintenance on Miss Pearl, who had a long fuel weeping spell that needed repair.
This involved replacing the upper panel of the 35 gallon custom tank as the rivets were coming loose. The right wing had to be removed as the tank slid out between the spars. The aileron cables had to be removed in the process. (Keep this in mind - it gets better). The tank was repaired success- fully and the wing installed with all cables connected and secured with fas- teners.
On a subsequent business trip to Texas, I noticed that the control yokes
were tilted to the right in level flight. The simple fix is to adjust the two ver- tical AN turnbuckles on the control column to straighten the yokes perfect- ly horizontal. (See pix). I would accomplish this adjustment when land- ing at FYV from Texas.
When adjusting an aircraft turn- buckle, its function is to be installed in line/middle of flight control cables to tighten, or loosen tension, and to, in this case, to adjust the control yokes. The mechanical nature of the PA-22 turnbuckle is that they have threaded cable eye/forked ends screwed into opposite ends of a brass barrel. The threads on one side of the brass barrel are a right hand thread; the other side has a left hand thread. (Now, children, put your thinking caps on!)
With the right hand threaded assem- blies on top and the left hand threaded assembly on the bottom, they are attached to the control cables, and turning counter-clockwise, you will tighten the cable - the same for the other assembly on the control column. (Now it gets interesting).
With the yokes turned to the right, and with the installed chain/sprocket mechanism to straighten/rotate the yoke to the left, the right turnbuckle has to be tightened counter-clockwise and the left turnbuckle unit, converse- ly, has to be loosened clockwise to keep the cables taut. (And you thought a Rubik’s Cube was tough!)
Here is a True or False test (see Bolt and Nut pix):
With a large nut vertically in the left hand, and a large bolt in your right hand, screw the bolt in the top of the nut. It goes in the nut clockwise - doesn’t it? OK.
Take the bolt out and screw it in from the bottom with the nut still in the same position and screw the bolt in clockwise position. T or F?
Note: Another confounding lack of ergonomic engineering was the sepa-
rate hot and cold faucets on the bath- room sink. To turn ON – hot, counter- clockwise; cold,clockwise. As you have observed, these valves have been replaced with a single rotational post unit that would have pleased Harry Houdini.
Upon adjusting my yokes statically on the ground, I decided to skip the safety wire that affixes the brass threaded barrel in place so that I can do minor adjustments while in flight.
There is an advantage to “in situ” flight testing. That is to say, any equipment, or hardware tested upon on-board aircraft, must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may work, but interference from nearby equip- ment may create unanticipated problems.
The flight to Mexico, MO, was on a beautiful clear day, with very little turbulence, and I landed at the Zenith Aircraft Manufacturing plant which is adjacent to the FBO. On the return trip at 7,500 feet, I decided to correct the yoke problem at this point in time as it was a two plus hour trip back to FYV.
The yokes were still in the same position as the static adjustment didn’t fix this problem. I trimmed the Pacer and achieved a constant altitude. I then leaned forward, arm under the panel, and with my face against the instru- ments. I started to rotate the turnbuck- le barrels with my left hand and my right hand was on the right yoke to keep the plane steady and on course. During the adjustment procedure, somehow or other I was loosening instead tightening and vice versa, but the yokes were turning un-explicably clockwise. What had I done wrong? My temperament got a hold of me and my Naval verbiage came spouting out! I continued turning the turnbuckles with my head pressed against the panel with only the VSI and Attitude Gyro in view in the corner of my eye.
At this point of time, the unthinkable happened. The left turnbuckle thread- ed end separated from the aileron con- trol cable and disappeared down into the control column boot to the bottom of the aircraft. I now had no left aileron.
It now occurred to me some serious decisions had to be made or I was going to be driven to the bone orchard.
The first thing that popped in my head was all of the training that vari- ous CFI’s over the years taught me and - “FLY THE AIRPLANE!” This edict came screaming out of my head.
Secondly, after getting over the shock of this predicament, lifesaving decisions started to formulate. My psy- chological attitude at this juncture was complete anger at myself and I was determined that I’d be damned if I was going to die this way! The humiliation
that I would die with was unacceptable and would haunt me to the grave.
With my head still against the panel, left hand holding on to the dangling yoke chain so it wouldn’t jump the sprocket wheel, the aircraft was still level and flying stable, but not for long. As I peeked over the panel, humped over, ahead at my altitude was some serious IFR and before I real- ized, I was in it. I had to descend to 3000 feet to VFR. With 25 hrs. of instrument training, my eyes were glued to the VSI, the attitude gyro, and the CDI. A descent rate of 500 FPM, 1500 RPM, and 10 minutes later I broke out of the clouds, level, and on course.
Now with the plane level, on course, with my mouth dry as death valley river beds, and discovering that I can let go of the left dangling yoke chain by keeping the tension on the right yoke, the chain stayed on the sprocket. The bottle of water on the seat sure did taste good as I sat back on my seat reflecting how in the hell did I get myself in this predicament.
Not surprising, another situation was developing. I was approaching Springfield, MO, Class C airspace dead on, with a 5300 MSL, 2500 MSL bottom tier. I had to turn Pearl to go around this controlled airspace. Calling Springfield Approach, and declaring an emergency, was out of the question. I knew Pearl could turn, with rudders only, as it had been done when eating a sandwich or performing a relief function. I also realized a coordi- nated turn with right aileron could be performed, but I opted for the rudders only, rather than have the chain com- ing off the sprockets. It paid off, and I was clear of the Class C and on course to FYV.
I was practicing gentle turns with rudders only while maintaining rota- tional pressure on the right yoke. I was
100
30 miles out of FYV, and unfortunate- ly, to my shocking surprise, the chain came off the right sprocket and both yokes did a 180 upside down with the two chains dangling happily with each other. With no aileron function at all, it was pucker time. I now knew that there was no way this PIC was going to become a statistic at FYV with fire engines, the press, the police and the FAA. I was now madder than hell and the adrenalin was coming out of my pores with the thought, “I am going to land this S*#!B.”
Still practicing gentle inputs on the rudders, a call was placed to the FYV tower notifying that N3383A was on a 10 mile final. With nonfunctional yokes in the upright position, the tech- nique of “leading in a turn” was applied. This is like turning a rudder of a ship to a predetermined heading, but stopping before you reach the heading due to the continuation of the ship’s mass. One could say it’s a “meander- ing yaw.”
A call to ATIS and I heard that the wind was 160 at 5 - right down the runway. The tower greeted me:
“Cleared to land 16.” “How you doin’ Franco?” “Just fine.” With a standard approach of full
flaps, 500 fpm, 1200 rpm, 75 mph, with very light inputs on the rudders, Pearl squeaked on the runway. I don’t remember taxiing to my hangar as I was in quiet meditation thanking the good Lord for being my copilot.
Godspeed, Franco
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