A pre­cip­i­tous loss of power


Flying - - Contents - By Stan Dunn

I dis­cov­ered avi­a­tion years ago af­ter win­ning a free hour in a United Air­lines DC-10 sim­u­la­tor. It wasn’t long be­fore I started tak­ing fly­ing lessons at Cen­ten­nial Air­port in Colorado, where I trained in the high-den­sityalti­tude days of sum­mer. If noth­ing else, the ane­mic air­craft per­for­mance taught me dis­ci­pline as it re­lated to air­speed: If you are un­sat­is­fied with your rate of climb at Vy, in­creas­ing pitch won’t help.

Af­ter an in­ter­mit­tent few years of flight train­ing, my fam­ily fi­nally prod­ded me into an ad­min­is­tra­tive po­si­tion at a flight of­fice in Los An­ge­les. I packed my bags and drove to the coast, plan­ning to quickly earn my com­mer­cial cer­tifi­cate once set­tled. In­stead, I filled a sur­pris­ingly af­ford­able room a block from Her­mosa Beach with surf­boards and sand, and six months later I had yet to fly over South­ern Cal­i­for­nia.

Even­tu­ally, I was in­tro­duced to an air­line cap­tain who also owned a flight school. He gave me the num­ber for a 19-year-old CFI, and we got to work fin­ish­ing up my com­mer­cial li­cense. Soon, all that was left was to build the pre­req­ui­site hours for the prac­ti­cal test. A flight up the coast sounded like a great way to waste a Satur­day, and the clam chow­der in Mon­terey is renowned. It was go­ing to be a long flight in the slow­poke Cessna 152, but I was ex­cited to see the sights and build some time.

I de­parted early from Daugh­erty Field in Long Beach. Dur­ing the run-up, the left mag­neto threat­ened to drop be­low the rpm limit; I ran the test sev­eral times be­fore I was sat­is­fied that it was sta­bi­lized on the bor­der­line of al­low­able. I thought, this is not nor­mal, but it is le­gal. It is a con­cept that I now know should raise red flags.

I took off from LGB and made my way across the tan­gled LAX morass, break­ing out of Class B airspace just past Mal­ibu. It was a beau­ti­ful day, smooth as glass. I had the Pa­cific to my left and the Santa Mon­ica Moun­tains to my right. The air­craft was trimmed and hum­ming; I was main­tain­ing alti­tude with gen­tle in­puts from my thumb and fore­fin­ger. The Pa­cific coast was slowly guid­ing me to­ward Peb­ble Beach, a few miles from Mon­terey Air­port. An ideal flight if ever there was one.

Then it hap­pened. All at once, the air­craft be­gan de­cel­er­at­ing. The en­gine was still crank­ing, but there was a pre­cip­i­tous loss of power. My heart hit my throat as I glanced at the air­speed in­di­ca­tor: There is not much room be­tween cruise and best glide speeds in the 152. I in­formed ATC that I was not go­ing to be able to main­tain my as­signed


6,000-foot alti­tude and re­quested vec­tors to the near­est air­port.

The con­troller gave me a head­ing to Ca­mar­illo, which pointed me di­rectly at a 3,100-foot ridge; I quickly sur­mised that my glide­path would not clear the hill. Still, the en­gine had not yet failed al­to­gether, and I hoped that I could milk enough power to crest the ter­rain.

The con­troller asked if I needed as­sis­tance. I im­me­di­ately de­clared an emer­gency. The fre­quency went silent as I ac­com­plished the emer­gency pro­ce­dures (and as the con­troller likely got on the line to Point Mugu Naval Air Sta­tion — which was a few miles closer than Ca­mar­illo — to let them know they might soon be host­ing an un­in­vited guest).

The first thing I did — with the weak left mag­neto fresh in mind — was cy­cle the ig­ni­tion to the right side. No luck. I con­firmed that the fuel se­lec­tor was fully open and the primer locked. I set the mix­ture to rich. As an af­ter­thought, I turned the carb heat on. A few mo­ments passed, and the en­gine re­turned to nor­mal.

A re­sponse to an in­put does not al­ways

mean that the in­put caused the re­sponse. Par­tic­u­larly when sev­eral ac­tions are per­formed in rapid suc­ces­sion, it can be dif­fi­cult to de­ter­mine which ac­tion (if any) ac­tu­ally pro­duced the out­come. Since the last thing I did be­fore the en­gine re­turn­ing to nor­mal was ap­ply car­bu­re­tor heat, it seemed like the two were re­lated. I was (at the time) flum­moxed: Car­bu­re­tor ice grad­u­ally re­duces power be­fore the on­set of rough­ness; I had been fly­ing in a per­fectly trimmed con­di­tion right up to the mo­ment when the en­gine sud­denly de­cel­er­ated. The symp­tom didn’t fit the dis­ease.

I wasn’t com­plain­ing as I pow­ered into Ca­mar­illo. I tax­ied off the run­way, found a park­ing spot and breathed. As I ex­ited the lit­tle plane, I saw the cutest air­port restau­rant I’ve ever laid eyes on. I grabbed a burger, called the flight-school owner, and we had it out.

I de­scribed the sce­nario, and he hollered at me for de­part­ing Long Beach if I had any con­cerns about the mag­neto. I had been fly­ing long enough to know that he would have been hol­ler­ing at me if I had re­fused an air­craft op­er­at­ing within limit. He was clearly more up­set with the in­con­ve­nience of hav­ing the air­craft stuck at Ca­mar­illo than he was re­gard­ing my close call. He told me to run it up and fly it back. He told me it was car­bu­re­tor ice. I let him know how con­fi­dent I was in an arm­chair di­ag­no­sis.

The mag per­formed the same as it had in Long Beach (right at the limit). I de­cided it wasn’t good enough. I called the owner and told him he could do what he wanted with the Cessna; I was go­ing to catch the shut­tle to LAX. He was un­happy, and I de­cided on the spot that I would not be fly­ing his Cessna 152s any­more.

For all of that, I still had a com­mer­cial li­cense to get. I even­tu­ally found a fly­ing club and got the hours I needed. The prac­ti­cal test re­quires a re­tractable gear, how­ever, and the flight club did not have one. Though I had sworn off the air­line cap­tain’s flight school, it had a Piper Ar­row for less than a hun­dred bucks an hour. I even­tu­ally re­lented and called the 19-year-old flight in­struc­tor to see about sched­ul­ing some time in it.

The in­struc­tor told me he wasn’t work­ing for the flight school any longer and the flight school was no longer owned by the air­line cap­tain. He ex­plained why, and sev­eral months later I read a Na­tional Trans­porta­tion Safety Board re­port that sent chills up my spine.

It was a typ­i­cal South­ern Cal­i­for­nia day — 71 de­grees, clear skies, with a 10-knot sea breeze. The only thing remarkable about the day was the date: Septem­ber 11, 2005, the fourth an­niver­sary of the ter­ror at­tacks. It would be the last day that this par­tic­u­lar C152 would fly.

Thirty sec­onds af­ter de­par­ture, the CFI who was fly­ing the Cessna re­ported poor climb per­for­mance and re­quested a re­turn to the field. Wit­nesses on the ground noted that the air­craft had a high pitch at­ti­tude, with the wings and tail waggling. In the at­tempt to turn back to LGB, the un­sta­ble flight pro­file be­came a stall, and the stall a spin.

The C152 crashed ver­ti­cally into a park­ing lot. The flight was a train­ing flight with a CFI and a stu­dent pi­lot. The CFI was 25 years old (the stu­dent pi­lot was not cer­tifi­cated, so the NTSB had no par­tic­u­lars re­gard­ing that oc­cu­pant).

A 100-hour in­spec­tion four weeks ear­lier had logged the en­gine at 2,762 hours; the rec­om­mended time be­fore over­haul was 2,500. Ly­coming rep­re­sen­ta­tives noted that only one cylin­der had spark plugs in ser­vice­able con­di­tion; all the other spark plugs were worn be­yond lim­its. The NTSB re­port men­tions that the air­craft was found with the mag­neto se­lec­tor in the “right” set­ting (“both” is the nor­mal po­si­tion). I had a sense of déjà vu.

No one can say for sure what tran­spired on that fa­tal flight, but given the fact that it oc­curred a short month af­ter my flight — and given the fact that main­te­nance was ob­vi­ously not a pri­or­ity on the air­craft — it seems likely that lit­tle was done to the Cessna fol­low­ing my di­ver­sion into Ca­mar­illo. The air­craft had bad spark plugs when it crashed; I am quite con­vinced that it had bad spark plugs when I flew it.

I was lucky. My event oc­curred at 6,000 feet, with time and alti­tude to spare. It did not oc­cur over con­gested ter­rain with mere sec­onds cor­ner­ing the abil­i­ties of a young man. Some con­di­tions in flight re­sult in an un­de­sir­able out­come no mat­ter the skill level of the pi­lot. Some are such a sur­prise that there is lit­tle hope of a proper re­sponse. Brief­ing the worstcase sce­nario be­fore ev­ery flight can help (in a sin­gle-en­gine air­craft this would in­volve a power loss be­low an alti­tude where a safe re­turn to the field can be made). Still, an ounce of pre­ven­tion is worth a pound of cure.

The pres­sure to com­plete a flight can lead to bad de­ci­sions. When we want some­thing, we have the ten­dency to un­der­es­ti­mate risks and over­es­ti­mate re­wards. The stronger the de­sire, the more blind we be­come to the con­se­quences. It can hap­pen to you. Never for­get that.


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