Unicom

May 2004 Issue




Unicom: 05/04

Cirrus vs. Cessna
I thought your article “Has Cirrus Delivered?” [Safety Review, March] was particularly interesting because it so happens that I owned a Cessna 182S and a Cirrus 20. When I checked the statistics and fleet size of the two airplanes, I discovered to my amazement that the 182S had a higher accident rate than Cirrus.

I am somewhat confused by the statistics in the chart that indicate that the 182S and 182T have suffered seven fatal accidents. When I checked the NTSB database, 10 fatal accidents are recorded, eight for the 182S [mine included] and two to the 182T. The conclusion that I reached that for the period of 1999 to 2002, was that Cessna had more accidents than Cirrus.

Personally I was amazed at the statistics because I was also of the opinion that the Skylane was one of the safest airplanes around. It is my opinion that the reason the 182S had such a high accident rate was because a new autopilot and GPS system was introduced and the buyers were not informed how to use the system. I know in my case, I was given the keys and that was it. Somehow, the aircraft manufacturers and/or insurance companies have become aware that with an airplane with new systems, a transition training is a must.

I also question the fleet hours you quote for the 182S/T. The average age of those 182S models is three years and the 182T is 1.5 years at most. My guess is that it is closer to 350,000-400,000 than the estimate of 644,640 you quote. You may be low on the Cirrus numbers. I know in my case the 182S had 300 hours for our two years of use, while the SR20 has 480.

I am now eagerly awaiting my new 182T, with a Garmin 1000, and I wonder if the factory will provide any transition training.

-Simon V. Haberman
Via e-mail


The data we reported in the chart were for U.S. aircraft only. Note that three of the fatal accidents you cite did not involve U.S. operated aircraft, even though two of them retained N numbers. (The fleet numbers and fleet hours were for U.S. operations as well.)

As far as the fleet hours go, we arrived at the Cessna numbers by counting the number registered (according to serial number) and multiplying that by the average yearly hours per aircraft as generated by Aircraft Bluebook Digest. They’re not perfect, but we accept them as a ballpark figure.

The Cirrus fleet hours were generated by the manufacturer, which is keeping track of flight hours to the extent possible as a way to measure ongoing airworthiness issues that may crop up in the airplane.

For what it’s worth, Cessna says it is developing a special transition training program for aircraft equipped with the Garmin 1000.

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The Chute Stops Here
In your article on Cirrus you state “the parachute would not likely have been a factor in any of the fatal accidents Cirrus planes have suffered.” This directly contradicts the NTSB report on the April 2002 fatal SR22 accident in Parish, N.Y., in which the NTSB says the cause of the accident was: “The pilots’ failure to maintain airspeed, which resulted in an inadvertent stall/spin. The continued spin to the ground was a result of the pilots’ failure to deploy the onboard parachute recovery system, for undetermined reasons.”

This accident occurred a little over a month after the first deployment failure mentioned in your article. It was less than a month after a Cirrus demo to restore faith in the CAPS system (3 planes were tested and 2 failed).

-Art Pileggi
Via e-mail


The NTSB did indeed cite the pilots’ failure to deploy the parachute, but we think the dynamics of the flight in question were too complicated to be certain about that conclusion. The pilots involved were flying aggressively – some say to the point of aerobatics – and it’s unclear from witness accounts exactly what maneuvers were taking place at the time of the fatal spin.

While you are correct in that deploying the parachute may have saved the two pilots’ lives, we think their flight profile shows poor enough judgment that the fact they didn’t deploy the chute shouldn’t come as much of a surprise.

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The Risk of Spins
Thanks for emphasizing risk management as the key to avoiding accidents [Editor’s Log, March]. As a traffic safety researcher and a flight instructor, I see things very much the same way. As you point out in the subtitle: “What’s the point of good stick and rudder skills if you make decisions that will lead to grief?” That’s exactly the point, and may I add the question: which is more fun to a pilot: training for stick-and-rudder skills, or training to restrict yourself from flying?

But toward the end of your column I fail to follow the conclusion. You advocate spin training as a “must” for pilots. For one thing, it seems to contradict the subtitle, as it implies dedicated stick-and-rudder exercises.

And if you look spin accidents, you will realize that 90 percent happen at an altitude where even an aerobatic champion will not stand a chance to recover. And evidence from places where spin training is required seems to show that pilots who have been taught to spin will kill themselves in spin accidents at a substantially higher rate than other pilots.

Of course I do not oppose to training handling skills in general, quite to the contrary. But it seems that training for something you should rather avoid altogether is, simply, dangerous. Perhaps that isn’t so strange after all.

Please stick to your initial, very good point about “decisions”. And please do not advocate general spin training in the name of safety, because as I see the evidence, it does not work.

-Henrik Vaeroe
Roskilde, Denmark


In our book, the value of spin training lies in what it teaches you about the aircraft’s handling at the slow edge of the flight envelope. This is an area we think many pilots are deficient in and we think that’s reflected in the huge number of runway loss of control and overrun accidents that stem from the fear of low-speed flight.

We don’t expect spin-trained pilots to be able to recover from a pattern altitude spin; we expect them to avoid it in the first place – without resorting to miles-wide traffic patterns and high speeds down final. Perhaps spin training is the wrong term for it. Maybe “slow flight training” is more precise?

We don’t really see a disconnect between risk management and such training. The important thing is that the pilots becomes aware of the aerodynamic forces involved in the slow-speed regime as well as the consequences of avoiding flying slowly in the first place.

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Trim Explanation
Since subject article is a “Staff Report”, I presume more than one author and proofreader was involved in the writing thereof.

It appears that a misstatement was overlooked. Under “Design Challenge” the second sentence, I think, is in error. It states, Quote, “When you trim the nose down, the trim tab goes down, nudging the elevator to deflect upward”, Unquote.

On every airplane I have owned or flown since 1958, to trim the nose up, the trim tab moves up and the elevator surface is caused to deflect downward, raising the tail and lowering the nose.

Did I miss something, or did you?

-Harry E. Bladow
Sierra Vista, Ariz.


You missed nothing. We put ourselves on double-secret probation.

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The Human Side
Just wanted to say thanks for an excellent commentary “The Easy Sell” [Editor’s Log, February]. Kudos to you!

And after reading John King’s article “Desperate, On Top” [Instrument Check, February], all I can say is: “Wow!” I have a newfound respect for the Kings. After seeing their ads in aviation magazines, they used to look a bit smug. But now, they seem so human.

-David Ellis
San Jose, Calif.


The Kings are very human. And they are the first to admit that they screwed up big time.