Pilot to Pilot

William K. Kershner

August 1, 1992

The television screen comes to life, and it shows a Cessna 150 in an extreme nose-high attitude. Suddenly, a wing drops, the airplane rolls over, and a spin develops. Make that plural — spins — 21 turn, to be exact. At every turn and a half, the Cessna's nose momentarily rises. "See that?" says Bill Kershner, "that's where the spin goes into a flatter mode, but just for a bit. Then the nose drops back into a normal spin."

Another tape is fed into the VCR. This one shows the same flight, but the camera angle is from the pilot's perspective. The ground whizzes by in a dramatic blur as Kershner counts the turns. "Six, seven, eight — there, the prop stopped — nine, ten ..."

Kershner displays unabashed glee as he plays his spin tapes. To those who don't understand Kershner's background, his pride in performing so many consecutive spins may seem, well, a bit unusual, even for a pilot. But Kershner is not your ordinary pilot. He's one of the nation's preeminent flight training educators and an expert in the fields of spin training, aerobatics, and airplane stability and control. He's served as supervisor of experimental flight testing at Piper Aircraft Corporation, as a naval aviator flying Corsairs and Cougars, and as a spin instructor for prospective test pilots at the Naval Air Test Center at Patuxent Naval Air Station. Oh, yes, he also gave spin training to astronaut Neil Armstrong while teaching at the University of Tennessee Space Institute.

Most know of Kershner by his very popular series of six flight training manuals, of which more than 1.25 million copies have been printed. The Student Pilot's Flight Manual alone has passed through the hands of 740,000 aspiring pilots. A great deal of his manuals' popularity is due not just to Kershner's facile writing style, but to his down-home humor as well.

His most recent manual, The Basic Aerobatic Manual, is testimony to Kershner's enthusiasm for aerobatic training. In addition to publishing his manuals, Kershner also conducts — on a limited basis — one-on-one aerobatic and spin training courses at Sewanee, Tennessee's Franklin County Airport. His spin training courses consist of three to four hours of ground school and two hours of flight instruction. In those two hours, a total of about 20 to 25 spins will be performed. Calling his one-airplane (a Cessna 152 Aerobat) operation "the nation's smallest flight school," Kershner has put some 400 students through the kind of paces that other schools cannot — or will not — provide.

We caught up with Bill Kershner one rainy afternoon in Sewanee and took advantage of the weather-induced lull in his activities to ask him a few questions.


AOPA Pilot: After seeing your tape and reading your manuals, it's obvious that you're a strong proponent of aerobatic and spin training. Why is that?

Bill Kershner: First of all, it's fun. But the main thing is that unusual attitude practice is becoming a lost art. You have a lot of pilots out there who are very uncomfortable with more than 60 degrees of bank or 20 degrees of pitch. That means that there's 240 degrees in bank and 320 degrees in pitch that they've never experienced.

To be a really safe pilot, I think you need to know how an airplane can behave in all attitudes.

Why 21-turn spins?

Well, I did that alone, with a parachute and a properly certified airplane. I did it so I was sure I knew the airplane's spin behavior. You saw how the 150 has a flatter mode at several points in the spin cycle — not that it's dangerous, but it's just a characteristic. Those flatter modes also debunk a lot of hangar talk about the 150 and 152. You hear a lot about how "boy, that 150 really winds up in a spin." But it doesn't. So without doing a lot of turns, you can't really know how the airplane will act if an extended spin occurs. Here's something else: The engine quits after eight turns in a 150. That's because centrifugal force moves the fuel away from the tank's ports. For the same reason, you can tell if you're in a spin — rather than a spiral — by looking at the 150's fuel gauges. In a spin, the fuel gauge floats are resting against the bottom of the tanks. In the 152, it takes 12 turns for the prop to stop because there's a couple of extra gallons of usable fuel.

Centrifugal force also makes the rudder ball move to the outside of the instrument - no matter which way you're spinning. So on the pilot's side, the ball will always be to the left. I've installed a slip indicator on the copilot's side of my Aerobat, and on that side, the ball is always to the right.

So once you're in a spin, don't use the ball to figure out which way you're turning. Use the turn indicator, or coordinator, as the case may be.

By the way, I figure I've done a total of about 3, 760 spins in my current 152. My record for most consecutive turns is 25.

Do you think spin training should be mandatory?

No, not at all. It's just a very good idea, and I think everybody should be encouraged to do it on a voluntary basis. But — and here's the big thing — only do it with a properly trained and experienced instructor. There are plenty of instructors out there who just aren't up to the task.

About 70 or 80 of my students were instructors themselves, but they came to me to make sure they got a full indoctrination. I teach spins under the hood, for example. I also teach spin recoveries that you might call survival training. For example, I've taught spin recoveries using ailerons only in my airplane, N7557L; in my 152, you can stop a spin by holding full aileron against the rotation. That takes about four turns to take effect. This kind of training can be very helpful if an instructor had a very strong student who froze with aft stick and holding a full rudder deflection.

Let me say right here that this method applies to my airplane. I don't want anybody to get the idea that this will work in any airplane. There are great differences between airplane types and between individual airplanes within a type. Slack control cables and poor rigging, to name just a couple of factors, can compromise spin recovery.

Have you ever had to put your own aerobatic training to use in a critical situation?

Yes. In 1950, I was on final for a landing at Memphis. I was right behind a flight of five or six C-46s, flying a Stinson 108.

Suddenly, the airplane rolled inverted. I'd been teaching aerobatics in a Meyers OTW, and so I reflexively pushed on the stick as I rolled. I made a recovery, but I was shook up. As I recall, they were using Runway 21, but I flew around and landed on Runway 27 instead. Anyway, I remember my legs were shaking.

We didn't know anything about wake turbulence back then. We just called it "prop wash."

Do you think your training prepares a pilot for a wake turbulence encounter?

It can sure help, but there's no guarantee of a safe recovery — especially at low altitudes. With my students, the best recovery I've ever seen from inverted flight consumed 150 feet of altitude. Remember, this was in a controlled situation where the pilot knew what to expect.

Now on that same flight, I pulled a trick. To distract the pilot, I called out traffic that was "real close." While the student was looking for the "traffic," I grabbed the controls, rolled inverted, then told the student to recover. This time he took 1,500 feet to recover.

Based on my experience, if a pilot gets upside down, he'll instinctively pull back on the stick every time — unless he's had aerobatic training. This, of course, is how you do a split S, which is bad news when you're down low.

Spin training aside, what do you think is the biggest deficiency in pilot proficiency today?

We need to see more attention paid to the basics. Just concentrate more on what the airplane is doing at all times, not just during landings. Not using a check list really bugs me. You hear a lot of people putting a high value on the instrument rating, saying, "Oh, he's instrument rated, he's got to know his stuff." Then you go flying with them and see all these very basic problems coming out. So by itself, an instrument rating may not really mean much at all, depending on the pilot's other skills.

Any pet peeves?

Not really. My life's been great. When I left Piper in 1964, people said I was crazy to leave a good job like that to move to Tennessee and write books. But for me, it was the fulfillment of a lifetime dream: to come back to my home state, do a little writing, and do a little flying.

I like to say that I retired at age 34. But I'm working harder than I did before; got an office at home and an office at the airport, right next to our airport manager, Glenda Hall. I have an airplane [and] two parachutes and take a few students from time to time.

The best part is, I love this countryside — I own 500 acres on that ridge over there.

What are your latest projects? What can we expect to see next from Bill Kershner?

Well, I'm doing some original work on locating the spin axis. I plan to use protractors and weighted strings to measure the strings' deflection angles during the spin. These measurements are made at various stations along the interior of the cabin. Once the angles are determined, I should be able to project their apexes. Connect the apexes, and you should be able to find the axis, but I'm not sure at this point.

I'm also in the middle of revising The Flight Instructor's Manual. So by this fall, it should be in print.

What would you say to those just starting their flying lessons, especially those considering a flying career?

First of all, I feel sorry for them. The fact is, it's harder to find a flying job today than it was back when I started — and it was bad then. But I would say stick with it. We're in a slump, and it may stay there for a while. But don't give up just because it looks bad now.

Pilots starting out now may well hit a period of peak demand later, when more professional pilots are needed.

Most of all, I wish them well.