New Pilot

With this issue of AOPA Pilot, we begin a new series of ongoing features. Grouped under the title "New Pilot," this collection of concise articles is presented mainly — but not exclusively — with aviation newcomers in mind. In the months to come, "New Pilot" will bring you stories dealing with the basics of flying, from pilot technique to airplane systems to first-person accounts of training experiences. You'll also see helpful tips on stretching your aviation dollars and minimizing risk. Whether you've just obtained your student pilot certificate or been flying for years, we think you'll find "New Pilot" an engaging addition to your magazine. — The Editors

Pilot to Pilot: William K. Kershner

A visit with the spin doctor

BY THOMAS A. HORNE (From AOPA Pilot , August 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 turns, 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 the 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 the 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 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 320 degrees in pitch and 240 degrees in bank 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, two parachutes, and take a few students from time to time.

The best part is, I love this countryside — 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.

How It Works: Making Sparks

BY MARC E. COOK (From AOPA Pilot , August 1992.)

For reasons of cost, durability, and redundancy, airplanes get along with ignition systems whose power player is the venerable magneto. Chief among the mag's virtues is the ability to provide its own power, but sophistication is not on its list of attributes. Being independent of the airplane's electrical system means that the motor will chug along even if you turn off the master switch or suffer a complete electronic shutdown in the cabin.

Broken down into its basic parts, the aircraft ignition system includes two magnetos, ignition leads, and the spark plugs. The mags make electricity and the leads carry it to the plugs, which in turn make the sparks needed for combustion. You have two mechanically and electrically independent magnetos for safety reasons; one could fail, and the engine will still run well enough for a safe landing. (Some Lycoming-powered airplanes have two magnetos in one housing, sharing the drive gear to the engine; these do not offer true redundancy. Look for a "D" at the end of the engine-model suffix, like the O-320-H2AD in late-model Skyhawks.)

Inside every magneto are bundles of wound wire (called coils, there is a primary and secondary) and permanent magnets. The stationary coils surround the spinning magnets to create the electricity that eventually makes its way to the spark plugs. Points, or contact breakers, determine when each pulse of electricity occurs, and a rotor assembly selects which ignition lead gets the juice.

In a perfect world, then, the magneto makes its energy, the points fire it off at exactly the right time, and the rotor, leads, and plugs turn it into a spark where (and when) it's needed most. But the world is not perfect, and that's why we test the ignition system prior to each flight. Though it seems simple at first, what you are really checking on the runup is the whole ignition system, not just the mags.

By turning the key from, say, Both to Left, you are in reality grounding the right magneto, causing its output to cease. (For reasons of description, magnetos have been labeled left and right, which is related to where the mag is on the engine, not which cylinders it serves. Typically, one magneto will serve all cylinders, with half the connections to the top plugs and the other half to bottom plugs. The exact arrangement varies by engine make and model.) The device that carries out this grounding is called the p- lead.

So when you turn the ignition switch from Both to Left, you should see a slight reduction of engine rpm. This is because a single spark plug is not as efficient at starting the combustion event as are two, and so less power is made. Then switch back to Both, let the engine speed stabilize, and try the other mag by itself. You should see the same results. Incidentally, the total mag drop and differential are set by the engine makers but are usually about 175 rpm and 50 rpm, respectively.

If there is no rpm drop on one magneto but a normal amount on the other, two things could be wrong. Either the p-lead has broken — because the system is designed to fail safe, a break in the wire will leave the engine running — or the suspect mag is timed incorrectly. No matter, the airplane should be inspected; a broken p-lead or bad ignition switch leaves the engine ready to run at the push of a prop, regardless of the position of the ignition switch. Be careful.

On the runup, you should also be looking for smoothness. A rough engine on one mag could indicate lead-fouled spark plugs — common on Cessna 152s used in the training environment but possible in any model — or another sort of magneto problem. Try running the engine at a slightly higher rpm and leaning until the rpm peaks, then re-try the mag check. If the engine seems to have smoothed out, it was probably lead; if not, have a mechanic take a look.

Ever wondered where that clicking sound comes from when you (carefully) turn the prop over? Because magnetos have a fixed relationship to the engine (in other words, their timing relative to the engine doesn't change) and most engines need slightly different timing to get good, consistent starts, there is a mechanism to aid starting. Called the impulse couplings, these devices use a clutch assembly to both retard the magnetos during low-speed operation (usually below 500 rpm) and provide a kind of slingshot effect that helps the mags overcome their natural tendency to be weak at low speeds. Still other airplanes use the so-called Shower of Sparks, which employs a battery-powered system to introduce more powerful sparks during starting.

Magneto ignition is not perfect, but it is what one might call (if somewhat tongue-in-cheek) "mature" technology and likely the only one we'll see in production airplanes for the foreseeable future.

Student Pilot Journal: A Stall Gone Wrong

BY MACHTELD A. SMITH (From AOPA Pilot , August 1992.)

I waited. The nose of the Cessna 152 was slightly above the horizon. Power off, full flaps extended, the airplane seemed reluctant to comply. My concentration slackened for a moment.

The stall caught me by surprise. A habitual heavy left foot on the rudder forced the airplane to skid, and the left wing dropped drastically. In an attempt to pull the wing up, I quickly applied right aileron. To make matters worse, I jammed the throttle into the fire wall, assuming that the stall break had occurred. The result: a spin entry to the left, with full power and full flaps extended.

I panicked. My instructor recovered the spin after a 90-degree turn. I was overwhelmed by fear of death.

The potential for a spin now loomed behind every stall I would practice, a terrifying thought that aversely affected my flight training. I became afraid of the airplane.

Until that day, I had not paid much attention to the placards on the instrument panel. Spin recovery procedures were prominently displayed on the 152's console. Reading them now, I was convinced that every flight was doomed to terminate in a spin. That thought occupied my mind during every lesson. It crippled my progress severely.

Spins were so much on my mind that when my instructor recommended spin training, I was ripe for the suggestion. This sinister fiend had to be slain.

I would learn how to enter a spin and recover from one. This would also boost my confidence, my instructor said. I agreed.

The day of spin training had arrived. I anxiously preflighted the airplane. I felt the urge to inspect every inch of the fuselage twice to make sure it would not come apart during the spin.

My instructor and I departed the pattern for the practice area. "It's now or never," I thought, white knuckles clamped on the yoke. He asked if I was all right. I nodded confirmation, determined to go through with it.

"Let me demonstrate the first spin. Keep your hands on the yoke and your feet on the rudder so you feel the input needed for spin entry and recovery. We'll do this one to the left," said my instructor. He set up a stall with a hint of power. At the break, he idled the throttle, maintained full aft yoke, and kicked full left rudder. The earth rotated in the windshield. My head seemed to snap backwards, and I became totally disoriented.

After my instructor pushed opposite rudder, the airplane stopped turning. We were in a dive. "Notice how I gently pull back on the yoke to avoid exceeding the redline," he calmly commented.

It now was my turn. A fly buzzed across the control panel oblivious to my fate. He seemed unaffected by the earlier spin. Encouraged by that thought, I flew the airplane into a left spin and once again, the earth came up to greet me. I was prepared. Right rudder and forward pressure on the yoke stopped the spinning motion. A glance at the airspeed indicator revealed that speed was accelerating toward the redline at an alarming rate. I instinctively wanted to yank the yoke back but then remembered to gradually pull the nose up.

It was an awesome experience. A feeling of relief swept over me, and my anxiety began to subside. I practiced some more spins to the left and several to the right.

Proud of my accomplishment, I felt like an ace when we returned to the airport. I had confronted the fiend and defeated it.

Spin training has been invaluable to me. Without it, I would have always been subjected to the fear of the unknown: the spin that looms behind every uncoordinated maneuver. With it, I have gained a better understanding of aerodynamics and of my limitations and capabilities. I now know how to cope with the worst that can happen when a stall goes wrong.