Negative Charge

What you know makes what you dont know harder to learn. Got it?


Its crucial to learn the right habits from your very first flights because they form the foundation of your skills for the rest of your flying career.

When the proverbial fertilizer hits the fan, people tend to revert to their earliest patterns of responses. The problem is, sometimes thats not the right response.

During a badly bounced landing for example, the pilot has very little altitude and airspeed to use in trying to execute a go around or other recovery. In most aircraft, a go-around requires bringing the nose up to about 5 degrees above the horizon and adding full power.

Thats apparently what the crew of a Twin Otter tried to do after a bounced landing. This tale isnt about a botched go-around though. Its about reverting to the habits you first learned and how those habits may backfire.

After touring the Grand Canyon, Canyon Five reported five statute miles northwest of the airport and the local controller cleared the flight to land on runway 21. The two air traffic controllers who were on duty in the tower described the airplanes approach as normal, and each controller diverted his attention from the airplane in order to locate traffic that was entering the pattern.

When they looked back at the runway, Canyon Five was off to the right of the runway with a cloud of dust at its tail. It was angling back toward the centerline of the runway in an unusually nose-high attitude. The airplane continued to climb as it passed the tower and reached an altitude of 150 to 200 feet above the runway.

Then it rolled to the left and crashed into trees on a hill on the east side of the runway. Shortly after impact, the controllers activated the crash alarm and telephoned 911.

During accident reconstruction, the NTSB determined that the aircraft floated down the runway at about 5 feet for about 1,000 feet. The aircraft bounced and flew another 1,000 feet before the wing tip touched the runway. Regardless of why the bounce developed, the airplane was airborne after the bounce and most likely transitioned to a near-stall condition.

The investigation sought to determine the factors that might have caused the pilots to lose control of the airplane during the go-around. The pilots reaction might have been to raise the nose and add power for the anticipated go-around.

At airspeeds near stall, the downwash on the horizontal stabilizer tends to raise the nose of the airplane, requiring the yoke to be pushed forward to maintain a normal pitch attitude for the same trim setting. If the pilot pulled back on the control yoke while adding power, this could have resulted in the airplane lifting off to a nose-high, power-on stall or near-stall condition.

In addition, the visual reference may have been misleading. According to the operations manual for the DHC-6, with full flaps (40 degrees), the airplanes deck angle is below the flight path during a go-around. Therefore, an increase in pitch to a typical nose-up reference attitude while the flaps were at 40 degrees would increase the possibility of aerodynamic stall.

The first time I received dual instruction in the Twin Otter, the check airman warned me about the go-around pitch attitude with full flaps. We did a practice go-around at altitude and you just naturally want to bring the pitch up to about 5 degrees above the horizon. Its very strange to leave the nose below the horizon for a go-around.

A helicopter pilot may think its normal to go-around with the nose below the horizon, but most fixed-wing aircraft normally go around with the nose above the horizon. It doesnt matter how much you tell yourself to be careful about the go-around, its all too easy to fall back into that first learned habits when time is short.

When previously learned techniques are inappropriate for the current aircraft, environment or procedures, thats called negative habit transfer. Its reported that negative habit transfer makes the chances of human error five times higher.

But Ive Always Done It That Way
Pilots who learned how to fly in tricycle-gear aircraft – which is probably 99 percent of the pilot population – have feet that tend to be somewhat lazy when compared with taildragger pilots.

Tricycle gear aircraft are definitely less prone to ground handling problems, and thats better for the overall safety of general aviation. But the downside is that the rudder has become a less-than-understood control. When you first fly a taildragger or a glider, you will find the instructor continuously reminding you of the rudder.

Most multi-engine pilots have been trained during engine failures to counter the roll and yaw into the failed engine with appropriate amounts of rudder and aileron. That works fine as long as you have enough airspeed and enough control effectiveness.

Of course near the minimum control speed, progressive use of the ailerons creates even more drag out near the wing tips and creates more control problems, a factor that is covered during initial training in multi-engine aircraft.

Unfortunately, the use of both rudder and aileron/spoiler on some multi-engine aircraft can lead to instant control problems. A common turboprop aircraft uses spoilers for roll control. During an engine failure on takeoff, the reduced propwash behind the failed engine creates a very big loss of lift and a large increase in drag, resulting in the roll and yaw into the failed engine.

Now lets say you counter the roll and yaw with both spoilers and rudder. By moving the yoke sideways, you destroy lift on the rising wing at a time when you need all the lift you can get. Experienced instructors in this aircraft shudder at the thought of a student moving the yoke sideways during a simulated engine failure on takeoff or go-around. It is a rudder-only maneuver.

If you transition to swept-wing aircraft, youll find that some past habits can be a real hindrance. During those simulated-engine failures on takeoff, youll find out very quickly that swept-wing aircraft can be rolled very easily with the rudder when the aircraft is at relatively high angles of attack.

When you yaw a swept-wing aircraft, the forward-moving wing experiences a relative wind that is more directly aligned with the wing. Hence, it creates more lift and less drag. Conversely, the rearward-moving wing experiences an airflow at a higher angle across the wing, created less lift and more drag. During high angle of attack maneuvers, the difference between the lift and drag of the two wings is very pronounced. That makes the rudder highly effective as a roll-control device.

This is particularly important for engine failures during takeoff, go-arounds with an engine inoperative, or during recoveries from abnormal attitudes. Last month during a proficiency check in the B727 simulator, I had to do the normal drills on V-1 cuts. (V-1 is the takeoff decision speed. In theory, an engine failure below V-1 can be aborted within the remaining length of the runway, while an engine failure above V-1 will allow the aircraft to accelerate and takeoff within the remaining length of the runway.)

In some of the aircraft I flew before the 727, the V-1 cut involved a lot of aileron movement. The turbine DC-3 required almost a full deflection of the yoke. It was a handful.

Even though the 727 has its engines fairly close to the fuselage, there is still a distinct yawing and rolling motion with an engine failure. If you try to counter the rolling instinctively with the ailerons, that sideways roll of the yoke will cause the aircraft to drift off heading even more.

Its very hard breaking old habits. I have to sit and mentally rehearse recoveries several hundred times with the rudder only. Its well established in aviation research that when we are confronted with a sudden situation that we tend to revert to the habits we first learned.

Well, I have bad news for taildragger pilots aiming for the big iron. Those busy feet that work so well in something made of tube and fabric can be a hindrance in other aircraft. The 727 is equipped with both ailerons and spoilers for roll control. While ailerons create adverse yaw during a turn, the spoilers help to counter this yaw because they create drag in addition to reducing lift on the lowering wing, hence reducing the tendency of the 727 to yaw very much during turns.

Well, some of us will always be taildragger pilots at heart and during my last proficiency check, the three other check airmen in the sim (all of whom were senior check airmen….how lucky for me!) all chuckled during my first turns. They remarked, You must be a taildragger pilot. I think the poor lady sitting at the rear bulkhead is feeling your rudder. Luckily they were also taildragger pilots so I was in good company.

You Do What?
An area of negative habit transfer that is the most worrisome is post-stall gyrations and unusual attitudes.

I started flying in sailplanes, and under a very regimented military program. When we were learning turning stall recoveries, we were ordered to use opposite rudder first. It didnt make much sense at the time but we still did it.

Instinctively you want to use the ailerons to help roll the aircraft. This however can make a post-stall gyration worse because it can induce a deeper stall on the wing, leading to a spin in many light aircraft. The nasty habit of trying to roll the aircraft with the ailerons can really make the stall recovery much worse.

To make matters worse, when you are confronted with situations that demand immediate action, you tend to revert to your originally learned skills. During the heart-rate-soaring event of a stall and a wing drop-off, its easy to revert to the originally learned pattern of lifting the stalled wing with the ailerons.

If you have flown many airplanes, you have learned first hand that each type of aircraft can vary slightly in its landing flare. Many pilots who learned to fly in Cessnas have the ingrained habit of cutting the power and holding the aircraft that final half-inch off the ground until it bleeds off enough speed to gently roll onto the runway. In fact, in most light singles it is normal to land with the power completed closed.

If you chop the power in the flare in a heavy single or a light twin, it will quickly turn into a hard landing. In twins, the propeller induces a high-velocity airflow over a substantial portion of the wing and therefore creates a significant amount of lift. If you reduce the power, the decrease in the lift is much greater than the immediate loss of airspeed. Bam! Hard landing.

Thats why it is important not to reduce the power to idle too soon in the flare in a twin. This becomes even more important when you fly an aircraft with tip tanks. A hard landing with tip tanks can cause a significant downward force on the wing tips and damage the spar.

The sight pictures for landing can differ substantially between aircraft as well. In most of the newer aircraft, the pilot has good visibility over the nose for the takeoff, landing and taxi. The first time you sit in the back of Pitts, or a J-3 Cub, you will quickly see why taildragger pilots must do S-turns while taxiing.

In most single-engine aircraft, you normally fly the final approach at a fairly low power setting. The nice thing about a piston engine with a propeller is that power is instantly available if you need to add power because of a wind shear or downdraft. When you check out in a jet, particularly the first generations of turbojets, you will be dismayed to learn that you fly the final approach at very high power settings.

Older turbojet engines did not produce much thrust even at 80 percent rpm. Reducing the thrust levers very far on those older turbojets meant reducing the thrust to near nothing. When you realized your mistake and advance the power, the turbojets take many precious seconds to spool up to speed.

When you were taught how to do go-arounds, the instructor made certain you moved the throttle completely forward. That was pretty critical in the underpowered aircraft most pilots learned to fly in. You wanted every single ounce of power to get the airplane speeded up and away from the ground.

With more powerful engines, moving the throttle completely forward can overboost the engine and cause engine damage. Go-arounds in some aircraft are executed at a power setting equal to the top of the green arc.

In turbocharged engines, those rapid throttle movements can easily result in overboosting the engine. As you move the throttle forward, it opens the throttle valve to the engine, which increases the fuel and air flowing to the engine, which means some more power, and more exhaust. This exhaust then exits the engine and drives the turbocharger, which adds additional compressed air to the engine.

The net effect is that there is a lag between throttle movements and power output. The manifold pressure gauge indicates small throttle movements satisfactory, but it doesnt handle big power lever movements very well at all. If you were to move the power levers fully forward during a go-around with most turbocharged engines, it would result in an overboost.

Firewalling the throttle is a habit you may have to modify when flying turbocharged engines, depending on the turbo system involved. With practice, you will know the approximate position of the power levers during a go-around, a position that will bring the manifold pressure to the correct setting without overboosting. However, during your initial attempts to find that position, you will find yourself staring at the manifold pressure gauge trying to fine tune the needles, which seem to move by large amounts every time you touch the throttles.

Transitioning into another aircraft is a prime time for negative habit transfer. It is vital to obtain a quality check out on the full range of the aircrafts performance features, system operations and procedures. Second, there is no replacement for practice.

Some of the manufacturers have deliberately designed their product line so your habits instilled from early flight training will apply well to the higher end designs. For example, once you learn how to land the Cessna 152, the same basic landing technique applies as you step up to the Cessna 172, then the Cessna 182, then the Cessna 206. Transitioning from one make of aircraft to another is a prime time for past habit patterns to become ineffective or maybe destructive.

Transitioning from land planes to float planes, or into other categories and classes of aircraft is another prime time for our past habits to cause some trouble or embarrassment.

The first time I taxied into a ramp area in a floatplane and wanted to slow down, I stomped on the top of the rudder pedals repeatedly, just out of habit. No matter how hard I smashed down on the rudder pedals, it wouldnt slow the aircraft. Im certain I wasnt the first floatplane trainee to do that.

If you really want an exercise in humility, take a helicopter lesson and try to hover. First let me warn you that your helicopter CFI will almost certainly take you out to a clear area about the size of a football field.

After flying fixed-wing aircraft for 10,000 hours, I was startled at how difficult it was to hover a helicopter and how my fixed-wing habits interfered with learning how to handle the helicopter. But boy, was it fun learning.

Is it possible to break your first-learned habits when transitioning to new aircraft or new procedures? Yes, and no.

Extensive practice will help to instill the new procedures. The airlines have cockpit procedure trainers where pilots spend many hours going through dry runs of the procedures for that aircraft.

While most of the general aviation aircraft do not have specific simulators, it is possible to sit in the aircraft, close your eyes, and mentally rehearse the procedures over and over. Practice does make perfect.

-by Pat Veillette

Pat Veillette is an aviation researcher and Part 121 cargo pilot who keeps trying to land his 727 like a Piper Cub.


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