Controls 201

Today's the big day! First real flight “lesson” early in the morning while the winds are still calm. The instructor, Walter Blumenthaller, says we're going to “get familiar with the flight controls and see if we can drive around the sky a little bit.”

Walt is an old timer, retired airline pilot, who loves to fly and instructs just for the fun of it in the two-place Challenger he built himself.

1. Preflight, Engine Start, and Taxi

After doing a rather extensive preflight in which Walt seemed to look at every nut and bolt as if he were seeing them for the first time, we get into the cockpit, buckle up, and prepare to start the Rotax 503 engine. Headsets are on loosely so we can talk without using the intercom.

We turn the switch key ON to activate the electrical system. Both the Left and Right mag (magneto) switches are flipped up to the ON position. Avionics master switch is OFF. Will not turn that ON until after the engine starts.

Walt has an electric fuel pump to pump fuel from the tank up to the carburetor bowls before the engine-driven “pulse pump” becomes active. We turn the fuel pump switch ON and hear the tick-tick-tick of the pump. After about five seconds, we hear a slight change in tone of the ticks, which indicates that the fuel pressure is up. We then turn the fuel pump OFF.

The choke (enrichener, actually) is moved to the fully ON position, throttle is closed to the idle position, and we hold the brakes. We are ready to “light the fires!”

“Clear Prop!” We press the starter button, and the engine turns over quite rapidly. After just a few revolutions, it comes to life, sort of rough at first. We immediately reduce the amount of choke to about half way, and quickly add just a touch of throttle. The engine picks up and smooths out at about 2700 RPM. Gradually we work the choke all the way OFF. We back off the throttle to give an RPM of about 2500 to let it warm up.

Now we turn the avionics master switch ON to supply power to the radio and intercom. Headsets and mikes are adjusted, and the switch on the intercom is turned ON. “You there?” “Yep, loud and clear.” We're talking!

The radio is then turned ON, and we check to see that it is set to the local frequency of 122.8 MHz. Turn the squelch until we get noise and static, and then back just a little until it quiets down. “We're ready to roll.”

We release the brakes, and the Challenger begins to move forward on the ramp. Even though the engine is just above idle, the plane moves readily. A gentle nudge of the left brake tab causes the nose to pull to the left. Same thing for the right. Brakes are working. Walt says it's good to check the brakes before you get to going too fast. Lot of high-dollar airplanes out here to run into.

The field elevation is 700 feet above sea level. We set the altimeter to read 700 feet as we move along.

As we emerge from between the hangars, a push on the left rudder pedal causes the nosewheel to turn and steer the plane as if it were some fancy three-wheel land rover. We are moving too slowly for wind past the rudder to have much effect on turning. A push on the right pedal turns us out across the main ramp area, toward the taxiway.

While we're trundling along across the ramp, we move the stick from side to side, and from front to back, as far as it will go. This ensures there is no binding or other strange “feel” that might indicate a problem with the control linkage. And, strick right gives UP for the aileron on the right. Stick left, UP on the left.

Walt keys the radio, “Davidson County unicom, radio check for Challenger niner Whisky Bravo.” And then, “Good morning, Walt, how ye doin' ?”

“Just a tad short of wonderful,” replies Walt, “We're going out to the northwest practice area and do some sightseeing. Be back in about an hour.”

A right turn onto the taxiway takes us down to the approach end of Runway 24. On the way down, we increase the RPM just a bit so that the Challenger is now rolling at a pretty good clip. Full back stick will now make the nose rise just slightly as the weight comes off the nosewheel, and we can steer without having to use the brakes. At Runway 24, we pull up and stop at the run-up position.

2. Run-up, Takeoff, and Climbout

Still well off the runway, we hold the brakes and run the 503 up to 3400 RPM. We can feel the thrust of the prop causing the C-II to shake back and forth as the propwash flows over the tail. Cylinder head temperatures are above 200 F. Now we check the mags.

The Left mag switch is turned to OFF. Now the engine is running only on the Right magneto instead of both, and the RPM drops by about 40 - 50 RPM. This shows us that the Right magneto is working. Left mag switch back to ON. RPM comes back up.

Now the Right mag switch is turned to OFF. Again the RPM drops by about the same amount. This indicates that the Left magneto is working. Then, Right mag switch back to ON, and a quick glance to be sure that, now, both mag switches are ON. Engine sounds good.

We reduce the engine power all the way back to idle, which is about 2000 RPM. It runs somewhat less smoothly at this low (for a two-stroke engine) RPM, but shows no signs of wanting to bog down and quit. That's good. We ease the throttle back in and the RPM goes back up to 2500.

“Davidson County traffic, Challenger niner Whisky Bravo departing Runway 24, Davidson County.”

We release the brakes and start out to the runway. A quick push on the right rudder pedal swings the plane around until we can see final approach and base leg for 24. No traffic in sight. As we pull onto the runway and line up on the center line, we look down the runway and up onto final and base leg for Runway 6. No traffic there either. Walt says, “Never hurts to look around. Somebody's little ol' radio may not be working or we might not've heard 'em.”

With the plane lined up on the center line, Walt comes on with, “I'll do this takeoff, but you put your feet on the pedals real lightly, and grab the stick lightly too, so you can feel what I'm doing. OK?” “Yeah, that'll be OK.”

Golly, Gee! We're about to take off ! Then over the intercom, from the back, “Hey, you've got ahold of the stick with the wrong hand! Right hand on the stick, and put your left hand on the throttle. Yeah, go ahead, put your left hand up on the throttle. You don't really need to hold on to anything! You won't fall out.”

Jeeze! Walt sure doesn't mince words. “You ready?” “Yeah, I'm ready!”

“OK, here we go, let's see if this thing'll fly!" But I'm not going to use full power on this one until right before liftoff. Less power will keep things from happening too fast. We've got a mile of runway. Might as well get some use out of it.”

The throttle goes forward smoothly, but not quite all the way. The engine RPM goes up to about 5800 and the Challenger begins to run down the runway. As the power comes up, we feel Walt pressing on the right rudder pedal, but the nose of the Challenger stays straight ahead.

“I'm holding a little right rudder to counter the propwash,” says Walt. “If I didn't, we would drift off to the left.” The plane accelerates quickly, even at reduced power. In almost no time, the airspeed indicator needle is off the stop and up to about 25 mph.

“I'm going to give it a little back stick now!” We feel the stick move backward just a small amount, and the nose of the Challenger lifts just a little. At the same time, the plane seems to be getting lighter, just skimming along the runway. Airspeed is now at 30 mph and increasing smoothly.

“I'm going to full power now,” says Walt. Airspeed's now 35 and moving on up. “I think it'll fly,” says Walt, and the stick comes back just ever so slightly, the nose rises, and the Challenger comes off the runway. Airspeed is now up to 40 mph.

As the plane lifts off, we feel some sort of a sinking sensation, like it suddenly slowed down, even though it didn't. The stick now moves the least bit forward and the nose moves back down just a degree or two. But we're climbing all the while. The airspeed moves up to 55 mph, and then the nose comes up again and we begin to climb out steadily and smoothly.

We feel slight movements of the stick to the right and left, and the rudder pedals are moving back and forth just a bit, but the right rudder pedal is definitely forward. “I'm still holding right rudder,” says Walt. “I'll tell you about it later.” And so we're climbing out, directly above the runway which already seems far below. Engine running at full power; RPM showing 6250.

“Let's trim it out to hold 55,” says Walt. “Hold the stick while I let go of it, but don't let the nose drop. Feel the backpressure?”

As Walt let's go of the stick, the nose drops a bit, but a gentle backward pressure on it brings the nose back up to where it was. “Now I'm going to adjust the elevator trim. You just keep the nose right where it is.”

As Walt slowly turns the crank for the elevator trim, the nose comes up slightly at first, but we release a bit of the backpressure on the stick to let the nose settle back to where it was. And as Walt continues to turn the trim wheel, the pressure becomes less and less, until finally no backpressure at all is required. “That's it,” comes over the intercom from the back seat.

The plane is now climbing as before, but without any backpressure on the stick.

“Davidson County traffic, Challenger niner Whisky Bravo departing straight out from Runway 24, Davidson County.” That was Walt making a radio call to let any other planes in the area know where we are.

“Now you hold the pressure on the right rudder for awhile. I'm getting tired.” So we feel the plane yaw to the left slightly as Walt obviously is not holding the right rudder pressure any more. However, just a little pressure brings it back to where it was, pointing straight ahead. A bit too much, and it yaws to the right. Thing is a little bit sensitive.

As the altimeter approaches 2000 feet, Walt comes on again, “Pull the throttle back to about 5700 RPM and let the nose come down until it's about level. Use the stick to keep the wings level, gently, won't take much, and adjust the rudder pressure to keep the nose straight ahead.”

Pulling the throttle back causes the engine RPM to drop. Down to 5900 ... 5800 ... toward 5700 ... Nose begins to yaw to the right. Ease off the right rudder just a bit.

“Let the nose come down,” says Walt. RPM now about 5700. Nose to right again. Now we're totally off the right rudder; no rudder pressure at all, but some forward pressure on the stick is required to keep the nose down on the horizon.

“Trim it out,” says Walt. We reach up and turn the trim wheel, and soon the nose will stay level without any pressure at all on the stick. And no pressure on either rudder pedal either. Airspeed is now up to 65 mph. Altimeter 2100 feet. The plane is flying all by itself.

“See that water tower straight ahead? Keep the nose pointed straight at it, and keep the wings level with the stick.”

3. Straight and Level

With only the slightest pressure on the rudder pedals every now and then, the nose of the plane stays glued on the tower. Well, almost. Too much correction and it sort of swings back too far in the other direction. Wings stay level almost by themselves. Doesn't take much pressure to level them back up when the wind or something causes one to drop slightly. Easy to overcontrol, however.

“What's your altitude?” Oh my goodness! Where's the altimeter? “2200 feet, Sir.”

“You're climbing a little. Are you holding back on the stick without realizing it? Lot of people do at first.”

So on we go for a few more minutes. We pass the water tower but keep on going. Everything is smooth and steady, except for the altitude, and it keeps going up and down a little as we experiment with the stick pressure and nose position, looking for where “level” is.

Finally Walt says, “You didn't know you could drive this thing did you?”

“Who me?”

“Yeah, who else?”

“Aren't you flying it?”

“No way,” says Walt. “I haven't touched it for 10 minutes or more.”

4. Gentle, Level Turns ... Sort of

“We're getting out pretty far from the airport, so let me turn us around and then we'll try something else. Watch the nose of the plane as I make the turn.”

Then the plane starts rolling gently to the right. At first, the nose of the plane doesn't move sideways at all, but as the bank develops, the nose seems to rise just a little, and then start moving along the horizon toward the right.

“This is a level turn at a bank of about 30 degrees,” says Walt from the back. “See where the nose is relative to the horizon?”

After turning about 180 degrees, “Now watch the nose as we roll out.”

The nose starts moving downward and its motion along the horizon gradually stops as the wings come back level. It comes to rest at the same distance below the horizon as before we began the turn.

“See there, nothing to it,” says Walt. Then, “Now you try it, but don't use anything but the rudder pedals. Keep the stick neutral. See if the rudder by itself will make it turn.”

“Which way shall I turn?” “Don't matter,” says Walt, “Aw, head back to the left.”

So very gently we press the left rudder pedal. The nose moves ever so slightly to the left, but then nothing much happens. At the same time, the plane begins to vibrate or shake just a little, like it's uncomfortable or something.

“Go ahead, push on that left rudder pedal. Don't be afraid of it! Push it in all the way.”

Apparently Walt thinks we're not giving it enough left rudder. OK. Here goes. Left rudder in quickly, all the way!

With this, the nose swings around to the left and the danged airplane gets all sideways with some obvious buffeting, and feels like it's scooting through the air to the right. “What's going on, Walt?”

“Aw, not much. You're just skidding through the air toward the right. This is a skid. Don't feel very good does it? You can ease off it now.”

We release the rudder pressure, but do it too fast. The nose comes back straight, and then overshoots to the right, and then wobbles back and forth to the straight ahead position.

After the plane settles down a bit, Walt comes on from the back: “Hey, I don't think you made very much of a turn. Try it again, but this time, just use the stick. Keep the rudder neutral. Go ahead, now, roll us into a bank of about 30 degrees to the left.”

Somewhat guarded, we push the stick to the left. The right wing comes up, pretty much as it did for Walt's turn, but the nose takes off to the right! It's going the wrong way!

“Hey Walt, what's it doing?”

“Aw, nothing much. Just hold what you've got for a spell.”

The nose stops its movement to the right, and then, reluctantly, begins to move to the left. But the plane doesn't feel smooth and comfortable. It's turning to the left, but not like it did before when Walt did it.

“OK, now roll it back level.”

We exert stick pressure to the right to level the wings, and sure enough, the wings start coming back toward level. But, the nose of the plane continues to move to the left, momentarily, even faster than before. Finally, when the wings are almost level, the nose begins to settle down and the plane begins to feel normal again.

“Wha'daya think? Did you like those turns? Not too pretty, huh?”

5. Coordinated Level Turns

“OK, Walt, what's the deal? Seemed like the nose wanted to go the wrong way! And No, I didn't like them very much.”

“That nose thing, ... you were seeing adverse yaw. To get a decent turn, you have to use both rudder and stick together. The rudder counteracts the adverse yaw.”

“Now try a turn, still to the left, using both the stick and rudder. Put both controls in at the same time, and see what happens.”

OK. Here we go. Left stick and left rudder at the same time. Sure enough, the plane rolls into a bank to the left, and the nose doesn't take off to the right like it did before. Well, maybe just a little. Guess not enough rudder. The bank angle gradually increases to 30 degrees.

But then it just keeps on going, getting steeper all the time. “Walt!”

“Huh, what? Did you say something?” Bank is now 45 degrees and still going!

“Yeah! Help !!”

“Aw now, don't get excited,” says Walt as he smoothly rolls the plane back to straight and level, in only a heartbeat.

“I think I forgot to tell you, when you get the angle of bank you want, you neutralize the controls. Come back to center with both the stick and aileron. If you don't, she'll keep on getting steeper with you. Sorry about that!”

“No problem, Walt; no problem at all.”

“OK, flyboy, try it again. Go to the left again, and this time neutralize the controls. And one other thing, you've gotta hold a little backpressure on the stick once the turn develops.”

With both rudder pressure and pressure on the stick to the left, the plane rolls up to a bank of about 30 degrees. The nose doesn't take off all by itself either. Then we relax the stick and rudder pressure, and the bank angle holds pretty well steady at 30 degrees.

“Backpressure! See how the nose is dropping? Ya gotta hold a little backpressure in the turn.”

We pull back on the stick just a little, and the nose of the plane rises slightly back toward the horizon, and at the same time, it seems to move around the horizon a bit faster.

“Now use both right rudder and right stick to roll out of the turn. You roll out just like you roll in, just the other way.”

Right stick and right rudder, together, causes the plane to roll out of the turn, but as the wings get near level, the nose suddenly climbs way up above the horizon.

“Release the back pressure. Ya gotta release the backpressure when you roll out of the turn.”

Sure enough, relaxing the backpressure lets the nose drop back to the level position, just below the horizon.

“Try a turn to the right now. Same thing, just go the other way. Use the stick to set up and control the angle of bank, and use whatever rudder is required to counter the adverse yaw and make the nose do it's thing on the horizon.”

Right stick starts the roll. Not quite enough right rudder ... nose bobbed to the left before it started its movement to the right. Soon, a 30 degree bank ...

“Hold backpressure. You're not holding the backpressure!”

Sure enough, the nose is down, and the vertical speed indicator is showing a decent. Lot of stuff to remember!

We roll out, and then do a series of turns, turning left and right 90 degrees to get the feel of it. Rudder is a little tricky to get the nose to do like it should. Too little rudder and the initial movement of the nose is in the wrong direction. Too much, and the plane skids to the outside of the turn and we feel the buffeting.

Also, the Challenger has a slight overbanking tendency. Once in a bank of about 30 degrees or so, it wants to get even steeper. Takes a bit of opposite stick to keep the bank form increasing.

And that backpressure thing. Keep forgetting to put in the backpressure going into the turn, and forget to release it when we roll out. The nose of the plane goes down in the turn, and then it goes up rolling out. Walt says its like riding a roller coaster.

Finally, Walt says, “Hey, you keep forgetting the backpressure in the turn. Let's do one without any backpressure at all. Roll into a 30 degree bank to the left, but don't use any backpressure in the turn. Continue the turn until we're headed back toward the airport. We're getting a little far out.”

We use both rudder and aileron to roll the plane into a bank to the left. It rolls in smoothly. Guess we had the rudder and ailerons pretty well balanced, or “coordinated,” as Walt says.

When the bank gets close to 30 degrees, we return both rudder and stick to the center position neutralizing the controls. The bank stabilizes, and the turn continues with the nose working its way around the horizon. Shucks, this ain't so bad after all.

Now where's the airport? Walt said to keep turning until we were headed toward the airport. Little right stick pressure to keep the bank from increasing. Bank is OK now. Where's the danged airport?

Then, we become aware of a slight increase in the wind noise, and the engine seems to have increased its RPM a bit. A glance down at the tachometer shows it squarely on 5800. We'd been running at 5700. The airspeed indicator, right next to the tach, is now indicating 70 mph. That's faster than the 65 we had.

Looking back outside, the nose is now moving around the horizon a lot faster than it was earlier. And it's down below the horizon too. While ago, it was right on the horizon, or maybe under it just a tad.

Uh oh. The angle of bank is now near 40 degrees, and it's increasing. We give a bit of right stick to stop the increase, Airspeed is now 75 mph, and rising. Engine is winding on up. Nose is down, way below the horizon.

From the back, Walt says, a bit more emphatically than usual, “I think you'd better go back to straight and level!”

Straight and LEVEL! Need to get the nose up because it's way down, and the airspeed is picking up faster now. We pull back on the stick, but the nose rises little if any, and the nose goes around the horizon now even faster than before.

Gotta get the nose up! Pull harder on the stick ...

Ugh, gad! What's that sinking feeling? Bank is now ... way up. Way way up close to 60 degrees. Nose is down, still, and getting worse. Pull harder to get it up. Airspeed is 80. Wind seems to be screaming, world is spinning sideways, feel heavy, wierd ... The nose won't come up! Nothing seems to work any more! !!

“Walt! Where are you? .... What are you doing? ... Walt!“

( To be Continued. See the follow-up, Controls 202. )

Author:   Doc Green