RANDOM THOUGHTS FROM THE BACK SEAT By Jeff Orchard
"Pardon me sir, your slip is showing."
I'm writing this on Labor Day, looking out on the remnants of Hurricane Edouard, which threatened, but didn't dampen the club outing at Franconia. All the Toms, Jeffs, Nancys and Terrys had a blast. Everybody had a blast. Except the dog. Oreo was simply astounded because up to now, she thought there were only about a dozen people on the planet.
We will all take memories away with us, and I'd like to share a few of mine... in no particular order.
The valley fog at The Kinsman...and later the satellite.
100 FPM up for about 8 seconds.
Smoke from the Cog Railway drifting slowly away from Mt. Washington.
Airshows at the end of the day.
The circumzenithal arc.
The newest Jeff's first solo...and his excellent adventure later that same day. Ask him.
Smokin' Harv and his A-Bomb on a trailer.
Wanting to say "Pepperell traffic...." every time I picked up the mike.
Dave Hibbard saying "Let me guess, carburetor heat?"
Tom Matthews saying, "more to the right, Bird Dog...more to the right".
Three times.
The Champ at idle power slipping in to a smooth landing.
Back in the old days, before there were flaps, there were slips. Today, we teach slips as a backup maneuver to use in case the flaps or the spoilers and dive brakes don't work.
Most students with less than twenty flights are still struggling with the concept of "a little stick, a little rudder" in the same direction, at the same time to make a turn happen. "Co-ordinate, co-ordinate,Cooo-oordinate those controls. OK, this time try it to your other left". The instructor is incessant, in as pleasant a voice as possible after saying it five or six hundred times this year..."make sure you press the rudder pedal in the same direction and at the same time that you move the stick...etc, etc". Then we drop a bomb. The slip is introduced.
The slip is usually introduced to the student without much warning, generally as a direct result of that student's actions causing the instructor to take immediate action to save lives... or at the least, a long walk. When I was first slipped, I thought we were crashing. I was looking sideways along the wing watching the water rush up at me. I thought it was darn close to miraculous that the instructor had been able save the landing by wrestling the plane to level flight at the last minute. I mean, we were actually falling sideways. Out of the sky.
A slip, as it turns out, is a normal flight maneuver designed and executed to put a flat surface (usually the side of the fuselage) into the flow of air which has the result of increasing the drag and the rate of descent without increasing the airspeed. And as it also turns out, a slip is accomplished by CROSSING the controls!
First attempts at slipping are predictable. The wing hesitates its way down and then the nose of the glider swings wildly the other way. Soon, there is enough movement in the stick to mix a pretty passable cake batter. As the bank of the wing steepens, primary stick motion settles to fore and aft jerks interspersed with random attempts to level the wings. Rudder use increases to the point that it seems possible that altitude will be gained by the fanning action. The dreaded yaw string goes crazy, finally wrapping itself around the pitot tube in a gesture of abject submission.
In my now infamous yaw string article (Towlines, 5-95) that described turns and control effect, I described something called adverse yaw. Briefly, adverse yaw causes the nose of the glider to swing to the outside of the turn if enough rudder is not applied when the turn is initiated. Are you beginning to see a fit here?
I teach slips by having the student start a turn without the rudder. The wing drops and the nose swings out the other way. All that has to be done then is to apply rudder pressure to hold the nose out there and keep the stick pushed in the other direction so the wings don't come back to level until you're ready for them to.
Let's assume a left slip for a demonstration. From level flight, holding the rudder centered, you move the stick smartly to the left. The left wing drops and the nose swings to the right. Before the glider starts to turn you push the right rudder pedal to keep the glider from turning. Voila, a slip, which is kept a slip by keeping the controls crossed and adjusting the pitch to maintain airspeed. Recovery is accomplished by the same procedure. Once again, adverse yaw works in your behalf. Holding the rudder, move the stick to the right until the wings come level. Then, and only then, the rudder pressure is released. And level flight ensues. Just remember, stick first, then rudder when entering and recovering from a slip. Stick first, then rudder. The wild swing goes away and it actually looks like you know what you're doing.
OK, you are on downwind and in lift. The spoilers are on and the glider is still going up. Since you are going to be making left turns anyway in the pattern, you start a left slip. Do you recover from the slip before the turn onto base? No way, Hosay. If you simply let the pressure off the rudder, the glider falls into a coordinated turn. You need to center the stick to keep from overbanking. When you get to the base leg, it is a simple maneuver to move the stick to the left and compensate with right rudder and you are back in your slip, selling altitude.
There are several rules that accompany the judicious use of slips:
1. Slip with the upwind wing low. This reduces drift.
2. Never slip to closer than a wingspan from the ground. Obviously.
3. In an aircraft with flaps, don't slip with them full on. Especially the L-19.
4. Don't wait until the last minute to apply a slip.
5. You may have to speed up in a steep slip to keep from turning.
6. Practice, practice, practice.
7. Have fun.