Wednesday, February 16, 2022


Flying the Schweitzer 2-33

The Schweitzer 2-33 has been the most popular primary trainer for prospective glider -- "soaring" -- pilots since I was a young man, long ago.  It is a simple beast, an aluminum can with a large, high, strutted wing.  The student sits in front with an admirable view of about 200 degs from under a semi-bubble canopy.  Instruments and controls are also simple -- altimeter, air speed indicator, "variometer" -- an instrument to tell you finely how quickly you are climbing or descending (yes, gliders do climb), old-fashioned stick and rudder pedals, a ball that releases your tow line, and a handle on the left that controls spoilers -- slats on the wings that defeat the lift of the wing to adjustable degrees so that you can drop like a rock if you want to without putting the nose down and hence picking up speed.

Lessons in the 2-33 generally last only about half an hour.  You are learning basically to take off, follow to altitude your tow plane, which commonly is a powerful Ag-Cat or similar crop duster, and land, with a little screwing around in between for good measure.

The tow component of the flight is way more difficult than it looks.  You are not supposed to fly directly behind the tow plane, because the turbulence caused by the propeller will mess you up.  Rather, you fly "high tow" or "low tow."  But if you get too high or too low you can interfere with the tow pilot's flight, and he may decide to just dump you from his end in extremis.  Also, if you are too high and you dive to get back into the preferred position, you may pick up so much speed that you close on the tow plane and the tow rope goes slack.  In such circumstances it may form a loop and wrap around some part of your glider, in which case you may be I almost said a bad word but certainly in a world of hurt.  And when the tow pilot makes a turn, you don't exactly mimic it; rather, you need to wait a bit and follow him in classic formation.

At about 3000 feet AGL (above ground level), the tow pilot wags his tail, which is a signal for you to pull the ball on the dash and let the rope go.  He breaks left in a dive, you break right and stay level or maybe even climb a bit, trading tow speed for altitude.  You make a few turns to get the lay of the land, and also to practice ... making a few turns.  In a glider you use a lot of rudder in turns so that the nose of the plane leads the way, minimizing drag, because drag means falling faster.  When you get established in a steep turn, you actually have to hold the stick against the turn.  Why?  Because the wings are long and the tip of the high wing is going much faster than the tip of the low wing, generating more lift.  If you hold the stick in the center you may flip to knife-edge flight!  Also, you pull back a bit on the stick in turns to maintain altitude.  Some of the lift is being used to turn you rather than to keep you at optimum glide ratio, so you need to compensate.

Otherwise, a glider handles just like any other light aircraft.  Novices and even some power pilots don't get it that the aircraft doesn't give a shit what is causing it to go forward and therefore to generate lift.  It could be an engine or it could be just having the nose pointed slightly down.  (It is common for gliders to be able to travel about 30 feet forward for each foot of altitude lost, in still air.  If there are rising air currents, which are the key to "soaring" like a seagull, then you may be falling within a column of air more slowly than the whole column is rising, and therefore gaining altitude even without an engine.)

Now it's time to go home.  You head for a predetermined landmark, maybe a barn or a church, that is your entrypoint into the pattern, at a predetermined altitude, let's say 1500 feet AGL.  You turn 45 degs onto the "downwind leg," which is as is described, flying with a tailwind, with the field typically off to your left.  You establish pattern airspeed.  It is critical not to fall below this, because you may stall, which is to say that the lift of the wing may break and you will no longer be flying but dropping like a brick.  You can recover from this but only if you have sufficient altitude, which is problematic in the pattern.  I was taught that pattern airspeed should be one and a half times the stall speed plus a cushion that depends on the wind speed at ground level.  In the 2-33 the pattern speed, from memory, might be about 65 mph.  

As you complete the downwind leg you monitor your altitude closely.  If you have encountered lift or "sink" you may have to make adjustments so that you will be neither too high nor too low for a safe landing.  You have, after all, only one shot at it in a glider.  But you have cracked your spoilers and they give you a tremendous cone of safety in this respect.

A 90 deg turn onto the base leg just past the end of the runway, being careful to maintain your speed.  In addition to using the spoilers, you can play around with how directly you are flying if you think you should be at a lower altitude, or you may fly deliberately "dirty" to increase drag.

Then a 90 deg turn onto final approach.  Typically at this point in a glider you are looking at a runway that is four or five times longer than you actually need for a safe landing, and you start to breathe easy.

When you are about ten feet above the runway you (ordinarily) close spoilers and "flare" -- raise the nose and fly straight and level, letting the plane gently descend onto the grass or pavement.  The ride on the ground is short but a little bumpy.

Always exhilarated by the miracle of powerless flight, you pop the canopy and with the instructor's help walk the beast back to its next take-off point.

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