![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
![]()
I'm planning to join the local soaring club and had my first ride last
weekend. I was eager to take the controls while being towed and was enormously humbled by the experience. I've had my ppsel for several years, but do not have many hours under my belt. Never the less, I was looking forward to this and thought: How difficult could it be? No P factor, just hang in there behind the tug. I was embarrassed. I could not keep the glider (a Blanik) anywhere close to remaining calmly behind the tug. I was all over the sky and was acutely aware that I must be yanking the tug's tail back and forth and up and down. Three times I was rescued by the guy giving me the ride, although by the last time I was beginning to understand that the tow rope itself could bring the nose back. I had not prior instruction before the ride, I really thought it would not be a problem. BZZZZZT wrong. Once we cast off, holding headings, holding airspeed and just keeping the wings level wasn't a problem. I was astonished at how far we could travel at 60 mph without seeming to loose much altitude. Heck, I've lost more altitude than that when I was flying cross country and TRYING to hold my cruise altitude. :-) One of the more expert glider pilots reassured me that all first timers have the same problems, and told me that I should concentrate on holding the wings the same as the tug, and using the rudder to stay behind it. I wasn't doing it that way, I was sawing back and forth with the stick and getting into all kinds of trouble. I'm eager to try again, but I thought I'd drop in here and ask how folks stayed behind the tug... If you all can remember back when you were at my stage. ;-) Thanks, Corky Scott |
#2
|
|||
|
|||
![]()
Glider instructors have lived this scenario for years:
The Schweizer just would not stop moving around behind the Cub. Left, then right and always up. Push-then too low, ease off the stick, then too high. The glider moves first to one side and then with a zoom across to the other. "I've got it. Look at how my wings are parallel with the tug. Your airplane." In the USA, the primary means of towing a glider is called aero-tow. A slow speed, relatively high-powered tow plane is attached to the glider with a 200-foot length of rope that meets regulatory strength requirements. The glider then flies a formation take-off and climb to a suitable release point. Even for experienced transitioning pilots, this maneuver is nearly as difficult as landing. In those first several attempts, students end up in an ever-increasing departure from the center. Like most pilots, one of my initial challenges in learning to fly gliders was mastering the aero-tow. As a CFI, I see my own difficulties reflected in current students as they fight the controls seeking the dead-weight spot where the glider just follows behind the tow-plane. The dead-weight spot is the point where the glider is imparting no other force on the tow plane other than the weight of the glider. Any displacement from this spot makes the tow more difficult for both the pilot of the glider and the pilot of the tow plane. When conducting flight tests, I see many problems from applicants during their demonstration of the Areas of Operation relating to Aero-tow. Since control of the glider while on tow is a requirement, it carries some weight on the outcome of the flight test. Nearly all two place sailplanes are constructed with a tandem configuration. This adds some difficulty to training, especially with the topic of transfer of control. A good preflight briefing settling this is essential. In conducting the preflight briefing, I follow the order of the flight beginning with the take-off, through the various maneuvers, and ending with the release from the tow plane. For the take-off, the dead weight example holds. We balance the glider on the main wheel until airborne, adjusting for any cross wind by crabbing so that no additional side load is imposed on the tow plane during his take-off run. There is a strong tendency for the glider to climb after lift-off as the tow imparts the same force on the glider similar to running with a kite. Were the glider to climb too high, the nose of the tow plane would be driven into the ground causing at a minimum a longer than normal take-off roll and a lecture from the tow pilot after your return. Students will suffer tunnel vision when under stress. This becomes evident while flying tow as the student becomes so fixated on the tow plane and maintaining relative position that he will not see even the horizon beyond. In order to maintain relative position behind the tow plane, the controls of the glider must be operated not for coordinated flight, but only to maintain position. Ailerons are used to match the tow plane's bank. Any divergence from the tow plane bank will cause lateral displacement, as the horizontal component of lift will rapidly overpower the stabilizing force of the tug of the rope. Some instructors will use the phrase in this case of "level your wings, steer with your feet" to indicate that the wings of the glider are not parallel to the tug. Too much bank in a turn relative to the tug will result in the glider falling inside the turn and below the normal tow position with a resulting slack towline, while too little bank in a turn will result in the glider accelerating around the tug and climbing above the normal tow position. Relative height behind the tow plane is maintained with the elevator. The typical training glider in the USA is the Schweizer 2-33. When the 2-33 is towed, it is flying at a speed that is nearly 40% above normal design flying speed. This will cause a need for constant forward pressure on the stick in order to prevent climbing well above the tow plane. Lateral position is maintained using the rudder-not the ailerons. At any one time, the controls in the glider are being utilized to maintain position, not necessarily coordinated flight. The goal is to merely be pulled up as dead weight. Displacement from the normal position will eventually result in a slack line and if the slack is not carefully removed a broken towrope will result. It is for this reason that the PTS requires a demonstration of slack line recovery. It goes without saying that any slack that develops not be allowed to foul the glider, so move away from any loop that develops. The action of moving away will tend to remove some of the slack. At this point the tow plane is relieved of the dead weight of the glider and will accelerate. Since the glider is not currently being pulled by the towrope, it will decelerate. If no further action is taken, and no other force applied that increases slack, such as turbulence; the slack will just go away. Any attempts to force a reduction in the slack by using an excess of drag will cause the rope to snap taught and possibly break. The PTS standard for the performance for aero-tow is only smooth and effective use of the controls. Snapping the rope would not be very smooth. During the typical glider flight, the tow is approximately 5-7 minutes. This concentrated time can make students confident for the remainder of the flight or distraught over earlier performance. Consider staying on tow a little longer on later flights in order to give your students more time. When I was a student, a long cross-country tow finally solved my problems with the tow. |
#3
|
|||
|
|||
![]()
Dead-weight is just a figure of speech. I have already been corrected
on that! Terry |
#4
|
|||
|
|||
![]()
The answer is (surprize!) practice.
Initially you get thrown around as you described. Then you actually begin to fly behind the tug. Later you'll find yourself staying in a reasonable position, ceasing to endager yourself and the tow pilot. Still later, you'll stay in that position even in turns. First in shallow turns, later in steeper turns, too. Gradually your yaw string will stay more and more centered. And someday you'll stay behind the tug even in moderate turbulence. But it's a long way to go. Stefan |
#5
|
|||
|
|||
![]() wrote in message ... I was embarrassed. Don't be! I have brought ATPs back down drenched in sweat after a quick initial lesson. I quickly learned to prepare such students for what usually happens so they would not feel humiliated if they could not immediately perform. I have had a few that could stay in position behind the tow plane on the first try...damn few. IMO Instrument time and helicopter time seems to help because they teach you not to over control. I could not keep the glider (a Blanik) anywhere close to remaining calmly behind the tug. I was all over the sky and was acutely aware that I must be yanking the tug's tail back and forth and up and down. Perfectly normal. Sooner of later you acquire the proper circuitry between your eyes, your brain, your hand and your feet. Then you will wonder why it was ever an issue. Three times I was rescued by the guy giving me the ride Only three times? That is actually pretty good! I have never had a student who could not eventually learn to do a safe tow. I had a hard time myself. Vaughn , although by the last time I was beginning to understand that the tow rope itself could bring the nose back. I had not prior instruction before the ride, I really thought it would not be a problem. BZZZZZT wrong. Once we cast off, holding headings, holding airspeed and just keeping the wings level wasn't a problem. I was astonished at how far we could travel at 60 mph without seeming to loose much altitude. Heck, I've lost more altitude than that when I was flying cross country and TRYING to hold my cruise altitude. :-) One of the more expert glider pilots reassured me that all first timers have the same problems, and told me that I should concentrate on holding the wings the same as the tug, and using the rudder to stay behind it. I wasn't doing it that way, I was sawing back and forth with the stick and getting into all kinds of trouble. I'm eager to try again, but I thought I'd drop in here and ask how folks stayed behind the tug... If you all can remember back when you were at my stage. ;-) Thanks, Corky Scott |
#6
|
|||
|
|||
![]() |
#7
|
|||
|
|||
![]() I was embarrassed. I could not keep the glider (a Blanik) anywhere close to remaining calmly behind the tug. Welcome to adverse yaw :-). In 10 years of instructing, I've had exactly 2 power transition students manage the tow with only verbal assist. It wasn't pretty, but the job got done. After a while, you'll realize that with a nose hook on aero tow, the glider really wants to fly behind the tug and if it ain't doin' that, it's you :-). Tony V. |
#8
|
|||
|
|||
![]() |
#9
|
|||
|
|||
![]()
Let's see, take two wildly different aircraft, tie them together with a 200
foot rope and go fly formation. Sounds like an airshow act. Bill Daniels wrote in message ... I'm planning to join the local soaring club and had my first ride last weekend. I was eager to take the controls while being towed and was enormously humbled by the experience. I've had my ppsel for several years, but do not have many hours under my belt. Never the less, I was looking forward to this and thought: How difficult could it be? No P factor, just hang in there behind the tug. I was embarrassed. I could not keep the glider (a Blanik) anywhere close to remaining calmly behind the tug. I was all over the sky and was acutely aware that I must be yanking the tug's tail back and forth and up and down. Three times I was rescued by the guy giving me the ride, although by the last time I was beginning to understand that the tow rope itself could bring the nose back. I had not prior instruction before the ride, I really thought it would not be a problem. BZZZZZT wrong. Once we cast off, holding headings, holding airspeed and just keeping the wings level wasn't a problem. I was astonished at how far we could travel at 60 mph without seeming to loose much altitude. Heck, I've lost more altitude than that when I was flying cross country and TRYING to hold my cruise altitude. :-) One of the more expert glider pilots reassured me that all first timers have the same problems, and told me that I should concentrate on holding the wings the same as the tug, and using the rudder to stay behind it. I wasn't doing it that way, I was sawing back and forth with the stick and getting into all kinds of trouble. I'm eager to try again, but I thought I'd drop in here and ask how folks stayed behind the tug... If you all can remember back when you were at my stage. ;-) Thanks, Corky Scott |
#10
|
|||
|
|||
![]()
Stefan wrote:
The answer is (surprize!) practice. I would add - "and proper instruction". Practicing poor technique will mean a long time learning. So, find a good instructor if you can, and read the towing section in soaring manuals several times. Initially you get thrown around as you described. Then you actually begin to fly behind the tug. Later you'll find yourself staying in a reasonable position, ceasing to endager yourself and the tow pilot. Still later, you'll stay in that position even in turns. First in shallow turns, later in steeper turns, too. Gradually your yaw string will stay more and more centered. And someday you'll stay behind the tug even in moderate turbulence. But it's a long way to go. Not so long if the instruction is good! My instructor was not very experienced, and taught a poor technique. By the time time I was an instructor, I could teach a student much more quickly than he did when he taught me. I realize "long" is undefined here, and Stefan and I might be talking about the same amount of time. I think he will agree with the importance of a good instructor in speeding the learning, however. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Newbie Question, really: That first flight | Cecil Chapman | Home Built | 25 | September 20th 04 05:52 AM |
A question only a newbie would ask | Peter Duniho | Piloting | 68 | August 18th 04 11:54 PM |
Newbie question on Rate of Climb | Wright1902Glider | Home Built | 0 | August 17th 04 03:48 PM |
Newbie Question - Vacuum vs Electric | Bill Denton | Aerobatics | 1 | April 15th 04 11:30 PM |
Newbie question Cessna or Beechcraft? | rbboydston | Piloting | 4 | August 13th 03 01:08 PM |