Glider Tow Question

[ebykowsky]

So, as far as useful load on an aircraft goes--how do gliders play into this? I would assume that they don't count pound-for-pound towards the useful load, but they must hurt t/o performance. How do you go about combining this with useful load, etc to figure out whether or not you're over capacity?
I'm thinking of going to a local glider flying club with a non-pilot friend, and they're offering a 30 min. flight for $100. However, if we both bought one and the one who wasn't in the glider for the first flight got to ride in the Super Cub towplane, that would make it more worth it. (That's why I'm wondering).

 

[tonycondon]

the glider only adds drag to the towplane, not weight. the extra drag definitely increases takeoff roll and decreases climb rate. No towplane in the US that i've ever seen has any sort of published data. It would be very difficult to come up with anything besides using experience. two gliders of the same weight can have drastically different drag contributions depending on how draggy they are.

talk with the operator about the possibility of riding in the towplane. some places do it, some don't. I used to but don't anymore except for training of course.

 

[docmirror]

No new weight restrictions on the tow plane for glider tows(most of the time). When I towed, I offered rides once in a while, but I took the stick out in back, and told them if they touched the rudder, after cut the glider away they would regret ever setting in my plane.

 

[ebykowsky]

Why is hitting the rudder so bad after it has been released but not before? And would you do all that if the person was a pilot? I'd love to sneak some tail wheel training in there.

 

[RussR]

I think he meant that if they touched the rudder, then after the glider was gone he'd make them regret it.

I haven't flown in a towplane, but I'm guessing that things can go pretty wrong pretty quickly with a glider hanging on back there.

 

[docmirror]

Why is hitting the rudder so bad after it has been released but not before? And would you do all that if the person was a pilot? I'd love to sneak some tail wheel training in there.

Unexpected pressure on the rudder of a TW type airplane is at a minimum annoying, and at worst, catastrophic. Non-pilots see those comfy foot rests down there, and decide they want to stretch out, and relax. I was referring to the time I'm in take-off and climb with the glider on. Once the glider is released, it's still annoying, but less dangerous. Maybe my post could have been worded a bit better.

 

[Bill Watson]

You know, just take the flights as advertised and enjoy.

I have experiences that suggest going with the standard offering and operation keeps things safer. Especially if it's a club.

Sometimes in Pgh eh? I dropped in on the club south of Pgh and almost pranged my glider on a screwed up tow behind a Supercub. I think the problem was that they had never towed a fully ballasted ship before. I take the blame for that one.

Hope you have great flights and get hooked.

 

[ebykowsky]

Haha--the club at Bandel airport?
I think a true sailplane rating will have to wait a little while.

 

[Bill Watson]

Originally Posted by cocolos
As a GA pilot how far are your usual Cross-countries? also what airplane do you fly? Lastly, what's the farthest you've traveled?

Just curious how people use their piloting privileges.

80's LS6 sailplane, straight line, one way - Pittsburgh (22D) to Solberg NJ (N51) - 247NM (flying it beat driving it with my wife and Mom who drove the trailer)

90's Maule, Durham NC (8NC8) to Houston (EYQ), twice - 923NM

2012 RV10, Durham to Phoenix (KSDL) via Houston & Santa Fe - 1,861NM

For that past 15 years, almost all my flying is cross country.

Thanks for asking..

...it was a long time ago at Bandel but glider club flying is one of the most enjoyable and cost effective ways to fly circles in the sky.

 

[gismo]

Unexpected pressure on the rudder of a TW type airplane is at a minimum annoying, and at worst, catastrophic. Non-pilots see those comfy foot rests down there, and decide they want to stretch out, and relax. I was referring to the time I'm in take-off and climb with the glider on. Once the glider is released, it's still annoying, but less dangerous. Maybe my post could have been worded a bit better.

Ignoring the fact that many TW airplanes have more rudder authority than there nosedragger cousins, rudder pressure is going to have the same effect in a tricycle gear airplane as it does in a TW as long as the airplanes are airborne. Plus lots of trikes are used as towplanes and I'd expect inadvertent rudder pressure to present the same symptoms there. And in any case the towed sailplane can easily overpower the rudder on any airplane so I'm puzzled why a tow pilot would be overly concerned about a passenger resting their feet on the rudder pedals as long as they didn't do it during takeoff and most importantly during landing.

 

[BillTIZ]

As Tony said, glider on tow adds no weight to the tow plane, only drag.
Some operations will not allow a pax in the tow plane during a tow. Some have insurance restrictions, some, the extra pax weight is just too much while towing.

A 150hp super cub towing a heavy ballasted glider is marginal at best, add heat for increased DA, not good.

We do not fly pax in the tow plane, it's any easy decision, single seat Pawnee.

Our 250HP Pawnee is 1300# below max GW with full fuel will climb at better than 1300fpm with no glider in tow. Towing a Scheizer 1-26 or Libelle, barely notice the difference that they are there. Tow a 1000# draggy 2-33 or 1200# Grob 103, with 2 up, climb rate reduces to about 600fpm. Imagine the same effect with a 150HP Super Cub.

 

[BillTIZ]

I think he meant that if they touched the rudder, then after the glider was gone he'd make them regret it.

I haven't flown in a towplane, but I'm guessing that things can go pretty wrong pretty quickly with a glider hanging on back there.

Play with the rudder, I'm guessing he would spin his way down.

Things can go wrong with a glider in tow, it's prudent to keep the glider behind you and at same altitude, that's on the glider pilot. Flying a good lead pilot, that's on the tow pilot. Finding that thermal so the glider will get off tow and leave you alone? PRICELESS. (just kidding)

 

[docmirror]

I'm puzzled why a tow pilot would be overly concerned about a passenger resting their feet on the rudder pedals as long as they didn't do it during takeoff and most importantly during landing.

The answer is in my quote, and in your post.

 

[Matthew]

It.'s enough work towing someone dragging your tail around from 200' back, I don't want another rudder input to have to deal with.

 

[docmirror]

I had a tow one afternoon out of eastern San Diego caused me some trouble. We broke ground, I looked through the green house in the mirror and everything looked good, a few seconds later I'm pushing on the right rudder more, and more, and more, and I look back and see the sail plane in a 30deg right bank! WTF? So I craned it to the right and down a bit and tried to keep him on, suddenly the tow came back level just before I was gonna release him. When we got on the ground I asked him what was going on back there and he said he had a big Mexican meal last night, and he had serious gas. He leaned over to work on a big release too much and bumped the stick. So we both almost plunked in due to a bad case of refried beans and tuna tacos, all washed down with some Dos XX.

 

[JHW]

It's easy. Open one side of the cowling of the pawnee. If you see 3 valve covers, you are good to go. If you see only 2, you are overloaded.

 

[Bill Watson]

I had a tow one afternoon out of eastern San Diego caused me some trouble. We broke ground, I looked through the green house in the mirror and everything looked good, a few seconds later I'm pushing on the right rudder more, and more, and more, and I look back and see the sail plane in a 30deg right bank! WTF? So I craned it to the right and down a bit and tried to keep him on, suddenly the tow came back level just before I was gonna release him. When we got on the ground I asked him what was going on back there and he said he had a big Mexican meal last night, and he had serious gas. He leaned over to work on a big release too much and bumped the stick. So we both almost plunked in due to a bad case of refried beans and tuna tacos, all washed down with some Dos XX.

I'm just ballast at the end of the rope but if you ever see anything like that again, punch 'em off!

I lost a tow pilot buddy to some itinerant idiot glider 'pilot' who seemed to get a bit disoriented during the beginning of a tow. He pitched up and pulled the tail of my buddy's Bird Dog up far enough to drive it into the ground. My buddy was very experienced. I'm sure he held off pulling the release just a second too long thinking that he didn't want to dump this dummy off in the weeds. By the grace of god, yours truly, who never missed day at the gliderport, stayed away that day and didn't have to help untangle the mangle.

If some joker needs to squeeze one off, let him do it solo. Seriously.

 

[docmirror]

Well, we don't usually get a full check if we do an emer release. Depends on the pilot and who owns the glider. If it's a private tow, we get paid no matter what. This was a club glider, and I got a block rate. If I drop them way early, it caused friction.

I would never let anyone put me in the turf though. When I was towing someone for the first few times, I always moved my hand from the throttle right down the release lever and left it there. Never had to drop anyone low, thank goodness.

 

[rottydaddy]

So, as far as useful load on an aircraft goes--how do gliders play into this? I would assume that they don't count pound-for-pound towards the useful load, but they must hurt t/o performance. How do you go about combining this with useful load, etc to figure out whether or not you're over capacity?

It's already been cleared up, I guess, but I'm surprised you didn't figure it out on your own. If you just watch an aerotow in progress, it becomes real obvious.
While the glider is rolling, the towplane is definitely dealing with additional weight- but only as a tractor, not as an airplane. Once the glider is flying, the glider's wings support its weight (the old trust/drag/lift/weight thing applies to gliders as well as power planes). Fortunately, most gliders will get airborne at significantly lower speeds than the towplanes, so the glider gets up first, allowing the towplane to accelerate better as it approaches flying speed.

Drag, however, is a factor throughout the launch (including the induced drag from the glider's wings lifting their load), so even with the glider flying, the towplane is going to be sacrificing a lot of thrust just to overcome the extra drag. So even the drag can still affect how much runway the towplane needs to get aloft, and its climb performance. And the induced drag will increase with the weight, enough to make a difference.
Having been in the 2-seater with other of various weights in the other seat, and solo, and in the single-seater, I can confirm that. The 200 ft AGL callout (minimum altitude to safely make a 180 back to the runway if the rope breaks or an emergency release is needed) comes a bit later and farther from the threshold when the glider is heavy.
So a tow pilot just has to have a good idea what will happen, and what that will mean based on runway length, density altitude, etc. A little math and a lot of common sense come into play.
For example, with our club's 150 hp Citabria and about 3000 feet of runway to work with, on a typically warm day during the soaring season, our tow pilots won't ever have a passenger in the back seat of the tow plane when towing the 2-seat glider with both seats occupied. They also don't top off the tow plane's tanks before a day of glider launches, preferring to keep the tow plane light and just monitor the fuel carefully. I's not like it would be impossible to go ahead with glider and towplane at their max gross weights... but it would be a stunt, not a normal launch. I don't know if turbo or the other tow pilots could draw you an accurate chart based on weight, but they know what works, and how to add some safety padding.


The single- seater, on the other hand, produces much less drag on tow and weighs a few hundred pounds less at max gross, so launches of that glider are better opportunities to get a ride in the tow plane.

 

[gismo]

The answer is in my quote, and in your post.

I did see that you mentioned "in take-off", which is why I specifically excluded that in my query. What I was asking (out of mild curiosity) was why it would be a big problem once you were safely in the air but still dragging a glider.

in take-off and climb with the glider on

 

[docmirror]

I did see that you mentioned "in take-off", which is why I specifically excluded that in my query. What I was asking (out of mild curiosity) was why it would be a big problem once you were safely in the air but still dragging a glider.

Well, actually - I think you're being pedantic or picayune about my post. I really don't want to explain all the ways a glider can kill you when you are off the ground and safely in the air. A poster just above mentioned a tow pilot being killed by a glider while they were in the air. I've mentioned a mistake by a glider while in the tow that had a semi-amusing ending. If you want to find all the ways a glider in tow can kill the tow pilot, I would refer you to the NTSB files.

Having a pax on the rudders while flying a TW plane is generally a hassle, but can be overcome most of the time. Having a pax on the rudders with a glider behind me, while he's paying cash money for a tow to altitude is unacceptable any time. It's a distraction that is easily avoidable, promotes safety, and makes everyone's life just a little easier. A pax during a tow is a courtesy unless one is training a new tow pilot which is not the definition of a pax.

Back when I used to tow banners and gliders, I had a reputation for maybe not following all the regs to the absolute letter. I may have done some spins while returning to the field after a tow, I may have done some short field landings after dropping the banner next to the runway rather than going around like you're supposed to. I may have landed after official civil twilight with no lights possibly. Those possible lack of good decision-making events were my own and I can accept responsibility for them. I won't be killed or crashed, or cause a low release of a glider by an errant foot by a pax on a glider tow at any time.

Hope this clears it up, cause it's the last I'm gonna write about it.

 

[Bill Watson]

I would never let anyone put me in the turf though. When I was towing someone for the first few times, I always moved my hand from the throttle right down the release lever and left it there. Never had to drop anyone low, thank goodness.

I hear that. But of course over 200', we're supposed to know what to do.

In the case I described, the pilot was a PPG who had flown on and off at this site over the years. He had flown at other sites too. Apparently some erratic flying at other sites encouraged him to show up at this site. I forget whether any dual was given before he was put back in the 1-26.

Never having towed, it was never clear to me whether tow pilots always knew who they were towing, especially when the line backs up.

When I got my Maule, I considered putting a hook on it and doing some towing. I could never pull the trigger on the upgrade because of this accident (and another one involving a mid-air).

Anyway, I swore to myself after this one that 1) If I ever towed, I would always 'know' who I was towing, and 2) As a tow-ee, I would never begrudge the tow-er a justified release.

Given all that, I recall that I was ready to shoot an old geezer that decided my wife needed to be tested as a newly solo'd pilot so he wagged her off at 1,000. Given there was no reason for it other than her sex, she was a bit shaken. I also recall getting towed during a contest in Minden where I took off fully ballasted with the spoilers unlocked. The pilot, bless his heart, kept me on while I figured it out.... he should have punched me off.

Keep doing good work out there Doc.

 

[docmirror]

I haven't towed for a long, long time.

As for the old geezer punching your wife off at 1000', I seriously doubt it was due to her gender. If we release, the glider releases and we gotta go hunt down the tow line, and sometimes it's lost for good. Also, tow ops are notoriously cheap outfits and it may have only been a paid tow to 1000 feet. I've done those for glider pilots who only want to practice low release, or landing, or they have a ridge nearby that they can get ridge lift, or they want to test out the plane, or some other reason. Of course I wasn't there, but it's unlikely that he released because it was a woman. If he really did that, I would go back to the geezer and get my money back for that tow.

 

[Witmo]

I haven't towed for a long, long time.

As for the old geezer punching your wife off at 1000', I seriously doubt it was due to her gender. If we release, the glider releases and we gotta go hunt down the tow line, and sometimes it's lost for good. Also, tow ops are notoriously cheap outfits and it may have only been a paid tow to 1000 feet. I've done those for glider pilots who only want to practice low release, or landing, or they have a ridge nearby that they can get ridge lift, or they want to test out the plane, or some other reason. Of course I wasn't there, but it's unlikely that he released because it was a woman. If he really did that, I would go back to the geezer and get my money back for that tow.

He didn't say the tow pilot released the glider (his wife); the tow pilot "wagged" her off, i.e. he signaled her to release by wagging his wings indicating he had some problem with his aircraft and needed to terminate the tow. I've wagged off gliders due to a rough running engine two times in 2000 tows. One was a magneto problem and one was a valve problem. Both were above 1000 feet.