Glider Pilot Relief ("Pee") Systems
"What Goes In ... Must Come Out"

Published in Soaring magazine, April 2010, page 27

Background - When I first became interested in cross country soaring, and especially when I entered my first contest, I knew that I would have to create an in-flight relief system ("pee" system). A good friend of mine routinely makes 5+ hour flights without relieving himself, which is something I cannot fathom. Relief is clearly an important part of the Sailplane Racing Association's the SRA Guide to Soaring Competition which issued this particularly stern warning; "Without question, this must be a part of your pre-contest practice -- neglect this subject at your peril!". Sounds like they are serious!

I found bits and pieces of the necessary soaring relief information here and there, mostly via resources like rec.aviation.soaring group ("RAS" for short). However, I never found a comprehensive guide to relief for sailplane pilots. After finding out what I could from other pilots, from web sources, and from the medical industry, I wrote my own RAS article on the subject in an effort to share what I had learned. This web site is the result of this research. Please send me your comments.

A Brief History of Relief - During the early days of soaring, flights were so short that rehydration and relief were non-issues. As flight times grew, there came a growing realization that rehydration (replacing bodily fluids, typically lost through sweating) was important, especially in hot climates. But XC pilots were reluctant to drink liquids while in flight as there was the ever present problem of "what goes in - must come out". That is, how to rid yourself of excess fluids. Unfortunately, the idea of relief during flight had a hard time overcoming 1) the lack of public knowledge and 2) the adverse opinion/embarrassment of the whole process. Luckily, world renowned soaring pilot Karl Striedieck, and wife Iris, broke through the roadblocks of ignorance and embarasement with his famous March 1996 Soaring article entitled "To ... or Not To ..., No Question About It" in which they brought the subject to the general soaring public's consciousness proclaiming that not relieving yourself is at best distracting and at worse potentially deadly. In flight relief was now out of the closet and, to a certain extent, became the "thing to do".

Relief technology has not changed dramatically over the years but access to information sources about available systems have exploded, particularly through the Internet. Many medical vendors and soaring equipment providers have taken up the task of providing the necessary equipment and advice. Acquiring the necessary relief ingredients has never been easier and more straightforward. The only problem is learning what products exists and then actually deciding to use them. I hope that this article helps to bridge these gaps.

OK, let's go! (sorry, I couldn't help myself)

Note: - Nearly all of what is written here is for the guys. However, there are a few solutions for female pilots listed below.
To go in flight or not? - There are those that hold it and those that don't. But as soaring pilots begin flying longer XC flights, most finally realize their physiological limitations and need some relief. There are a few choices (catheters, aim-into-a-receptacle, diapers, etc) but I am only going to talk about the male external catheter (MEC) approach.

What an External Male Catheter looks like - An external male catheter looks and is applied much like a prophylactic condom except for a few important differences. The most important difference is that there is an hole in the end to allow urine to be captured and disposed of. Secondarily, there is adhesive to hold the catheter in place during the considerable pressure created when you urinate. You will find more details below on application, removal and use.

Brand/Model - The brand/model which is my current recommendation is the Coloplast (formerly Mentor) brand, models "Clear Advantage® with Aloe" or "Freedom Clear®". It seems to be the best for staying on leak free and, more importantly, coming off fairly easily. All single use catheters have adhesive along the inside to keep it attached. Cost is about $1.50-$2.50 each for a single use, single day, item. For places to purchase catheters, see the Sources section below.

Below are some "Clear Advantage® with Aloe" part numbers;

Item # Size
6100 23 mm, Small
6200 28 mm, Medium
6300 31 mm, Intermediate
6400 35 mm, Large
6500 40 mm, X-Large

Sizing - Gentlemen, in the case of catheters your size does in fact matter. If you try to use a catheter that is too small, you will be uncomfortable after a few hours. Too large and you may end up sitting in a wet spot, which is equally uncomfortable after a few hours. To help out, there are handy-dandy sizing guides available on the Internet (I am not kidding about this). This process may be embarrassing but it's important so just shut the door to the bathroom (loo, WC, wood shed, outhouse, etc) and get the job done. See these Coloplast/Mentor and Hollister sizing guides.

Catheter Application - Before application, and no mincing of words over an particularly embarrassing sub-topic, you must trim the hairs at the base of your penis. The catheter's adhesive is quite sticky on purpose and when adhesives and hairs intertwined there can be painful consequences. You have been warned.

Begin application by reviewing the how-to pictorial guides printed on the Mentor/Hollister packaging. This guide is rather simplistic and makes catheter application and removal look like a walk in the park. Unfortunately, the path to leak free application and "painless" removal has a learning curve.

Application steps - Make sure that your penis is dry or the adhesive will not adhere properly. The adhesive starts mid-way down the inside of the tube of the catheter and stops about 1/2" above the tail end. As you roll on the catheter (again, like a condom), the adhesive first appears on the OUTSIDE of the catheter (you will understand this more clearly when you first roll one on). The adhesive should be on the shaft of your penis, should not be on the head or extended down close to the base (those pesky hairs again). You need to roll the catheter onto your penis until all of the adhesive is against the shaft and the non-adhesive end is deployed fully. This means that depending on the length of your penis, you may need to start with a larger or smaller "reservoir" at the head so that the non-adhesive tail is fully deployed against the shaft. Leaving some of the adhesive on the outside is an invitation to catching hairs. If you find that there is any adhesive left at the bottom, cover it with some toilet paper or facial tissue. Experimentation is the key to success here.

Finally, press the catheter's adhesive firmly all the way around. You may not want to do this (worrying about later removal) but you need to do it to prevent leaks.

WARNING: You may be tempted to save a few dollars by not putting on the catheter until you are in-flight and know that you will really need one. This is a bad approach. Application during flight is strongly discouraged. First, you have probably already sweated some and the catheter will not adhere properly. Second, the process of proper application while reclined, with belts on, with clothes on, with a parachute on, and while flying, is practically impossible (ask me how do I know this). Therefore, it is critical that you put your catheter on while safely on the ground. You spent thousands on a glider, go ahead and spend a dollar or two on a catheter for each flight.

Urine Disposal in Flight - There are three general ways to dispose of your urine while in flight - each with its own pros and cons.

… a "container" - This idea is to use a bag or bottle of some sort (often without a catheter) to capture the urine. I have seen funnels, bottles and plastic bags. Sometimes the bag or bottle is filled with an absorbent material (i.e a sanitary napkin or purpose made jelled product) to help prevent spillage.

  • Pros: Simple and inexpensive.
  • Cons: Disposal after the flight. Can spill and smell as there isn't a sealed nor a permanent connection between you and the container. You have to fiddle with something before flight. Without a catheter, you may miss the container with inevitable results.

… a "hose over the side" - Many pilots have rigged up a pipe to connect the catheter's tubing directly to the outside world. See Chip Bearden's article below or Darryl Ramm's blog for more details. Placement of the outlet pipe is critical as urine (basically warm salt water) must not find its way into areas which can cause corrosion and damage. Placement of the exit tube on the rear edge of a gear door places the outlet is as far away as possible from the glider. I am no expert on this approach but the trick seems to be finding a spot with enough negative pressure so that the urine is sucked out of the tubing but not too much so that the urine might not leave the under surface of glider. You can rinse out the system during flight by using a Y connection into which to blow water.

  • Pros: Nothing to dispose of after the flight or store during the flight.
  • Cons: Some risk of corrosion (see below). You may need a certified mechanic to sign off on your modification. You have to fiddle with something before urination (i.e. the gear doors, rinsing). Can cause yellow "rain" or "stain". Can freeze up and clog.

… a "leg bag" - This is a standard medical supply item which was designed precisely for this application (but not necessarily for aircraft). It has a one way valve at the inlet (to prevent back flow) and a on/off valve at the outlet (to prevent poorly timed outflow). There are several sizes available (250mb, 500ml, 1000ml). I find that 500ml is good for a six hour flight. However, your physiology may need the larger 1000ml bag or even multiple bags. An alternative to a bag is a bicycle water bottle which has the advantages of being more reusable, cheaper, rigid and non-transparent. Just be sure to mark it with a very large "P" to prevent any confusion about its intended use!

  • Pros: No fiddling with gear doors, rinsing, etc, just go whenever you need to. Reduced risk of leakage. You can hide the bag in the leg of your pants.
  • Cons: Disposal after the flight. Cost, the bags are $4-$5 each but one or two will last a typical season.

Clothing - If you don't "deploy" prior to each flight, it is important to wear clothing that allows access while in flight. At sites with a heavy use of catheters (Ridge Soaring Gliderport springs to mind), I have seen several pilots already unzipped and connected up before liftoff. Again, less fiddling during flight is the important thing to remember.

Tight blue jeans are generally not optimal. I find what work very well are the loose fitting, and quick drying, nylon pants found at outdoor supply stores. There are also purpose made PeeTot Pants which sport a very large zipper along the crotch which are said to work well. Underclothing considerations are also important. You will just need to find out what works best for you.

Going - Once you have all the plumbing in place (do this before takeoff) then you can just go when needed, hopefully with as little fiddling as possible. Depending on your glider and position of the bag, you may have to urinate a bit up hill. This might seem like an issue but I haven't found this to be a problem. You may encounter an odd sensation caused "back pressure" which will feel strange at first. After your first anxious moments, you will relax. Practice on the ground so that you know what to expect.

Back on Terra Firma - So, you're back on the ground and you have a bag full of urine. Now, what do you do with it? There is a certain amount of embarrassment factor to deal with. My advice is to just to get over it and act like it is the most natural thing in the world. Newbies may stand in wonder at your expertise and ask for advice. Others will go "ooooo, YUK!". Just ignore them. After each use, wash out the urine bag with clean water containing a small amount of bleach and then allow it to dry.

Catheter Removal - So now comes the interesting part...removal of the catheter. This is the part the probably prevents many pilots from even trying to use a catheter. First, as Douglas Adams of Hitchhikers Guide to the Galaxy would say, "DON'T PANIC!" The catheter is intended to stay put and not leak (which is good) but this also means that it doesn't just fall off at the end of the day (which can be bad).

I have had the best luck with simply reversing the application procedure and rolling off the catheter a little at a time. This is when you will discover if any hairs got involved in the adhesive. Others recommend a warm shower which is not a bad idea after a long flight in any case. In all cases, proceed slowly! Another recommendation is a product called Detachol(R) which is an adhesive removal product described as "...a gentle, non-irritating, adhesive remover used to remove dressings, wound closure strips, tapes, tubes..." which I find works pretty well. Again, you will have to experiment to determine your own best approach.

The Bottom Line

  • Use a catheter and fly without worries.
  • Practice.
  • It is not as difficult as you think.
  • This will help your cross country flying by removing the fear of "I have to land because I've got to go." syndrome. A full bladder can be a significant distraction and potentially dangerous.
  • Finally, you simply will be a safer pilot.

Sources of Equipment - The Internet has a wealth of sites which specialize in these devices. There are also several soaring supply sites listed below which can be used (let's support our own!). The first time around I suggest that you might want to visit a local medical supply store who know about such things. Don't worry about being embarrassed, they handle this type of thing for a living and cannot be caught off guard. But that you may get a few perplexed looks when you explain why you need it (soaring). They can definitely set you up with everything that you will need (bag, catheter, tubing, etc). You can also purchase "starter kits" with all the necessary items.

Chip Bearden's article on externally vented relief systems
as re-sent to rec.aviation.soaring by Eric Greenwell

Subject: Re: Relief Bags
From: JNBearden

[anonymous question]
> I'm having my own plane configured to have the relief tube exit through the gear door.
> This is what an old friend of mine did, he said you have to be very
> careful because it will cause corrosion in the undercarriage.

There should be no problem so long as you put the exit end of the tubing on the lower aft corner of a gear door. This is the technique Karl Striedieck wrote about in his excellent article, entitled "To Pee or Not To Pee" in Soaring magazine. Ed - Not the correct title of the article

The idea of getting the dump tube away from the fuselage actually goes back at least 15 years (probably much more than that). The first time I saw it was (as I recall) on Kai Gertsen's 301 Libelle in the early 80s at Elmira. I radioed to tell him his wheel was down while on course at the Nationals and wondered why he ignored me! Kai attached the tubing directly to the landing gear which, on the Libelle, got the exit port well below the fuselage.

Six years ago, after I heard all the horror stories about urine accumulating in the bilges, etc., and while contemplating the difficulty of getting a tube installed in the fuselage skin aft of the wheel well in the diminutive fuselage of my new ASW-24, I installed the same thing as Kai, but put the dump tube on the gear door, thinking I wouldn't have to extend the gear all the way. In fact, I found that in the '24, I only had to lower the gear slightly to flip the doors open 90 degrees, so the corner of the door is perpendicular to and farthest away from the fuselage.

Karl--who with a few other ridge pilots had made the external catheter socially acceptable in today's cockpits--then took things a step further and performed some experiments with colored water on his ASW-20--the '20s having been notorious for sucking urine into the low pressure area at the base of the vertical fin and corroding the lower rudder bearing--and demonstrated conclusively that this method avoided the problems of the typical exit on the bottom of the fuselage. The rest is history.

Another method I've heard of (on a '20) is an extendable tube which the pilot pushes out into the airstream perpendicular to the fuselage through a small hole drilled in the belly near the seat back rest. This gets the exit even farther away from the fuselage and might be the best method of all. I much prefer the external catheter/dump tube method because it's easier than using bags (no hands required for peeing), especially for ridge and gaggle flying (from experience, though, pilots below you don't always react well to seeing your wheel come down in a gaggle). Plus I hate the idea of littering the countryside with non-biodegradable plastic bags. To say that a few more bags won't make much difference in the general clutter seems like saying that it's OK to steal a little money from a fairly well to do pilot because he won't be able to tell the difference.

When a method works better AND avoids the litter problem, I can't see why anyone wouldn't go to the little bit of trouble to install the system on his own sailplane. No problems with skin irritation so far as I know. The slight bit of negative pressure at the exit port seems to collapse the catheter and empty it pretty well. Known problems: If it's below freezing, use a "T" and another length of tubing to blow out the dump line (don't confuse it with your water bottle tube!). You haven't experienced everything flying has to offer until you've looked down to see a rapidly expanding catheter "water balloon" about to blow off your male appendage at 15,000 feet in the wave.

Fortunately in my case the blockage melted quickly, releasing the "tension", as I was fast running out of ideas (and bladder control) on how to defuse the situation. The other problem also relates to urine which remains in the low point of the tubing under the seat, which can back flow either when the nose goes down on final approach (from experience, bad if you've already unhooked) or in the trailer after the flight. Solutions include not unhooking until after you've landed (from experience, don't roll to a stop right next to the spectators), installing a small valve in the line close to the catheter fitting, removing the catheter but leaving it attached to the tube and tying a knot in it (from experience, this can be fun on fast final glides!), and using air or water to blow/flush out the tube after landing (from experience, make sure your crew is not washing the dirt off the belly as you do this!)

Other issues for the senstive male: Can't recall whether Karl's article mentioned it or not but sorry, guys, size DOES matter. Unlike condoms, external catheters come in different sizes. If you were too embarrassed to buy condoms when you were younger, this won't be any easier. Not to worry, the literature for the product says that if it's too big (the catheter, that is), just squeeze the excess together so the adhesive sticks to itself and forms a fold. Still, too big is too big; buy a few and find out what size you need. Surgical supply houses sell them, sometimes at wildly different prices though even then the cost is minimal ($1.25 to $2.50 each).

Sometimes you can get a quantity discount so maybe several pilots can pool their purchases (and the bravest one can go buy them). Don't know for sure what the shelf life is but I've used some which were several years old without problems (it's not like you carry one around in your wallet in case you get lucky with a friend's ASW-27). Also, I find it easier to put the thing on before launch. From experience, just make sure no spectators or crew persons of the opposite sex wander up to your cockpit as you're finishing up the "assembly" process or you're likely to get some strange looks. Chip Bearden ASW-24 "JB"

Back to me: (Eric Greenwell) At the 2004 SSA convention, Dick Johnson said a flying with a slight slip while using a relief system will ensure the liquid is blown away from the tail boom in all but the poorest installations.


What would you add? Send email to with any questions or comments.