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Extended soaring flights require that provision be made for urinating. Common wisdom says that unless the pilot needs to urinate during long flights, he is not drinking enough water to be properly hydrated. And dehydration is a major safey issue. Pilots who allow themselves to become dehydrated often make judgmental errors leading to incidents and accidents.

There are several popular pilot relief systems in use by soaring pilots today. Some use ziplock bags filled with absorbant material. Somehow they manage to fill the bag while flying and either keep it in the cockpit until they land, or shove it out the canopy slide window to land who-knows-where. Some use a turkey basting bulb to temporarily collect the urine which they somehow expell from the glider. This too stretches the imagination to understand how it can be done while soaring.

The most convenient method is to use the same medical supplies developed for wheelchair bound invilids. The essential item is a male external cathetar, which connects to a relief tube. Depending on how the tube is connected, the pilot needs to do little or nothing special when the time comes. Like a bird, the pilot can use this system at any time with little or no effect on his flight activity.

OxAero sells Pilot relief system supplies.

What is a male external catheter?
Basically, a male external catheter (MEC) is a condom like device with an open end designed to attach to a urinary relief tube. The inner surface is treated with an adhesive to secure the MEC and prevent leakage. There is a bit more to a MEC designed for extended use, but this is the basic idea.

What are the options for routing the relief tube?
Option 1: Some pilots drill a hole in the seat pan near the control stick and install a permanent tube from that point to a gear door or out the belly of the glider. They connect to this tube in-flight or when they prepare for launch. With this system, the pilot must unzip to make the connection.

Option 2: Others prefer to run the MEC tube down a pants leg and connect it to a glider relief tube starting near the rudder pedals. This obviates the need to unzip, but requires connecting before launch. Onlookers may be temporarily confused and may even ask what you are doing. This will challenge you to answer with appropriate tact and humor.

Option 3: Another option is to use a urinary collection bag strapped to the calf of one leg, just as wheelchair invilids do. This has the advantage that one may use the system in a glider that is not equipped with a relief tube. This would be an option for when you fly a rental glider or perhaps tag along in the rear seat on a long cross-country flight in a friend's ship. The main problem with this system is that the bag has a limited capacity, and it would be hard to imagine the anxiety felt when it is at capacity. A large bag typically has a 32 oz capacity and that is sufficient if the flight is not too long, or not being the main pilot, perhaps one could get by with drinking less. Avoiding caffein is another important consideration.

Since urinary collection bags are equipped with a valve at the bottom for evacuating the bag, another option presents itself. That is, using a collection bag connected to a permanent relief tube in the glider. That is, rather than having a plain tube running down the leg, there is a collection bag in the circuit. This provides a cut off valve at the bottom and presents options both in flight and on the ground. At high altitude, glider relief tubes have been known to freeze up. With a collection bag inside the glider next to your warm leg, you have a backup capacity. On the ground, all too often the need arises at places remote from bathroom facilities. The bag offers an inconspicuous alternative.

Options 1 and 2 require that the end of the MEC connection tube be terminated with a cutoff valve to avoid spills. Option 3 has such a valve built-in as an integral part of the collection bag.

The glider relief tube Most often, the glider relief tube terminates at the inside rear corner of a gear door. Many gear doors have some sort of fitting there for attachment of the door-closing bungee. The relief tube can be routed to that point in such a way that it does not interfere with the wheel or retract mechanism. Usually the tube is wired to the fitting in such a way that it empties aftward. This arrangement requires the pilot to lower the gear before using the tube. This is also a great way to scatter the gaggle below you in a thermal, just lower the gear.

Another option is to drill a hole in the corner of the gear door or elsewhere in the belly of the fuselage. You can then extend the tube through the hole and fix it so it protrudes say 1/4th of an inch. This has the advantage that you do not need to lower the gear (not an option on sime gliders) and there is no chance that you will urinate all over the retract mechanism and into the tail boom of the glider. The corrosive effects can lead to maintenance problems. For most people, the additional drag of an external terminationis acceptable. You are likely shy away from this option with a new glider. But if you choose it and later change your mind, it's a small matter to cover the hole with tape as you do so many other holes in your ship.

I have used both methods, but I finally settled on the external gear door termination. I can lower the gear to move the tube away from the fuselage, but I have never found any evidence of staining on the fuselage in either case. This may vary from glider to glider, however.

A concern, mentioned above, is that the relief tube may freeze at high altitudes. This is normally dealt with by installing a "T" in the line and a blow tube to clean out the main line before it freezes. For obvious reasons, this line needs a cut off valve. For this I use an old outlet valve from a discarded collection bag. Having flown with this configuration for several years, and having been in high-altitude wave for maybe a few hours in all that time, I think that a blow-out line is unnecessary, expecially when I fly with a collection bag. Pilots who spend a lot of time at high altitudes may take a different view.

Special Considerations
As with other systems, the MEC system requires some getting used to. Everything will not necessarily work flawlessly. Problems can be avoided and improvements made by modifying the equipment and taking preparations. Here are some suggestions:

• Skin Irritation
  Urine on the skin over time can cause burning. So, care should be taken to select a MEC designed to minimize this problem. Hollister Extended Wear MECS are cleverly designed with an annular flap that prevents urine from flowing back up the sheath. You can see this clearly in the image on the right. This flap really is very effective.



• Respect the adhesive
  The adhesive is very well designed for the job. However, there is one problem that may have occurred to you. It loves hair and that can be painful. This can be minimized by taking care when donning the MEC. If you are going to commit to this system, you will need to cut away problem hair. Removal of the MEC is best accomplished by pulling the edge of the MEC to stretch it as wide as possible. The skin then pulls away.



• Backflow
  Some people wonder "what keeps urine from flowing back up the connection tube from the collection bag?" The answer is that the inlet to the bag has a one-way, flap valve to deal with this. So there is no need to worry about whether the leg bag is too high in your glider's seating position. The image on the right shows the inlet to the leg bag, but the valve cannot be seen because it is inside the bag. This valve is so effective that you can blow the bag up with air and it will not leak.


• Blockage
  The collectioin bag inlet valve can be a problem. After the inlet valve is wetted by the first use, it becomes very effective and there is a tendency for the bag to suck a vacuum. This will collapse the end of the MEC. As a result the inner surfaces stick together and block flow until they slowly unstick with usage. Uncomfortable pinching may also occur. Hollister sought to aleviate this problem by designing annular ridges in this area, but the ridges need some help. Small, circular key rings solve the problem nicely. Place a 1/2" ring into the foremost annular ridge and a 5/8" ring in the aft ridge. These will stiffen the ridges and positively prevent them from collapsing, and everything will work just as Hollister intended. Remember to retrieve the rings before doscarding the used MEC.
  
  One last thing that can cause blockage. If the connection hose puts a significant torque on the MEC, it can twist the soft MEC tip. This will severely restrict the out flow. When this happens, the MEC will swell like a balloon and threaten to break loose. You will know when this happens and stop the flow. In time it will leak past the restriction. After that, you will use the relief system with great caution. The solution is to take care when attaching the connectoin hose to the MEC, so that it does not twist the MEC.



• Remove the end cap
  For some reason, the Hollister urinary connection tube comes with a cap over the tapered plastic end piece. Be sure to remove this before attaching the tube to the MEC, otherwise the system will fail catestrophically.



• Cleaning
  It is important to clean the connection tube and bag after every use. If you don't, black stuff that is impossible to get rid of will grow. Use water and bleach. First rinse out the tube and bag by flowing hot water through them. Then use a spray bottle to squirt bleach and water into the connection tube and then connect the ends together to contain the solution. Finally, squirt some into the bag and slosh it around. After soaking overnight, rinse them out and they are ready to use again.



• The connection tube inlet fitting
  After much use, the inlet fitting on the connection tube might easily slip out of the tube. Normally, you should replace the connection tube after a year. However, you can fix this problem permanently if you wish. Tape can be used to hold the inlet fitting to the tube. But it will become ragged in time. As seen in the image on the right, the joint can be permanently strengthened by stretching a larger piece of tubing over it.



• Old equipment
  With use, the leg bag will stiffen. After a year of use, it may begin to leak where the outlet valve connects into the bag. So, you should replace the bag annually and carry a spare with you. They can be hard to find when you need one.



• Leg straps
  The leg bag is held in place by elastic straps that go around your leg and attach to buttons on either side of the bag, above and below. The elastic tends to slip loose, so you will need to find the right length and stitched the elastic together to prevent this. (See the image with a strap above.) In time these will become dirty and will weaken. You can get replacement elastic at any fabric store. After a whole day of wearing a collection bag, the elastic bands will irritate the skin. One good way to deal with this is to put fabric between the elastic and your leg. Placing the lower band over your sock deals with this problem at the bottom. At the top, a sweatband for the head works well. Just put it around the leg before connecting the upper elastic strap.



• Outlet valve modification
  Don't throw away the inlet tips from discarded collection bags. You can use them to create a tapered connection to the outlet valve. This will make connecting to the glider relief tube easier. The problem is that the fitting is just a little too small for the opening. So a little vinyl tape is needed for a tight fit. The image on the right shows this modification.

Jim Hendrix

OxAero sells Pilot relief system supplies.