Trailer Preflight 101

This short discussion is not the best subject to review, but it may be the most important for your sailplane investment.

When you arrive at a glider port, what do you usually see? Some gliders? A lot of decrepit trailers, some rotting away? Or does the 3-year-old JS-3, AS33, Arcus, Twin Shark, etc., look like it has the plague?

What does the inside look like with both? The condition of the pilot’s trailer tells me a lot about the pilot's thought process. The outdoor covers as well—another subject for later.

Trailer maintenance is very important—more important to the competition pilot who drives 500+ miles a year to a contest or farther. How about your local pilot? Yes, trailer maintenance is essential. Does it not carry your valuable sailplane in it? We need to keep our trailers more “road” worthy.

Let’s go over some items. Trailer preflight 101. Let’s start with the tires. According to Cobra, your trailer tires should be replaced every six (6) years; others say earlier. Some thoughts:

 
• Check tire pressure every month
 
• Some say to replace your tires every 3-5 years
 
• Rotate your tires
 
• Keep your tires out of direct sunlight (covers work)
 
• Keep your tires dry (in a grass area for a long time, then roll up on some bricks, etc.)
 
• Ensure your safety chains are attached properly, and you have clearance in turning (in Europe, they do not use safety chains, just the safety cable for the emergency disconnect brake)

In the Cobra Trailer Manual, will you notice no references to trailer chains? Tounge weight: Cobra mentions 4% but also says more may be better. I run my tongue weight at 10%. It's recommended to be between 10-15% of the TGW (trailer gross weight) in the USA. If it is too heavy, you may have control issues, and with the light trailer, it will sway. Please remember to follow all posted speed limits. I have found that my DG-1000T, TGW is approximately 3000 pounds and rides nicely at 70 MPH; also, remember to give yourself at least the 4-second rule for the vehicle in front of you. Other maneuvering precautions are a must!

Please don't use the plastic Cobra hub caps. They usually depart the hub within 100 miles!

The above are just a few. When you buy new tires, how do we find out when these new tires were made? When buying new tires at an auto or tire dealer, check your tires carefully; you may be purchasing 2-year-old tires! On the tire is a series of numbers, tire dimensions, Max PSI, etc. Look for four numbers. That is the tire's birthday:

This example is 2118. 21^st week (roughly 26 April) in 2018
 

The Cobra Trailer web page has 18 pages of detailed information on the trailer's operation (Cobra Trailer Manual). There is no need to continue here; I recommend to download the manual at:

Brakes seem to be an issue with Cobra trailers. It's not their fault; it's usually an operator error. Read their manual! How to test your wheel brakes (Cobra Trailers):

Test: Activate the hand brake and push the trailer back by hand. If the hand brake lever – moves back more than 90°, it is time to adjust the wheel brakes. The brake handle should not move.

For adjustment of the brake handle, visit this link:

Maintenance_Manuals/Bremsenwartung_ALKO_Bremsanlage_E_v01.pdf

As you preflight your glider, you should also preflight the trailer more thoroughly since your valuable sailplane lives in it during ground transportation. If your brake handle does not retract to approximately 90 degrees (straight up), the brakes may also need cleaning.

If you decide to conduct preventive maintenance on your trailer; one good thing is to obtain an aluminum fence post, hear me out. About 3-5 feet long. This is the perfect device to quickly remove your wheel cap (to check for grease, which after 2015 are sealed; if you have grease, something is wrong) so you can remove your drum (hub) and check or clean your brakes. This method saves time and prevents damage to the caps by using a hammer, screwdriver, or large pliers. Use brake cleaning fluid; this cleaning should be done once a year, especially if you travel a lot.

There will be those who may have different ideas, but more than a small review is needed. By the way, if you decide to work on your brakes (Cobra or any others), review the manual and ensure you have another knowledgeable person on the adjustments (behind the drums), etc. Drive safely!

Banner photo by Sean Franke

 Shawn Knickerbocker has been flying gliders since the mid-sixties. Is a retired FAA DPE who held designations in Airplanes, Helicopters and Gliders for all rating, including the elusive CFI initial, plus numerous type ratings, he has over 62 FAA authorities as a DPE/SAE/SMFT.  He also possesses a TCCA (Canada) License with ATP Ratings for airplanes, all classes (SMELS), plus numerous type ratings and Aerobatic Instructor (ABI) in Gliders for Canada. He was the SME for the FAA in rewriting the Airplane Handbook, Helicopter Handbook and the Glider Handbook and PTS in 2000. He was instrumental in developing the CAP Glider Program for Florida back in the mid 90’s to include the “wing runner & tow pilot manual” and has developed many other training programs for the military and US Government Aviation Agencies.  He is the current Program Manager for the SSA Cross-Country Instructor Pilot Program. Shawn been flying 58 years, a FAA Master Pilot with over 25,000 hrs.  Shawn lives at Seminole Lake Glider port. Email; [email protected]. C- 904.382.9614