AVweb's Kennon FAQ: Frequently Asked Questions About Kennon Products
External Cabin Covers or Reflective Sun Shields:
Both work, but which will best protect my airplane?
Kennon builds the finest external Cabin Covers, and is also known worldwide for its excellent Sun Shields that wedge inside the window molding and fit without fasteners or suction cups. It is hard to discuss one without mentioning the other.
We are often asked which cover is best. Both Cabin Covers and Sun Shields have distinct features and benefits. To help you make the right choice for your needs we attempt to answer these frequently-asked questions.
When is it advisable to use an external cabin cover instead of internal sun shields?
- If your aircraft has a leak and you are taking on water inside the cabin and you suspect that the source of the leak is a window.
- You want to keep snow, ice and frost off the windows in the winter.
- Your plane is exposed to blowing sand, sea salt or atmospheric pollutants.
- You're concerned about the long-term effects of the ultraviolet radiation on the plexiglass windows.
Does an external cabin cover scratch the windows?
This is probably the question we're asked most frequently. When using an external cover, every precaution must be taken to make sure it doesn't scratch the windows. The windows must be clean before you put on the cover. The cover must be clean. If the cover is lined, the lining must be clean. Most important, the cover must fit well and not allow the wind to blow sand or dirt between the cover and the windows. A properly-fitted cover won't move in the wind so it will not chafe the windows. That's why at Kennon we're so very fussy about perfect fit.
Why would I want to use Sun Shields rather than an external cover?
- If your airplane does not leak, and keeping your windows free from snow, ice, frost and blowing sand or salt spray is not a concern...the sun shields may be just what you need.
- Sun Shields are installed inside the aircraft where it is cleaner and safer. They are
unaffected by the wind so they may be safer for your windows than most covers.
Note: Kennon's external Cabin Covers fit very snugly, and our deluxe cover is lined with satin to help prevent scratching. We even build covers over the door handles to improve the fit. These extra precautions are necessary...because the wind can get pretty nasty at times.
- Anyone can lift your external cover to see what you have inside....but they can't do that with an internally-installed Sun Shield. Sun Shields stop prying eyes.
- Kennon Sun Shields keep the cockpit cooler than Cabin Covers.
- Kennon Sun Shields are more economical because they cost less than an exterior Cabin Cover.
Don't Sun Shields reflect the sun back through the windows and hasten the damage to the plexiglass?
That's a very good question. In fact, prior to 1992, manuals produced by Cessna advised against using sun-reflecting screens. But after the Air Force tested and accepted Kennon Sun Shields for use in DOD aircraft, Cessna removed the warning.
Heat is one of the major causes of crazing. Plexiglass is produced as a flat sheet, then shaped with heat. When it gets hot again, it tries to return to its original flat shape. This stress on the curved areas of the windshield causes distortion of the plexiglass which is commonly known as crazing. Crazing is very often first discovered on the curved portion of the windshield.
So how do windows get hot? Heat is produced when the sun's rays are absorbed. Plexiglass is transparent and does not absorb the sun's rays very well. But when they are absorbed by the interior of the aircraft, heat is produced. As the cockpit temperatures rise, so does the temperature of the plexiglass.
Kennon Sun Shields reflect about 93% of the sun's rays back through the clear windows before they are absorbed and produce heat. The cockpit stays cool and windows stay cooler.
What makes Kennon Cabin Covers better than those of the competition?
Kennon uses the very best materials that are made to withstand the sun.
Kennon's covers are constructed from a breathable woven acrylic canvas called Sunbrella. Sunbrella is designed to withstand the sun. It is used in the boat-top and awning industry. Sunbrella is breathable so it won't trap moisture between the cover and the window. Trapped moisture causes mildew. and also may permanently cloud the plexiglass windows.
Some competitors' covers are made from nylon laminated to a soft fuzzy material. Kennon does not use laminated materials because the lamination process interferes with the breathability of the fabric. Nylon is less expensive...but how many boat tops and awnings are made from nylon? Nylon does not hold up in the sun.
UV inhibitors applied to nylon wear off and need to be reapplied. Kennon chooses to use only the best material that is proven and warranted to withstand the sun for a minimum of 5 years.
Some covers are made from vinyl or materials which contain plasticizers. Never should such a cover be used against the plexiglass because plasticizers actually change the chemical composition of the plexiglass and cause crazing of the windows.
Some manufacturers use a flannel cotton lining or other fuzzy lining. Kennon does not...instead we use a satin lining. Sand and dirt can stick to or hide in fuzzy linings...satin is so slippery that nothing sticks to it.
What else makes Kennon's Cabin Cover design superior?
- Kennon builds a pocket for every door handle or latch. It takes extra time and effort but then the cover fits better. Fit is everything when building a safe cover.
- Kennon's Cabin Covers have a scalloped (curved) hem design with two straps, one fore and one aft of the wing. The scalloped design makes the cover fit snugly against the plane.
- An entry flap is built into every cover to allow you to get into the plane without taking off the cover.
- Both straps have quick release fasteners on both sides of the aircraft so the straps can be adjusted from either side. The straps can be removed completely and stored or washed separately from the cover.
- Every high-wing cover incorporates a fiberglass stiffening rod that keeps the cover snugly secure to the frame at the top of the windshield, so the wind cannot blow between the cover and window.
For answers to other aircraft covering questions, feel free to contact us by e-mail.