Cold Climate Helicopter Operations

A full set of installation instructions are shipped with each system, which makes for easy installation by any technician experienced on that model helicopter. Ongoing maintenance and inspection instructions are specifically called out in the Instructions for Continued Airworthiness (ICA) that accompanies each Tanis electric preheat system. These ICAs should be made part of the aircraft’s maintenance program. General maintenance and inspection practices for 100-hour or annual inspections include such tasks as:

• Examine the cabling system for abnormal wear and integrity at attachment points and bulkhead penetrations, and the shoreline power plug and each individual cable lead for continuity to its respective heat pad element.

• Heat pad elements should be visually checked for cable lead integrity and security of the bonded pad to its heated component. If any portion of a pad heat element comes loose, it may be re-bonded using only factory specified bonding compound. The use of standard tool crib adhesive is not acceptable for use as a bonding material as it will interfere with heat transfer properties of the heat pad element.

• If a pad heat element exhibits a gray discolored area, it is likely due to an air bubble under a poorly bonded element and will require replacement.

• Once the visual inspection is satisfied, verify with an ohmmeter proper heat pad element resistances as published in the installation handbook.

Wendell Stadig, ERA Helicopter lead maintenance technician for LifeFlight of Maine’s two Agusta 109E helicopters, says, “The electric preheat systems are really trouble free and require very little attention. The only trouble I ever had was trying to remove heat pads from engines or transmissions being removed from the helicopter for overhaul. The pads do not come off very easily! Now I just leave them on and install new pads on the replacement component.”

A few safety tips worth passing on regarding the handling of heat pads are, never apply electrical power to heat pads until they have been properly installed to the designated aircraft component. Applying power prematurely can potentially destroy a pad element before it is installed. Also, resist the temptation to touch a heat pad with your bare hand to see if it is working. Heat pad elements performing properly will radiate noticeable heat, so with electrical power applied touch the component adjacent to the pad to determine that it is working correctly.

Helicopter operations in severe winter conditions can create a special set of mechanical stresses on critical driveline components and engine starts. One method of overcoming these stresses is through the use of electric preheating systems. Stadig concludes, “The best part is that we just plug them in shortly after the last flight while the oils are still warm. It’s easier to keep the components warm than to get them warm.”

Information for this article provided by the following:

Jim Conn, business development manager for Tanis Aircraft Products. Jim holds a commercial pilot certificate and has been a user of Tanis products since the 1980s. He has established and managed aviation departments for small businesses, and in 1995 was cited “Wisconsin Aviation Person of the Year.” Jim can be reached at jim@tanisaircraft.com or (320) 634-5149.

Dirk Ellis, engineering manager for Tanis Aircraft Products. Dirk has been part of the Tanis team for 20 years and he holds an Airframe and Powerplant certificate. Dirk can be reached at dirk@tanisaircraft.com or (320) 224-4425.

For more information: http://www.youtube.com/watch?v=vPwI_A7yUE0&feature=youtu.be