Learjet Spring 2000

• What Are Those Burn Testing Documents For?
• 39-309 Vs. 39-309-1 Anti-Skid Valve

What Are Those Burn Testing Documents For?

Flammability testing, or burn testing as it is called in the industry, is an often misunderstood regulatory requirement. Not understanding it correctly could cost you down the road.

If your aircraft interior was recently refurbished or modified, it is likely that you were given burn test documents by the completions center. These documents contain valuable certification information and you should keep them with the other modification/certification records pertinent to your aircraft.

Federal Air Regulations per 25.853 require that the materials used in corporate jet passenger cabins be “self extinguishing” when exposed to flame in order to enhance the safety of passengers. To meet this requirement, each material used in building or refurbishing an interior must pass certain tests individually, or as an assembly combined with materials on which they are applied. Samples of these materials are subjected to direct flame for a short, specified period of time. The burning material then must self-extinguish within a specified period of time to pass the test. Records of the test results and the origin of the material tested comprise the bulk of the interior burn certification documents.

Burn test certification is required of the entire aviation community. However, you may experience varying levels of compliance at completions facilities around the country. Burn testing is a complex and often confusing process, so you may want to ask a Duncan Aviation representative to explain more about requirements and regulations. Duncan Aviation is happy to provide as much information as you’d like about burn testing.

Aircraft owners have the burden of proof concerning burn testing. Burn testing documents provide the proof of certification required for an owner to demonstrate compliance and may be required in the future to:

1. Prove FAR compliance when an aircraft is being placed on a Part 135 certificate.
2. Prove FAR compliance for pre-buys (when an aircraft changes ownership).
3. Prove FAR compliance when an aircraft is being exported or imported.
4. Verify interior materials for future repairs or replacement.

Understanding the issue and asking questions up front could save you time, money and a lot of frustration.

39-309 Vs. 39-309-1 Anti-Skid Valve

Over the years these valves have been removed for exchange, repair/overhaul and have been worked on by many repair facilities. The result is that there are various anti-skid valve assemblies in service that may not have proper servo valves installed on the anti-skid valve assembly.

The 39-309-1 anti-skid valve assembly should have two each servo valves installed, PN 37-285. The 39-309 anti-skid valve should have two each servo valves installed, PN 37-015 or PN 37-02946.

Duncan technicians have found servo valves, PN 37-015 installed on the 39-309-1 anti-skid valve. Hydro-Aire Crane has never approved these to be installed on the 39-309-1 valve. If the servo valve has been installed incorrectly, the anti-skid valve can still be installed on the aircraft and should function correctly.

When installing a 39-309 or 39- 309-1 anti-skid valve, it is worth a few seconds of time to verify the assembly is a proper, approved assembly. It can be a costly maintenance event if the electro servos need to be changed.

For info, contact Chris Gress in LNK at 800.228.4277 or contact Pete Kilmartin in BTL at 800.525.2376.

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