FAA Compliance

FAA compliance of windsocks is determined by adherence to the FAA guidelines on windsock construction as seen on their FAA Specification for Wind Cone Assemblies publication AC No: 150/5345-27F.  

The Specification for Windcone Assemblies is published by the FAA and updated periodically with the last update being in 2021 (AC No: 150/5345-27F). This specification refers to two very specific tests for textiles. For a windsock to conform to the FAA specifications, it must pass these two tests.

The two tests are 

• “Strength and Elongation, Breaking of Woven Cloth; Cut Strip Method” standard defined in of FED-STD-191A
• Method 5671, “Colorfastness of Textile Materials to Weather; Accelerated Weathering Method” of FED-STD-191A.

The methodology of testing for both of these tests is found in FED-STD-191A, which is a federal standard for textile testing. This document outlines many different standard tests for textiles (physical tests, chemical tests etc) and served a common guide for testing for Federal and Military specification. The FED-STD-191A was published in 1978 and was then later replaced by ASTM standards. The entire Federal Standards shifted to ASTM standards, which are created by industry professionals rather than the Federal Government. ASTM is a standards organization that develops and publishes voluntary consensus technical international standards for a wide range of materials

Having said all of this, the FAA Specification for Windcone Assemblies still refers to the very old standards stated in the 1978 publication of FED-STD-191A.

The two tests mentioned in The Specification for Windcone Assemblies are obsolete and are no longer being practiced within the United States. All fabric testing labs have moved onto the current industry standard testing, that is, ASTM testing.

After much searching, we at the Custom Windsock Co, have not been able to find a laboratory to test on the 1978, FED-STD-191A standards. All commercial laboratories have directed us to the "equivalent" and current ASTM testing for the same properties, namely: fabric tensile strength and UV resistance to fading.

The Custom Windsock Co has invested in testing its' fabric with the current ASTM stadards as well as real-world conditions. We have tested our fabric on:

• ASTM D5035 Standard Test Method for Breaking Force and Elongation of Textile Fabrics (Strip Method)- Type 2C
• Our fabric results of the above current test methodology: 1218 N Warp and 1221N Weft  
• The outdated tests stated in the FAA Specification for Windcone Assemblies require a passing tensile strength of:  667 N Warp and 667 N Weft 

• ASTM G154-21 Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Materials
• Our fabric results of the above current test methodology: Slight change in color over the exposure period
• The outdated tests stated in the FAA Specification for Windcone Assemblies require require:  “Good” or “Excellent” rating for colorfastness 

As seen in the above, the Custom Windsock Co has invested in real-world and laboratory testing to determine the quality of its' fabric and ensure it complies to the highest standard. However, due to factors out of our control, the exact testing required to prove compliance cannot be obtained.

We have gone through the process of testing our competitors fabrics that claim to have passed the tests stated in FAA Specification for Windcone Assemblies, and our fabric has come out the same or superior in the above two ASTM equivalent tests. 

Conclusion

We are confident that, if the FED-STD-191A standards were being tested today by any commercial laboratory, our windsock fabrics would meet or exceed the requirements stated in FAA Specification for Windcone Assemblies as they have surpassed the equivalent current industry standards.