A nondestructive test for aircraft Halon bottles, the development of an acoustic emission application

An acoustic emission test for aircraft Halon bottles has been developed in response to a need expressed by the US Airline Industry. During this development many choices had to be made about test methods, procedures and analysis techniques. This paper discusses these choices and how successful they were. The test itself was designed to replace the currently required hydrostatic test for these bottles. The necessary load is applied by heating the sealed bottles. Acoustic emission is monitored, during the heating, by six sensors held in position by a special fixture. A prototype of the test apparatus was constructed and used in two commercial Halon bottle repair and test facilities. Results to date indicate that about 97% of the bottles tested show no indications of flaws. The other 3% have had indications of possible flaws in non-critical areas of the bottles. All bottles tested to date have passed the hydrostatic test subsequent to the acoustic emission test