A local builder ran into an administrative glitch during the final inspection of his RV-3 last week. The MD-RA inspector insisted that he could not approve the aircraft as it had a halon-filled fire-extinguisher. He had been told by MD-RA headquarters that Transport Canada had sent a letter which said that they should not approve aircraft with halon-filled fire extinguishers.

The builder asked me if I could shed any light on the subject. I dug into the TC regs and guidance material, and couldn't find anything that should preclude the use of a halon-filled fire extinguisher. I then sent an e-mail to the TC inspector who is responsible for coordinating the airworthiness policy for amateur-built aircraft. He replied that halon-filled fire extinguishers were completely "legal".

Just in case someone else runs into this problem, here is the body of the e-mail I sent, and the various replies:

There is some confusion about whether halon-filled fire extinguishers are acceptable on amateur-built aircraft. An MD-RA inspector recently refused to accept a halon-filled fire extinguisher, citing a letter from TC to the MD-RA. However, there is no mention of any prohibition of halon-filled fire extinguishers on the TC or MD-RA web sites.

AWM 549.13/1A says "Portable fire extinguishers (ref. Chapter 549, para. 549.13(a)(4)) are required by E&I Manual Part II, Sect. 3.5 para. 3.5.2 for all aircraft, except for amateur-built aircraft with open cockpit and non-powered gliders. AMA 500 C/4A addresses this subject and provides interpretation of FAA Advisory Circular (AC) 20-42C. " (ref AWM 549-13-1A)

AMA 500 C/4A has been canceled, and superseded by FAA AC 20-42C (ref AMA 500).

AC 20-42C has extensive coverage of halon-filled fire extinguishers, and there is nothing in this document that would prohibit their fitment on amateur-built aircraft (ref AC20-42C).

I can't find any M&M ACs, SIs, or PLs that cover this issue. Thus I have to assume that AC 20-42C is applicable to amateur-built aircraft. If this is not the case, please point me to the document that has over-ruled AMA 549.13/1A.

He replied (sending an info copy to MD-RA):

Halon-filled fire extinguishers are "legal" in amateur-built aircraft. No doubt about that.

MD-RA responded:

The letter in question, if I remember correctly was not a prohibition of Halon extinguishers, but rather a notice that there are no approved refill stations for them. So what you have is a one shot extinguisher, as there is no possibility of refill.

Here is the letter

-----Original Message-----
From: ........
Sent: Thursday, August 26, 2004 12:13 PM
To: .......
Subject: Halon 1211 Handheld Replacement Extinguishers

Further to inquiries received over the past many months, this is to advise that there are currently no Halon 1211 handheld extinguisher replacement agents/systems approved for installation/use on Canadian-registered aircraft. (We are also not aware of any approved installations in the US or Europe.) Although a certain number of replacement extinguishers have been certified (by UL in the US) as complying with the hidden fire test specified in the Minimum Performance Standard (MPS), there are still a number of issues which need to be addressed including, amongst others, toxicity (-vs- cabin volume), number/size of replacement extinguishers, cold soak and procedures/training. TCCA is working with the FAA and European Authorities to resolve these. We had hoped for completion of the work by this Fall, but progress has been slower than expected. We will keep you advised. Please feel free to contact me or .......... if you require additional information

Regulatory Standards
Aircraft Certification
Transport Canada

Office Manager
MD-RA Inspection Service
2469 Aviation Lane
London, Ont.
N5V 3Z9

The e-mail that was referenced simply says that nothing has been approved as a replacement for Halon 1211. I.e. nothing else has been found that works as well. It doesn't say that Halon is not approved. The fact that I may not be able to get the fire extinguisher refilled is a non-issue. I want the fire extinguisher agent that works the best (i.e. halon). If I ever have to use the fire extinguisher, I'll buy another one.