The short answer to your question is that there is no law or
requirement to use TSOA headsets in any aircraft by any crewmember,
under any operating rules, whether Part 91, 135 or 121, or under Part
25 or Part 43 or any other FAR.
This information was provided by Inspector Bures, the Aviation Safety
Inspector (Airworthiness- Avionics) of the FAA Flight Standards
District Office (FSDO) in San Antonio, Texas, with whom I spoke by
The contact page for that FSDO is here:
He said that the FAA's TSO program with regard to headsets and
microphones is for the purpose of establishing a standard, or
benchmark for such equipment, but that the FAA has not mandated nor
regulated the use of such equipment.
Many manufacturers choose to avail themselves of the TSOA process in
order to assure their customers that their equipment does meet this
standard, but they are not required to by law. Furthermore, many
pilots prefer to use their own equipment, which can be and often is
modified in any number of ways, none of which are prohibited, but any
of which might mean the particular headset no longer strictly meets
the specifications of the particular TSO.
So the mere establishment of a process for certifying equipment in
this case does not require certification for use, but only as a
demonstration of adherence to the established standard.
Of course, this is not an official, written opinion. If you're in need
of such, you might contact the Aviation Safety Inspector
(Airworthiness- Avionics)at the nearest FAA Flight Standards District
Office to your location. You can find a nationwide listing here:
Now, all that said, it is possible in many cases for individual
companies to set their own rules requiring the use of certain
equipment, using any standard they choose, including, for example,
that headsets be officially TSOA. Inspector Bures did say that, for
instance, one large national shipping company he knows of did set up a
policy to standardize this type of equipment, and that other companies
and airlines might do so as well. That would be their individual
prerogative, and would govern their particular operations, but again,
is not regulated by law.
So if you had a question about such requirements with regard to any
particular company or companies, it would be a good idea to contact
them directly and inquire as to their policies affecting cockpit
Here's an interesting article from the Aircraft Electronics
Association entitled, "What is a TSOA?" It says in one place that TSOs
"reflect standards that the FAA has deemed to be both safe and
beneficial." If you'd like to read the entire article, you can find it
You'll need Adobe Acrobat Reader to view the file, so if you don't
already have it, you can download a free copy of that here:
So finally, just for your information, here is some related reference material.
As you know, the current applicable TSOs to your question are
TSO-C57b covering headsets and speakers, and TSO-C58b covering
microphones. However, you may be interested to know there is a new TSO
up for approval, TSO-C139, which would include and possibly supercede
these two. Its comment period ended in March of this year, and it is
now on the table awaiting final approval.
Here's a reprint from the Federal Register of Feb. 25, 2005 with
information about it:
And here's a link to the text of the proposed new TSO:
The "Aircraft Configuration Control Job Aid" (AFS-900-002-F-03), here:
says, "In combination with the referenced FAA regulatory and advisory
guidance materials, it serves as the primary guide for performing
AFS-900 Aircraft Conformity Team (ACT) evaluations to determine
conformity to Title 14 of the Code of Federal Regulations (14 CFR).
However, it may also be used for conformity inspections by other FAA
Flight Standards offices, or to assist operators in developing and
performing their own aircraft conformity and acceptance programs."
Essentially, this is a document that shows how to conduct an
inspection to be sure an aircraft meets all the regulations and
requirements. Scroll down to the bottom of page 32 on "Radio
Equipment - Communications." All it says is that Part 25
aircraft(which covers commercial operators) must have a two-way radio
communication system that includes two microphones and two headsets
(or one headset and one speaker). Period. There is no mention of
TSO-Authorized equipment. The referenced regulations are
121.345; 121.347; 121.349
I hope this information fully answers your question. If it does not,
or you need further clarification, please do use the "Request
Clarification" feature to ask before rating and closing your question.
I want to be sure you have what you need.
Like you, I began by reading the regulations. I did make use of the
links you provided, and then searched further, using these terms:
[FAA headsets TSOA]
[FAA approved headsets]
[TSO radio communications equipment]
[TSOA avionics communications]
[FAA "communications headsets" rule OR regulation]
After reading through the results, and finding the pages from the AEA,
and Federal Register, I emailed both the FAA contact listed, and the
AEA, but receive no response. I then telephoned my nearest FSDO, and
spoke with several people before being steered to Inspector Bures, who
was able to answer the question. I will clarify the question if I
receive any additional information from the other places to which I
Clarification of Answer by
14 Jul 2005 09:51 PDT
Yes, I agree that on the surface this apparent dichotomy seems
incongruous and illogical, and my conversation with the FAA inspector
did touch on that point.
My understanding of his explanation of the FAA's position with regard
to TSOs and headsets is that they are mobile equipment and, as such,
are not included in nor covered by type certification or subsequent
STCs, or even ADs, as they can be and are used in any number and
variety of aircraft, indeed, even carried from one to another. Because
they are mobile and not attached to the aircraft, they don't affect
its flight controls or characteristics, nor overall airworthiness, and
therefore there is only a defined, but not regulated standard.
For instance, if you read 121.345, you'll notice that certain TSOs
*are* mentioned with respect to radio equipment, but the equipment
referred to is on-board panel-mounted equipment and permanent
antennae, not mobile carry-on equipment like headsets.
The inspector didn't say this, but I inferred the same rationale would
apply to other mobile equipment, for which there are TSOs, but also
for which I could find no corresponding regulatory requirement, such
as life preservers (TSO-C13f), portable megaphones (TSO-C137), or
lithium batteries (TSO-C142), to name a few. See 121.309, 310, 339 and
340 which address inspection of these items, but don't specify that
they be TSO'd. A list of TSOs can be found here:
To sum up, neither the inspector nor I knew where to find a published
rationale explaining why there exists a TSO for headsets but not an
accompanying regulation requiring the use of TSOA'd headsets. But
since the FAA's functions include advisory as well as regulatory
responsibilities, I would conclude that the existence of TSOs for
aviation communications headsets (or any other non-regulated item)
therefore falls under the advisory role, rather than the regulatory
That's the best I can do as far as explaining my opinion on and
understanding of why this apparent contradiction exists. I hope it
helps some. Please let me know if I can offer any other assistance.
And thank you very much for your kind words and five stars!
Clarification of Answer by
14 Jul 2005 16:31 PDT
I'm glad to hear you agree on the most likely rationale regarding this
situation with regard to headsets and TSOs. As you likely know, it's
not always easy coming up with sensible explanations for government
actions, or inactions as the case may be!
To answer your last question, no, I don't work in the aviation
industry. However, I am a certificated pilot, holding a Commercial
certificate with Instrument and Single-Engine Land ratings. While I'm
a relatively low-time pilot, and out of currency at this time, I have
nevertheless had the good fortune in the past to have had quite varied
flight experience, as well as enjoyed opportunities to be involved in
aviation activities on a number of different fronts, including
legislative lobbying at the state and local level; community
involvement through AOPA and the Texas Aviation Association; Civil Air
Patrol as a Mission Pilot (CD and SAR qualified); and fringe
connections with military aviation through family and friends. I'm a
dedicated aviation afficionado, with a lifelong love of airplanes and
all things related. I've known and experienced enough to have an
aviator's esoteric knowledge of where to go and how to look for
information, some of which is just not intuitively or easily available
to the general citizen without an aviation background.
As to consulting, as Google Answers Researchers, we are not allowed to
have contact with our customers here off the service, so I would have
to say no to your question as asked, but with the caveat that I would
be more than happy to work through this service on any
aviation-related questions that might be directed to my attention.
Thank you for asking. Please do let me know if there is anything else
I can do for you.