Widget Of The Week
Airmed Airlite 71 Aviation Headset, 1972
If you ever get a chance to go up in a light aircraft
take it! It is as far removed from flying in commercial airliners, as it is
possible to get. It’s proper flying, and you can even open the window (though
it can get a bit windy…).
However, the real joy of this kind of flying is being up
front, seeing where you are going, and trust me, even on the dullest of days, the
view from a couple of thousand feet, in the cockpit of a small aeroplane, is
something you will never forget.
Flying in a small plane is a blast for all of the senses, and something else you won’t forget is the noise. It is really loud,
inside and out, you literally can’t hear yourself think, which is why
you will need one of these. It is an aviation headset and whilst it might look
like a pair of fairly ordinary headphones, with a microphone attached, it is
actually a breed apart. Regular hi-fi headphones, even ones with designer labels and boom
mikes, simply couldn’t function in the range of conditions general aviation (GA) headsets
are designed to cope with, and all of those unique features are clear to see on
the Airmed Airlite 71.
In most other areas of technology the Airlite 71
would be classed as vintage equipment. They first appeared in 1972, but another
oddity in the world of fixed wing aircraft is the apparent slow rate of change
and the basic design parameters of this headset date back to the 1940s. Not
only can this headset be used in most of today’s fixed wing aircraft, headsets of
this type are still in production.
Noise insulation is obviously a very high priority and this is handled by the all-enveloping ear cups, and very
effective they are too. Normally they would be encased by a light cotton or
foam cover, which helps seal the gaps, soaks up the sweat, and easily changed, when they get manky. Number two on the list of key features is comfort. These
headsets are designed to be worn for extended periods of several hours, so
there has to be a balance between weight and the tightness of the
sprung headband, to keep them firmly attached to the wearer’s head, and
maintain sound insulation, whilst avoiding the stress and discomfort of being
too tight. The moveable pad on the top also helps distribute the weight, not
that this one is very heavy, but after only an hour or so you start to notice a
badly designed headset, and taking them off for a break during a long flight
isn’t really an option.
The headset end of the microphone boom is mounted in
a ball joint, allowing a wide range of adjustment, and it swings through more than
180 degrees, so it can be worn on the right or left side of the wearer’s head.
There’s a fairly unusual feature at the other end of the boom and the
microphone module on this headset is held in place by a simple clamp, so it can
be removed, and exchanged. Different types are available, or can be made to
order by the manufacturers, Clement Clarke Communications, to allow it to be used with
a wide variety of comms equipment – on the ground and in the air -- and it also
simplifies cleaning, repair and maintenance.
Finally, we come to one of the strangest features of
most aviation headsets, the double jack plugs. One of them, connected to the
headphones (wired in parallel for mono sound, and redundancy, in the event one of them fails), is a standard 1/4-inch mono jack (aka PJ-055). The other one is an odd beast, variously known as a PJ-068, M642/5-1 or the 206 General Aviation
Microphone Plug (it’s .206 of an inch in diameter). This has four contacts, three of them connected,
for the microphone, ground and the push-to-talk (PTT) switch. The latter is used
when talking to air traffic control or in intercom mode, so that the pilot, co-pilot or
passengers can talk to one another. The use of different sized jacks also means it is impossible to get them mixed up, when plugged in. Headsets like these can also be used in
other types of aircraft, like helicopters, which have a single plug system, using
readily available adaptor leads.
That would normally be the end of it, except that
like all equipment designed to be used in aircraft, it has to be built to
astronomically high standards. Failure of any safety critical component or system,
and that includes communications, is simply not an option when you are swanning
around the sky, and even though this headset was made more than 4 decades ago
not only does it still work as well as the day it was made, it will probably
still be working in another 40 years.
What Happened To It?
Both the Airlite range (now into the 100 Series) and
Clement Clarke Communications, who these days are based in Edinburgh, are still going strong
and you have to look quite closely at current models to spot any major differences between
them and this old Airlite. Of course there have been some significant changes in
aviation headset technology but these mostly relate to systems used in
commercial aircraft. The light aircraft and general aviation industry moves at a much slower pace
though, and there is, and always has been great belief in the tried and tested,
and the old adage that if it ‘aint broke, don’t fix it.
This is one of several headsets that I have owned
over the years and I swapped some aviation gear for it in the late 90s, when I used to do a spot of flying.
At the time I had a much-prized David Clark headset (another vintage classic) but
it’s always a good idea to have a spare set, as a backup and for the use of
passengerst. They didn’t get much use
whilst they work well, they never felt as comfortable as
my trusty old Clarks.
I have not been able to find out how much they cost
when new but like most things to do with aircraft it was probably a small
fortune. A fair few would have been made, probably in the low thousands and in
addition to light aircraft owners, customers included the Ministry
of Defence, Civil Aviation Authority, Air Traffic Control and so on. Because they are so expensive, reliable and change so little relatively
few aviation headsets end up in the public domain but when they do, they are
generally sold by someone who doesn’t really know what they are about. Potential
buyers often mistake them for language lab, computer or AV industry headsets,
or are put off by the double jacks, so prices for GA headsets, sold outside of the
aviation market, rarely reflect what they are worth. A pilot might expect to
pay anywhere from £30 to £100 for a headset in good working condition, and substantially
more for top brands like David Clark, but over the years I have seen a fair few
at car boot sales, selling for as little as £5 – 10, so like a lot of specialised vintage
tech, it’s basically worth what someone is prepared to pay for it.
First seen 1972
Original Price £?
Value Today £20
x earphones, wired in parallel 150 ohm impedance, fully adjustable headband,
dynamic mike, interchangeable microphone module
Power req. n/a
earphone: 85 x 105 x 50mm
Made (assembled) in: England
Hen's Teeth (10 rarest): 6