Why don't voice radio communications use FM?

"Mxsmanic" wrote in message
...
Ron Natalie writes:

No actually, it's just historical. Early av radio used AM, and for that
reason we still do.

If that were the only reason, nothing would ever change in aviation.


Actually, not much does change in aviation compared with other fields of
human endeavor . But changing to FM would require a new radio to be
simultaneously installed in every cockpit in the world. The only way to
accomplish that would be for every plane with a new radio to transmit in
"parallel" (as someone already suggested) for a period of years on both the new
mode and the old mode. What are the chances of AOPA allowing that to happen?

That said, I would really like to see it. It would be great to have enough
frequencies to go around so that you would not have to be constantly mentally
filtering out the transmissions from adjacent uncontrolled airports.

Vaughn

"Vaughn Simon" wrote:
But changing to FM would require a new radio to be
simultaneously installed in every cockpit in the world. The only way
to accomplish that would be for every plane with a new radio to
transmit in "parallel" (as someone already suggested) for a period of
years on both the new mode and the old mode.

That need not be the case, as evidenced by dual-mode cell phones that allow
access to analog and digital cell sites, though not both at the same time.
Newer radios could certainly be made capable of either mode and a future
cutoff date X years in the future could be set for required switchover when
older model radios would be required to be replaced. This would certainly
ease the transition woes.

Actually, not much does change in aviation compared with other fields of
human endeavor.

It does seem that way. Unfortunately I don't think there is anyone in the
FAA or even the avionics industry who is both sufficiently knowledgeable
about recent advances in communications and has the clout and vision to
push for a radical improvement of aviation communication.

"Jim Logajan" wrote in message
.. .
"Vaughn Simon" wrote:
But changing to FM would require a new radio to be
simultaneously installed in every cockpit in the world. The only way
to accomplish that would be for every plane with a new radio to
transmit in "parallel" (as someone already suggested) for a period of
years on both the new mode and the old mode.

That need not be the case, as evidenced by dual-mode cell phones that allow
access to analog and digital cell sites,

The problem I was thinking of that is solved by parallel operation is where
you have two planes in the same pattern who can't hear each other because their
radios are not compatible. The only way I know to solve that is dual (parallel)
operation.

A good example of that concept is what they are doing with TV today. Many TV
stations are transmitting in both analog and digital (HD) so that we are covered
no matter what type of receiver we happen to own.

Vaughn

Vaughn Simon writes:

Actually, not much does change in aviation compared with other fields of
human endeavor.

I don't think that is necessarily a bad thing. It does worry me that
the things that change in aviation are things that I'd rather see
stable. I have my doubts about fly-by-wire systems or glass cockpits,
which seem to be increasingly designed for the convenience of
programmers who grew up with Windows rather than for the convenience
of pilots.

But changing to FM would require a new radio to be
simultaneously installed in every cockpit in the world. The only way to
accomplish that would be for every plane with a new radio to transmit in
"parallel" (as someone already suggested) for a period of years on both the new
mode and the old mode. What are the chances of AOPA allowing that to happen?

I don't see why it would be so objectionable. It isn't even necessary
that the AM be phased out. The FM would simply be available to those
who wish to use it, for the added clarity it provides.

When multiple frequencies are available for the same communication,
you could allocate some to FM and some to AM. Initially all would be
AM. Gradually they'd be shifted to FM as time passes, with plenty of
documentation. Eventually only one AM frequency would be left, which
could be kept active indefinitely.

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Mxsmanic schrieb:

I don't see why it would be so objectionable. It isn't even necessary
that the AM be phased out. The FM would simply be available to those
who wish to use it, for the added clarity it provides.

Yeah. One pilot talks on AM and the other listens to FM. Great idea.
Adds a lot of clarity to the communication.

Stefan

Stefan wrote:
Mxsmanic schrieb:

I don't see why it would be so objectionable. It isn't even necessary
that the AM be phased out. The FM would simply be available to those
who wish to use it, for the added clarity it provides.

Yeah. One pilot talks on AM and the other listens to FM. Great idea.
Adds a lot of clarity to the communication.

Huh? How is that problem different from something transmitting on 121.5 MHz
and someone else listening on 406 MHz?

Why is having multiple channels all using AM not a problem but if one added
more channels using a different modulation now suddenly presenting a
communication problem?

Stefan writes:

Yeah. One pilot talks on AM and the other listens to FM. Great idea.
Adds a lot of clarity to the communication.

It adds more than you would have with both pilots using AM.

However, you're not supposed to listen to other pilots; you're
supposed to listen to controllers. All conversations are air-ground,
not air-air.

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Mxsmanic schrieb:

However, you're not supposed to listen to other pilots; you're
supposed to listen to controllers. All conversations are air-ground,
not air-air.

You haven't ever actually flown a plane, have you?

Stefan

On Sun, 03 Sep 2006 13:33:36 +0200, Mxsmanic
wrote in :


However, you're not supposed to listen to other pilots; you're
supposed to listen to controllers. All conversations are air-ground,
not air-air.

You'll have to cite a source for this nugget of knowledge. Are you
familiar with Common Traffic Advisory Frequency (CTAF)?

Larry Dighera writes:

You'll have to cite a source for this nugget of knowledge.

FAA AIMs and CFRs make it pretty clear that communications involving a
controller are pilot-controller exchanges, not pilot-pilot exchanges.

Are you familiar with Common Traffic Advisory Frequency (CTAF)?

Yes, but it and similar schemes don't involve a controller, so
obviously the communication is between aircraft directly.

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