On Sun, 6 Jun 2004 19:11:38 +0100, "Julian Scarfe"
wrote:

"S Green" wrote in message
...

tend to agree. Look who controls the GPS infrastructure. without
assurances
that the integrity of the system was not at the whim of the US Department
of
Defence, I cannot see the UK authorities being prepared to rely on GPS.
Ultimately this does become a safety issue.

But the UK authorities already rely on GPS at least to the same extent. As
well as having to carry ADF, VOR and DME for IFR flight in controlled
airspace, anyone wanting to fly at or above FL100 (note that that's
equivalent to 10,000 ft, perhaps not what US pilots are used to for flight
levels) needs B-RNAV (B for Basic). The only economical way of meeting the
B-RNAV requirement is to carry a TSO-C129a class A GPS receiver. I have in

Here I have basick RNAV and it doesn't even have a GPS input.
Strictly the old KNS-80, but it is RNAV ... over here.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

the back of my mind that, ironically, it has to be class A1 (approach
capable) because B-RNAV imposes some extra requirements beyond the A2 spec,
but I'm not sure. Thus if the GPS infrastructure disappears, the
unavailability of a few overlay approaches or even standalone GPS approaches
is the least of our problems!

I'd like to see:

a) a relaxation in the requirement to carry all of ADF, VOR *and* DME if
there's also a TSO-C129a GPS receiver and the conventional nav equipment
allows sensible backup.

b) the ability to fly overlay NDB approaches without ADF, again provided nav
equipment is carried to enable an approach at an alternate.

Sometimes, and I know its rare, politics falls before a rational argument...

Julian Scarfe