View Full Version : Do I need 1 or 2 FM Immune Nav for Airways Fit on G-Reg?
irish seaplane
15th Aug 2008, 16:08
Hi,
Just wanted to see who could shed light on this. Do I need 1 or 2 FM immune NAV radio's for a UK Airways fit on a Golf Reg aircraft?
Also has anybody installed any Overhauled King Avionics and been happy with them. I had looked at Narco but hear people have had a good deal of issues with them after installation.
Thanks
William
Shunter
15th Aug 2008, 17:10
I believe it's only 1 FM immune set required (but I'm sure someone will correct me if I'm wrong). Incidentily, having access to FM transmitters I tried to interfere with a non FM immune set a while back. Nothin' happened. Red herring if you ask me.
Got 2 FM immune Narcos in the Cardinal. Had no bother from them at all.
IO540
15th Aug 2008, 19:49
Most of the 1990s King avionics stuff is actually very good; arguably the best of the crowd of that era. E.g. KX165A.
A good source for overhauled avionics is Southeast Aerospace (http://www.seaerospace.com) in Florida. Excellent service. Much of their overhauled stuff looks just like brand new.
Heard that Narco had been sold to repair only organisation. Can anyone confirm this?
irish seaplane
16th Aug 2008, 11:15
I see from AIC 87/2000 that you only need one FM immune Nav... In that case would I be better off getting a King KNS 80/81 as NAV2. My thinking is that it would make you RNAV compliant for the odd above high jaunt, give you a DME and a good backup to GPS?
Anybody had any luck with these units... Know they're old etc. Had'nt heard that Narco were sold....
W
IO540
16th Aug 2008, 13:21
In that case would I be better off getting a King KNS 80/81 as NAV2. My thinking is that it would make you RNAV compliant for the odd above high jaunt, give you a DME and a good backup to GPS?A KNS80 will give you legal BRNAV only if the installation is thus certified, AIUI.
If you want the capability, not necessarily legal, get a used IFR GPS.
An IFR GPS is vastly better than a KNS80 because (airways context) ATC treat all waypoints as RNAV waypoints and will happily send you to XYZ where XYZ (which just happens to be a VOR) is 200nm away. A KNS80 is thus useless for RNAV. You could get a KNS80, get it BRNAV certified, and then you go up and ATC give you a 200nm DCT and then you are stuffed. And it's a lot of work, whereas doing a DCT with a GPS is as fast as setting up the waypoint name.
A KNS80 is also not FM immune unless you spend the £700 or so on an antenna filter.
An IFR GPS will also give you the OBS mode which is a really clever trick, dead handy for all kinds of stuff :)
irish seaplane
18th Aug 2008, 10:38
Sounds like your right IO-540.... I'll scrap that idea with the RNAV. Just looking at the quotes I got for 2xKX155's, 2 Indicators, DME and 2nd ALT makes me cringe.
I have 1xComm, 1xNav, 1xADF, 1xTXPR - so maybe I'll get quotes on the GNS430W and see if I can bear the pain. Would the Garmin "one box" fulfill the role of DME? An instructor once told me that GPS's read "Slant Range" too - but I wouldn't believe him......
W
IO540
18th Aug 2008, 11:16
The best way to do avionics is to get it new or refurb from the USA e.g. Southeast Aerospace (http://www.seaerospace.com) and then find a friendly avionics man to install it on a daily charging rate.
The Q whether a GPS will do for a DME has never been settled. The normal wording in the equipment carriage regs is "distance measuring equipment" and it doesn't say it has to use the DME beacon. IMHO using a GPS instead of a DME is stretching the bounds of imagination but I am not a lawyer. I don't know of any prosecutions (UK or Europe) under the equipment carriage regs, but I don't think that is ever the problem in aviation - the real issue is insurance not paying out on a flight which was illegal to start with.
A more practical view is what kind of kit you want to backup a GPS. I would have a VOR/DME. ADF is not so good but it remains essential due to the large # of NDB approaches in Europe; again one actually flies them with GPS but checking the ADF at the FAF is a good idea.
S-Works
18th Aug 2008, 11:49
I am with IO on this, GPS is by far the best way to go. A good IFR GPS will beat hands down anything else you fit. The perfect solution is a Garmin 430/530 as you get IFR GPS and ILS and 8.33khz FM immune kit all in one box.
Couple it to a Garmin 340A Audio panel and you are quids in.
I have a 430, King DME, King ADF and an MX170B with a 340A audio panel connected to a NS360 HSI and the Garmin LOC/ILS indicator and a King indicator for the 170B.
Perfect interference free installation.