Ken Ibold said:
There are lots more options, and with each one you get a different set of pluses and minuses. Your choice also depends on what else you have in the panel. If you have two nice com radios, for example, you might get a few bucks for one of them if you go for a Garmin 530. If you go with something like the Garmin 155XL TSO or the King KLN 90B, you might end up with so much installation cost for the annunciators that it makes more sense to go with a Garmin 430 (internal annunciators) instead. You are embarking on a complex undertaking.
I'd suggest you go to
www.avionix.com and in the "Avionics Guidebook" section visit both the "GPS (panel mounted)" and "GPS/COM (panel mounted)" sections. It will tell you what kind of annunciators and indicators each one pairs with. Despite the fact that this site is trying to sell you avionics, I have found their editorializing remarkably candid and accurate.
I have owned a KLN-89B, and a KLN-94 and can say with no reservation that the '94 is way better than the '89B. I've also flown with the KLN-90 (King's first IFR approach capable GPS) and strongly recommend you skip that one. With some time behind Garmin's GNS-4/5xx I'd rate them as slightly better than the '94 WRT GPS (of course the nav/comm features give this Garmin line a big leg up on the KLN-94.
BTW I happen to have a KLN-94 that's about to become available at a reasonable but so far undetermined price if you are interested drop me an email at
lfisher@*delete-me*cyberoptics.com.
Here's a post from another webboard about IFR GPS installations that you might find interesting:
-----Original Message-----
From: John Collins [mailto:
johncollins at carolina.rr.com]
Sent: Thursday, July 24, 2003 9:25 AM
To:
beech-owners at beechcraft.org
Subject: B: Where does the expense come from on GPS installation
There are several factors that add into the total expense of installing an
IFR GPS.
1) For a GPS to be approved for non precision approaches, it needs to be
interfaced to a CDI in the primary view of the pilot.
The CDI needs to have at least the signals for left/right and to/from to be
available for Northstar and Apollo and in addition, the OBS resolver signals
for King and Garmin. Unfortunately, the majority of installed CDI's do not
have these signals available. Examples that do not have them available are
KI208, KI209. Examples of CDI's that do have the required signals are: all
HSI's, the KI206, KI207, KI208A, KI209A, and the Collins IND 350/351.
What complicates matters is that if a CDI is to be shared with a Nav
receiver, it must be compatible with both the Nav receiver and the GPS. If
the aircraft has an HSI or the Nav receiver uses a compatible CDI, the
existing CDI may be used. Examples of common Nav receivers that use a CDI
compatible with the GPS are: Collins VIR350, VIR351, KX165, KNS80, and
KNS81. The KX155 and the KN53 do not directly interface to a compatible
CDI, but can interface via a box called an "LOC/VOR Convertor". The KI208A
and KI209A have a built in LOC/VOR Convertor to interface with a Nav
Receiver and a GPS relay to provide the raw signals needed by the GPS. So
changing out an existing KI208/9 with a KI208A/9A is often the most
economical solution. CDI's can cost up to $1,600 new and Loc/Converters over
$1,000.
If a shared CDI is indicated, there needs to be a switch and relay to switch
the signals between the GPS and the Nav receiver. This can be done with
discrete components, but it is often better to use an annunciator control
unit such as an MD41. MD41's cost between $750 and $1000 new.
2) For all GPS'es except the Garmin 4xx/5xx and the new UPS CNX80, there are
required indicators and switches for the control of the GPS and approach
functions . They may be done with discrete components or use the built in
ones in an Annunciator Control Unit such as the MD41.
3) All GPS's must interface to an encoding altimeter as part of the IFR
installation.
4) The installation must be field approved (except the CNX80 if it has an
STC for your aircraft) and as part of the IFR approval there needs to be a
Flight Manual Supplement approved for your particular aircraft and its
unique installation.
5) When you purchase a used GPS and Annunciator Control Unit, you need to be
sure it is compatible with your aircraft voltage. Many of the early Garmin
430's are 24 volt only and need a 14 to 24 voltage convertor if installed in
a 14 volt aircraft. Also, the MD41's are either 14 or 24 Volt, so buyer be
aware of what you are buying. A 24 volt to 14 convertor can cost up to $600
new.
6) Another consideration is where to mount the GPS antenna. The best spot
is directly above the cabin, often where the Beech V antenna is. If you
decide to move antenna locations or change out antennas, this can add quite
a bit of expense. Also, many existing Com installations interfere with the
GPS and notch filters ($40 to $50) need to be added to obtain satisfactory
performance (my experience this is needed in about half of the
installations).
7) Many GPS'es generate a lot of heat and require a forced air fan. This
can cost $150 new.
8) Installation can take anywhere from 20 to 40 hours of labor to install a
GPS.
So, what is the least expensive IFR installation. Probably a used M3 with a
dedicated CDI such as the MD40. It has all of the required annunciators in
the CDI and doesn't require any switching. Installations with HSI's or
compatible CDI's are less expensive. Installation costs of new Garmin
4xx/5xx or CNX80 with an existing HSI are often very competitive and a
better value than installing an older unit. If you are deciding between a
430 and a 530, you can usually work a better deal with a 530 as there is
typically no additional installation cost. I would work the best deal on a
430 and then propose the dealer take the same dollar markup on the 530, so
if the 430 was $7000 plus installation of $2500, I would offer $10,450 for
the 530 plus $2500 for installation. The dealer makes the same, gets your
sale, and there is no extra effort.
What I recommend is to get your installer to review a potential installation
before you buy any equipment. Then it is less likely that you will be
unpleasantly supprised when the bargain you got on the GPS doesn't pan out.
Regards,
John Collins
