Letters: 11/04

Mag Feedback
A customer brought a copy of the July, 2004 article regarding Bendix or Slick mags. Id like to make a few points that werent brought out and would also like to mention that as both an A&P and a pilot, I really have no preference other than Bendix mags are a bit easier to install and adjust.

Bendix is the only manufacturer of the 2200/3200 series mags that are the single drive/dual mags as used on a number of Lycoming engines. When doing an in-between overhaul mag brand change, you have to figure in a new ignition harness for the respective mag since Slick and Bendix use different harnesses. That can add another several hundred dollars and additional labor.

While you mentioned the Bendix mag ADs, Slick has had its share of ADs in the past and there is currently a 250-hour repetitive AD on inspecting-guess what-their impulse couplings as opposed to Bendixs 500-hour repetitive AD on same.

-Frank May
via e-mail


Panel Upgrades
I always enjoy Aviation Consumer; I think you give the best advice in the business. I just read the Budget-Savvy Upgrades in the September issue. What is the saying, I agree 100 percent with 90 percent of what you say? So here is the other 10 percent.

Putting in a VFR panel-mount GPS is a waste of money. I have a Bendix/King KLX-135A in my Citabria and I am sorry I bought it. I find that my Garmin 90-much less a later model handheld-is a more capable GPS and just as official with the FAA for navigation.

I could buy a capable handheld and get a comm transceiver installed for half the money (or less) as a VFR panel mount would cost and Id end up with more capability. Id also have good back-up nav for a failed alternator/battery.

When you put in a GNS 430, why put in a KX155 in your nice-to-have stack? I could see putting in a second transceiver but why not just put in a radio? I did this in my Maule. The total installed price of a new ICOM 800 was about $1300 (on sale at OSH) and it works great as a second radio to the GNS 430. And I guarantee that I dont miss having a second VOR.

Really good advice on the GNC300XL. Many are so hung up on the GNS430/530 that they forget about this wonderful TSO C129a GPS box. The GX60 is another. Also, folks use a 430/480 or even a 530 to drive a multifunction display! What a waste. A GNC300XL will do the same functions for less money.

-Vince Massimini
Kentmorr Airpark, Maryland


ADC Flilters
Your review of the ADC filter in the September, 2004 issue missed one option that is as important to me as its superior filtration: a low-oil pressure warning light. Few GA aircraft have any sort of warning other than the gauge. With the optional low-pressure light, a pilot might have knowledge of impending engine failure minutes earlier. At 140 knots, that might mean making a field that otherwise would be out of reach.

As to performance of the filter, I had one for 600 hours before installing a reman Continental IO-520 in a Cessna 206, which I have flown 1000 hours since. I have never replaced a cylinder for compression issues and both engines maintained compressions in the 70s. I cant prove the ADC filter makes the difference, but something is going right.

The only complaint is the filter is messy to open up and clean. A one-quart plastic oil container with the top cut off helps. Last, ADC is great on service. With the new engine, we had problems with the bypass light coming on constantly. ADC was with us at every step, including providing a replacement spring for free to help troubleshoot the problem.

-Chris Welsh
Newport Beach, California