Letters: 02/04

RAM Mounts
I recently purchased a RAM Mount with suction cupfrom the King catalogue. I doubt that I have ever been more dissatisfied with any purchase Ive made for my aircraft than I was with the RAM mount.

After trying unsuccessfully to get it to adhere on any window in my aircraft, I returned it to King. I also enclosed a letter stating that I felt it was an inferior product and infact dangerous to have in the aircraft because the suction cup always released at the most inopportune time.

Last week, I received another mount, G-Force GPS mount,from PropellerHead. It is so far superior to the RAM mount that there is no comparison, in my view. Less weight, greater range for finite adjustments and excellent suction cupthat holds a Garmin GPS 295. I really think you could pull the window out before it released.At $45.90, you cant find a better buy.

No, Im not working for the company. Just a very happy customer and hopefully you do areportso other pilots can learn of this excellent product.

-Charlie Adams
Adams, New York

You can find the G-force mount on the Web at this URL: prophead2003.sectorlink.org/G-Force.htm. Well be examining one of these products in a future issue.

Frankly, we cant imagine why you couldnt get the RAM to stick. Weve tested these devices twice and one of the only complaints we have is that they are difficult to free from window once stuck in place.

Weve heard no reports of them popping loose at inopportune times.


On page 13 of your December 2003 edition, you show a picture of a computer sitting on a RAM mount. I cant help but notice that it appears that if one would pull back on the yoke, placement of the mount/computer would interfere with full control movement. Just a thought. I could not have been the only person to notice this.

-Marc L. Aronson
Via e-mail

Actually, you are. And you may be right, the mount might interfere with the yoke. On the other hand, it can repositioned so it doesnt interfere, something that ought to be done before every takeoff.


Tablet PCs
I noticed that youre doing a study on tablet PCs. I am very interested in your findings. My idea is that this is the perfect flightbag computer and PC for on-the-fly travels.

I had noticed that HP states in their specs that their tablet is OK up to 10,000 feet. No other manufacturer mentions an altitude limitation, although many may have this limitation.

I just wanted to alert you to question the manufacturers closely on this, something which could rule out its use as a flight computer. We in the west who have to fly at 15,000 feet and up for weather and terrain clearance need a tablet PC that is not limited by a low altitude.

Speculating about what it is about the computer that limits it to 10,000 feet, maybe the cooling fan cant cool the processor in thinner air?To my knowledge, handheld iPAQ PDAs used for flight dont have this limitation.

I would like to see in your report what it is specifically that imposes this limitation. Perhaps only the screen is not as readable due to low air pressure, which would not be a deal breaker. Anxiously awaiting your report.

-Jeff Hurst
Via e-mail

We doubt if the 10,000-foot limitation is really a limitation but more likely the altitude to which the machine happened to be tested. When computers first appeared in cockpits a decade ago, there was some concern that highspeed hard drives wouldnt function correctly in the thinner air of high altitude. While this may be theoretically true, we havent heard any reports of altitude-induced failures.

In any case, we would be delighted to hear from owners of various tablet computers, pro and con.


Why No Lancair?
I just read your excellent comparison of the Diamond and the Cirrus in the December, 2003 issue of Aviation Consumer. While I am not in the market for a new airplane, I like to keep up on what is out there.

Why did you not compare the Cirrus SR22 and the Lancair Columbia? It seems that they shipped about the same time, have similar roots for development and seem closer cousins than the Diamond, which has its roots in European sailplanes? I would have at least expected a sidebar on the Lancair.

While Lancair does not seem to run its business as well as Cirrus, in the sense that they continually have to get funding, I believe they have not gotten the proper recognition from the aviation press for a most excellent airplane.

As your magazine is independent and not run by advertising-a small conspiracy theory on my part-I would expect you to hold up a truly good product or if it is not a good product, explain why it is not.

I do not work for Lancair, or own one, but a good friend has built a Lancair ES, so I am familiar with the homebuilt product and company. It is completely separate from the production side of the house.

-David Young
New York, New York

We didnt include the Lancair in our Diamond/Cirrus flyoff simply because it isnt in the same class, performance wise.

The SR20 and Diamond Star can be considered entry level airplanes while the SR22 and Lancair Columbia are not. For a comparison of those two aircraft against the Mooney Ovation, see the May, 2002 issue of Aviation Consumer.


Battery Query
A question for Kim Santerre in regard to the AGM battery. We had a Concorde installed in our Trinidad a number of years ago and after not flying for a few months, the battery voltage was low.

This could not be corrected by flying and I recall we were told we needed a special charger for this type of battery.

The FBO was not enthusiastic at the time (we were his only such battery) so we ended up getting a conventional lead-acid battery again. Has something changed over the last few years or were we misinformed back then?

-Andrew Doorey
Wilmington, Delaware

Kim Santerre replies: There has been an evolution in AGM battery technology since they were first introduced a decade ago. These batteries have improved significantly but the one flaw they still have is a sensitivity to overcharging.

In service, 14.2 volts is the best charging voltage and although 14.5 volts wont kill an AGM battery, its too high, even for a wet cell, except in cold weather.

Special chargers arent required for AGMs but are required for gel cells, a close cousin and older technology. The AGM chemistry is the same as the flooded wet cell, just configured differently.

But an AGM needs no more voltage than the wet cell to charge, so I suspect the battery could have been defective or your charging voltage a bit low, thus it wouldnt fully charge.

It takes quite a while for a battery to charge if the airplane has been sitting for a long time or if you have lots of avionics and/or lights on for several hours.

Charging systems are notoriously marginal for aircraft with extensive avionics installations. This is a maintenance bug many shops simply dont diagnose or correct.


Cellphone Weather
I have been a subscriber over 20 years and love your publication. I have seen ads on companies claiming to get radar displays on a picture cellphone. (My-cast.com/pilot is one, contact 866-669-2278.)

Do you have any info on them or any evaluation? If it works, it would be an inexpensive way to bring weather into the cockpit for us poor folks.

-August Belmont
Via e-mail

We plan an evaluation of cellphone weather providers in a future issue. We welcome comments from readers who have tried these systems. E-mail comments to the address below.