Misc

Pump Pros and Cons
I want to encourage the FAA and/or the NTSB to institute a change in the instrumentation of small-airplane vacuum systems so that a vacuum failure is more survivable in heavy instrument conditions.

Having watched the ABC Prime Time Thursday report on 9/3/01 and having had two vacuum pump failures myself, I understand the problem. I think that the solution could be very inexpensive.

There should be no need for a potentially failure-prone back-up pump but a warning to the pilot that there has been a failure. Currently, the vacuum pump pressure gauge is the smallest indicator on the panel and is we’ll out of the scan pattern.

If an additional indicator…

Pulse Oximeters
I am a long-time subscriber to Aviation Consumer and have been a pilot for more than 26 years.  Your two recent articles on pulse oximeters were excellent. 

However, there’s a critical misunderstanding about pulse oximeters which needs to be explained.  As a practicing anesthesiologist, I use oximeters every day.  The oximeter indirectly measures the oxygen available to the tissues by calculating the percentage of hemoglobin molecules saturated with oxygen. 

However, the relationship between the oxygen available to the tissues and the oxygen saturation percentage recorded by the pulse oximeter is not a linear relationship. 

Pilots should not be fooled…

New production may end for awhile, but long-term parts support is too big a business to pass up.

Safety Priorities
By and large, I agree with your order of setting priorities, as noted in the August issue. I have a fewexceptions.

The first is de-icing gear. Most of my flying is in the Northeast and evenly distributed throughout the calendar year. As an instrument-rated pilot, I fly in IMC often. At least six months of the year, there are airmets calling for icing in clouds.

If one wants to have a reasonable dispatch rate and adhere to the letter of FAR Part 91 regs, deicing gear takes on much higher priority especially when flying over the mountainous areas of New Hampshire, Vermont and New York, where MEAs can be 7000 to 8000 feet. Even with it, I will not launc…

How one mans quest actually made sense out of buying a new airplane…in a qualified sort of way.

Ten years after leaving the factory, most new airplanes bottom out in value. But some regain value sooner than others.

Bendix Dual Mags
Reference your report in the August issue on Bendix dual magnetos: Another reason to be wary of these mags wasnt mentioned in your article, possibly because this isn’t a problem in Mooneys.

In the Cardinal installation, both fixed gear and retractable, the prop governor on dual-mag equipped engines comes with a metal plate that goes between the engine and the governor, sandwiched between two gaskets.

This plate blocks some oil passages which arent needed for that application. About two or three times a year, someone will R&R a Cardinals prop governor, toss the metal plate in the trash with the old gaskets, install the new governor without the met…

Cirrus Comments
I liked your article on the SR22 in the June issue of Aviation Consumer. I thought you did a very fair piece and accurately addressed a lot of the issues, both pro and con. However, your analysis of the speed does not correlate we’ll with my experiences.

While I have gotten used to manufacturers overstating specs on speed, in my opinion, Cirrus has been fair on this one. In fact, I seem to consistently be within a knot of book claims, plus or minus, and use less fuel in the process. At 75 percent power, I have consistently seen TASs in the 178 to 182 knot range. Fuel flows were around 17 GPH.

The primary reason for this response is that you used 170…

Its bad business for insurance companies to deny claims but occasionally they do it anyway.

Ice Detector Woes
I enjoyed your article on carb ice detectors. Id like to relate to you an incident that happened to my aircraft partner and I, where the carb temp indication system delayed our decision to use heat.

During an approach into Las Vegas in IMC with snow, we were slowly losing engine RPM and then altitude. The carb temp indicator was we’ll above the yellow caution range. Im an A&P and I had recently checked and confirmed the carb temp indicator for proper accuracy. Because we were convinced that we couldnt have carb ice due to the indicated temperature, we spent precious time looking for other reasons for the loss of power.

At 800 feet below our assigned…

Beeper Box Notes
Reference your pre-heater article in the March 2001 issue, its unclear to me why anyone would buy the RS Beeper Box when much less expensive options are available.

Any catalog of home automation products will have numerous gadgets that allow remote telephone control of AC-powered devices. So if you have a phone line in your hangar, youre set.

Even if you don’t, the monthly tab for basic phone service has got to be less than for a pager and no worries about pager dead spots or dead batteries.

Possibly the simplest solution is the X10 Telephone Responder (about $65) in conjunction with an X10 Appliance Module (about $14). Plug the Telephone Responder…

Lightweight Starters
Id like to comment on two articles in the January issue of The Aviation Consumer. First, the article on lightweight starters. I installed a pair of Sky-Tec starters in my Duke about four years ago. They work as advertised. Theyre light and spin the prop so fast I think I could taxi with them.

One of the starters, however, died after two years and had to be replaced. Regardless, I am still happy with them and would recommend them to anyone.

Second, your article on LASIK surgery. I had mine done 3 years ago and couldnt be happier. I had 20/20 vision when I started college but needed glasses by the time I graduated because I became nearsighted. …