Letters 03/98

Simpler GPS
I enjoyed your article on simpler GPS in the January, 1998 issue. Standardization of the design and operation of these devices is desired if for no other reason than for safety.

Many pilots fly more than one aircraft with navigation equipment manufactured by various companies and across various model ranges. If the pilot inadvertently uses the wrong sequences or pushes the wrong button or becomes transfixed by what the unit is displaying, his attention is diverted for too long a period and you have a 100 MPH-plus guided missile.

ARINC would be the ideal organization to create a specification or standard agreed to by the manufacturers and the FAA. ARINC is subsidized by the aircraft industry and is naturally suited to coordinate this work. Here are some suggestions for standardizing:

Input controls: Function placement, nomenclature.
Display: Dimensions, format, nomenclature.
Operation: Inputs required to create and display the information to satisfactorily navigate in IFR conditions.
Alarms: What should happen when.
Operating manual: Format and organization should be defined.

-John Flick
Rockford, Illinois

Im sure there are thousands out there like me waiting on IFR GPS, for whom you have provided a great service. What comes through in this article very clearly is the difficulty in operating these units.

Who needs this? The VOR/DME, ILS and compass locator system is simple and intuitive. As a non-professional who flies the occasional hard IFR to a busy terminal, the last thing I want is the risk of error from the increased complexity inherent in current GPS. When I start flying the bush, maybe Ill get one.

-Bill Lyons
Falls Church, Virginia


Your coverage of ANR Headsets was excellent and timely for me. I have been in the market for a new headset for several months. I borrowed a friends Bose headset and was impressed with the performance but felt it was overpriced.

After reading your article, I decided on the LightSPEED 20K. After using it for several months and comparing it to my experience with the Bose headset, Im convinced that it may be more comfortable and at least technically equal. I wear glasses and find that most headsets tend to irritate the temporal area. Not so with my LightSPEED 20K.

-Will Watt
Texas City, Texas

Some readers have called or written to complain about audio squeals in LightSPEED 20Ks. We plan a follow-up article in a month or so.

Very good article on E-6Bs in the January issue. I lucked out when my wife bought me a Sportys for Christmas. The only thing I can add is that for calculations, it only goes up to six places, so pilots of heavy aircraft using the adjusted weight method of CG are stuck.

Also, the clock tells time in three zones, but gains about 20 or 30 seconds a week. My wristwatch keeps better time than that. Other than that, its a very good unit.

-Nathan Kimble
Atlanta, Georgia

After we went to press, Sportys reduced the price on its E6B to $59.95.

Baron Landings
In your Used Aircraft Guide on the Baron in the January issue, you made reference to the landing speeds and short-field performance. Ive flown our 1989 Baron 58 for several years and put about 2000 hours on it, flying Part 135. As with any aircraft, if you want book performance, fly it by the book. You make mention of landing speeds and CG position. The missing key factor that must be adhered to when making a short-field landing in a Baron-or any other airplane-is the descent rate.

If you read the handbook performance section under landing distance, associated conditions, you will see it calls for power retarded to maintain 800 ft/min on final approach. Making a flat approach at book speed will not give you book landing performance.

-Ted Stanley
via fax

Lean Forevermore
With reference to your article on the Lost Lore of Leaning (sounds like an Edgar Allan Poe, . . . dreaming of lost leaning lore, richer now forevermore …) in the September 1997 issue, Ive always suspected the gurus advice, that running rich is cheaper and safer, was right up there with never operating oversquare.

It may be correct, but its not based on any real science. A couple of things Id like addressed in the next 15 years or so. The engines are different now.

Were turning higher RPMs. Doesnt apply to the GTSIOs mentioned, but those engines don’t have transatlantic flight history to show how great they were.

The valves are different now. Better, presumably, but different. The fuel is different, too. This one may really be significant, especially if you run autogas in winter, with alcohol. Using the WAD technique in my engine leads to a potential problem: the mixture doesnt necessarily stay the same as I push in the throttle. And, for a given MP and fuel pressure setting, I don’t necessarily get the same EGTs at different altitudes.

Of course, I don’t have GAMIs yet, since they don’t have them for I0-360 Lycomings. The stoichiometric mixture-presumably close to peak EGT may not leave the least deposits. The chemistry is sufficiently complex that not everything can wind up fully reacted at any given oxygen concentration, at least not in the times were dealing with. So either rich or lean, there’s stuff left over to gunk up your engine.

One thing Ive already decided on is to lean more aggressively when descending. No more of this back off the throttle, then richen the mixture. If its okay to lean at idle, it should be okay when running at 40 percent power in a descent. Its analogous to cruising at 15,000 feet and full throttle, able to hold only 15 inches MP.

Id definitely lean the engine under those circumstances. With all the extra cooling from the increased airspeed, it seems I should be at peak EGT just in self defense.

Great article; my mechanic will get a copy. I just wish more research were being done in this area, but maybe its coming sooner than in 15 years.

-Dave Chuljian
Port Townsend, Washington

Progressives Pro
Im writing to add to your body of commentary on progressive lenses. The timing of the article in your October 1997 issue was good, in that Id just purchased progressive lenses for the first time, just before the article came out. I had decided on bifocals and against progressives based on your original article about eight years ago. Youll recall that in the earlier article you suggested the state of the art was such progressives could cause vertigo and hence were not recommended.

I mentioned this to my optometrist and he said nonsense. He argued strongly that progressives are used successfully in all endeavors, including flying. He offered a money-back guarantee if they didnt work out for me.

He said, as you did in the article, that it mattered who made the lenses, since poor quality could result in an unacceptable set of lenses and make them impossible to use. He also stressed, as did you, the importance of committing to a few days of adjustment and to absolutely not alternate between progressive and conventional lenses.

I found the adjustment process quick and easy. I was concerned, as I always am when I change lenses and go flying for the first time. I had an instructor with me and it was a non-event, except I could see the panel better, even when dealing with a vision restrictor.

A distinct turn of the head (point with the nose) is required, but if you do that, youre rewarded with a crisp view and legible instruments.

This is probably irrelevant, but I found I couldnt play tennis with bifocals, because the ball would jump as it crossed the lens lines. I was forced to use the distant vision lens, because when you serve there’s no way to use the near vision lens. However, with progressives, I can play and not have any problems at all.

-Jim Ryan
Hillsboro, Oregon