Letters

I read with great interest " Airframe and Powerplant: Going Stainless" (March Pilot). However, I must take exception to the author's dismissal of the potential for dissimilar-metal corrosion. The U.S. Navy has spent a great deal of time and money figuring out the difference in electrochemical potential between metals, and between the alloys used in stainless steel aircraft hardware and the aluminum alloys used for the skin and support structure. I can assure you there is quite a difference.

When exposed to moisture, this difference in electrochemical potential creates what amounts to a battery that will pit the aluminum under the stainless steel screw heads preferentially. The use of fiber or nylon washers is strongly recommended to break this galvanic cell, and to prevent this type of corrosion.

As we have learned through reading Pilot, just because you can't see something does not mean that it isn't there. While the staff members interviewed have not seen such corrosion, I certainly have in several cases. Dissimilar-metal corrosion is a concern in any situation where two different metals are combined, whether they are stainless steel and aluminum, or carbon steel and stainless steel. Both have reactions, and in all cases, one will preferentially corrode the other. Unfortunately, history has shown that no amount of vendor hand waving or individual disbelief stops corrosion.

George Wilhelmsen AOPA 1004652
Morris, Illinois

I enjoyed "Airframe and Powerplant: Going Stainless." I have converted numerous aircraft to stainless over 20 years and have never seen any corrosion resulting from contact of dissimilar metals. This is more of a theoretical than a practical problem.

A tip for the detail freaks among us (I am one of the worst!): The heads of stainless fasteners can be easily polished to a chrome-like brilliance that is highly durable. Chuck the shank of the fastener lightly (hand tight — to avoid damaging the threads) in a variable-speed drill, spread a small dab of metal polish (Rolite works very well) on a soft cloth or paper towel, and spin the head of the fastener at slow speed against the cloth and polish. In less than a minute, the finish on the head looks like chrome instead of the dull gray typical of stainless. This produces a show-plane look with very little extra effort.

Fredric R. Boswell AOPA 333084
Amherst, New Hampshire

Weather-service perspectives

I enjoyed very much reading Phil Boyer's " President's Position: Météo en Grève" (March Pilot). May I add my comments to complete the picture, for the benefit of all AOPA members?

The weather service in France is a public service which is allowed to strike like all public services in France, with the exception of the armed forces and those with some limitations: police, emergency medicine, etc. Civil servants — 25 percent of the work force in the country — have a lifelong guarantee of employment, and the majority of them work 35 hours or less per week. Weather services in France are not free anymore, and you have to pay each time you get an automated briefing by phone or speak to a briefer. Soon IFR flying will include a fee, as in other European countries. No wonder GA has gone down the drain gradually during the past 25 years.

Because of an 80-percent taxation the price of gas in France is four times what we pay in the United States. Finally, the Bureau Veritas, a private company, has the monopoly to stamp, on behalf of the Ministry of Transport, all mandatory maintenance work done on aircraft — at a prohibitive cost. I cannot agree more with Boyer that we should watch out very carefully that the same trend does not take place in the United States. AOPA is the only tool we have to prevent this unfortunate and costly evolution.

Jean-Pierre Verdier AOPA 1317115
Conifer, Colorado

I am a flight service specialist currently employed at the Princeton Automated Flight Service Station in Minnesota. I recently read "President's Position: Météo en Grève," and I am in absolute agreement with Boyer on the need for the federal government to commit the necessary resources to the flight service system.

I greatly appreciate your understanding of the value of a properly funded flight service system. I feel we are essential to the safe and efficient flow of all aircraft in the nation's airspace. With the support of organizations like AOPA, I am optimistic that we will be able to continue to serve the aviation community through the twenty-first century and beyond.

Paul E. Ferry
Dayton, Minnesota

Head over heels

In " Safety Pilot: Low-Impact Aerobatics" (March Pilot), Bruce Landsberg subtly suggests aerobatic flying is a joyful experience. That's true, and in my case it saved two lives — my check pilot's and mine.

Our Beech Bonanza was cleared for takeoff behind a four-engine turboprop. Unfortunately the tower gave us too close an interval, and we hit the propjet's vortices, flipping us over at an altitude of 75 feet. Automatically I pushed forward on the control column, followed by an aileron roll to upright flight. My aerobatic training saved the day, and as Landsberg wrote about aerobatic training, "Go for it!"

Arthur J. Mirkin AOPA 084161
Indianapolis, Indiana

I've been in favor of some aerobatic training for private pilots and have insisted on my students enduring some of the same for all of my 25 years as an instructor. At a minimum, precision spins, entered and exited at precise headings, including simulated entries on a turn to final. I've had one student not participate — he bought an Ercoupe and got his certificate in it.

My wife had an interesting experience. Stalls frightened her until she completed some aerobatic training. She loved the aerobatics, and stalls were never a problem for her again. I've also found that many flight instructors I've ridden with for flight reviews are not really familiar with spins and have never tried one with precision. They met the "demonstrated" requirements for a logbook entry and never visited that part of the flight envelope again. This is a sad commentary. They are ill-prepared, and their students miss a great opportunity to learn and improve their skills while gaining another edge on safety. Keep recommending light aerobatics; they're fun and a great training tool.

Dave Dodson AOPA 329492
Granger, Indiana

The humble approach

I wish Rod Machado's "License to Learn: In My Humble Opinion" (March Pilot). could be required reading for all "pilots who are too sure of themselves." Distinguishing between logically established truth and fallible opinion does seem to be a growing problem in our society and among pilots. In aviation, understanding and safety are affected. An additional but less critical observation: Have you ever noticed that pilots who are more humble tend to handle their aircraft more smoothly? (Not more timidly, but more smoothly). I'm not sure (note my humility here), but I think I see this correlation.

William S. Marshall Jr. AOPA 703043
Midland, Texas

I read with interest "License to Learn: In My Humble Opinion" and would like to offer an opinion I learned from an instructor who coached me through both my private and my instrument tickets. The issue is when to lower flaps in the pattern, and specifically the idea of not doing so in the turns. I too was taught this principle, and here is the logic: If, because of a problem with the flap motor, flap travel, or any other mechanical portion of the flaps, you experience an asymmetric flap extension in the turn, it could cause quite a surprise — especially considering the low altitude. Naturally, the extent of the problem would be dictated by the direction of the turn and which flap extended less or more than the other. But if it caused a tightening of the turn, it could spoil your whole day!

Although I understand that the likelihood of this happening is very slim, I wait until I have rolled out level on base before lowering the second notch of flaps. And likewise, I wait until I'm fully lined up on final before selecting full flaps. It may seem a little over the top and overly cautious, but surely that is how we are taught to think — always have a plan for the unexpected, right?

Jonathan Sweatman AOPA 1371236
Atlanta, Georgia

Rod Machado responds: There's nothing wrong with being cautious. Your instructor taught you well. But if it's ever necessary for you to apply flaps in a turn, there's very little chance that you'll be worse off for it.

Hitting home

" Waypoints: A Pilot's Treasure" (March Pilot) hit home with me. I, too, drive a 15-year-old car to and from work but when I get up in our club airplane, it's worth not spending all that money on car payments. I bet Thomas B. Haines' wife drives the good car (less than five years old), like mine.

I hope to one day own an airplane of my own, but that will be after my daughter goes to college (she's 4 now). Keep up the great work.

John Davis AOPA 1367014
Myrtle Beach, South Carolina

Taxi-diagram thanks

I want to commend you on adding the taxi diagrams to the AOPA Air Safety Foundation's Web site. I downloaded the diagram for Corpus Christi, Texas, for use just this past weekend. I remember as a new pilot the difficulty I had figuring how to enter the correct traffic pattern and then, once on the ground, where the heck I was going. I am sure that this will help with the runway incursion problem. Once on the ground, if I didn't know where I was going, I just waited until somebody yelled at me to move (by the way, this works best at controlled airports). Many thanks.

George Farris AOPA 1379517
Austin, Texas

Errata

" Answers for Pilots: The Insurance Question" (April Pilot) stated that Avemco no longer insures flying clubs. Avemco does still insure noncommercial flying clubs — that is, those clubs that are equally owned by their members. However, Avemco no longer insures commercial flying clubs that are essentially aircraft rental businesses.

The identifications of Mary Durst and Jackie Mascaro were inadvertently transposed in a photo caption (" Pilots: Jackie Mascaro and Mary Durst," April Pilot).

The URL for the National Weather Service's Aviation Digital Data Services Web site was missing a hyphen in " Future Flight: Beaming Up the Weather" (March Pilot). The correct URL is http://adds.awc-kc.noaa.gov/projects/adds/.

We welcome your comments. Address your letters to: Editor, AOPA Pilot, 421 Aviation Way, Frederick, Maryland 21701. Send e-mail to [email protected] . Include your full name, address, and AOPA number on all correspondence, including e-mail. Letters will be edited for style and length.