AVmail: March 30, 2015

I am a single-engine aircraft owner and private pilot that only flies VFR. So the following question is based on my 2,000 hours of flying over the past 33 years. My Grumman Cheetah is equipped with the standard altimeter, and my airplane has a Mode C transponder. I also have three GPS instruments, two portable and one panel-mounted. The panel mount is strictly a VFR unit with no WAAS capability. One of the two portables has a WAAS capability.

Over the years, flying at 8,000 to 10,000 feet in Nevada, I have noticed some remarkable variations in the altitude reported by the three GPSs versus the altimeter when corrected for barometric pressure. Since most of my flying is in mountainous terrain, these variations that approach 500 feet make me wonder why we rely on altimeter readings rather than GPS altitudes.

I am assuming that GPS altitudes are within 50 feet of the true altitude, and, I must admit, this has always been my experience regardless of whether I have used a WAAS or non-WAAS GPS. It seems rather archaic to use an instrument that can cause such a large divergence from what I assume is a more accurate instrument and one that virtually every airplane can use. Why does the FAA continue to require pressure-measuring instruments in our aircraft when it would be easier and less expensive to use a GPS for that purpose? By the way, I wouldn't mind reclaiming that three-inch hole in my panel for something more useful.

Vern Schulze

I much prefer to get my airplane delivered. If it is not airworthy, I might as well let another pilot find out first.

My first step for every acceptance of an airplane now, regardless of the work performed, is delivery by the shop pilot. It's amazing how things work out so the shop pilot returns to home base alive!

This is 180-degree change from my behavior ten years ago. Shop pilots are highly motivated and in fact can be more knowledgeable of the aircraft than owner-pilots.

Be well, guys. Always a pleasure .... .

Dr. Dan Lawson

On behalf of myself, the Archie Carr Center for Sea Turtle Research, N.O.A.A. fisheries, and the New England Aquarium, I would like to extend our heartfelt appreciation to you and the general aviation community that came together this winter to avert an endangered sea turtle tragedy in the Cape Cod area. Thanks to your efforts, more than 550 Kemp's Ridley sea turtles were rescued and transported to facilities in Maryland, North and South Carolina, Texas, Louisiana, Mississippi, Georgia, and Florida. Even Disney World and Sea World received some of these amazing turtles from our teams.

Pilots N Paws, NAFI, LightHawk, Angel Flight, P.O.P.A., the U.S. Coast Guard, and many other volunteer groups and individuals came together in this unprecedented and unique rescue endeavor. Many sea turtles were saved, pilots and their families made lifelong memories, and general aviation raised community awareness of the necessary, but often unseen, role we play every day across this great nation of ours.

We are in the process of creating several social media sites to share the stories and photos from those who volunteered. Please join and share your experiences with others. Additionally, these sites will be used to share future volunteer/rescue opportunities and distribute information to other general aviation social media groups. We are interested in hearing from individuals or companies in helping with creating the new Facebook and Twitter accounts. Let your friends, family, and clients know how you are supporting your communities.

Leslie J. Weinstein

Absolutely great set of photos (PotW) the week of March 16, folks. Every one could easily be winner of the Picture of the Week contest. How do you choose a winner from these when they are all winners?

Great pix!

Michael Woodrow