AVmail: Aug. 27, 2007

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Can You Feel The Turn?

The author of this article (about the blind passenger's ability to sense going into or out of a turn unless the rate was slow) states that it matched his preconceived notion on the subject (The Pilot's Lounge, Aug. 13). Actually, numbers can be put to this. The human body is not likely to sense going into or out of a turn if the turn rate is less than two degrees per second acceleration. This doesn't sound like much, but in less than 10 seconds, a bank of 45 degrees can be achieved and, if done smoothly, a blindfolded passenger will not be able to sense the turn.

Many of my engineering buddies didn't believe this; I would have them close their eyes and hold up their hand to show me whether they thought the aircraft was flying straight or left or right. When they closed their eyes, I would let the aircraft roll slowly one way or the other and their hand stayed straight. Then, rolling out of the turn into straight flight more quickly, their hand would immediately signal a turn. I would have them open their eyes.

On a more serious note: This shows just how quickly a pilot can get disoriented in zero-zero.

Evan Yoder


Alaska FSS OASIS Failure

I would like to thank the pilots and all of base operations (commercial and military) of Alaska who have been very kind and understanding while the Alaska FSS OASIS and AISR computer equipment had its major meltdown from August 10 to 17. Our meltdown was so bad that the old Model One FC equipment was dusted off and reinstalled so that we could try and provide a little bit of service. There is nothing as frustrating as not being able to provide a service to our users and friends.

Again, thank you for your kindness.

Mary Ellen Cunningham


FAA TFR Web Page

This is in reference to Mr. Memmer's letter about the FAA TFR Web page (AVmail, Aug. 20. I work in Flight Service and guess what? Our source for TFRs is that same Web page. TFR information is sometimes incomplete in the FS21 system and we are supposed to use the FAA Web page as a reference for TFRs.

If you look on that page, you're getting the same info we at Flight Service use.

Name withheld by request


Runway Incursions

A few words from an old fighter pilot. These [runway incursion] incidents are caused by pilots and will only be cured by pilots (AVwebFlash, Aug. 19). The first rule to safe operations is "see and be seen" at all times. To blindly follow anyone's instructions without visual confirmation is at least suicidal and probably murderous.

If the workload in the cockpit keeps all eyes glued to the instruments or a checklist, then the aircraft should not be in motion, on the ground or in the air. The information provided by ground personnel should be used as information that confirms what you, the pilot, have already observed. If some of us are under too much pressure to conduct safe operations, both on the ground and in the air, then maybe we should rethink our choice of profession.

Lee Goettsche


Relying on AI Reliability

To Thomas P. Turner:

Several years ago, I took accelerated instrument training from GATTS in Manhattan, Kan. Their instructor picked me up in Rochester, N.Y., and the trip out was part of my training. After determining some useful airspeed/throttle setting combinations, he covered the attitude indicator (AI) and that was the last I saw of it until the examiner uncovered it for the practical test. Never missed the instrument and still don't. Much more precise data is supplied by the VSI and TC/TB. Besides, as you and GATTS point out (Leading Edge, Aug. 20), the AI is the instrument most likely to fail and to cause you problems.

For what it's worth, solid-state attitude references are much more reliable than the typical GA mechanical gyro. The price is right, too, when you consider no wear-out-prone vacuum system is required. Service life costs should be less and safety enhanced.

Rick Lafford

AVweb Replies:

I'm familiar with the GATTS philosophy. In fact, given that I'm not terribly distant from Manhattan (I live near Wichita), I hope some day to take a little IFR instruction with GATTS to brush up on my emergency skills.

You're right that modern solid-state attitude references are less prone to failure than mechanical gyros, especially gyros dependent on even more failure-prone pneumatic systems. The recent spate of Garmin G1000 AHRS failures and my brother's experience with faulty Avidyne primary flight displays in his Cirrus SR20, however, suggest that even solid-state systems need redundancy in the form of adequate back-up instrumentation and a well-trained pilot.

Thanks for writing, and for reading AVweb.

Thomas P. Turner


Marion Blakey's New Job

I personally will be glad to see Marion Blakey leave, but I was wondering why no one has brought up the subject of her taking such a job (AVwebFlash, Aug. 22) when Federal law says that she has to wait for a year before taking such a job due to conflict of interest. I know that there will be a "rational explanation" of why this law doesn't apply to her. Politics and money talk louder than the law of the land.

William R. Twa


Facility Fees

I learned today that the FBO at Ocala, Fla., is charging a facilities fee. On a twin, it is $25 or 25 gallons. On a single, it is $15 or 15 gallons. Fee does not apply if you use the restaurant on the field. Hate to see a facility fee applying to general aviation.

Palmer Gehring


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