Mary Sue Musser
Vista, California
More On Control-Surface Failures
I have been following the exchanges on control failures with great interest ("Flight Forum," August AOPA Flight Training, and "Losing Control: Compensating for Failed Flight Controls," June). Vince D'Angelo's observations about trimming in reverse are well taken, but only where the elevator is disabled in a fixed position. When the elevator simply becomes inoperative but remains mobile (i.e., if the control cables just snap), trimming to control pitch works in the normal sense - trim up, nose up. However, the extent of trim authority depends entirely on the design of each plane and should be investigated by each pilot in actual flight conditions before an emergency occurs. Moreover, a jammed elevator in the up position may in certain airplanes require a reduction in power to prevent a power-on stall. Again, it depends on what you are flying.
Do get to know your airplane before you have an actual control failure, and remember that the one control mishap that can really ruin your flight is an elevator failure on takeoff. That is why I have been taught always to do one last elevator check "on the numbers" before takeoff. Finally, on the subject of control failures generally, I strongly recommend Chapter 9 of Rich Stowell's excellent book Emergency Maneuver Training, as well as the practical experience of flying module II of his EMT seminar, which deals expressly with that subject.
Marco Schnabl
Rockville Centre, New York
Another Worthwhile Aspect Of GA
Colleen Turner says it beautifully in her recent letter ("Flight Forum," September AOPA Flight Training). I'd like to add another worthwhile group to her list of worthy aviation organizations. LightHawk ( www.lighthawk.org ) is an all-volunteer pilot organization dedicated to our environment and can use all the support you can give them.
Robert J. Ovanin
Via the Internet
The High Vs. Low Debate Continues
In the article "Movin' On Up" (July AOPA Flight Training), Budd Davisson states that other than blind spots, there are no significant differences between high- and low-wing aircraft. This is not exactly true. We must not forget that ground effect is much more noticeable in low-wing aircraft.
Suppose you are a newly minted private pilot and your training was in a low-wing craft like a Piper Tomahawk or Warrior, or perhaps a Diamond Katana. Both the Tomahawk and Katana have substantial ground effect lift because they are light and have large wingspans. Even very experienced instructors find it very easy to float up 10 or 20 feet during the flare. If a new pilot moves into the Warrior, floating is less likely simply because the Warrior is much heavier. However, when first landing a Cessna 172, without proper instruction, the pilot could drive the nose into the runway. This has happened at our flight school. The 172 and the Warrior are about the same weight, but the difference in wing height is enough to reduce ground effect dramatically.
The instructor who checked me out in a 172 was quick to point this out to me. It was good that he did. As this is a magazine for pilots in training, and most avid readers will be students or new pilots, I think the magazine should be clear about this possible hazard.
Steven Nagle
Lincoln, Massachusetts
Accident records show that low-wing and high-wing aircraft designs have similar safety histories. Floating is generally the result of excess airspeed on the approach, and landings of both low- and high-wing aircraft will benefit from good airspeed control in the pattern. We certainly agree that proper instruction is the key to any successful aircraft checkout. Ed.
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