Unicom

June 2000 Issue




Any Ol’ Bank Won’t Do

Mountain winds can also help a climb if you know where to look

At the end of an excellent article on engine-out procedures and preparation for landing [Reality Check, April], Wally Miller states: “... fly the airplane ... trim for best guide speed and do not give up an inch of altitude.”

I am somewhat perplexed by that statement. if you lose and engine, I always felt that you should pitch the plane up to the best glidespeed, thereby gaining altitude.

I fly a Mooney 201 which cruises at 145 to 150 KIAS. My best glide speed is 85 KIAS. If I lost an engine, I would pull the nose up and immediately trim the plane for 85 KIAS. During the pitch up and trim, I would gain several hundred of feet of altitude, which could buy me a better landing spot. I realize, of course, that the danger is that you could stall if you were not paying attention to the airspeed during the climb.

-Michael Bard
Via e-mail


Mr. Miller replies: Few pilots are aeronautical engineers, but every pilot can easily find out if his or her machine has any worthwhile “zoom.” A reasonable test might be to: 1) set up the “normal” cruise speed and configuration, 2) fully retard the throttle, 3) wait 4 seconds (the FAA “swimming in glue” estimated pilot reaction time for situations like this), then 4) see how much “zoom” the aircraft has before the nose must be pushed over to establish glide speed. If the capability is there, by all means use it. In most cases, however, there will be none.

Give consideration to the “maintain level flight” approach for a couple of reasons. The first is visibility, the second is human nature — the way we tend to operate in emergency situations.

After noting the engine loss, lots of things should be running through the pilot’s mind (looking around, validating the wind, looking for hazards, moving selectors or running checklists, whatever). While all this is happening, more airspeed is being lost. How much varies depending on the airplane, pilot, circumstances, etc.

For most general aviation aircraft, the safest plan, in my view, is to maintain altitude and follow the general procedures recommended in the article. Nothing is really lost be maintaining altitude while the airspeed is decaying. Fly the airplane, pick out your “spot,” trim for airspeed and set up your pattern. Failing to “zoom” will lose you little if anything. The same can’t be said of trying to zoom the wrong airplane or zooming the wrong way.

For example, trimming the airplane while pitching up would put you into stall territory if the airspeed bled off too much while you were focusing elsewhere.

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Wind in Your Sails
The circumstances depicted for an engine failure five miles east of a suitable field for landing brings up another possible solution that reduces altitude loss. Use the wind.

By noting a 15-knot wind from 180 degrees, positioning can be planned for a northerly wind drift that can place the aircraft at the abeam point or possibly at the base leg thus saving approximately 250 feet to 500 feet of altitude loss due to turns downwind and/or the base leg for final approach.

Nobody says that an engine out approach for landing has to be pretty. A forward slip can adjust for excess altitude on final approach. Anything you can do to improve the chances of walking away from a forced landing (like using the wind to your advantage) is definitely worth it.

As a very wise flight instructor once told me, “During a forced landing, altitude is life!”

-Ron Harper
Elk Grove Village, Ill.


Good point. Remember also that the shortest distance is a straight line.

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April Fool’s?
I’m an avid reader, but in the sidebar “Try Before You Fly” in “Crash Like A Pro,” April 2000, Wally Miller makes the observation that a “standard rate 180-degree turn costs you thirty seconds.” A breaker tripped each time I reread this as I visualized what it really is that’s painted right there on my turn coordinator. To make sure I wasn’t hypoxic, I dragged out the books (it was early and I was still a cup short). Don’t do that to me! (Or was this a test?)

-David Howe
Atlanta, Ga.

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What to Try First?
I read with great interest your article “Crash Like a Pro.” I began to do the exercise titled “Try Before You Fly” and found a discrepancy with my understanding of standard rate turns. In the discussion regarding altitude lost in a turn it was stated “A standard rate 180-degree turn costs you 30 seconds, during which you will descend 480 feet.”

The FAR/AIM 2000 defines standard rate turn as 3 degrees per second, which makes the time for a 180-degree turn equal to 60 seconds. The descent during the turn would be 950 feet, on the basis of the aircraft specifications in the illustration.

I am also curious about the impact on rate of descent during a standard rate turn. I would expect the rate of descent to be higher than for best glide speed in straight and level flight. Your comments will be appreciated.

-Paul D. Leeke
Via e-mail


We haven’t figured out who to fire over that boneheaded “standard rate turn” error, which was introduced during editing. Mr. Miller’s comments, calculations and simulator test flights were made using a 30-degree banked turn, not a standard rate turn.

The effect of a turn on descent rate is complicated to calculate but easy to test in the airplane. And since every plane will have its own characteristics, we suggest you try it yourself.

In an emergency, how steeply you should bank depends on where the target point is. A shallow turn will offset you more from your flight and will preserve more altitude than a steep turn. A steep turn will keep you closer to your original flight path. For more information, see “The Impossible Turn” in the November 1999 issue of Aviation Safety.

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CFI Care
Your editorial concerning CFIs was interesting [Editor’s Log, April]. Let me offer a comment on the topic.

I have been flying for more than 50 years, and when retirement loomed some 10 years ago I decided to scratch a long-term itch. I figured I would become a flight instructor.

I thought I would a pretty good one. I love flying, have lots of hours in many kinds of airplanes, and am not trying to build time to get on an airline. I am not afraid to do stalls and spins.

I have had my share of cockpit nightmares and I have made almost every boneheaded mistake you can make in an airplane and still be alive and I’m willing to admit to them. I am an engineer by profession, a homebuilder by avocation, and an A&P, and so I have an appreciation of the technical aspects of aviation.

After taking early retirement from a large computer company, I joined the faculty of a major university for a few years, so I have some teaching experience. I got my CFI, CFII and IGI, and then encountered the facts of life for flight instructors. I guess I knew them all along but was just in denial. The competition dictates the pay and employment conditions for flight instructors; no surprise.

As long as you have people who are willing to “pay their dues” for a career in aviation by working for peanuts, the flight schools will pay $12 to $15 per hour actually flown, and maybe pay for some of the time spent briefing and debriefing, preflights, etc. For this pay you get to hang around the airport all day waiting for students to show up and the weather to improve. You can’t fault the flight schools; it’s a very tough business.

Also, there is the question of liabilty. When you are 20 years old and have no assets to speak of this is no big deal. When you are at the other end of your life and have lifetime of hard-earned assets you become a target for a liability suit if some student or even ex-student does something wrong and someone gets hurt or killed.

You can get insurance for this, but it takes a lot of hours at $12 to $15 to pay for it. I now do some freelance instructing, just for fun and my own amazement and mostly in vintage airplanes, which I understand better than some of the younger folks. I also participate at Wings Weekends which establishes a relationship with the FSDO which in turn faciltates CFI renewals. There is of course still the liability issue, which does make me a little nervous.

As much as anything, I am distressed by the fact that student pilots don’t have role models hanging around the airport to engage in hangar flying. I learned a great deal just listening to those old guys tell tales about their experiences. Even if some of the stories were somewhat embellished, they were based upon years and hours of real experience.

I’m not knocking the young CFIs, but there is no substitute for experience. As long as this situation prevails, and I have no reason to believe that it will change soon, the present state of flight instruction will not change.

-George Abbott
Via e-mail


You’ll get no argument from us on that matter. Many pilots struggle along with glaring deficiencies until a subsequent instructor suggests a fix. Low-paid instructors will always be around because there will always be people counting their flying pennies. But all pilots should try to get the best instructor they can afford – and these tend not to be the young time-builders favored by the flight schools.

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Twisted Logic
“Cheating the Turn” [Airmanship, April] contains an inaccuracy. In the discussion of wing twist in modern aircraft, one way the sentence should read to be correct is “... you can see that the outboard end of the wing is twisted to a lower incidence angle than the inner portion, ensuring that it always has a lower angle of attack and will stall after the wing root stalls, allowing aileron effectiveness into the stall.”

The wing tip incidence is set at a lower incidence angle compared to the wing root so as the angle of attack (AOA) of the whole wing is increased, the wing root AOA increases past its critical angle of attack and begins to stall. The wing tips, with their lower angle of incidence, are still slightly below their critical AOA and still creating lift. This allows the ailerons to still be effective and the aircraft controllable even when a majority of the wing is stalled.

-Robert Henderson
El Paso, Texas


Higher, lower. Wing tip, wing root. You really expect us to be able to keep those kinds of details straight? We’re busy around here playing with the new avionics package. Seriously, you’re right. We were wrong. ’Nuff said.

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The Docile Stall Progresses
I have seen a good video showing tufted Hershey bar wing stalling, very progressively from root to tip as angle of attack is increased.

With flaps extended, the stall speed differential between root and aileron is increased, which is probably why control in the stall seems better with flaps down.

The Tomahawk has an untapered wing, and stall strips, but no stall strips have been used on stock Cherokee wings, straight or tapered.

The straight wing 180, by experiment, will remain aileron-controllable during a long stall that loses over 2000 feet. Just make sure the ball is centered and the cg forward.

I did like Mr. Levy’s article by the way.

-Dallas Vaughn
Holliston, Mass.


Many airplanes use both twist and stall strips to tame the stall, including Piper’s Hershey bar-winged PA-32s and Mooneys from the mid-1970s on.

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Don’t Call Me High-Risk
As a builder of an kitplane (GlaStar) I take serious exception to Miles Diller’s article “Think Twice” [Risk Management, April].

He lumps flying homebuilt aircraft in with high-risk behaviors such as buzzing, flying with known equipment deficiencies, etc.

I feel that my aircraft is every bit as safe as a factory-built aircraft, and in many ways safer. I intimately know what condition my aircraft is in since I personally built it. If something goes wrong in flight I feel I am better prepared since I know my aircraft better than the average pilot of a factory-built aircraft.

Please don’t let incorrect statements such as Mr. Diller has made get into future issues of your magazine.

-Richard Yerian
Phoenix, Ariz.


The sad truth is, flying homebuilts is more risky than flying production planes. Comparing accident rates between experimental and production airplanes is difficult because of the assumptions about usage, but it appears homebuilts are about 30 percent more likely to be involved in accidents.

You bring up several good points about the benefits of flying an airplane you built yourself, and none of them should be dismissed lightly. You appear to have the right attitude. But not everyone who builds an airplane does it competently. Some let their flying skills atrophy during years of construction. Some build more airplane than they can handle. Some take advantage of the repair authorization to defer needed maintenance.

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Not So Risky Business
Miles Diller seems to have it in for homebuilt aircraft enthusiasts. He states that merely flying them is a “high-risk behavior,” apparently on a par with buzzing and flying under the influence – listed in the same sentence.

I know the statistics show more accidents in experimentals, but his unqualified statement is unfair.

Later, he states that — “if you fly a poorly maintained, high-performance experimental aircraft, your accident risk is higher than the rest of general aviation.”

I am sure that this is true, but the statement seems to imply that experimental aircraft are (always) poorly maintained.

I am a longtime subscriber to Aviation Safety and find it very interesting and rewarding. This is the first time I have been offended and felt the necessity to write.

-Stewart G. Willoughby
Via e-mail


The behaviors he listed do, in fact, carry more risk, making them high-risk behaviors by definition. Nowhere did Mr. Diller imply they were all equally risky. Likewise, the reference to poorly maintained high-performance home-builts serves to mark one end of the risk scale. If you re-read the paragraph, it should be clear that we’re talking about a risk group here, one that is affected by a variety of other factors.

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You Can See the Pride
Making unsubstantiated claims that homebuilts are as dangerous as flying under the influence of drugs will bring the EAA down on the head of Mr. Diller. He is demonstrating his ignorance. Examples of inflight failures of homebuilt aircraft are very rare in your publication. You are the keeper of statistics. Mr. Diller had better be able to back up his statement.

People who invest 3,000 hours in building an aircraft are very careful with them. In my visits to Oshkosh and Lakeland over the years, I am continually amazed at the fit and finish of the homebuilt aircraft. It must make the factory people cry when they look at it. To make factory aircraft look that good would double the price.

-John Stark
Via e-mail


In the first place, looks and fit/finish are just part of the equation. Certified airplanes also have handling requirements that do not apply to homebuilts. Loss-of-control accidents involving homebuilts are a much bigger problem than structural failures, but only slightly bigger than mechanical failure on the whole.

Second, vintage car shows have the cream of the crop, too, but that doesn’t mean there aren’t a lot of clunkers on the road.