Unicom

March 2001 Issue




Delusional Vision

Spotting traffic is no solution to traffic avoidance in congested airspace

Jeff Schweitzer’s article “Beyond See and Avoid” [Instrument Check, January] is a good start.

I have been flying just shy of 30 years, but 500-plus hours in the Northeast in a Skywatch-equipped Bonanza over the past 22 months have shocked me. We are fooling ourselves if we think “see and avoid” is much more than a snare and a delusion in congested airspace.

The new boxes give you a fair chance when an intruder is coming from behind or climbing rapidly from below, offer a second chance for distracted pilots in rapid-convergence situations, expand the circle of safety for pilots (IFR or VFR) in marginal VMC, could have prevented a number of multiple-fatality midairs involving high-performance aircraft, and are invaluable in congested landing patterns.

If all pilots always followed all rules and clearances, the new technology might be less of a godsend – but we are a far cry from that. Anyone who flies a fast airplane near Class B airspace should take a half-hour test flight on a busy day in an airplane equipped with collision avoidance technology. After doing so, I believe they will rank these boxes a lot higher on the avionics upgrade list than suggested in the article.

-John M. Coleman
Cambridge, Mass.


Jeff Schweitzer replies: Your point about the value of collision avoidance equipment is well taken. I acknowledged the value of flying with a Skywatch system. As I said, that was a real eye-opener. Having said that, though, I think the relatively low priority for collision avoidance equipment I assigned is justified by the accident record.

Many more pilots are killed flying into nasty weather than through collisions. Therefore, it seems that a higher priority would be weather avoidance gear first (radar and lightning detector).

If money were no object, I agree that every panel should have a Skywatch or Ryan TCAD. But given budget constraints and the other causes of accidents, I think it is reasonable to put collision avoidance pretty far down the list.

But as I jokingly mentioned in the article, if you ask 10 different pilots, you’ll get 12 answers about priorities. If your personal experience leads you to conclude that traffic avoidance is a higher priority, that is certainly a justifiable position.

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Does FAA Acknowledge Medical Facts?
I enjoyed reading the article by Bruce Chien that addresses the vestibular system (inner ear) [Medical Matters, January]. As an ear specialist, I found the information to be quite informative.

At the risk of sounding like a film critic, I would take issue with two points. First, cessation of blood flow to the labyrinth causing vertigo is exceptionally rare in the absence of severe hearing loss. Ischemia (diminished circulation) of the inner ear most likely produces a hearing loss, which may be reversible if treated in a timely fashion. The dizziness that accompanies this is transient, with total recovery being the rule.

Second, Chien implies that Meniere’s disease is the armageddon of all vestibular disorders. This, too, is misleading. Over 60 percent of the patients I treat consult me because of dizziness. Most of these have Meniere’s disease, and the majority of these individuals have been misled about their disorder.

The vertigo that results from Meniere’s is curable. It might require a surgical procedure, but I tell all of my patients with Meniere’s that I can eradicate their dizziness. It is the verdict of the AME as to their fitness for flight. We have also learned that with early and aggressive treatment, it is quite possible to maintain useful hearing in many Meniere’s patients.

Anyone with dizziness should promptly seek the advice of a specialist. In most cases, these stories have a happy ending.

-James E. Benecke, Jr., M.D.
Via e-mail


Bruce Chien replies: Dr. Benke is quite correct that the medical course of the majority of patients with vestibular diseases is recovery. But, as a matter of public policy, FAA Aeromedical is very cautious about suddenly incapacitating illnesses, especially those in which prediction as to future course is uncertain.

As with manic depressive disease and epilepsy, prediction of the future is so difficult that writing “Meniere’s disease” on 8500-8 is sure to result in major deferral difficulty.

Whether this proves appropriate or not only time will tell.

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FAA’s Position Is, Well, Depressing
I strongly concur with the letter you published in the January Unicom in which the writer expressed his opinion of the FAA’s views regarding antidepressants. I have no doubt that there are many pilots who are not pursuing diagnosis and treatment for mild depression or anxiety because their careers would be ruined if they did. People in all other walks of life, many who perform critical tasks under pressure, use these drugs.

If the FAA took a more enlightened and rational view, flight safety would be improved, not diminished. I would far rather know that the captain of an airline flight was managing depression or anxiety with SSRIs rather than worrying what he or she might be covering up for fear of being grounded.

In “Thou Shalt Not” in the same issue [Risk Management], Pat Veillette notes “It’s no secret that many aviators use one physician for “real” medical problems and another for their medical certificates.” Given the medical competency of the FAA, I would say, “thank goodness.”

When the public widely perceives depression as a treatable disease (like high blood pressure), the FAA may be moved to consider the use of SSRIs. In the meantime, however, it’s a shame that the FAA will continue to base their decisions on political expediency rather than science.

-Geoff Pope
Via e-mail

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ADF Spots Problems Elsewhere
First, let me congratulate Gary Picou on a wonderful article on troubleshooting radios [Systems Check, January].

I would like to add a few words concerning the ADF, however. I have found, through many years of working in and running an avionics shop, that most ADF problems are actually alternator/alternator filter problems.

If the ADF refuses to point and you can hear the station, try turning your alternator off. This will get you through in a pinch, and you can then get your alternator replaced (bad diodes, usually) or the alternator filter replaced/re-connected. The other possible ADF problem is a bad plug lead shield. If the above does not bring the ADF to life, try the ADF on the ground with the engine not running.

The ADF is very sensitive to any kind of electrical noise and will refuse to point if there is ‘noise’ in the aircraft. Proof of this sensitivity is that it will actually point to thunderstorms.

-Dan Colburn
Via e-mail

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The Error of My Ways
In “Educational Trip” [Learning Experiences, November], I wrote about the mistakes I made that caused the crash of my Aerostar at Northampton Airport. Mike Regish, who is based at Northampton, responded in a letter in the January issue.

While he starts off being “impressed” that I had the courage to publicize my accident, he then goes on to castigate my errors.

Specifically, from his point of view of being based there at 7B2, he can’t imagine how I could have lost my situational awareness and tried to have taken off from a taxiway. Somehow he misses that this is the whole point of my description of the accident.

I’m based at Midway Airport. Recently a transient pilot was cleared to land on 31 Left and jeopardized many lives by trying to land on 31 Center. I know not to do that, but does Mr. Regish? All pilots were stunned by the crew of the Singapore Airlines plane that attempted to take off from a closed runway in Taiwan, resulting in many deaths.

Just saying, “Nothing could be fairer, call it pilot error” is not useful.

I suggested six things that could have avoided my accident. One of the six was standard runway and taxiway markings at Northampton. Should I, could I, have avoided the accident without them? Yes, as my article spells out.

I think that Northampton is a great little airport. I am delighted that its runway was redone this fall. But even “Whip” Saltmarsh, the chairman of the Massachusetts Aeronautical Commission, in dedicating the new runway two months after my accident, said that the old one “was let go for a long time for lack of money.”

I am also delighted that the FAA has made a recent big push to standardize runway and taxiway markings, in large part to help transients who are not as familiar with an airport as Mr. Regish is with 7B2. I hope that the new runway at Northampton has those markings.

I agree with Mr. Regish that my mistakes that September morning went beyond “any deficiencies of the runway [or] weather conditions.” It is the “anything else” he mentions that should cause every reader of Aviation Safety to consider what they can do to make every part of their aviation operation safe, and not just shake their head when an experienced pilot makes what seems like a dumb mistake.

-Frank Blair
Via e-mail


Too many pilots consider themselves beyond the “stupid mistakes” they detect in other people’s crashes. What pilot can’t think back on a flight or two where the brain didn’t quite engage correctly and wonder how close he or she came to winding up in the NTSB database?

In few activities do participants dissect mistakes with such vigor as in aviation. But as risk tolerances and aircraft performance vary so widely, there is no one-size-fits-all solution to every problem. Only in talking – and listening – can we each decide what is right for us.

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Call Me Conservative, But Call Me Safe
First let me say what a great article, “Thou Shalt Not” was [Risk Management, January].

I would like to comment on a few of the subchapters in that article. 1. VFR weather minimums. I fly from a non-towered airport with ILS and VOR A approaches. It is my thought that VFR traffic in the pattern should cease when the cloud bases are less than 1500 agl. The pattern altitude is 1000 agl and bases at 1500 agl gives you your 500 ft clearance.

2. VFR cross country minimums. My wife and I use 3000 agl ceilings and 10 miles as minimums before launching on a cross country greater than 25 miles. This gives us some wiggle room when it starts to deteriorate.

3. Fuel reserves. We fly an old, non-IFR, 1964 C-172. It holds 38 useable gallons and burns 9+ gph at 1500 msl and about 7.8 gph at 8,000 msl. We flight plan on 10 gals per hour which would give us 3.8 hours until the prop stops and we plan our trips for 2.5 hour maximum legs. We navigate primarily GPS or loran direct, with small airfields, rather than VORs, as waypoints, so if our ground speed is slow or the weather goes south we can land early.

4. We have created a standard form which includes our weight and balance with full fuel and oil and us two in it as a standard condition. This makes it easy to check the takeoff data in the performance chart and we double the takeoff distance and verify the field conditions will support such a takeoff distance.

5. We have made a personal rule that we both must agree before we attempt a flight or continue a flight if the conditions change. The minute that funny feeling in your stomach starts is the time to begin discussing Plan B.

6. Wind. I don’t like turbulence. We check winds at 3000 and 6000 and if the low level winds are 20 knots or more and if the surface winds are getting above 15 kts we think about delaying or postponing our flight. Cross winds, 15 knots, and little or no flaps. I personally think our airplane is difficult to control on a blustery day when the winds are to 15G25 or more – and the accident statistics support this – unless your technique is very good.

I know all of this will seem very wimpy, but these are the actual rules my wife and I use, and I would encourage any new or student pilot to think about these self-imposed limits. The FARs alone will give you plenty of rope to hang yourself.

-Mark Hutchins
Via e-mail


If your self-imposed guidelines work for you, great. Everyone should have a set, but as each pilot’s experience, skills and equipment are different, each will have a different set of personal minimums.

The question of how to manage risk must be answered by the person taking the risk. What seems conservative to you might seem insanely chancy to me. And vice versa.

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Keep the Ears Peeled, Too
I just read “Speck in the Windshield” [Accident probe, January]. It is very sad when something like this happens.

What did I miss in the comments on the investigation? Did the Cessna 172 listen to the radio communication between the Bonanza and the tower?

I am always on an extra alert when flying within an airport’s radio boundaries (10 miles) to hear what exactly is going on. And when not 100 percent clear to me, I ask the position of the other traffic via the tower. I think it is a must to listen to all the radio communication on a tower frequency when in that area, especially when flying through the airport’s airspace.

-Cornelis Docter
Via e-mail


The Cessna/Bonanza collision was certainly an accident where, even though the questions may never be answered, the lessons are profound. It also points out the danger of using local vernacular (eg., “the crib”) that may be totally unfamiliar to transient pilots. To us, “Report five miles” works much better for everyone – as long as everyone remembers to report. And the 172 pilot’s failure to report passing abeam the airport as instructed by the tower may have been a key element of the collision.

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Who Was Minding the Store?
I just finished reading the “Phone Home” story [Learning Experiences, January].

As I began reading the article, the author talked about checklists and deciding that with two hours of fuel on board there was time for troubleshooting the gear problem. He then described how the cell phone helped.

At the end of the article he describes the problem finally being resolved by a suggestion from the ground and a resultant successful landing. He describes this episode as an excellent example of cockpit resource management. He then goes on to say they had five minutes of fuel left when they landed. If I interpret this correctly, this means that they circled for almost two hours trying to solve the gear problem and that the decision to land was not precipitated by concern about critical fuel status but because the last “fix” happened to work. Even if circling over an airport, to spend two hours trying to fix a problem and getting to within minutes of engine failure because of fuel starvation, all to avoid a gear up landing does not seem to be very good judgment.

Every article and seminar I have been exposed to has suggested that the danger of a situation is increased by focusing exclusively on avoiding damage to the aircraft and losing the big picture of the safety of the occupants. Going to the edge of fuel exhaustion to avoid a gear up landing would seem to be an example of this.

-Bob Donahue
Akron, Ohio


You raise some good points, to which we would add that, when faced with a gear-up landing, you should pick concrete instead of grass and remember that most gear-up landings do not result in serious damage to the airplane or injury to the passengers.

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Know Thy Turbo
The “fairly experienced pilot” in “Too Rich for my Blood” [Learning Experiences, November] should take the time to understand his airplane’s systems.

The turbocharger provides pre-compressed air to his engine, but only when there is enough exhaust gas present to spin the turbine. At idle and low power settings the turbo won’t get enough exhaust gas to provide any significant boost. Indeed, an automatic wastegate is probably open at low throttle settings, allowing the exhaust gas to bypass the turbine completely.

Consequently, if a pilot selects a full rich mixture during approach to a high density altitude airport, he or she will very likely have an engine stoppage caused by an over-rich mixture when the power is reduced on short final or after touchdown. I’ve seen several cases of this at high altitude airports.

On the other hand, when taking off the turbo is supplying at least sea-level pressure air, and probably more. The engine can easily make full rated power, and will need a rich mixture to keep the engine cool. With the intake air also heated by compression, detonation is much more likely. In a turbocharged aircraft you must run the mixture full rich for takeoff. The “fairly experienced pilot” was lucky he didn’t blow a hole in a cylinder on his leaned-out takeoff.

The most difficult situation comes when you must make a go-around at a high altitude airport; with the mixture leaned for the low power setting on approach, you suddenly go to full power. Don’t forget to also go to full rich mixture.

It is unfortunate that most Pilot Operating Handbooks give very scant information on ground and flight operations at high density altitudes, especially for turbocharged aircraft. Maybe some of the manufacturers will read this.

-Larry Haight
Via e-mail