Unicom

December 2001 Issue




A Dose of Reality

Thanks for shining light on Concorde investigation details

You put out an amazing issue in October. In getting in from the office at 11:00 last night, I stayed up until 1:30 reading the issue cover-to-cover. John Lowery’s Concorde piece, “Fallen Icon” [Reality Check] – was well done. It was a breath of fresh air to read a realistic piece about the Concorde crash.

It’s a bit sad to see the way both companies and governments sometimes react to crashes. BEA blames Continental for their DC-10 dropping a metal strip; BEA similarly blamed the pilots of the ATR at Roselawn, claiming the pilots did not react correctly to the situation. I’m not attempting to blame the Europeans, but it does seem to be a consistent pattern in different accidents/incidents.

It’s frightening to think of the ramifications if such attitudes are true. The FAA could be similarly guilty for this, in reference to the Monroe, Mich., crash of the Comair commuter, in which the NTSB directly blamed the failure of FAA oversight.

Again, please do not stop churning out such excellent issues. Of all the magazines I get, I really believe it helps my attitude and technique. And, in many cases, the writing is real, powerful and to the point.

Too many of the magazines are filled with “happy” flying and seem to beat around the bush on tough issues. Don’t ever stop taking a stand.

-Andrew Stanley
Via e-mail


Thanks for your gracious comments. We love the feedback - positive or negative - but we’re much happier when it’s positive. Thanks for reading.

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Cheat Sheet Translation
In “Flying a Fleet” [Proficiency, October], Ron Levy includes his cheat sheet from his Cougar. In it, he lists Va (105-120), which is familiar to any pilot. But following that is “Turb” at 140, unless it’s a speed for a given weight. If that is what it is, please clarify; I am always willing to learn something new.

-Pete Rose
Via e-mail


While Va is a good number to use for penetrating turbulent air, the Cougar has a published turbulent air penetration speed of 140 mph.

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Too Lean on Truth
Shame on you guys for promoting another old wives’ tale regarding engine management in “Why Engines Fail” [Systems Check, October]. Running too lean does not cause engines to run hot. In truth, engine temperature (EGT/CHT) increases as the mixture is leaned until reaching peak temperature. Continued leaning after reaching peak temperature (operating lean of peak) causes engine temperature to decrease.

It would have been correct to say the “improper” leaning can cause the engine to run too hot.

Today’s powerplants are far too expensive to permit an oversimplification of proper leaning technique. Pilots reading your article will likely avoid leaning altogether to prevent the trouble you improperly planted in their minds.

I suggest you have the author of this article do a better job on his homework or allow him more space in your journal to accurately describe appropriate leaning techniques.

Again, shame on you guys.

-Robert J. Miller
Via e-mail


Okay, we’re guilty as charged on the issue of oversimplifying the issue by boiling down leaning into one sentence. Obviously, it’s more complex than that. But we think your notion that pilots will avoid leaning altogether on the strength of our article is ridiculous.

We used the example of a high-power cruise climb or takeoff, in which running too lean – for example 25 degrees rich of peak rather than 100-degrees rich or full rich – can definitely elevate CHTs.

Despite its advantages in some airplanes, the fact remains that many light aircraft with stock fuel systems won’t run well lean of peak. We’d lump all carburetor-equipped engines into that category, as well as many Lycoming fuel-injected four-cylinderengines. The majority of light aircraft can cruise rich of peak and for those neither pre-disposed nor equipped for lean-of-peak, we think ROP is a sensible option.

Lean-of-peak operations are useful in engines equipped for the purpose but we would guess that those who venture there understand the technique and instrumentation required to do it safely. It certainly saves gas and the engine runs cleaner and cooler. We’ll examine that in another issue.

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Why Engines Fail
Regarding “Why Engines Fail” [Systems Check, October], one reason for the failure of fuel-injected Continental engines has been in-flight flooding when the throttle is advanced after a descent at low manifold pressure. Many of these incidents occur at altitude and do not lead to accidents, but near the ground, accidents do ensue.

For example, Lance Neibauer, founder of Lancair, told me that his TSIO-550 engine quit on final when he forgot to turn off the boost pump prior to landing. He turned off the pump and the engine restarted.

Continental’s “Tips on Engine Care” dated 07/00 states on page 57: “Turbocharged engines have a unique problem during acceleration. If the fuel flow increases before the turbocharger has time to build up to speed and increase the airflow proportionately, the engine my falter from an overly rich mixture.”

The engine has no feedback from the manifold pressure to control the fuel flow. The only control is from the position of the throttle valve. Why are not the flooded engine failures being reported?

The Air Force reported the problem in the 1960s in the T-34 version of the Bonanza. One pilot told me Air Force instructions were to clear the engine every 500 feet during the descent.

For about two years I have been looking into the issue of engines flooding in flight during the approach to landing. During that time, there have been a number of accidents in which it seems this problem may be a likely culprit.

-Robert E. Froelich
Via e-mail