August 2004 Issue

Unicom: 08/04

Experience Yourself
Paul Bertorelli’s article (June 2004) describing a flight from Florida to Oklahoma through a line of thunderstorms ended with his co-pilot wondering aloud how a less-experienced pilot—say a new Cirrus owner with 300 hours—could learn to do what they had just done. It got me thinking how I’ve been approaching the answer to this question.

I am just shy of 300 hours and earned my Instrument rating last fall. I’ve actively sought out flyable IMC, amassing 50 hours of actual instrument time, and I purchased a well-equipped Grumman Tiger. Knowing your personal flying machine is a prerequisite for safe IFR flying. For me, that’s been the easy part. I bought a make and model that I had already flown extensively and I had pretty well tamed flying the plane by the numbers.

Learning its avionics was another matter. I didn’t have the luxury or desire to buy a new airplane, complete with three days of factory training CD-ROM training tools. In my case, aircraft “checkout” consisted of the prior owner handing over a stack of avionics manuals; I had my work cut out for me.

I started by mastering one box at a time, starting with functions that would immediately enhance safety and lower my workload—an important consideration since much of my flying is single-pilot IFR in busy airspace. I plan to cap this portion of my personal checkout process with a full day of IFR training and focusing on GPS approaches. It takes considerable time and effort to become fully familiar with the features of a modern, well-equipped aircraft.

Flying safely requires setting appropriate limits that reflect a pilot’s experience, currency and aircraft capability. I made several recent flights in IMC conditions, including one that would keep on the ground many pilots I know with far more hours. I’m comfortable in low IFR provided that I remain current.

One trap I’ve found is that I’ve been so conditioned to follow ATC instructions that it feels like an unnatural act to say “unable” or, in my case, “unwilling.” But ATC has proven accommodating to request for a diversions and routing changes.

Having said that, I wouldn’t have launched into the conditions described Bertorelli’s article. Why? Because this is my first thunderstorm season since getting my IFR rating and I don’t have enough experience. I hope to gain more confidence in picking my way around thunderstorms (or knowing when not to). But this can only occur if I’m willing to push the envelope of my personal flying experience.

So to return to the question Paul Bertorelli raises in his article—how does a 300-hour, new plane owner learn to safely fly in thunderstorm season? My answer is: one flight at a time.

First off, avoid the traps. As PIC, it’s my call, not ATC’s, when to play the hand I’ve been dealt and when to fold.

Push the envelope: Only by getting in the system can one gain the experience and confidence to fly when the weather is uncooperative. Finally, know the airplane.

I wish there were shortcuts to learn some of these lessons faster. But some things like safe flying and vintage wine just take time.

-Len Sherman
Via e-mail


Not The Right Extinguisher
Your recent article, “Hangar Fires,” (June 2004) included a sidebar, “The Right Fire Extinguisher,” stating the A-B-C (2A/20BC) extinguisher is the “right” one to use in the hangar. If used on an aluminum aircraft, this type of extinguisher will destroy your pride and joy, even if the fire doesn’t. The right extinguisher to use would be the B-C type. There may be an A-B-C extinguisher in the hangar; just don’t use it on the airplane.

-James R. Miller
Crowley, Texas

Author Dick Coffey responds: Mr. Miller has a point. Most ABC extinguishers—used to fight fires of combustible materials, fuels and electric—are filled with monoammonium phosphate, a sticky chemical that may damage the electronic components of an airplane. BC extinguishers—suitable to fight fuel and electrical fires—are usually filled with sodium bicarbonate or potassium bicarbonate, which leaves a mild corrosive residue. The residue produced by dry chemical extinguishers help to snuff out the fire and prevent re-ignition. There is no question that dry chemicals may do damage but, presumably, the availability of an all-purpose extinguisher will keep a fire from spreading until the pros arrive. Mr. Miller is also correct to suggest that a BC type extinguisher is most appropriate to fight fuel and electrical fires and an owner might well be advised to have both types of fire bottles available, particularly if the hangar is used for maintenance. We still think the ABC bottle is the best bet for general use but, as we suggested, a hangar owner is well-advised to stop in at the fire department for advice before buying an extinguisher.


Which is It?
In the article “An Engine Near Miss,” (June 2004) the author states that “detonation normally does not influence EGT while pre-ignition most certainly does” (causing it to go downward in his example). However, in the sidebar to the article it states that with pre-ignition the “CHT will definitely rise and EGT may or may not.” Which is it? Could you clarify that for me?

Thanks for a great publication! As far as I’m concerned, it’s a “must read” for pilots of any level.

-Wesley Von Seggern
Via e-mail

This was a test. You passed. Seriously, yes, the caption is confusing. J.P. Instruments prepared the graphics for us from their examples of various engine maladies, many of which were crafted from “conventional wisdom” on the subject of detonation and preignition. However, we’ve seen tests showing more clearly that a preignition event will definitely show a dramatic rise in CHT and a drop in EGT. That’s because the combustion event is taking place so quickly, with such profound vigor, that there’s not much left when the exhaust valve finally opens. There’s no substitute for data. Hope that clears up the misunderstanding.