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I decided recently to open up an area guaranteed to raise blood pressure out there. Not because of expected disagreement, but because the subject is one that regularly angers a fairly large group of pilots. The issue: wide, extended (very large) "B-52" traffic patterns (flown by others, of course).

Last month's column ended with this sentence: "The conflict surrounding wide traffic patterns vs. narrow ones comes down to a single issue: risk management." This conclusion is based on my observation that the best arguments against wide patterns are all based on safety–it is not a good idea to fly at 800' AGL beyond gliding distance to a runway.

Before getting started again, it's important to get a basic truth out of the way: you are no more likely to experience engine failure close to an airport than far away. Thus, if you personally fly 800' AGL out in the boonies, you are as guilty as the guy flying the big pattern–both of you are likely to be in trouble if you have mechanical difficulties.

And there's even more to this point. If pattern safety is really your concern, it's essential you review the glide performance of your own plane to see if your habits in the pattern meet basic safety requirements when you aren't forced to follow other pilots. Simply put, can you glide to the runway from the place and altitude you normally choose to turn base? If you can't, or if you don't know, you may be guilty of the same essential safety error as the "B-52" pilots that get all the complaints.

All the figures that follow assume zero wind, no flaps, quick reflexes and excellent aircraft control. In other words, you should expect a reality substantially less satisfying.

Example 1. Cessna 172s are lightly wing-loaded and have a respectable glide ratio: 9:1 at maximum gross weight. Provided there is no headwind, that gives you 7200' lateral reach from 800' AGL. If you fly your downwind leg at 1/2 mile offset from the runway and start descent abeam the threshold, you will be able to stretch the downwind about 3/4 of a mile before you progress beyond glide distance back to the threshold. Close, huh?

Example 2. If you fly downwind wider than 1/2 mile–and almost everybody does–the base turn has to be made much sooner, A downwind flown 3/4 of a mile from the runway creates the necessity of turning base approximately 1/2 mile past the threshold. Try this sometime. Most pilots and most CFIs call it a "short approach"–something unusual–which provides a very useful clue to the basic mindset out there.

Example 3. You fly the downwind about a mile offset from the runway–pretty much the standard. You will eat up 3/4 of your glide distance just getting to the runway from the threshold abeam point. Virtually any distance flown past that point will put you out of glide range.

As noted, these examples are all best case scenarios. Add flaps or a headwind and you can expect a significant glide decrease. Higher performance airplanes are also unlikely to offer 9:1 in the glide, so as you move up in aircraft complexity you need to change expectations. When you see a Bonanza turning base two miles out, it is a good guess the pilot has failed to think things through carefully.

Pilots talk about pattern safety; very few practice anything close to it, even when not forced to follow "bombers." Conclusion–the huge majority of single-engine GA pilots everywhere fly unsafely in the pattern. Next month: some ruminations on how things got this way and how you can change to improve the odds..

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