AVIATION SAFETY NEWSLETTER
Thought for the month..... Chili starts with a basic recipe that we improve with various ingredients. The trick is knowing when to stop before it's too hot to handle.
A Little Knowledge... I was out at the airport one day and watched as a pilot in a
Cessna 172RG came down the taxiway at a high rate of speed. It's not unusual to see people taxiing too fast, but
this was faster than that. Because of the speed, the pilot was having some difficulty holding the centerline and
as the aircraft approached the turn for the ramp, there was no reduction in power, just hard braking and about
a 2-G turn. Even on the ramp, the pilot didn't reduce power and the nose bobbed up and down as hard braking was
applied. This was clearly airplane abuse and as a member of the SPCA (Society for the Prevention of Cruelty to
Airplanes), I felt compelled to discuss what I felt was poor technique, with the pilot.
It turned out that the pilot was a relative new comer and had recently been checked out in the RG. The pilot's previous training had not been in Cessna's, but in a fixed gear trainer. Some of the things the pilot had learned didn't carry over to the RG. One thing in particular was that in the Cessna, if the pilot reduced power to taxi slower, the low-voltage light would begin to flicker and then stay on. After doing a little homework in the operator's manual, the pilot had determined that the reason the low-voltage light illuminated was because of insufficient rate of charge, and one of the consequences of low voltage might be a "trip-out" of the alternator.
The real concern the pilot had was that the gear and flaps on the RG are electrically operated and if the pilot allowed an insufficient rate of charge, the battery power could be low possibly creating a bad situation if it was needed to extend the landing gear in the event of an electrical problem. Clearly what we had here was not intentional abuse, but the result of a little bit of knowledge, not fully understood. The pilot was carrying higher than necessary engine RPM to keep the low-voltage light from illuminating, in-accordance-with the procedures outlined in the operating handbook.
I looked in the POH and verified what the pilot was telling me. The book gave no guidance on how long ground operations could be conducted with the low-voltage light on before it created a problem. It simply said the light would go out at higher RPM, and that's what the pilot was doing. I assured the pilot that reducing the RPM during taxi would not create a problem but that taxiing too fast might. I confirmed that it was probably a good technique to bump the RPM up to around 1000 at times when the airplane was stopped, such as when waiting for a clearance, etc. That would keep the light out and the engine cooled.
The pilot was pleased to learn the new information but eventually looked at me with some frustration and said; "How am I supposed to know all this stuff? The book gives specific information but it doesn't provide any techniques."
The concern the pilot had was real and although the first response I wanted to give was that it was the responsibility of the flight instructor who conducted the checkout to include "good operating" procedures during the training, after thinking about it I realized that wasn't completely fair. Naturally, the flight instructor always takes the heat when we're talking about whether a pilot is adequately trained. But we also beat them up if they teach techniques that aren't consistent with the manufacturer's recommendations or approved guidance.
"Best practices" is really the term I'm describing. It's one of those concepts we can all appreciate but it is difficult to actually define. Best practices are the most suitable ways of doing things that produce safe and successful results without compromising guidance or rules, or the spirit of any rules. By the "spirit" of any rule I mean those things that are not specifically identified in a rule, but support the purpose of a rule. For example, 91.103 states: "Each pilot in command shall, before beginning a flight, become familiar with all information concerning that flight." Even though the rule doesn't specify it, a best practice is to always have current charts of the area we intend to operate in.
The problem with best practices is that we have to really determine that they are the "best", and not just the most expedient or most economical. A best practice done for the wrong reason is no longer a best practice, if that makes any sense. A best practice when operating at a non-towered airport is to use the radio to announce my position in the traffic pattern. If I use my radio to misrepresent my location in the pattern so I can sneak in ahead of another inbound aircraft, it's no longer a best practice. Good procedure - applied inappropriately.
Best practices are the result of experience and operational history. The very best practices are more than outcome-based behaviors - we do it, we like it, we'll do it again. They are procedures that have been scrutinized and evaluated to ensure that they don't create a hazard and minimize risks. Best practices are more than, "that's the way we've always done it". They are: "that's the way we've always done it, and we still do it that way because….(add the results of thoughtful evaluation here). Like homemade chili, we begin with a basic recipe (knowledge) and then add various ingredients to make it better. The trick is knowing what to add before it's too hot to handle.
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Let's Not Meet By Accident
Operations Safety Program Manager
800-322-8876 ext 4835