The "Dirty Harry" Principle

by Paul H. Davis
Reprinted with permission of FAA Aviation News

There's a line from an old "Dirty Harry" movie - I'm sure you know the one I'm talking about - where Clint Eastwood, as Inspector Harry Callahan, makes the now famous assertion that "a man has got to know his limitations." Well, nowhere is that concept truer than in general aviation.

The secret to avoiding an aircraft accident is knowing what and where those "limitations" are and knowing how not to exceed them. For every flight there is a LINE that when crossed may result in an aircraft mishap. I say "may" because sometimes we cross that line and then retreat behind it in time to avoid the mishap, or maybe we're just fortunate enough to wind up wandering back behind the line; but the potential for a mishap is still there.

There are three major elements for each flight: the pilot, the aircraft, and the environment. The first two of these are subject to limitations. The third usually imposes limitations on the other two. Every year hundreds of aircraft accidents occur simply because the pilot chose to, or inadvertently exceeded, these limitations. What might cause a pilot to do this? Let's look at a few reasons.

First off, many pilots either don't know, or have forgotten, the limitations of their aircraft and also may ignore pilot limitations for themselves. The regulations require that aircraft operating limitations be carried on board the aircraft, but how many general aviation (non-part 121 or 135) pilots regularly take time to refresh themselves with this information? Do you know all the applicable speeds for the aircraft that you fly? When was the last time you went out and practiced doing various types of stalls? How about the maneuvering speed for your aircraft or the weight and balance limitations? Do you remember how much usable fuel your aircraft is capable of carrying or what the ACTUAL fuel burn rate of the aircraft engine is? When was the last time you went out and practiced ground reference maneuvers or short and soft-field takeoffs and landings with a CFI (if you're rusty, of course) except maybe during a flight review? Now are you starting to get the picture? Many pilots just don't do much training until it becomes mandatory, but why?

One of the reasons I have found for pilots avoiding regular training is that some feel like they just don't need it to be safe pilots. Others are quite content to simply fly from point A to point B and may actually be uncomfortable performing training maneuvers. The bad thing about this is that the less training maneuvers are practiced, the more uncomfortable they may become because of lack of proficiency. Many pilots who get to this point, and I never have been able to figure this one out, are very reluctant to contact a flight instructor for some good refresher training.

Then, there is the weather. This is an area of flying where it is very easy to exceed limitations. If you don't believe it, check out the National Transportation Safety Board (NTSB) aircraft accident report pages. They're chock full of mishaps that occurred because the pilot either didn't know or chose to exceed environmental limitations. Continued VFR into IFR conditions remains one of the leading causes of general aviation accidents. What causes pilots to exceed weather limitations? Well, sometimes it's the need to be at a certain place at a certain time, or maybe the pilot feels pressure to make the trip anyway because of the desire to not look bad in front of passengers. You can be assured that whatever the reason, in retrospect, it's not worth dying for, yet these types of accidents continue to occur all too frequently. There are plenty of other reasons that pilots exceed limitations. Remember those five hazardous attitudes: Macho, Anti-authority, Invulnerable, Resigned, and Impulsive. You can be sure that these have a pretty big influence on pilot decision-making and have been responsible for more than a few mishaps.

So what can we do to stack the deck in our favor? The best place to start is with a "Personal Minimums Checklist" (PMC). As far as I'm concerned it's one of the best concepts the FAA ever came up with. The Personal Minimums Checklist helps pilots to assess their piloting skills and piloting resources to determine if they are properly trained and equipped to make any flight under given conditions.

The pilot should also set up a personal training program or agenda with the aid of a local CFI/Safety Counselor. Most CFI's and pilot examiners that I know are available for any questions or training concerns a pilot may have. They would be more than happy to sit down and help set up a personal training agenda. Most airlines mandate training programs for their pilots at least semi-annually. What makes us (general aviation) think we need regular training any less than they do? If you have an opportunity to attend Cockpit Resource Management (CRM) training and hazard awareness training, then by all means do so. If there are no such programs available to you, call your local FSDO Safety Program Manager or Aviation Safety Counselor and set up a program. They will be more than willing to accommodate the pilots at your airport.

Analyze yourself, the airplane, and the environment, thoroughly. Find out where that limitations line is and then make sure you are operating comfortably behind it at all times. I've been criticized more than one time for repeatedly "what ifing" a situation, but that's all right, because "what ifing" has ultimately saved me more than a little bit of grief quite a few times, and I'm sure even saved my life somewhere along the way.

One other thing I need to mention. Over the years I've learned that we sometimes exceed our limitations because we don't want to disappoint our passengers. We all know what happens when we meet our friends or loved ones at the airport on a beautiful spring day for an enjoyable sightseeing flight only to find: a puddle of oil under the airplane, a dead battery, or broken starter. The urge to replenish the oil, jumpstart, or handprop the airplane is overwhelming. Don't do it! Call the owner or local mechanic and have the airplane fixed properly. Your PMC should have stopped you right away, along with Federal Aviation Regulation Part 91.7 (Civil Aircraft Airworthiness).

What about the unforecasted weather that moves in when the original forecast called for "clear and a million?" I have found the best ways to deal with this situation is to sit down well before the flight and incorporate my forecast weather limits into the Personal Minimums Checklist. In other words, I draw my limitations line and then with feet firmly planted on the ground (usually the day before the flight) I inform my passengers as to conditions I will and will not accept as being satisfactory for the flight. A good example of this is the fact that I set wind gust limitations for each airplane that I fly. I might set a higher wind gust limit for a larger aircraft that I know will accept the higher gust factor more comfortably, especially when I am flying near mountainous terrain. I also review mountain flying techniques for that area and am well familiar with all the local terrain features and hazards well before I make the flight. I have found that passengers respond to this method very well and are much less disappointed and more understanding when they know ahead of time that you are adhering to your PMC and have their safety and well-being at heart. It also lends credibility to your being a safe pilot for those who have the opportunity to fly with you.

The FAA has a form for the PMC that you can download right off the Internet or check with your local FSDO and the Safety Program Manager will be happy to share copies with you. While you're at it, be sure to attend local FAA sponsored safety meetings and "WINGS" seminars at your airport. If your airport is not having any, call the FSDO Safety Program Manager and ask to be included on their Aviation Safety Meeting Schedule.

Remember, the more you practice good risk assessment with your PMC, the better you will become at learning all your limitations. You will become more confident and better at making good decisions and that friends and fellow pilots will make the skies safer for everybody.

Happy Flying....

Paul H. Davis is with the U.S. Coast Guard, but is an FAA Aviation Safety Counselor in Alaska. He is a commercial pilot with Instrument, Multi-engine, Single-engine, and CFI ratings.