When I wrote “Hazardous Duty” (Flying, May 2005), I was learning about missionary aviation but had never actually been to the mission field. Everything I wrote came from descriptions and accident reports written by others. That has all changed. Last month I had a chance to travel to Papua New Guinea (PNG) and Papua, Indonesia, to give my Preventing Human Error seminar to missionary pilots, mechanics and other personnel serving in that area. While I was there, I had an opportunity to fly along with missionary pilots on typical missions.
I flew in a King Air from Port Moresby to Goroka, PNG, and then on to Vanimo, followed by a short trip in a Cessna Caravan to Sentani, in Indonesia. I flew in a Bell Jet Ranger from the Interface education center near Goroka to the Aiyura strip serving the Ukarumpa missionary center. A flight in a Cessna 206 out of Aiyura gave me a chance to see some of the mountain airstrips in that area. At one point we landed at Owena at an elevation of 5,200 feet. It was a rough 1,200-foot strip with a 15-degree slope located on the side of a mountain with a vertical cliff at the top of the strip. The strip chart noted that it is “slippery when wet.”
Later I flew out of Sentani on a typical five -leg flight in a Cessna 185 with Al Gingerich, the program manager and chief pilot of Tariku Aviation. We landed at a short grass strip with considerable water (more like a small lake) at the midpoint. At another village we had a clear approach over a small cliff to a dry, level strip which then went up a fairly steep hill, requiring almost full power to reach the flat parking area at the top. Before we took off, villagers stationed themselves down the hill, which was invisible to us, to make sure it was clear, and removed a dog that was sitting in the middle of the strip. Another 1,200-foot strip required a steep approach over tall trees.
As I flew with these pilots, I learned that there are no weather reports or forecasts available. They can access satellite photos on the internet, but they don’t show much because it is generally cloudy, especially in the afternoon. The aeronautical charts note “Relief Data Incomplete” and have large areas where it says “MEF (Maximum Elevation Figures) Indeterminable,” or “MEF Believed Not To Exceed 12,300 Feet.” There is only one instrument approach at Sentani for the entire area.
As I observed these pilots in action, safely conducting flights in conditions that would give pause to even the most foolhardy individual, I noticed some common elements that might be worth considering for the typical general aviation pilot. First, I noticed their strict adherence to procedures. Even though many of these individuals had been flying in that area for years, I didn’t observe any complacency-any tendency to skip a step or hurry through a preflight inspection, even though there could be a lot of temptation to cut corners.
For example, fueling is done from barrels. Due to heavy passenger and freight loads, they typically don’t carry any extra fuel beyond what is needed for the planned flight with appropriate reserves. On my flight in the Cessna 185 we had some minor changes, with unexpected passengers at our first stop who wanted to go to a landing strip that was on the way to our second destination. It would have been easy to brush off any fuel concerns by saying that it would hardly take anything extra, but I watched Al carefully stick the fuel tanks, take a hose to a shed, siphon some gas out of a barrel into a smaller container, and then climb up on the wing and pour the gas into the tank. Al said he was pretty sure we had enough fuel even with the unexpected stop, but just to make sure, he was going to put a little more in.
This is a good lesson for us. When unexpected winds or stops or detours have eaten into our reserves, it is easy to be tempted to save a few minutes by assuming there will be enough fuel to make it. As the missionary pilots know, it just isn’t worth the risk. Another lesson involves a specific procedure they follow if they get into a low visibility situation. In a manner similar to a ship rigging for bad weather, they will slow down and put out a notch or two of flaps. This gives them more time to respond to any obstacles and also allows a much tighter turn radius if they do have to make a sudden turn. One of the reasons they are able to function so well in such a difficult environment is that they all work together and try to help each other as much as possible. Basic communication is by HF radio. Before departure the pilot will call the destination to determine what the current weather is. Since trained weather observers are not available, the pilot has to question how high the clouds are on a mountain ridge or whether the individual can see the end of the landing strip.
Once under way, the pilot continues to check with the destination, but he will also talk with other pilots in the area. The pilots operating out of Sentani have established a sector system of VHF radio frequencies. All the pilots flying in a sector will monitor the specified frequency. They will then give location reports and keep other pilots informed on the weather conditions they are experiencing, especially at critical mountain passes.
With the amazing amount of weather information many pilots have available in the cockpit these days, it might seem like pilot reports are not so important anymore. However, we are the world’s leading expert on the conditions in the area we are flying in, so we need to keep making those pilot reports when the weather is marginal. You never know when the report you make might save another pilot’s life.
Above all, I was impressed with how I saw the missionary pilots consistently utilizing the Conservative Response Rule. When there was any question or doubt, they went with the conservative decision. Like us, they can be under considerable pressure to complete the trip, and there are many unfortunate examples of what can happen when they don’t listen to that little voice that one reader called his “safety angel.” Since I was there a commercially operated Twin Otter has crashed after pushing on into deteriorating weatherc conditions.
Like the missionary pilots, you may fly in an area where there are limited resources. Or, as is more likely, you may be operating with detailed information including the latest Nexrad, metars and TAFs right in the cockpit. In either case, all it takes is one instance when we feel too rushed to turn around or put on extra gas or wait for better conditions. No matter how many resources are at your disposal, the key is to take the conservative response unless you can prove to yourself a different response has an adequate safety margin.
