This is a two part story. Lately some of our supporters who are pilots or more technically inclined have been asking hard questions about the flying techniques and challenges that we face each day as pilots serving in PNG. To meet their request we have produced this story with a more technical theme. We also recognize that some readers are less inclined to know about the technical issues and are are more interested in the stories about the work and the people we encounter. Part II of this story is about people. Click Here to jump to Part II
Story by Michael Dupuis. Photos by Judith Dupuis and Michael Dupuis
A few weeks ago, I achieved a milestone as a PNG pilot. After completing a couple of days of training as some of the most challenging airstrips, I demonstrated sufficient competency to have some airstrip and landing weight restrictions lifted. Despite having many hours flying a Cessna Caravan in Africa, I had little experience on airstrips as complex as the ones in PNG so I had to fly for several hundred hours with restrictions. The immediate effect my new unrestricted status was to open up many more airstrips where I could operate. It would also mean that I will be carrying payloads that are at the upper limit of what can be safely carried into short or confined airstrips where aircraft and pilot performance is crucial.
One such airstrip is Megau, in the Western Highlands about 25 minutes from Mt. Hagen. at 3200ft above sea level, it is located about half-way up the side of a mountain inside of a large bowl shaped valley rising to about 7500ft. On final approach, the aircraft is aligned directly at the mountain and the bowl-shape makes it more and more difficult to abort the approach the nearer the aircraft gets to the airstrip. To complicate matters, the airstrip has a small but nearly flat landing threshold followed by a gradually rising slope which gets steeper, higher up the airstrip. At the very top, the slope is very steep, making it difficult to turn around. When heavy, it takes plenty of power to get up the last 50 meters from the parking area. Landing uphill certainly helps to shorten the landing roll which is why the airstrip can be so short The average is 8.1% but the top is closer to 12%. Taking-off downhill helps too but with only 420 meters available, it is not enough to carry a full-load with the Cessna Caravan.
This was my first unsupervised landing at Megau. I was aware of the challenges, having flown there a few times with a very experienced PNG pilot, Capt. Irwin Hodder to guide me. I learned that the most important aspect of landing at Megau is flying a consistent circuit pattern reaching very specific altitudes and descent rates or “gates” during the approach. This is particularly important at an airstrip that is situated up the side of the mountain because there are no usable landmarks or features to help visually guide the base turn or final approach. The ground drops rapidly beneath the airstrip, resulting in a cliff-edge at the start. It feels like the landing surface is suspended in mid-air until the last few moments before touch-down. The constantly changing slope of the airstrip adds to the visual illusion of being very high during the approach making it even more important to establish a consistent decent rate of 500 feet per minute while maintaining a constant final approach speed. Failing to do either will result in a very hard landing or possibly not making it to the airstrip at all. If the approach speed or sink-rate are not established and stabilized early on final approach, a go-around is prudent. After passing the committal point on final approach with several hundred feet yet to descend, an attempted go-around will result in an inevitable crash into the mountain. The only redeeming factor is that a landing too far down the runway will only result in crashing into the trees at the end of the airstrip rather than off a cliff or over the sides.
When I arrived overhead the airstrip, some cloud was lingering at the circuit pattern height as well as one small cloud that was sitting right on the end of the runway, extending out in front to block the approach. I advised Madang Flight Service that I would circle for up to 15 minutes using some “holding fuel” with the hope that the early morning sun would quickly burn off the cloud. At the 14-minute mark, the cloud on the runway was transformed to a faint mist so I began my approach with a slight modification, starting about 100 feet low to stay under a thin patch of cloud that was encroaching on the downwind leg. I determined that I could still fly the “gates” even with the slightly lower circuit pattern, so I decided to continue with my attempt at the landing. Due to some cloud close to the base-leg and the lack of visual cues I turned to my final approach leg, slightly off heading. I was able to correct it quick enough that I did not have to go-around at that point but I was ready to abort the landing if I did not have the aircraft stabilized well before the committal point. From there, the remainder of the approach was “by the book”. I touched down where I planned and whizzed by a large group of bystanders who were gathered close to the bottom of the airstrip along the edge near the touch-down point. After landing, I had to add some power to get up to the parking area near the top of the airstrip. From there, my take-off would start after a very short taxi uphill about another 30 meters. I would have to taxi up the steepest grade at the airstrip and turn around on some longer grass that was now glistening with droplets of dew. Wet grass slows acceleration. I was thankful that the sun was now shining brightly.
I found it very odd as I climbed down the ladder from the cockpit that there was only a few people waiting by the small parking area. None of them appeared to be ready for a flight. I asked one man where my passengers were and he said they were waiting at the bottom of the airstrip. A couple of minutes later a man who had run the length of the airstrip and gasping for his breath, asked me to taxi the aircraft down to the bottom of the airstrip and pick up the cargo and passengers. Speaking in Tok Pisen, I explained, as well as I could, that I could not move the aircraft. With the wet grass and steep slope, it was unlikely that I could get back to the top for take-off unless the aircraft was very light. It took some tactful discussion and a bit of firmness and I was able to convince a reluctant group of men to carry all of their cargo up to the aircraft.
A typical flying day with MAF can have up to 10 sectors. Delays in loading and departing can cause a pilot to carry a great deal of stress. Thunderstorms often engulf the home base of Mt. Hagen in the late afternoon making it difficult, if not impossible to get home for the night. The delay at Megau would extend my ground time by close to one hour, putting me well behind schedule.
While the cargo was being hauled from the bottom to the top of the airstrip, passenger Mel Kroenert offered to show me some of the construction work that he had been doing next to the middle portion of the airstrip. (See Part II) A house had been built for a medical worker using materials that had been flown in by the MAF Twin Otter only one week earlier. It was nearing completion and would provide accommodation for a medical staff-member for the small medical clinic which was completed about a month earlier.
When we returned to the aircraft the quantity of tools, ladders and assorted cargo was far more than expected and I was doubtful that I could safely carry the 900kgs of passengers and cargo that had been hauled uphill. This was about 300kg more than I was expecting. I knew before I landed that I had a penalty of a 212kg and I had carried a bit of extra fuel due to the risk of lingering morning cloud. A penalty means that I must reduce the payload so the aircraft is at least 212kg below maximum take-off weight. This does not take into consideration that fact that the grass was fairly long requiring a further reduction of about 200kg. The most that I could safely and predictably get airborne was about 750kg assuming that I was gauging the surface
conditions correctly. It was still a bit more than I had anticipated. If the aircraft was too slow accelerating, I would have no way to stop and try again at a lower weight. The steep slope requires an abort-point little more than a few seconds after the aircraft starts rolling. Beyond that point, any attempt to stop would likely result in the aircraft going off the cliff at the end of the runway. Wet grass and a steep downhill slope do little to aid in the braking force required to stop more than three tonnes of aircraft, passengers and cargo!
More time was spent between the passengers debating what would stay and what had to go. Power tools and the passengers’ personal effects were the priority as was a generator. Several large bags of peanuts and some roasted pig carcasses would have to stay behind, even though they were gifts to the workers for their time in Megau. After weighing and loading each item and strapping down the generator in the back of the cabin, we were ready to board the aircraft for a maximum effort take-off. The take-off today would be my first at this airstrip with a maximum allowable load. In every way, the flight today was testing everything to my maximum limit so I said a brief prayer of thanks to the Lord for his guidance and began to taxi up to the top for take-off. It required more than double the usual power to get up the hill and I had to be especially careful as I turned around to avoid digging in a tire into the soft ground.
I carefully picked out my airspeed check point (ACP). This would be the best indication of whether or not the aircraft would make it off the ground before the end of the runway. I looked for a tree, bush or marker cone to identify where I believed that I would reach about 42kts or 70% of the speed needed to fly. At steep and short airstrips, the abort point (APT) is often ahead of this point instead of closer to the middle of the runway. Today, the ACP and ABT were nearly co-located. If the acceleration was too slow in the first 100 feet of the take-off run, I could still safely abort the take-off. Beyond that point? …..well, don’t ask…
Trying to apply maximum power before releasing the brakes was difficult. The grass was too slippery at the top where the runway was partly shaded. I let go the brakes and we began hurtling down the airstrip like a runaway freight train. Acceleration was a bit sluggish compared to the light-weight take-offs that I had done under supervision but the steep slope made the acceleration rate quick exhilarating. We were still on the ground as the aircraft dashed by the usual lift-off point that I knew at lighter weights. When the aircraft was finally airborne we still had about 15% of the runway remaining. We went over the edge of the cliff climbing skyward rather than tumbling earthward. The whole effort was executed by the book but I still used the maximum runway allowed by regulation. There was no room for error. Had I attempted to take-off with all of the intended cargo, I would not likely be around to write this story.
MAF has plenty of experience with these types of airstrips. The training we receive as pilots is second to none; it has to be. The quality of airstrip data, performance calculators and penalties has been worked out and proven time and time again. That is one reason why MAF-PNG has been able to continue operating to the MAX in one of the most difficult places in the world to fly. Sadly, it is not possible to say that MAF has not had any accidents however, the organization has an excellent overall safety record. In fact, it is an outstanding safety record for bush-flying that is envied by airlines and charter operators working in far less challenging conditions. I believe that it is due to the prayers support of MAF supporters world-wide. Without this support, MAF could not reach out with the love of Christ to so many in need in places like Megau. Thank you for your continued support!