PNG Rapid Response - Work

As you know, Mark has been helping out another mission with an aircraft that was damaged during a landing. This is his blog entry to try and explain all the where, what, why, who, when questions!!

Back in the early part of 2011 in Papua New Guinea, Summer Institute of Linguistics (SIL) Aviation department's King Air B200 had a major problem with their main landing gear whilst doing some touch-n-go's. They couldn't get three green lights which indicate that the gear are in a locked down position. in the end they had to try and land and hope for the best. They managed to land safely and get the engines shut down, but as the weight of the aircraft bore down on the landing gear, the right and then left gear collapsed causing damage to the flaps, right engine nacelle, right prop and rear fuselage.

As Tyler Weaver, who is an aircraft engineer at SIL, was also a graduate of MMS Aviation, he knew about Rapid Response teams, so they approached MMS Aviation to request a team to help them with the repair. Not long after, Jim Newman, Andy Swanson and myself got ready to go to Papua New Guinea for three weeks.

Tyler Weaver with the KingAir

The RR Team: Jim, Andy & Mark

On Friday 20th January, we said our goodbyes and started our three days of travel to the other side of the world. We finally arrived in Ukarumpa, PNG, Monday lunchtime and had a chance to finally see the damaged aircraft in person and to assess the damage that we'd have to repair. Our job was to repair and replace the damaged skins and frames in the rear section of the fuselage. In total, we had to replace three frames, two skins, one stringer and numerous brackets and doublers that were attached to the damaged frames.

The King Air B200

Tuesday morning, it was time to start on the repair. Andy and I worked on preparing the three frames that would be have to be fitted first. We had to remove any parts that were going to be transfered to the new frame and try to position them in the correct place. Some of these were quite critical like the brackets that held the flying control pulleys. If they went back in crooked, the cables could bind on the pulleys and cause major problems. The best way to position them all was to install the frame in the fuselage and backdrill all the holes from the existing structure.

While we were doing that, Jim worked on preparing the fuselage by removing all of the old sealant that was on the surround skins, getting rid of any old rivet tails that were still stuck in the structure and removing anything else that may get in the way of installing the frames and skins. 

It's worth noting that as we started on this repair, neither of the skins were actually in the hangar. They had been ordered way back in November, but as they had to be fabricated by Beechcraft, they had not yet arrived. This would have hampered us as we couldn't finish the job that we went out to do. Near the end of the first week, we heard that one of the skins was in the country and getting ready to arrive. We were all hoping that it would be the bottom skin as this has to be installed before the side skin. Unfortunately it was the side skin. We had to make do the best we could and prayed that the bottom skin would arrive before we left.

Side Skin has Arrived!!

By the middle of the second week, we finally got all three frames drilled, prepped and installed into the fuselage. In some places it took quite an effort to instal the rivets, but with some ingenuity and double jointed wrists ... we got it done.

Now it was time to start on the side skin. We had to trial fit it to make sure that we got it positioned in the correct place. As you can see from the picture below, it has a complex bend running down the centre. This had to line up with the same bend on the stringers. Once we got it right where we wanted it, it was time to start drilling the hundreds of holes needed to fix it to the fuselage. One of us would be inside back drilling whilst the other two were outside ... one to push the skin tight against the structure and the other to instal a Cleco (a sheet metal holder that is spring loaded) into every other drilled hole. By the end of the second week, we had completed all that we could. The three frames and stringer were in place, and the side skin had been drilled, dimpled and countersunk read to be installed. now were were waiting on the bottom skin. Would it get here in time for us to work on it ... or would we be passing it halfway over the Pacific?

In the mean time, we helped Tyler with other locations that were damaged on the aircraft. We helped install an angle and cover plate around the R/H Wing, Outbd Flap, Inbd Track (On the back of the wing). We also helped to troubleshoot a problem with a Raisbeck wing locker.

On Wednesday of the final week, we had the good news. The bottom skin was in Port Moresby and once they worked out how it get the large panel into the Kodiac, it arrived by lunchtime. The original plan was for us to leave Ukarumpa on the second flight on that final Friday, which meant we had two days to get it all done. Thankfully, SIL decided to put on a special flight just for us on Saturday giving us an extra day. So it was time to knuckle down and do what we could in the short time that was left.

The Bottom Skin finally arrived.

It does line up ... whew!!

Looking pretty inside.

The same thing now applied to the bottom skin as to the side skin, drill lots and lots of holes (Tyler thinks there were about 3,000 rivets in the two skins), debur the inside and countersink the outside. This took a lot of time, clecos and elbow grease.

Finally, both skins were ready to be installed. Unfortnately, as the King Air is a pressurised aircraft, both skins and EVERY rivet had to be installed with sealant. This is a brown smelly gloopy substance that will stick to anything. Thankfully tyler had purchased a sealant with a 20hr working life. This gave us enough time to smear the sealant onto all the joining surfaces, and onto each rivet tail before installing them. With time running out, we made sure that we installed enough rivets to hold the sealed edges down and also enough in the rest of the area to pull the skin up tight. As you can see below, we may not have got it finished as we had hoped, but we got a lot more done than we had dreamed after finding out that the bottom skin may not have even arrived. SIL just needs to find two guys enough time to drive about another 2,000 rivets!!! 

The finished team!!!