King Katmai Flight Report

[Todd Peterson]

Now that I have returned from the Utah trip with the new King Katmai, I would like to pass along my thoughts, observations and some pictures of the new IO-550 powered King Katmai and its high altitude performance. I will break the flight test report into three or four different segments over the next couple of weeks. I will also post some pictures of a couple of back country strips I flew into while in Utah. The beauty surrounding these strips is beyond words. Unfortunately someone crashed their airplane at one of the strips I flew into during my stay in Utah. More on that later.

I would also like to say thank you to a new friend I met while staying at the Carbon County Airport in Price, UT. Larry Newby of Redtail Aviation www.redtailaviation.com, obviously has the same back country sense of adventure I do. He welcomed me to the area, was extremely helpful, and offered to show me some of his favorite (and secret) back country strips. I wanted to give him a ride in the new King Katmai as bad as he wanted one, but I had a head cold that continued to get worse, so we agreed to get together this fall. Thanks again to Larry for all his hospitality.

The trip over and back was uneventful which is always nice when you are flying behind an engine with only 11 hours TT. The things that stick in my mind the most about the flight over and back center around the power available at the higher altitudes and the fuel burn. With the stock TCM injector nozzles the engine could be run LOP at altitudes below 5,500 feet. At these lower altitudes the engine LOP is smooth with fuel consumption rates similiar to the IO-470 ROP. The problem I encountered was at the higher altitudes. The EGT spread was in the area of 100F which is way too high to give a smooth engine when LOP. This was verified with a large power reduction and some vibration when run LOP at the higher altitudes. Due to this, I ran ROP for most of the trip which produced fuel flows from 16.5 gph to an eye watering 19 gph depending on altitude and percent of power used. This gave me my first King Katmai lesson. All the King Katmais that leave our facility must be capable of running LOP at the higher altitudes when the customer picks up the airplane. My guess is most of the King Katmais will require GAMIjectors, and we will need to install those prior to delivery. It would have been much nicer seeing fuel flows in the area of 14.5 gph LOP vs. 19 gph ROP. In the long run I think the engine would also be happier with the lower fuel flows.

The King Katmais cruising speed with the 29 inch Bush Wheels ran from 130 knots to 143 knots TAS at various altitudes and power settings. At the lower altitudes I consistently saw 134 knots on 12.8 gph LOP. My impression is at altitude we should be getting 134 to 138 knots with the fuel flow around 13 to 14 gph LOP. If one wants to go ROP, the speeds will run around 144 kts. Based on this I would expect the new 300SE to have cruise speeds in the 160 plus knot range. The engine/prop combination is very smooth. I spent considerable time researching this as there have been vibration problems in the past with both the 520 and 550 engines. These vibration issues seem to center around certain props, so I was careful in selecting the one we used. I think it paid off. Take off, climb, and cruise produce a very, very smooth engine. This is the second thing I learned about the King Katmai. The engine/prop combination we selected has no adverse vibration issues which had been a real concern of mine.

The CHTs and the Oil Temp all ran in the normal range throughout the trip in spite of some pretty hot weather. With the cowl flaps closed I was recording oil temps in the 180F to 193F range most of the time. This was often with outside temperatures in the low 90's. This trip pretty much demonstrated there will be no cooling problems with this engine installation. Even during climb out on these warm days, the Oil Temp seldom ran above 190F. Likewise, the CHT's never gave me a second's worth of trouble with most of the CHT's in climb no warmer than 385F.

On the return trip I landed at Taos, NM for fuel. When taxiing out the ASOS said the density altitude was 9,100 feet. Nothing to sneeze at to be sure. After I departed I made a tight down wind departure, and by the time I reached mid field I was already at 2,000 ft AGL. The rate of climb was a staggering 1,500 fpm. I then turned directly east and just went straight over the top of the mountains. No muss, no fuss, just straight over the top. It was great. Mountains just don't have the significance they used to when you can maintain a high rate of climb at 12,000 feet.

When I arrived back at EQA the engine had 29.2 hrs TT, and I am now going to a regular AD oil. I removed the cowl for the oil change, and the engine is clean with no items needing attention. It should be more than ready for our Idaho trip in mid June.

In the next segment I will deal with the handling characteristics of the King Katmai on the demo flights I flew while in Utah. The final segments will be on the back country strips I took the airplane into, my thoughts as to the King Katmai's actual performance vs. projected performance, and some thoughts on what it takes to safely fly into and out of some of these hazardous strips. I will also announce the production schedule for the King Katmai and the 300SE.

Stay tuned...

[kwmoore]

Click here. (http://www.260sepilots.org/gallery/King-Katmai)

More will be added over several days.

[Todd Peterson]

As I previously mentioned I found the IO-550 likes a lot of fuel if run ROP and the engine I had just wasn't able to run smoothly LOP at full throttle. I therefore ordered, received, installed and have already run a flight test on a new set of GAMIjectors in our new IO-550.

Right out of the box the stock GAMIjectors cut the EGT spread from the 100 to 115F range to a spread of 50F at WOT. We still have some work to do however because the fuel flow spread is running about a full gallon an hour between the first cylinder to peak and the last. With all that said the engine will now run smoothly LOP at 8,000 ft with WOT. The comparison between LOP and ROP is interesting even at this point. Both sets of numbers on the King Katmai were derived at 8,000 ft with WOT and 2,500 rpm. The cowl flaps were closed.

LOP...Cruise speed was 135 kts TAS at 13.6 gph. The CHT's were #1 373F, #2 368F, #3 298F, #4 340F, #5 340F, #6 298F. I didn't really stay here long enough to get a totally stable temp on the cylinders. The CHT's were still coming down a little when I terminated the test. Oil temp was 170F.

ROP...Cruise speed was 143kts at 19.7 gph. The CHT's were #1 376F, #2 387F, #3 318F, #4 377F, #5 374F, #6 338F. The CHT's were still increasing a little when I terminated this test. Oil temp was 178F and still very slowly creeping up.

If this doesn't make a good case for LOP then I don't know what does. For what I think is a relatively small increase in speed you're burning a lot more fuel, you have a lot more combustion byproducts to clog up the rings and valves and on top of everything the engine is running hotter.

I will be fine tuning the GAMIjectors over the next week or two and I will keep you posted on the final results.

[Todd Peterson]

I just finished the flight test with the replacement GAMIjectors and things are looking good. The fuel flow spread from first to last peak has narrowed from one gallon per hour to .5 to .6 gallon per hour. The engine will now run very smoothly at 50F LOP at 8,000 ft, WOT at 2,500 rpm. The guys at GAMI said they may try to fine tune it a little more but weren't sure if I needed it. They said the big thing is a smooth engine while LOP. I would also say the power loss with this set up is relatively small with a EGT spread of 40F.

At 8,000 ft, WOT with 2,400 rpm the cruise is 131 kts TAS on 12.7 gph. At 6,500 ft the cruise with WOT at the same 2,400 rpm is 133 kts TAS at 13.5 gph. While the cruise speed came up a few knots when running 2,500 rpm I liked the sound of the engine kind of loafing at 2,400 rpm so that is probably where I will run it. This now meets my expectations. Overall the King Katmai is now cruising in the speed range of a standard Skylane on a similiar fuel flow. This while carrying those huge 29 inch Bush Wheels that give one the capability to land almost anywhere. That is pretty efficient in most anyone's book.

I have also decided to remove the bubble side windows on our Katmai. These same windows caused a good 4 kt speed loss on a C185 located at a nearby airport. While I like them they are not worth a loss of cruise speed so we will be going back with the standard side windows. If one looks at the window cross section the exposed area is about the same size as a nose wheel tire. I'll let you know the results.

[Todd Peterson]

My first mini-adventure came on the day of my arrival. I decided to check out some back country strips before it got dark as the air was fairly calm and I had an hour or two of daylight left. I heard the strip at Mineral Canyon was beautiful so I decided to go there first. Finding the strip presented little problem, and I over flew the area checking the surface wind and runway surface. Everything looked good so I proceeded with the approach. As the strip is relatively long at 1,800 feet, the tendency is to let your guard down a little. To be honest, after flying in and out of 200 foot jeep trails this strip looked like an international airport. One has to remember though this strip is in the bottom of a canyon, it is very soft, there is no wind, the density altitude is well over 7,000 feet, and after take off you need to maneuver down the canyon as you climb. I began the approach by slipping below the canyon rim and slowing to 60 knots. At 60 knots I had enough excess speed to deal with any turbulence I might have encountered, yet the King Katmai was slow enough to dump off the extra speed quickly as I neared the landing strip. The approach itself was totally uneventful as I followed the river enjoying the beautiful scenery of the canyon and river. As the strip got closer however, I started to focus on the task at hand. All my attention was now on the strip and setting the approach up properly. As the strip came into sight, the King Katmai was comfortably slowed to 50 knots with just a hint of power. The approach attitude was still completely flat, and I had a very good view of the dirt strip next to the river. As I got closer I slowed to 45 knots and took one last look down the length of the strip to check for obstructions, wind, and get one last look in general at the strip’s condition. Everything looked great, and I must admit it was a little exciting even though the length presented no challenge at all. There is just something wonderful about lining up on a strip of dirt next to a beautiful river in the bottom of a canyon. You’re all alone in the beautiful outdoors with nothing but your skill and a great airplane. It does not get any better than this.



Now I’m on short final, the speed is coming back to 45 knots, and I’m searching for just the right spot to touch down. I see a good area about 100 feet beyond the threshold, and I begin the flare. As the speed comes back to 30 knots those really, really big Bush Wheels start to roll, and I’m down and stopped in about 300 feet without the need for heavy braking. As I begin the turn around I now have time to once again take in the absolutely spectacular scenery and shoot a few pictures. The sun is setting, and the top of the canyon is still bathed in sunlight with the lower reaches now in the shadows. It is just impossible to explain how this touches the depths of one’s soul. As I taxied back enjoying the sights I thought how wonderful it is to be able to visit this remote area in a totally safe manner. I could not stay long however, as the sun was getting low. I taxied to the end of the strip, turned around, took one last look, and pushed the throttle forward. The King Katmai was off in short order and, even with the high density altitude, I immediately had a ROC that exceeded 1,300 fpm. As soon as I lifted off I started a gentle turn down the canyon to begin the climb back up to the top. I quickly climbed above the canyon rim and headed back to Price, UT. With the sun beginning to set, the rock formations, colors, and shadows all combined into an unforgettable view.



Here are some random thoughts about this first strip. Even though the Mineral Canyon strip is relatively long, you cannot become complacent. Anyone who takes back-country flying lightly will undoubtedly have a problem at some point. You have to be on guard every minute and totally focused on the task at hand. One of the traits I find most helpful in back-country flying is the same trait that helped me with flying airshows. That is the ability to focus on the task at hand and tune out all the distractions. You also need to be able to fly the airplane safely with a minimum amount of attention. It’s just like shooting an instrument approach. If it takes 90% of your attention and skill just to fly the airplane, there isn’t much left over to deal with communications, weather, missed approaches, turbulence, etc. If you do not have the skills, precision, or airplane to do this kind of flying safely, wait until you do. Unfortunately a Piper just went into the river at this same strip.



With the King Katmai back at Price and my cold getting a little worse, I headed back to the motel. I thought this was a good day. I left Wichita, KS late morning and comfortably cruised over the Rocky Mountains arriving in Price, UT late afternoon. I even felt good enough and had enough of the day left over to fit in some back-country time. Tomorrow will be great also as I plan on hitting a few more strips in addition to the demo flights I have scheduled.

[kwmoore]

Mineral Canyon photos here. (http://www.260sepilots.org/gallery/album01) :cool:

[Todd Peterson]

The following morning dawned cool and clear. It looked to be a good day although the winds and temperature were forecast to increase later in the morning. In short order two pilots arrived that wanted a ride in the Katmai and we began to chat. I don't think it is an exaggeration in saying everyone at the airport really liked the looks of the Katmai. At times there were two or three pilots just standing there looking at it and saying nothing. The airplane is truly magnificent for the back country types.

We loaded up for the first ride and I had not really decided where we would go until just after take off. I had seen the strip at Mexican Mountain the day before and it looked like it would be a lot of fun to visit so I headed off in that direction. The strip appeared to be about 1,100 ft long, the density altitude was just under 8,000 ft and the surface looked to be somewhat soft. There was no wind to help either. The round trip took less than an hour and it was just long enough to enjoy the cross country capability of the Katmai and its autopilot. The Katmai with the 29 inch Bushwheels still has the cross country speed of a stock C182 and it is heavy enough to take the bumps well. We slid over the top of the ridge and proceeded to descend into the valley. While we hit a few bumps the approach proceeded well. I had never been in this strip before so it was fun for me also. I dropped the flaps to twenty degrees, slowed to about 60 knots and then we just enjoyed the approach. The view was spectacular and in due course the strip slid into view. As I approached from the east we needed to maneuver a little to get lined up with the strip as the rocks came out into the final approach path a little. Speed on short final was slowed to 50 kts and then we continued to slow into the mid 40's as we came up on the strip. Before you knew it the tires started to roll and we were stopped. What a beautiful sight. We looked around and snapped a few pictures. It was just great. As I had a second ride to give we decided to depart and head back. The take off was a non event. I let the speed build far more than needed for lift off and we still used less than half the strip. Once off we started an immediate turn down the canyon and began to climb out. The climb was once again near spectacular and we quickly topped the canyon rim. If memory serves me correct I think my passenger even commented at some point that the IO-550 powered King Katmai might be just a little overpowered at the altitudes we were flying.

Once back at the airport I loaded up the second gentleman and off we went. Back to Mexican Mountain to repeat the landing. It went just as well as the first time and I had a little more time to relax and enjoy the sights. The scenery was just as spectacular and I promised myself I would go back just as soon as time permitted to spend some quality time there.

Once back at the airport we relaxed and talked about airplanes and flying for a while before they departed. It had been a great morning. I don't know how anyone could have enjoyed it more. Well, me not having a cold would have helped I guess.

The following day I arrived at the airport for an early morning departure. I had planned on visiting a few more back country strips on the way home. On take off the oil pressure needle had been sitting just about one needles width below its normal position and I had been watching it from the start up on. I decided to land and take a look in the engine compartment just to make sure everything was okay. I thought the slightly lower oil pressure was just a little junk under the oil pressure relief valve but I wanted to look everything over to verify I did not have a problem. Once on the ground I gave the engine a once over and all was as it should be. I found nothing wrong and while standing there looking at the airplane I decided between the cold and the cold medication I had no business going into some of the strips I had planned to visit. I just wasn't sharp enough. I hated the thought of passing them up but good judgement prevailed and I headed straight back home.

A few random thoughts about the demo flights and my talk with the local pilots. Everyone that rode in the airplane thought it was great. The ability to get in and out short and safe combined with the cross country capability really won the day. In addition it just plain looks cool. The local back country pilots took to the airplane immediately and I will head back this fall to do some flying with them. All in all the Katmai could not have been better or made me happier.

[joejenie]

Yes, Todd, the first rider did tell you that the plane was overpowered!:D I think the 260 SE will have plenty of power. The only reason I can see getting the 300 SE is really short strips in the mountains or because you have more money than you know what to do with.

That was a fun ride by the way and I look forward to camping by that strip.

One thing you didn't mention is when you got back from the two demo flights that one of the idiots signed a contract for his new Katmai as soon as his demo ride was over! That's how you know you have a great plane!;)

Joe Rainey

[Squeege]

the two demo flights that one of the idiots signed a contract for his new Katmai as soon as his demo ride was over!

WHAT? :confused: Only 50% signed after the demo?

The other 50% now knows what he/she is missing.

Louise

[joejenie]

Don't worry Louise! The 2nd person plans on buying a 182 and putting on a Kanard wing as soon as he can get his commander sold! So Todd's batting average for that weekend was pretty good!:)