Peter

About Peter

plbarrett.com | Certified Flight Instructor (Single & Multi-Engine, Instrument, and Advanced Ground) | Commercial Helicopter

Flying & Performance – First report   Recently updated !

This entry was posted in Flying on by

As of today, I’ve logged 7.3 hours in the aircraft. The airplane is flying well, but there have been some maintenance issues. So lots, to cover. We’ll cover things one topic at a time. First, lets take a look at engine performance so far.

First up, CHTs. Unfortunately, I did forget an SD card on a couple of my flights, so they are not all represented here. But we’ll start with first flight on June 13. You can see the maximum CHT reached is 383 after takeoff. The spread between highest and lowest is 52 degrees. Cylinder 3 is running the hottest – with the cylinder directly in front of it, running the codes. There is only 9 degrees between the two cylinders (2 & 4) on the left side of the engine.

I missed logging the date from a 1.1 hour flight on the 16th. So the next flight shows the engine after it has 2.2 hours on it. I have also added some metal foil tape to cylinder 1 to try to decrease its airflow, and increase airflow to cylinder 3. The CHT spread is now 41 degrees but between cylinder 3, and cylinder 4. The spread between 1 & 3 has dropped to 23 degrees. I also added some tape to cylinder 2, which was a mistake. All in all these numbers are really really good for an engine during break in!

I did two flights on the 18th, and you can see the CHT trend remains the same.

I missed the SD card again for a flight on the 19th. I did do a compression test after the flights on June 18th. Cylinders 1, 3, & 4 got 78/80. And cylinder 2 scored a 76/80. Removing all the bottom plugs showed them to be mostly dry, with cylinder #2, showing a little bit wet.

Now the plane went into a maintenance phase to correct several issues, that I will cover later.

Here is the CHT data from today, July 2nd. CHT max is 353. The maximum delta is 35 degrees. Cylinder 1 to 3 is now 17, and Cylinder 2 to 4 is 5 degrees. The numbers are all trending in the right direction. I’d like to get CHT 3 a bit lower, so I’ll play with that. Either way, what I take from these numbers are 2 things. First, this engine is cooling very well. Every flight has been maximum power for takeoff and initial climb, followed by periods of 25 squared or 24 squared. The engine has been run hard, and she’s running very cool! Second, as the CHTs are coming down, this is a good indication that proper break-in is occurring.

Now lets take a look at oil temps. I’m not going to do as many graphs for this one, as oil temps have remained solid, and are not indicative of break-in. Here is the latest flight. Oil temp basically between 176 and 189. 180 is optimum, so oil temps are right where I want them. Angle valve engines are known for running cooler CHTs and hotter oil temps. For this reason, I installed the bigger oil cooler, and so far that decision seems to be good all around. This baby shouldn’t have any problems with temperatures!!!

I have some preliminary speed data, but all the while I’m screaming around rich of peak for engine break-in, they should be taken with a grain of salt. Here are the speeds from a flight where I did the airspeed box.

At 25 squared I was getting about 181 to 184 KTAS, and at 24 squared I was getting right around 170 KTAS.

I have done a couple of stalls, and collected that data. Here you can see a stall series I did on June 18th. Stall with full flaps was at 53 KTAS, and 48.5 KIAS. I’ve only done a couple stalls, really just to establish safety of flight for the landing pattern. I will return to much more in-depth stall testing, when I’m comfortable that the majority of engine break-in is complete, and going to lower power settings will not harm break-in.

Ok. Now some fun photos and reports.

Some views from the cockpit on June 18th. It is such an absolute thrill to have my own airplane in the air!

 

And from today, July 2nd.

Last note on in-flight performance. Between the last flight on June 19th, and today’s flight on July 2nd. I did a lot of maintenance items, which I will cover in a subsequent post. I did do the on-ground configuration of the auto-pilot. So today was a good opportunity to give that an initial test. There are some procedures for doing in-air setup. Mainly centered around gains and torques. Today’s testing seemed to show everything working perfectly. I did heading and altitude holds, as well as turns, climbs, descents and even let the flight director pick up navigation to a direct waypoint. I don’t think much, if anything, will need to be tweaked in terms of gains, or torques. Auto-trim is currently turned off, so we’ll circle back to that at a later time too.

 

First Flight!!!!   Recently updated !

This entry was posted in Flying Maintenance on by

The first flight of N22UP was on the evening of June 13th out of KDMW in Westminster, Maryland. My planned flight was 45 min of basically engine break-in. I was fortunate enough to be assisted by Mike Bullock flying his RV-7 as a chase plane, and Mike Rollison running a ground safety vehicle.

I spent the day replacing access panels and doing another final inspection on the aircraft. I fueled up with 13 gallons per side and did some basic flight planning. My intent was to take off, climb to 4 or 5000 feet and basically orbit the airport at 25 squared for engine break-in. My transition training instructor, Bruce Bohannon, had really focused my attention on oil pressure and CHTs – so my goals was to make sure I had the former, and I managed the latter. I was expecting high CHTs due to initial engine break-in. Mike Bullock and I did a final walk around of the airplane, then we took a flight around the pattern in his plane to recon potential off field landing locations in the event of a low altitude engine failure. Once back on the ground, it was time to jump in the plane and take it flying.

I was cautious on takeoff – easing the power forward I kept it nice and straight. She shot down the runway and was airborne in no time. I pulled power back quite quickly and was in a rapid climb in no time. My engine temperatures stayed excellent throughout the flight. I did a little slow flight, a full flap power off stall, and then returned to the airport for a low pass followed by a long wheel landing.

Afterwards, review of the airplane reviewed the following squawks. There was some oil in the cowl. Some we suspect from the breather tube, but there also might be some leaking from the prop oil return line. The nose seal also might have a small leak. The propellor governor maximum rpm will need to be adjusted down. There is some rubbing of the cowl on the horizontal induction snorkel. All in all – a great first flight!

I will post more with engine data analysis later!

Video on Instagram

Airworthiness Inspection!

This entry was posted in Final Testing on by

Today was the big day. My DAR, Darrel Watson, arrived via his Kitfox at 9am. We also had an FAA ASI (Shaun) who needed to shoulder surf one of his inspections on site. Turns out that Shaun was also a Marine – and Darrel was Navy. Three veterans meant there was some good story telling on top of the very thorough inspection Darrel performed. Darrel noted that my build was one of the cleanest he’d ever inspected and noted in particular that my firewall forward and sheet metal work was well done. HIs comments were a huge confidence boost for me. Having built it, i’m aware of almost every ding, dent, and mistake!

We started out with paperwork, then moved to compliance – data plate, placards, log books and the like. With that out of the way Darrel started firewall forward with all of the engine controls and the moved to the rest of the aircraft.

All said and done, N22UP now has a special airworthiness certificate and is cleared hot to begin phase 1 flight testing. As a bonus my operating limitations allow me to do either the 40 hours or the task based flight testing. I plan to do the latter. I spent the remainder of the day putting inspection panels back on the aircraft and doing another inspection of my own as I went.

As a final note, I would definitely recommend Darrel as a choice of DAR. He was very cordial and helpful in working through the AWC application process. He did a thorough inspection – a good thing when you are looking to strap the plane on and take it flying!