Archive for November, 2014

Hobbs 24.5 – Flying and Maintenance

November 30, 2014 Leave a comment

Sunday Nov 30, 2014

I had the chance to fly several times over the Thanksgiving holiday weekend and the Hobbs is inching up toward the magic 40 hr mark. Today was mainly a maintenance day since I needed to pull the cowl for an inspection. It has been about 12 hours since the last time. Just as well since it was cloudy today and it even rained a couple of times in Corona.

While I had the lower cowl off I adjusted the idle mixture 1/2 turn richer. I did this after reviewing my engine data over several flights which showed a very low fuel flow at idle on the ground and in the air during simulated engine out tests. According to Don at Air Flow Performance the idle fuel flow should be about 1.2 gph at idle. I was seeing as low as 0.5 gph.

While I had the lower cowl off I drilled out the three rivets that hold the air deflector in front of cylinder #1. This  cylinder typically has run about 20 degrees hotter than the average of the other three on climb out and 12-15 degrees hotter during cruise. I am taking it off to see how much effect it has. This photo shows the #1 cylinder after the air deflector was removed.



After inspecting the engine visually and finding no leaks or loose hardware I reinstalled the cowling and took the airplane out for a couple of trips around the pattern. After the mixture adjustment I am now seeing about 1 gph fuel flow during idle. That is close to my target. I’ll fly with that a couple of hours and see how it runs. I am hoping it improves the smoothness of the engine at idle when it is hot. I need to wring it out to find out.

The temperature of the #1 cylinder dropped significantly after removing the air deflector. The temperature of #1 was about 10-12 degrees below the average of the other three during climb out. That’s a reduction of about 30 degree F. More than I expected. So it tells me I need to trim about 2/3 of the exposed area of the stock air deflector and reinstall it. That should make all cylinder temperatures match within about 10 degrees F which would be great.

Categories: Flying

Hobbs 16.3 – Continuing Flight Tests

November 9, 2014 Leave a comment

Sunday Nov 9, 2014

The hobbs meter hit 16.3 hours today. I am approaching the half way point of the flight test phase. Here is a short video of the view from inside the cockpit while dodging puffy clouds during my flight last week.


Here is another video taken today while returning to KAJO from the flight test zone and landing.

Categories: Flying

Installed Main Gear Fairings and Wheel Pants, Koger Shade

November 2, 2014 1 comment

Sunday Nov 2, 2014

Yesterday was cloudy and raining. Not a good day to fly. So I installed the main landing gear leg fairings and wheel pants and put the cowl back on. Time to see how fast this thing really flies.


I also installed a Koger sunshade inside the canopy. This will cut the heat when the sun is really blasting overhead and reduce the risk of sunburn.


This morning it was cool and calm at the airport. There were puffy clouds on the horizon but not directly overhead. I launched the airplane for the test area. Here is a shot of KAJO as I departed to the east.


It was one of the best days to fly in months. Cool, relatively smooth and lots of little clouds to fly around and between. This photo is from the western edge of the flight test area as I was heading back toward Lake Elsinore. That is Santiago Peak at the right of the scene.


The gear leg fairings made a huge difference. I picked up 16 knots at 65% power and 8000 feet altitude. And when I opened it up at 6450 feet I hit 170 knots TAS (196 mph) in level flight (see screenshot below). It should be a little faster at 8000 ft, and I should pick up a few more knots when I install the upper gear leg transition fairings and get the mixture tuned out to peak power. It looks like the performance will be pretty close to Vans published numbers. Note the rpm hit 2730. That’s really close to the 2750 predicted by Craig Catto, the maker of my prop.


I did three stalls to calibrate the angle of attack system and you can now see the AOA display on the EFIS. I also did a time to climb test from 4250 ft to 6650 ft at 105 knots in 1.68 minutes for an average rate of climb of 1428 ft/min. That is way better than any Cessna I have ever flown. I can’t believe the difference the gear leg fairings and wheel pants made. It almost flies like a different airplane.


Categories: Flying