Flying #532

[jhughes]

I am no expert but when I was getting ready to fly the first flight I was looking for all the information i could get so I decided to write down my experience for anyone who comes after. I finished building #532 in October of 2012 and got it inspected on October 12. Now I had to think about flying it. I had flown cubs and super cubs in the early days of my flying career by towing banners and fish spotting in a Citabria. I have about 300 hours of tail dragger time but that was 25 years ago.I spoke with 2 EAA Flight Advisors and they recommended that I get some super cub time and biplane time if i could find it. The only guy i knew who owned a super cub would not be available for a few months so that was out. I went to Hampton NH and rented a J-3 with an instructor for a few hours that included some good crosswind landings. When I had gotten up to speed i went back to Lawrence Mass. and did some taxi tests to check out that the plane tracked straight and the controls and brskes would as they should. I had been advised by several sources to avoid high speed taxi tests as a large per centage of accidents result from them with questionable return. It seemed like good advise. However I noticed with a power setting of about 1500 rpm as i gained speed i seemed to have to hold in a lot of left rudder and the plane seemed to track about 10 degrees nose right.. Then I remember that the stabilizer was adjustable and I put it in the center spot until I got a chance to test it. I went bsavck to the hangar and put in the offset 1 inch to the left and tried it again.It was much better. So much so that the plane lifted off before I realized it. I am not saying the plane would have been uncontrollable with the stab in the other position be it was certainly more comfortible in the off set position. Anyway the flight advisors had told me to be ready for the possibility of flying before I was expecting too. I had advised the tower of this possibility also so when it happened I had a plan and tower was aware of it.
I had drawn up several flight test cards based on the FAA Advisory Circular AC-90-89A on flight testing homebuilts. For the first flight it recommended climbing out to 1000 feet and keeping the speed at 1.5% of stall speed. By my calculations that was about 53 MPH in a Hatz with a 150 HP Lycoming in it. That would be a pretty low power setting. The FAA circular went on to recommend that several climbs be down 1000 feet at a time up to 5000 feet at different speeds to get the best rate of climb speed. This was to be followed by descents, with the power pulled back, to 1000 feet to get the best glide speed. Then practice slow flight and landings all the time noting the readings of the engine and flight instruments and writting them down.
I mentioned this to my mechanic friends and spoke with the guy who rebuilt my engine and was told in no uncertain terms that if I did this with a new engine before it was broken in I would in all likelyhood ruin it. The Circular might be alright for a used engine but for one that needed to be broken in a different approach was needed. I decided that with my prop and engine combination requiring a 40 hour Phase 1 test period there would be plenty of time to expand the flight envelope. The engine builder and my friends recommended I spend at least 5 hours and 10 hours would be better running the engine at 75% and above an hour at a time. The engine builder went on to recommend I limit my clims to around 500 FPM in order to insure proper engine cooling in the climb until it was broken in. Running a new engine at lower power settings woud not allow the piston rings to seat right and would glaze the cylinders which would lead to excessive oil consumption and require the cylinders be removed and honed before reinstalling them. The climbs and descents could result in thermal shock that cracked those very expensive cylinders and cause them to have to be replaced.
Well not only did that eliminate the climbs and descents but there was no way I could run the engine at 75% and keep it below 53 MPH.
After lift off I informed the tower I was climbing to 2000 feet and would be circling the field at that altitude for the next hour unless a problem developed. I then gentlely moved the controls to see that they responded properly and without any unusual vibrations. Climbing to 2000 feet would put me well above the normal pattern altitude of 1000 feet and 500 feet above the biz jet pattern which should keep me out of the way. I did not reduce power until I reached 2000 feet to avoid the chance of engine failure that often occurs with the first power reduction. At least this way I would have enough altitude to glide back to the field.At 2000 feet I reduced power to 2200 RPM and the speed settled in at about 75 MPH. As the speed increased I was watching for any unusual vibratins or control pressures. Fortunately there were none and I even trimmed the plane out to fly hands off. There was a very slight left wing low tendency but it is so slight that at this point I don't think I will mess with it. I am running an open cowl without an oil cooler which I read in the forum that several guys were doing with O-320's so I was particularly interested in the oil temperature. On climb out it climbed to about 180 F and about 70 PSI on the oil pressure. With various high power settings that the engine builder recommended I use to aid the breaking in process I noticed the oil temperature cimbed to about 220 F which was still well below the 250 F max. I saw in the forum that Steve G was running a little hot and had said that by adding a one inch lip to the bottom of the cowl to improve airflow through the cowl he lowered his oil temp I decided to try it and see what happened.
Towards the end of the hour I pulled the power back to practice some slow flight and got down to 45 -50 MPH with no adverse results. I then desended and reentered the pattern and did a low approach. I normally fly a Citation for work and approach at around 110-120 Kts. When I slowed to about 65 or 70 MPH I felt I was about to fall out of the sky so did the low approach at that speed. I then came around for a landing agsin not feeling comfortible much below 70 MPH. I entered the flsir and of course the plane was no where near being done flying, it floated and floated and then dropped out of the sky and I tested the spring gear pretty well and bounced. At this point I decided to go around. I went around and set up an approach at he proper speed of 45-50 MPH and the plane landed with no spectacular antics. I put a strip of aluminum on the bottom edge of the cowl and when I get bsack from work hope to find the weather still warm enough to try it.

[hatz215]

Thanks for the great pirep. I think you're going to enjoy your airplane.

Steve G

[jhughes]

did a second flight with the new lip installed and the oil temp dropped from a high of 220 F to a steady 195 F. wouldn't have believed it would make that much difference but it did. also went up for a 3rd flight during which I noticed the oil pressure fluctuating while at a steady power setting. Pressure normally has held between 55 and 65 psi but it dropped to about 40 then slowly returned to 60. On the ground it dropped to about 15 at idle and then went up to 30. checked with a mechanic friend and he suggested it might be the sender but to be sure with put another non electric gauge on and I have run it at idle and it held at about 60psi but I wasn't able to get the oil temp up very high due to it being windy and cold (35F). Supposed to hit 60 F this weekend so I will run it up again and see it it holds pressure. Paid $112 for that sender and another $75 for the gauge going be pretty disappointed if if only lasted less than 2 hours of flight.

[jhughes]

Did a third flight found out my limit is 43 F for air temp. I only lasted 40 minutes. Had a slight problem with my oil pressure gauge it held steady at 60 and down to 55 when it warmed up but then started to leasurely wander down to about 35 and back to 60 so I between the cold and the oil gauge I decided to come down.We put another gauge on the pressure gauge and ran it up on the ground and it held steady at 60 PSI. so the electric gauge and sender failed after 2 hrs! $112 for the sender and $65 for the gauge junk.you get what you pay for so I bought a Scott pressure gauge with a line right to the panel and have put it on and run it up and it looks good. now need to hope for some warm weather to go up again. In New Hampshire in winter those days are pretty scarce. Also had a used solid wheel 4 inch scott tail wheel on the plane that wouldn't unlock to the lefty. Took it apart and saw quite a bit of wear. Put it back on and now it won't follow the rudder at all so ordered a new 4 inch wheel at $230.00 from Aviation Systems that a guy who owns a christen eagle has had good luck with so hoping to put that on. If the weather doesn't allow flight I think I will also enlarge my small windshields for a little more protection while I wait for warmer weather.

[hatz215]

J,

I can remember when I used to fly the Hatz at below freezing temps. Now I like for the temp to be at least my age (53).
I'm not sure how much comfort you'll get from a higher windscreen, most of the air in the back seems to come down from the center section right on top of your head. That's part of the fun though, refining things till you get what you like.

Steve

[jhughes]

I think you are right Steve. it probably won't help the temperature problem much. like you say I think anything much below 50 degrees or so is going to be uncomfortable. 15 or 20 minutes or so may be ok but with so little room to move in the cockpit the cold does seep in. The open wind is why I wanted an open cockpit in the first place but I think my head is just a little too much in the wind and fighting it for an hour is kind of like banging your head against the wall.......It feels so good when you stop! So I think I'll make it a little higher and wider and see what happens!