Ground Testing:

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6/02/2007

I started reading advisory circular AC90-89A. I tested the pitot and static systems for leaks with the method described in the advisory circular. I found that the leaks were too extensive to pursue with the time I had left today. I will have to continue them another day.

For taxi-testing I have designed a set of taxi-testing cards. These cards have specific speeds for my plane. Other models will be different:

You can download the entire set in PDF by clicking here. Remember, the speeds are for a Glasair I FT.

6/05/2007: Pitot/ Static system integrity test:

I've scheduled to have my pitot/static system certified on the 6th of June. I spoke with Chris at Pacific Coast Avionics to determine what was OK for leakage. It wasn't good. It was time to revisit the leaking systems. I started by attaching a couple feet of surgical tubing to the pitot tube. I attached enough so that I could see the airspeed indication on the EFIS Lite screen. By slowly and tightly rolling up the hose I was able to attain 150kts. At this airspeed I pinched off the line with forceps. I waited about 15 seconds for the reading to stabilize (it never did) and I started timing it for one minute. According to Chris it should drop less than 5kts over a minute from 150kts. At the end of the minute, mine showed 30kts... wait... this is what it reads without the hose attached!

Little did I know at the time, I had my work cut out for me. I started by connecting the surgical tube directly to the back of the EFIS Lite and testing the instrument directly. This was no easy task since the instrument panel was completely assembled. I added the first two joints at the instrument and tested again. This time I found that the drop was about 25kts over the minute. I removed the two fittings and short piece of tubing between them and examined them. I found that the tubing had hairline scratches in it from installing and removing the line over the last couple years while building. Upon replacement of the short line and reconnecting the fittings, the first two fittings tested at 1kt over 1 minute. I proceeded down the pitot line all the way to the pitot mast with the same process, attach next fitting and hose and test. I found three hoses leaking and 4 fittings. Once repairs were complete I performed a couple complete pitot system tests and managed an average of 0-2 kts drop over the one minute test.

The static system wasn't much different except that you need to roll the hose up tight before attaching it so you can unroll it to simulate going up in altitude. According to Chris the static system is OK if it tests less than 100ft drop from 1000ft over a minute. Again I did miserably at first seeing about 500ft drop over the minute. With repairs, I managed to get off a little easier with only 3 fittings and 2 sections of hose this time. Several complete system tests finally showed 60-80ft over the one minute test.

6/06/2007: Pitot/Static certification and calibration. Pacific Coast avionics arrived at the hangar on time and with some pretty cool equipment. Once the equipment was connected to my plane it didn't take long to certify the EFIS Lite altitude encoding and the Garmin 327 transponder.

Airspeed on the EFIS Lite was another issue. The aircraft lines tested good. The airspeed would read about half of what the PCA tech was feeding into it. We started recalibrating. I had been over the recalibration procedure several times with people online as well as with the plane. I thought maybe I messed it up. It was refreshing and frustrating at the same time to find out that I wasn't nuts. The calibration tables would not directly affect the reading of the altimeter. We gave up testing the airspeed and made the airframe logbook entry for the static certification.

After the tech left I removed the EFIS Lite, boxed it up and sent it back to Blue Mountain Avionics. Several weeks later, after installing new software and deciding that they were still just as baffled, BMA replaced all of the internal sensors for the airspeed and attitude with newer versions. This corrected the problem. Because I purchased my EFIS Lite several years ago I have to say that BMA was extremely generous in this situation as they didn't charge me for any of their weeks of work and I received an almost new unit back from them.

Continuing from Engine Testing below here:

I had to stop ground testing for several months after a conversation with my insurance company. They informed me that I needed to have my required Glasair time logged prior to any in-motion coverage. With 166 hours SEL and an instrument rating they required that I have a total of 5 hours in make. I confirmed with them that this meant "any" Glasair (I, II or III).

I first called New Glasair for a list of their "approved" flight instructors. With list in-hand I made several phone calls and e-mails to interview instructors. I was quite surprised to discover what a few of the people on this list were charging. After several discouraging conversations I decided to post my search on Glasair.org.

It wasn't long before Kurt Gearhart responded that he may be interested in helping out a fellow Glasair builder. Kurt is a CFI and owns a flying Glasair II S FT. He is also building a Glasair II S RG. Once we ironed out the details we set a date in January for me to fly to Phoenix. Unfortunately I caught a bad cold the weekend that I was to fly out and had to cancel. Almost immediately Kurt made changes to his schedule and had us back on schedule to fly from February 14th to the 16th.

2/13/2007: I flew down Wednesday evening and we were able to get two flights in on Thursday. Somehow the Oregon weather had followed me to Kurt's place and we had fun with crosswinds the entire day. The next morning, more Oregon weather had Kurt wondering if we should fly. I reminded him that this is normal in Oregon and we managed to get two more flights in on Friday by staying under the weather and doing mostly touch-n-goes in relatively calm weather. Saturday the weather looked a little better to the south and we headed to Casa Grande for the last flight we would make for my training. Altogether we flew 5 flights with a total of 27 landing and 5.4 hours flight time.

2/23/2008: Upon returning to Oregon I was able to get my insurance in place. I spent the next  weekend making another final inspection and completing assembly of the stuff that was removed for the airworthiness inspection.

After assembly I performed another test. This time it was a full-power, nose high fuel flow test. I ran the plane at this setting with the engine turning 4200 rpms (2300 prop) for 20 minutes. During the test I observed no fuel pressure decline.

After the testing I removed the fuel pump pre-filters and cleaned them. I was surprised at the small amount of debris.

3/2/2007: Performed several high-speed taxi-tests today. I had my father-in-law on the ground with the "rescue" vehicle and a hand-held radio to monitor my progress. The first two runs were to 50kts after which I used hard braking to remove the glazing that was causing very poor braking performance. I verified this by making the third run at 60kts and being able to stop sooner than the first two runs. By the fourth run I was up to 76kts and the nose wheel was off the ground momentarily. I performed a couple more of these runs and decided to test exactly when the plane would leave the ground.

I decided to let the plane cool down a bit first. During these tests the cooling stabilized at about 206 deg F while I was taxiing back to the runway. After each run it would be back down to about 199 deg F. Upon taxiing back to the hangar it reached 220 deg F after a few minutes at low power just prior to shut-down.

After lunch my wife joined the crew on the taxiway. The first run was another 76kt run. While taxiing back for the second run of the afternoon I decided to proceed with finding out what the lift-off speed is. I began the run from a stop and applied full throttle quickly. The plane accelerated very well and coved 1200' before reaching about 80kts and jumping skyward. I say "about 80kts" because I couldn't remember after the surprise "jump" off the runway. I immediately applied forward stick to level the plane and noted that the left wing dropped quickly. I corrected for the left wing and pulled throttle to 1/3rd and held about 50' AGL while evaluating the left wing. This took about 260 yards and I gently set the plane back on the runway with plenty of room to stop.

I relaxed and headed back down the taxiway to the runway for another run. My thinking is that the fuel had transferred through the flapper valves to the left side of the plane from all of the right turns during taxi-testing or while parked. I decided to stop at the run-up area to let the fuel settle before trying again. At this point a Cub and a 152 decided to start touch-n-goes. After a minute or so I noticed that the temps were back up to 207 deg F and I decided to go ahead and try another lift-off to evaluate the left wing.

This time the wing felt a tad better but I could tell that it needed more time for the fuel to settle before I would be sure this was the only issue. I taxied back to the hangar and cooled the engine down again. This time the traffic didn't let up so I decided to wait for another nice weekend. The pictures below are the last high-speed run and short flight. The first photo I am taxiing by the crew. In the second photo I'm beginning the take-off run. In the third photo you can see the plane has just lifted off and the left wing is evident. In the last photo I am just setting the nose wheel back on the ground.

Exciting Stuff !! Now to absorb...

To Flight Testing...

 

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