Test Flight Report
The day finally came to test fly the PST Panther. My Panther (serial number 8 I believe), was delivered via special freight in Novemebr 2005. Mine was shipped in primer and painted by me, so you can find those particulars in another thread. I used the PST pipe, custom PST retracts and wheels with hydraulic brakes. No speed brakes nor inboard (fuse) flaps. Powered by PST 600R with PST fuel tank and BVM UAT in the nose. The plane required about 14 ounces of lead in the nose to balance at the reported CG of 3.75 inches rear of the LE of the wing at the root rib where the wing attaches. Temps today in the low 90's with a pretty stiff breeze, 7-10 with gusts to 12 down the runway, from the south. Humidity around 85%.
Engine fired right up, temps were in the 400's, everything looked good. Nothing but butterflies in my stomach to keep if from flying at this point. Taxied down wind for turnaround, flaps down to 15 degrees, turned into the wind and applied the brakes. I throttled up and released the brakes. Previous taxi testing had showed that you want lots of expo in the steering, the nose gear is very sensitive. So this time I was easy on the steering and she stayed right on the centerline, I eased into the elevator and she lifted off at about 200' and started skyward with authority. My immediate response was one of elation and my concern about it being too heavy faded. I retracted the gear and it was amazing to see the gear doors operate like they were supposed to do. The flaps came up and she immediately started to pick up speed. I decreased the throttle to cruise at around 75%. The aileron throws as suggested are very responsive, use expo in them to make it more manageable and soften it up. I noticed it took a little more elevator in the turn than my Ziroli, but that is probably due to the extra weight. As the Panther burned off fuel I noticed it became a little more pitch sensitive but did not appear to need more trim, it just became more sensitive. After take off I only needed about three clicks of up to fly level. This thing is beautiful in the air, pics to follow.
The interesting part of this story comes in around the 4.5 minute of the flight. I started to enter the pattern for landing and dropped the gear. I noticed right off that the speed started to decrease when the gear deployed so I increased the throttle a bump or two to maintain speed. I entered the down wind leg and everything felt fine. I put a few clicks of down in to maintain a solid rate of descent. When I dropped the flaps to the first degree (15 degrees), she immediately dropped the left wing. I throttled up immediated and started to retract the flaps. I was only about 80 feet high. THe engine was coming up to full power, but the gear was down. I gave it right rudder and she straighted up, but it was obvious that it was going to hit the ground. I hit the engine kill switch as it hit a small hill at about 30 degree angle. The plane bounced back into the air hitting at its front. It landed about 15 feet from where it first made contact. There was no fire.
Damage assesmment. The airframe was totally destroyed. The two main gear were destroyed, a testament to how well the landing gear blocks were in place. The frames were both twisted and the trunions ripped out, but the blocks were still in place. The tank ruptured, but there was no fire. The pipe was not hurt. The engine got a small ding in the can, but everything appears to move freely, but I have not attempted to start it again. One servo was destroyed, the rest appear to have made it thru without damage. The pilot lost his right hand
Lesson learned. The CG as quoted appear correct but the elevator is really sensitive here, make sure the fuel tank is empty when you check the C.G.. I did this, and even cut a small hole in the duct to move the engine as far forward as possible. If I get another one I will do the same but may even add a little more weight in the nose. The plane flew fine but felt like ti was becoming a little tail heavy as the fuel burned off. You may want to make sure that you have a good bit of expo in the elevator for the first flight at least when it is on high rate. Make sure you are on high when you start introducing the flaps and do not add the last bit of flaps unless you have altitude and throttle in play. The plane stops on a dime as the flaps come out. I had a little tail wind which contributed to my demise here. I let it get to slow, when you take into account the wind at my back. The plane flies nicely and looks so damn good in the air. I am mostly sick because I paid so much to get it here months ago, now mine is gone and there is a waiting list to get one....[:'(]...also my gear damage will have to be repaired at the factory. The brakes work nicely and are very realistic and smooth. The plane flies well on 14 pounds of thrust. Pay attention to the CG and be conservative with the flaps. PST has a winner. I just need to get back on the horse....
Tommy