Tuesday, September 06, 2011
Lots of flying over the Labor Day weekend. The big item was getting N701GV up to 17990 and running out of VFR airspace. The climb took 38 minutes and 100+ FPM of climb was still left at 50MPH indicated.
Parts were ordered for the roller-bearing mod on the nose gear. This should improve the feel of the rudders in the air. I will also adjust the lower strut bearing to see if it can be tightened and remove the V-notches the nose strut sits on.
Thursday, September 01, 2011
Reached 10 hours in the air. Changed the oil and did another under the cowl inspection.
All indications from the magnet filter and oil look good, break in is going well.
Found some evidence of an oil cooler fitter rubbing against the engine mount. This was more flex than expected. The filter was moved and secured down additionally to stop this.
After adjusting the turnbuckles more, it appears that 18lbs tension is the magic number. The slight left turning bias on the ground was traced back to a trailing \ not yet broken in brake pad.
There is still more friction that I would like in the rudder system, so I will install the rolling bearing mod on the nose strut.
The airframe now has about eleven hours in the air.
Thursday, August 25, 2011
Monday, August 22, 2011
Monday, August 15, 2011
The weather has not been very cooperative for test flying recently. Taking advantage of this down time I opened all the inspection ports and did a full day inspection on the plane.
Additional grease was required and I vacuumed out more chaff that has appeared. More grease was required in the inspection bays around the controls and bearings. Some additional grease was required between the nose strut and the accessory shelf.
In addition I added velcro fasteners to all the seating and installed a document holder.
Sunday, August 07, 2011
I added another 1.6 hours today in the air.
Several tests were done. First was a temperature measurement of the avionics area during taxi, pre-flight and in flight. Next was a test of flap deployment and retraction. finally I measured time-to=climb and have first numbers for Vy.
The ambient temp was 82F during the test flight. During run-up and taxi the area near the Dynon reached upto 95F. Opening the air hatches reduced this closer to 91F. I may need to install a fan tied to the master bus in the area of the Dynon.
Climbing out to 4000 I explored slow flight some more. The force it takes to deploy the flaps above 60MPH is very high. Realistically you need to be lower than 55MPH, or even 50MPH. I found the flap deployment produced a strong nose down attitude, but ample authority was available in the elevators and ailerons.
With the flaps deployed I attempted slow flight at 40MPH. I may attempt slower flight later. An attempt was made to stall the plane with the flaps deployed, but once again the elevator does not have the authority to produce a high enough attitude to stall the plane.
The transponder was re-verified and flight-following was used during most of the test-flight.
Additionally I reversed the bend of the trailing edge to the elevator. Currently the bend is now about neutral. This helped reduce the amount of nose up trim required for cruise flight. I suspect reflexing the flaps slightly will be the final solution to not requiring too much nose up trim in cruise flight.
The rear locking pin on the pilot side works well, although the door is slightly harder to close.
I did several measurements for Vy. The initial winner for a 4000-5000' climb is 45MPH. The time for 45MPH was several seconds faster than 50MPH. I did attempt 40MPH and 35MPH. The nose attitude of 35MPH is amazing. The ground reference plane of the Dynon just goes out of view. The other runs were made at 70, 65, 60 and 55 MPH.
After landing I did find a small drip was coming from a fuel sampler fitting. After cleaning the area with a cloth and examining it, it looks like the drip is coming from the sampler's hole. I checked the tightness of the fitting and it is secure. Furthermore I pulled on the fitting to make sure that it was fully down and not stuck slightly up. I may need to drain the tank and replace the fitting.
The plane now has 5 hours in the air and 4 flights\takeoffs\landings.
According to the indicated fuel levels, 5 gallons were used in the 1.6 hours of flight. Fuel burn was at 3.1 gallons an hour.
Saturday, August 06, 2011
The area above AWO started getting bumpy beneath the 4000' scattered layer over AWO, so I took the plane out of the pattern. There is a nice stretch of pasture the runs NW from the airport to the shore.
I ended up climbing all the way to 6k indicated and the plane still had plenty of power, refreshing compared to a 150\O-200.
While up there I did several things. First I contacted Whidbey approach and verified they could pick up the transponder. At first they were just picking up the discrete code. It took me a while to realize that the transponder was on, but not on ALT.
While climbing I played with my airspeed to at least partially verify Vy. Without doing a specific, A\B test, it looks like 55MPH indicated is the answer.
I also explored slow flights and attempted power off stalls. I took the plane all the way down to 40MPH and the plane exhibited good control characteristics. Even with low power settings substantial right rudder was required with the nose high attitude.
Power off stalls were approached with caution. In the end the elevator ( as often reported ) does not have enough authority to stall the plane. The altimeter unwinds ( but not too fast ) and you still have authority in the ailerons and rudder.
I also attempted to pull some Gs and perform tight turns. I was able to turn inside my wake, not hitting it until I straightened out to reverse the turn. Forty-five degrees was as far as I was willing to take it. Even then it was hard to pull more than a G or two, the plane is just that maneuverable.
Enough grease and lube has been added that the rudder now straightens itself out gradually. As the nylon block wears in the rudder should loosen even more.
Part of the testing was fuel usage measurements. The plane started with 10 gallons. After 1.4 on the hobbs the final indicated fuel amount was 5.5 gallons. Power was well below cruise for most of the flight, so 3.5\hour for cruise should be reasonable with 11.5deg pitch.
Today's landing was the best yet. I kept more power into the landing than before and made a good effort not to flare until last minute. Keeping the power up and settling on long final with a slightly nose high attitude ( like a seaplane ) really added a lot of stability to the approach. The improved rudder lubrication also showed through.
The 701 really rides thermals and updrafts. The low wing loading combined with short wings also gives the ride a unique feel. You hear some metal rattle a split second before you get tossed up in the sky. Crossing through a disturbance on one side of the plane produces what I can only describe as a "burble"... like crossing a power boat's wake in a canoe.
The next several flights will be taking the turns tighter, hitting VNE and then adding simulated passenger weight.
After the flight I ended up installing a rear locking pin on the pilot side.
Tuesday, July 26, 2011
Sunday, July 24, 2011
The good news is that the door pin on the passenger side worked. I noticed some puckering on the pilot side today, so I will repeat the mod on the other side.
The efforts to reduce the rudder stiffness worked.
Today was a hot day which mad me think about cooling: specifically of the Dynon. The Dynon does not have any fans. After the flight it was hot near the Dynon. I am thinking a NACA style duct may be a good idea to promote cooling of the electronics.
The flight was a basic repeat of the first flight, with the exception of attempting slower flight. I took the plane down to ~50MPH and experienced the same shudder\bobble that I felt in the plane I transition trained in.
When I took off, winds were calm and mostly down the runway. When I landed I had a good cross wind.
During the landing the plane certainly seems to want to shuttle cock into the wind. That or there is a left yaw tendency. I checked the rudder alignment and it appears fine. If the third flight exhibits the same behavior then I will adjust the dorsal fin.
This landing was another firm landing due to flaring too high. I have also noticed that adding power to attempt to slow the settling will result in a ballooning. Adding power just makes the plane climb.
Thursday, July 21, 2011
In retrospect the post I wrote Wednesday night\Thursday morning was a ry, technical report written in exhaustion and under the influence of a few celebratory drinks.It is probably time to fill in the rest of the story.
There was of course a large amount of initial nervousness on my part, let alone my wife. Vivian only had gave me conditional permission to execute the first flight if Tom was there flying chase. In turn Tom made me promise not to mar his perfect history of first flights without an incidents.
The real pre-flight inspection was done on the 19th to make sure nothing was missed due to nervousness. I had practiced some of the first flight in the 150 on Sunday with Tom riding as an instructor. We also practiced HAPL.
On the 19th after the DAR visit, my own inspection and putting all the hatches back together I wanted to do a run up. This way I knew I would have enough battery to start for the first flight and maybe catch a few issues. The weather was extremely good and the airport was empty so I did some taxi testing on 34. The first pass was just to see how far I had to go for the airspeed indicator to come alive. Then I went as far as to rotate the nose. At this point the rudder still did not seem THAT stiff.
Flash forward to the 20th. I flew up to AWO from BFI for the test flight. Flying immediately before hand was probably the most calming thing I could have done. It got me in a flying mind set and also let me know the real conditions aloft. There was no guessing if the air was smooth or not.
Going over emergency procedures, bailout procedures, ect was a little stressful. The idea that that I may have to trust a parachute packed by someone else just seemed wrong. If my day was going that bad, then how much worse could it get, right?
We removed everything from the plane and vacuumed it out once more. Only stuff riveted, bolted or screwed down remained except for the bottom section of my seat cushion. I only had a three printed pages ( two pages of checklists\procedures and the test card ) and a voice recorder taped down and jacked into the intercom. The tape of course ran out during the flight.
The run up seemed to take forever. And it really did. You can’t fly the Rotax until the oil gets to 120F. That meant some idling to get the engine warm enough.
For this flight there was a clear division of labor. Tom was going to handle the radios from the Cessna. I just needed to stay on frequency to communicate with him. He was to keep traffic clear and advised.
With the run up done and the pattern clear there was nothing left to do but to just get the flight over with. This was the peak of my nervousness.
I had this expectation that as I advanced the throttle every single bolts and rivet would flash through my mind. That did not happen, instead I actually relaxed a bit and tried to enjoy the ride. Concentrate on the signals the engine is giving you, keep down the middle and wait for the bird to leap.
At this point the closest aviation experience I’ve had was my first solo… that combination of a familiar plane climbing unfamiliarly fast paired with “now I have to land this by myself”. By 1000’ that was out of my mind. At 3000’ I was getting a little bored of turning left and climbing.
Then another strange thing happened. Tom was trying really hard to stay out of view and the 701 was doing a really good job of running away from my poor 150. Looking down and seeing my 150 more than 1000’ feet below trying really hard to keep up was very strange. Then during some of the turns I caught sight of it again through the big door windows, but much closer. It was something like watching the race scene from “Iron Eagle”. There was this little white plane with a red stripe turning so beautifully against the mountains and clouds. The 701 also slows down MUCH faster than a 150 and Tom went darting past me whenever I cut the throttle back.
The turns to the left and to the right were no big deal. I really had to restrain myself from going more than standard rate.
The 701 does not have a centering spring in the rudder or pedals. In addition it uses an all flying rudder with wetted area ahead of the hinge. If you push left rudder, it stays left rudder until you push it back. This is hard to remember. You also really need to lead your turns with rudder first, which is also hard to remember to do after so many years in a 150 where generally you use rudder and ailerons at the same time. Every once and I while I would see I was un-coordinated and push the rudder causing a bit of a skid.
When coordinated the 701 turns VERY tight. It is reasonable to fly the pattern only ¼ mile out, do a standard rate turn and expect to lined up for final. Hitting the rudder to get coordinated would skid you into coordination and really remind you of this.
The practice approaches were really nothing special and I have nothing more to say about them.
Landing was the ugly part. I knew I had tons of runway to allow myself to settle in. I knew I needed to carry power into the landing. I knew I had to hold the flare until last minute. These things blanked on me until I had already started to flare and felt that sinking feeling that makes every pilot think they will have to bend the gear back into shape. So of course I added power, but a little too much and got back up to where I started. Letting power out that time gave me a better sink rate but it was still a firm landing. Then I had the steering\rudder stiffness to contend with.
My thought is that the landing may have loaded the bungee strut putting more pressure on the front contact area, making the stiffness worse. Maybe stick back pressure would have helped.
All said and done the first flight took about 25 minutes and it seemed like 25 minutes. I didn't not any sense of time dilation or contraction. I remembered to breath and did some instrument scans. I was only tense for a few moments, most of which occured during the landing.
Thanks again to everyone who has helped, voiced support, stopped by my hangar, ect.
Tuesday, July 19, 2011
The friendly regional DAR stopped by on Tuesday morning.Overall it was a pretty easy experience. A fellow 701 builder, Curt Thompson, was there to observe the process and see what the DAR would look for in a 701. He also wanted to avoid any mistakes I had made.
The appointment was for 10AM and the plane was mostly already opened up, IE all access hatches, inspection plates, ect. Only the top cowling had not yet been removed.
I had a table setup with all the paperwork in order.
The basic safety inspection started at the nose, moved back to the cabin, to the pilot side wing, control access hatch, the empennage, passenger wing and finally back in the cabin.
Generally he checked that cables and wires were properly secured, gas and electrical separates, bolts were tight and proper length, ect. He also checked control continuity and correctness for the engine, flaperons, elevator, elevator trim and rudder.
Placcards were also checked.
As always what you worry the most about never receives attention. I spent a long time worrying about details like the registration numbering. The FAA has very strict guidelines concerning the spacing of the numbers. He just looked up and made sure it was there.
Then there were things that I was sure he would think were wrong, but are by plans. The prime example are the control surface hinge bolts. The Zenith design uses a bearing surface squished between two bolts, no cotter pin. I have spent so much time explaining that the bolts are never under rotation that I had bookmarked the plans page. He had just done a 750 so it never came up although he did check the bolts.
Of course he found some minor issues, but nothing that would block an airworthiness certificate. I was able to address his punch list within a few hours.
After a break and a lunch I reinstalled all inspection plates and the cowling. That was then followed by a complete walk through taken from my POH for both pre-flight and 1 month inspection routines.
I had not touched the plane for a few weeks so the combination of running electrical for the inspection and the Garmin GPS trickling a small charge gave me a hard start.
Runup went well and I took my time doing it to charge the battery. I taxied the plane onto AWO 34 and performed a few taxi tests. Everything went smoothly, but I really didn’t do much. Airspeed comes alive on the Dynon at ~25MPH just as the nose wheel gets light.
I decided to trim the wing root covering some more to help reveal the forward wing-root cover bolts. I also found a few bolts without torque-seal.