Sunday, July 6, 2014
Saturday, July 5, 2014
Wednesday, March 2, 2011
Saturday, December 12, 2009
Bruce Perkins always seems to get good pictures of Whispers. Here is a shot of the "blog plane" during the Bethlehem airshow. Murphy's law resulted in the radio aerial wire getting a dry joint upon arrival at Bethlehem...hence the use of the handheld radio
Monday, July 20, 2009
The imported tailwheel is supplied with unsealed bearings. These are ok if greased regularly. If you are not keen on removing your tailwheel often and/or operate off a muddy dirt strip you may want to consider installing sealed bearings. Unfortunately the unsealed bearing is 1+3/8" (imperial). A local metric bearing can be made to fit but the bore in the wheel needs to be opened up slightly to 35mm. Two adapter spacers also need to be made for the centre of the bearing (see pic).
Sunday, June 21, 2009
Testing the actual glide performance of your motorglider is fairly simple. I chose a "dead" winter's day with little or no thermic activity and did a series of climbs to just over 3000'. I then cooled the engine for a while, shutdown, feathered the prop and closed the cowlflaps. I established a pre-determined glide speed and maintained this as accurately as possible. As I descended through 3000' I started the stop watch and noted the time every 100'.
Monday, May 25, 2009
Saturday 23rd of May was the day. All went well. The cooling was one of the unknowns BUT even during a sustained full power climb I cannot get the oil temp above 95C. Water stays at around 80C. Engine off glide performance seems good. MGL EFIS is behaving well. Hobbs time already 2.1 hrs after 7 short flights over the weekend.
18/6/09 - testing still going well. Apart from a stuck needle and seat in the one carb there have been no snags.
Tuesday, May 19, 2009
Monday, May 11, 2009
The signage shop decided to supply the reg as ZJ-FDI. I assume it is because of the presidential inauguration that was happening that day. So apart from waiting for a "U" letter and the official paperwork -she is ready!!! After the final inspection and whilst doing the engine ground runs I did taxi on the runway a few times. Observers are convinced that they saw a few mm of sky between the tyres and the ground but that of course is not possible. Hopefully will have the paperwork by the coming weekend.
I love this task....because it means you're nearly ready to aviate!
With zero fuel and full oil we positioned ZU-FDI on the 3 scales with the canopy sills level. Using a plumbbob and a long tape measure we determined the distance between the wing leading edge and the main wheel centreline and the tailwheel centreline. Determining the exact position of the humans and fuel is normally a little difficult so this time I climbed into the aircraft whilst it was on the scales (not that easy!) and from the readings worked back to obtain the exact moment arm. I did the same with the fuel. See spreadsheet below.
Please don't forget this all important bolt! Apart from flight loads it also looks after the fore/aft loads imposed by exuberant wing handlers on the ground. One needs to decide whether to make it perpendicular to the top wing surface or the bottom. I prefer to split the difference which will result in moderately tapered stepped spacers - BUT they will be required top and bottom.
Drill the hole 7.5mm and REAM 5/16".
Wednesday, May 6, 2009
The beauty of building your own aircraft is that you can tailor the cockpit to exactly what you want. Personally I like to have it as simple as possible hence the spartan layout that you see in the picture. If the fuel is turned off the lever pokes into your leg thereby reminding you. The fuel sight gauge is against the tank hence it can be accurately calibrated for the 3 point attitude on the ground. Prior to take off the total will be entered into the EFIS which will then determine fuel remaining by means of the fuel flow. The electrical system is also very simple with automotive blade type fuses which can be removed if a system needs to be disabled.
This 90km trip happened last wednesday just in time for the Whisper Fly in.
In the interim I painted the wings and fitted them to the fuselage. This weekend I will attach the ailerons, setup the aileron travels and weigh the aircraft.
Next week it is paperwork and then we fly - watch this space!!!
The teflon bushes are built into the wing. They start out with a 19mm hole into which the pushrod fits snugly. If left like this there is too much friction in the system. To eliminate most of the friction one can ream the bushes "in situ". Various reaming devices work but the most successful so far seems to be a step drill. (Thanks Kelvin!)
I am normally not in favour of complicated mechanisms and hence normally use a simple cable mechanism to close the top cowl flaps. If one wants to adjust the amount of opening of the top cowl flaps in flight though - quite a bit of force is required to overcome the aerodynamic loads on the flaps hence I am trying an electro mechanical setup. I hope to be able to close them partially in flight. Whether or not the system works remains to be seen - watch this space! Oh and if the electrics fail I have a cord that I can pull in the cockpit which disengages one of the ball ends connected to the cowl flaps thereby opening one of them in an emergency.
Friday, April 17, 2009
The pics show the routing of the brake pipe. If you are having brakes for left and right seat pilots then you require 2 master cylinders with reservoirs and two without reservoirs. The ones with reservoirs are the most "upstream". The Grove parts come with a sketch showing how to plumb all of this. I am installing the cylinders with the reservoirs on the pilots side (left). These then route to the co pilot cylinders and from there to the wheels. Bleeding is easiest with an oil can connected to the bleeding nipple via a short length of flexible tube. Pump fluid in until the pilot's reservoirs are full. You need a helper to tell you when to stop!