June - July 2000

Finishing:

There are no words (I can use here) to describe how dull this stage of the project is.

I will say that the pre-formed panels saved hundreds of hours of work and likely, my sanity (which hangs by a thread at the best of times).

In the "things to do differently next time" category I would make the following entries...

- Do the finishing and priming earlier in the project. Finish the lower surface of the wings/fuselage/empenage while the a/c is upside down for the glassing of the stubs. Sanding and filling overhead is a great way to develop upper body strength.

- It would be nice to do all of the finishing and painting prior to hanging the motor, installing the panel and interior. The a/c is much lighter and more manageable at this stage. If you carefully plan the layout of things like motor mount backing plates (especially the uppers), cables (throttle, mixture, cabin and carb heat), fuel lines (include the primer lines if installed) and electrical wiring (especially the voltage regulator) this can be done. Remember, once the main fuel tank and upper deck are installed your access to the back of the firewall is very limited. Essentially you need a left-handed midget to do any real work up there at all.

The hardest part of this phase (after the mind-numbing boredom) is, knowing when to quit. I believe it's important to resist the temptation to keep adding layer after layer of filler in search of the perfect finish. The more filler you add the more dead weight the aircraft will have to carry around. The more you sand the greater the chance you willl inadvertently cut into the skin and weaken the structure. Some of the hardest working airplanes I know are the ones that look just a little rough around the edges. So if you see C-GGFW around your airport one day, that's my excuse.

Paint the a/c with the cowl, canopy and all access panels/doors off or open. Make sure to keep some paint for touch-ups.

Fuel Flow Test:

In order to confirm an adequate supply of fuel to the engine the following test was performed.

The main gear was raised approximately 12" imparting a nose up angle of 14 degrees. Add to this the angle of incidence of 3.5 degrees (at the root) resulting in a simulated angle of attack of 17.5 degrees. This should be within a degree or two of the stall angle for this airfoil.

The main fuel tank was filled with a little over 1 gallon of fuel. The fuel supply fitting was removed from the carb and placed into an empty gallon can. The end of the line was secured at the level of the carb fitting and the time to drian 1 gallon of fuel was measured to be 5 min (+/- 8 seconds).

This gives a worst case fuel flow of 12 gph. Earlier tests gave 13.9 gph in the 3 point attitude with a 35% full tank.

FAR 23 mandates 1.2 lbs/hr for each HP (at take-off). If we accept the 75 HP claimed by Revmaster for the D2100 with these cylinder heads this gives us 90 lbs per hour. 12 gph equals 72 lbs/hr. This is 20% below FAR23 requirements. FARs also accept a minimum fuel flow of 150% of maximum fuel flow required at take-off power.

Rex Taylor (Hapi engines) recommends a minimum demonstrated fuel flow of 7.5 gph based on a maximum take-off fuel flow of 5 gph. Revmaster also advises a maximum take off-fuel flow of 5 gph and recommends a minimum 10 gph demonstrated fuel flow.

Transporting:

Transporting the a/c requires some preparation. The possibility of having the a/c fall off its' trailer at 90 kph on one of the busiest highways in North America has been the subject of a few spectacular nightmares. While the fuselage complete should only be about 500 lbs its' size requires a large trailer.

The Diehl gear gives you a track of 80" and a wheelbase of 121".  Since I didn't have acces to a trailer quite so wide it was necessary to fabricate a mounting fixture. This is secured to the deck and provides a solid place to secure the mains.

The tail is propped up for clearance and secured. It is important to secure the elevator with a control lock as well.

The motor mounts and gear provide the best locations to secure the a/c to the trailer. This was done with 1000 lbs test ratcheting straps.

Assembly:

Anyway...

The final assembly stage is as exciting as the finishing stage is dull.

Cleaning up after painting included removing masking tape from (and checking clear) pitot/static sources, fuel vents (3) and scupper.

The wing attach fittings lined up quite nicely and required very little persuasion to insert the bolts. Prior to bolting up the right wing the pitot/static lines were connected.

Next the nav and landing/taxi lights were terminated with bullet type quick disconnects. Ground straps were simply bolted together per Bingelis.

The rudder was installed, hinge bolts and AN310-3 castle nuts with cotter pins were used as on the elevator hinges. AN23-10 clevis bolts with castle nuts were used to connect the cables to the bellcrank. The tail wheel hinge bolt is an AN3-17 with a castle nut as well.

The ailerons were mounted and the final balance was checked.