Bought October 2011
This is N19WT, a Viking Dragonfly built by
Walter Triplett with
flown in 1987 (details).
The late, Walter Born bought the plane and it was hangered since 1993.
In November, I trailered
it to Huntsville AL:
These can be mailed to: firstname.lastname@example.org.
Past and Current Project Log
Earlier, project logs by month:
2016_03 - initial circuit sketches;
2014_03 - medical and Arduino review;
2014_02 - IVOprop initial review;
2013_02 - Jason Mace built Dragonfly crash;
2013_01 - tri-gear analysis begins;
2012_12 - LED testing and prop controller;
2012_03 - engine analysis, instruments, landing light and bye-bye HAPI;
2012_02 - wing disassembly, navigation lights, and planning;
2012_01 - work table, shed, paper work, and starting wing;
2011_12 - purchase, towing, and work-shed.
2016/03/29 Getting Back To Work
Major medical for Holly and myself suspended the project for two years with
2015 being the worst. Fortunately, health issues are resolved and now
to get back on the project. Things to do:
- Get firewall-forward parts in house and work area(s)
- Begin engine mount and firewall mock-up pre-build
- Begin prop and engine integration - pass through and brush assembly
- Survey electrical loads - everything critical to engine operation.
2016/04/02 Firewall Forward
The first problem is to make a duplicate of the firewall. So I bought a piece of
regular grade, plywood (this is not a flight article) large enough to
make a duplicate. For a pattern, I used the existing cowling:
There were problems:
Instead of burning the plywood, I used a large piece of cardboard
and traced the cowling. Then I took the cardboard to
the plane and verified the outline was not an exact fit:
- Flexible - machine screws to hold the two pieces to together
- Oversized to plywood - because the the bottom of the cowling is the cooling air and
former engine exhaust
Ok, the lesson learned is to do the sides first with something like a large
construction or shirt-cardboard. I'll fold an edge and clamp it to
the engine mount "L" structures. Then I can trace both the edge and relationship
to the engine mount.
One good thing is it now gives some metrics that will improve the project:
By extending the trailing edge of the cowl flaps, they will also work as
Then adding a valve on the cabin side, safe heat from the radiator.
- Eliminate the bottom air exhaust - this will reduce the profile drag significantly.
- Side blisters trimed and new radiator exhaust - this will trim the blister profile and become
symetrical, cowl flaps and speed brakes. In effect, something like these:
- Weight reduction - probably a pound or two, it will save a little weight and provide
access for the cabin heat.
- Buffer two-stroke exhaust - the passenger side cowl exhaust provides an 'air curtain'
to keep the two-stroke, oil in the exhaust from running directly against the left side.
It won't be perfect but should reduce the stain.
2016/04/10 Firewall Forward
So after several attempts that had errors, I finally 'cut plywood':
Not perfect, it is close enough to build out an engine test stand.
The goal is to get the mounts and stress and strain operation.
This composite shows the inside of the cowling fitting over
the plywood cut out. Due to the camera paralax, the sides are not 'straight':
The camera was put at the cowling inlets to take these quick shots.
I will repeat the shots with the camera located the the outside edges of engine air inlets to
correct the parallax.
This is the cowling which fits around the firewall:
We need to measure the blister and lower exhaust areas.
Right now, we think the passenger side blister will be needed for the exhaust muffler.
Now to rough-out the engine mounts in this firewall.