1988 Modifications to Long Ez N 67EB
The
canopies are shown separated by approximate thickness of the D section
roll bar on the aircraft. Notice the better penetration angle of the front
section. Except for the increased width of the forward section, the rear
canopy is essentially stock and blends into the turtle deck of the original
plans. The front canopy is made from a stock COZY canopy that was pulled
together at the sides, a little at a time, and "trimmed" back until the
bottom lip and sides were flush with the fuselage. The Long-Ez that this
system is fitted to is hung from the roof of the T hanger and was not accessible
for these photos. The finished appearance and functionality of the design
can thus not be seen or fully appreciated. For example, the amount of canopy
in front of the pilot is almost twice that of the original design. There
is no eye-brow effect on the instrument panel; all of it is plainly visible.
The instrument panel could be made several inches higher if desired and
provide increased utility.
The Rear canopy made from heat formed 0.125" Lexan
The original canopy was completed but was accidently destroyed during a trucking incident. Dissatisfaction with the original prompted the redesign to the 2 piece design you see here. The completed canopies were finished in 1988. Unlike the Berkut that followed later, the front canopy hinges on a 2" x 3" deep, full span Sitka Spruce crossmember secured to the canard bulkhead. Conventional or piano hinges will not work on the front canopy as all the top surfaces of the fuselage and forward section of the canopy have a curved surface. Kitchen cabinet hinges, a marvel of linkage design, were pressed into service and work perfectly. Since they only support the front canopy when entering or leaving the plane, they do not need to sustain flight loads. The rear canopy hinges to the right, just as on the original, using piano hinges.
The COZY canopy worked beautifully when "reduced"
Yes! It's wide! After carefully pulling the sides in
with straps, the COZY canopy was trimmed so that the sides of the canopy
blend smoothly into the outside of the fuselage sides. The first time I
tried it on, I was euphoric! The windows I'd worked so hard to install
inside the front strakes, were no longer needed. I could easily see the
ground close by. The engine cowling cylinder blisters still represent the
widest portion of the aircraft immediately aft of the canopy so while the
wider front canopy has increased wetted area some, the total frontal area
remains what it was originally. Better penetration of the COZY canopy should
help reduce plate drag. The forward canopy uses four spring type, over
center latches to secure it to the longerons.
N67EB "at altitude" 20 feet AGL!
Close-up of "D" Section
Even with the tangle of ropes and wires, the D section
is plainly evident. A piece of wire at the base of the D looks like
a lip. It's not; The D blends smoothly into the fuselage sides. A conventional
cabinet lock, built into the top of the D section locks it. That dark slot
at the top of the D is where the locking pall pivots out to engage the
canopy frame to secure the system. The lip against which the front canopy
seals is plainly evident here too. You can see the small "window" in the
lower side of the strake covered with masking tape. It's a superfluous
modification given the improved visibility of the new canopy.
The "D" Section roll bar and canopy mating surfaces
This
"D" section is built up from numerous plies of BID, UNI and high density
foam. If I were to do it all over again, I'd start with a cold formed inverted
"U' section of thick walled 2024T3 tubing, secured to the fuselage
sides and floor as well. Then I'd form the fiberglass D section around
that. The details of the canopy frames, the D section and the construction
methods used are forthcoming.
With all these modifications, the entire plane, equipped
for IFR weighed in at just over 730 pounds, with a Lycoming O-235. It was
18 pounds over the calculated estimates made previously using the actual
weight of unassembled but completed parts. Burt Rutan was given the Lotus
123 spreadsheet that showed the actual weight of every piece in the machine.
Fanatical attention, including prodigious amounts of vacuum bagging was
done as part of the commitment to keeping the plane light. Every piece,
EVERYTHING, even the fuselage, was weighed on a UPS shipping scale.
A new 3D solid Model of the complete plane is in progress
A 3D Solid Model of the complete Long Ez design was undertaken using SolidWorks software. One of the configurations was to have included the canopy modifications shown here. However, priorities are such that there is insufficient time avaialble to complete this project.