The DoubleQuick was everything
the name implies, twice the power. It had a 430 Cuyuna engine, the most popular
used at the time. This engine replaced the 15 HP Yamaha.
Some changes were made in the DoubleQuick as a result of the new engine. The
underneath mount was used, placing the engine directly above and slightly behind
the pilot. The drive line consisted of a 1 1/2 inch diameter coupler and a long
1 inch shaft with a heavier pillow block bearing at the rear with the prop, a
36 incher, at the rear of the shaft.
This setup proved very powerful
compared to the Yamaha. Consider that it required, say, 12 HP to actually keep
the plane in the air. This gave an excess of three HP for climb. Consider the
Cuyuna with 30 HP might require 15 HP, a little extra weight, to keep the plane
in the air, The extra climb HP of 15 was five times that of the Yamaha.
This was the good news. The bad news was, the Cuyuna was an axial flow engine,
cooling the rear cylinder with the hot air which had passed through and cooled
the front cylinder. This made the rear cylinder run somewhat hotter than the
front cylinder. Also, in an attempt to save some money, most companies, Eipper
included, sold aftermarket muffler systems rather than the Cuyuna system. Most
proved extremely short lived due to burn outs and cracking, loose internal
This plane proved very capeable of flying floats, even with retractable gear
setups. It would climb straight up, or so it seemed. The small fuel tank size
of less han three gallons was rather limiting for cross country flights but
tieing several small jugs on the rear axle was commonplace.
The first DoubleQuicks were shipped with a 'J' shaped muffler that wrapped
around and straight across the back of the engine. It was shaped like a candycane.
The later ones were shipped with the Fisher or Protopipe systems. None of these
were any good.
Control of the DoubleQuick was just like the Yamaha Quick, weight shift for
pitch and a harness controlled rudder for yaw/bank.
The DounleQuick was easy to assemble. The engine was removed for transport,
the tail parts are removed and the wings folded after the tribar is rotated
Removal of the wings from the tricyle part was difficult since one bolt connected
the wire shackle and both members of the tri-bar.
The DoubleQuick was sold in the era of the FAA required footlaunch capability,
so the axle had the large hump in the center to accomodate a runners feet during
take-off and landing. This axle was slightly longer by and inch and a half
per side than the more recent straight (slight bend at the center) axle.
DoubleQuicks all came with a small lever controlled trim tab. This was somewhat
effective controlling pitch. The plane wanted to climb at full throttle, often
catching a light weight pilot off guard, sending him to the rear of the hang
cage, further aggrivating the CG and increasing the climb. Only reducing the
throttle would help at this point.
My first DoubleQuick had the 36 inch prop. It reached supersonic tip speeds
at full throttle and could be heard for miles. Quite often, my first early
morning flight would signal others that it was indeed flyable and come on out
to the airport. I only bought one of these small prop models. The noise was
extrordinarily loud both for the pilot, and the local neighborhood as well.
My next order for six new kits was contingent on getting the reduction drive
using the 52 inch prop with the 2 to 1 cog belt drive. The factory quickly
altered the design to include the reduction on the DoubleQuick as well as the
The plane climbed so well, that you often felt as if you had little control
to lower the nose. The speed and lift combined with the low gross weight made
for stupendous climb angles.
I was making a few parts during this time period, and fabricated/sewed an actual
elevator for the DoubleQuick that was actuated by a string from the back of
the seat. It was very effective and on one ocassion, produced a good laugh
at a friends expense.
I had installed the system on my another friends plane, matching the sail pattern
and color. the only giveaway that it was not quite factory was I had used silver
This second friend was in the habit of allowing planeless folks to fly his
plane, and when the first friend took off with the new mod, he looked like
he was going up a set of stairs as he climbed, moved forward and leveled off,
then climbed steeply again,
The large trimavator surely did tame the DoubleQuick down, and made it fly
much as the MX did, with good control. The small trimtab supplied by the factory
was almost ineffective. The factory did install a full width trim tab on the
Quick E model, but it didn't have the large effect that mine did as mine was
about half the size of the large MX elevator.
These trimavators didn't go up above level with the stab, just down, to help
lower the nose under higher power settings.
A couple of the locals installed these kits, and added fairings, brakes and
such just as would an MX driver.
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