BOXART STORY
#11167
Text: Richard Plos
Illustration: Adam Tooby
Box design: Jan Zdiarsky
Trainer in a good shape
The Z-26 two-seat trainer, aptly named Trenér (meaning “trainer” or “coach” in Czech),
first flew on October 20, 1947. The result of
the work of the design team led by Karel
Tomáš answered the requirements of the
Ministry of Defence, calling for simple-to-operate aircraft suitable for pilot training. The wooden design of the wing and
tail surfaces was soon replaced by an
all-metal one, thus creating the Z-126 version, the archetype of several other versions of the Trenér, which gradually got a
more powerful six-cylinder engine instead
of the original four-cylinder one. First, the
Walter Minor 4-III with a maximum output of
77 kW (105 hp) was replaced in the Z-226B
and Z-226T versions by the technically
related WM 6-III unit with an output of 118
kW (160 hp), and later by the more modern M-137 engine with an output of 132 kW
(167 hp). The latter also powered the last
type of the Z-226 series, the MS version,
equipped with the pitch-adjustable propeller V-503A. At that point it was clear the
Trenér line needs a substantial upgrade.
The design team of the Zlín company decided to equip the Trenér with a retractable
landing gear to reduce aerodynamic drag.
Furthermore, there was a modified wing
with enlarged fuel tanks (from 35 l to 45 l)
to extend range and endurance or a new canopy for better visibility. In addition, external fuel tanks could be installed on the wing
tips. The new version was designated Z-326
Trener Master, or C-305 in the case of the
38
INFO Eduard
military version and was also the first of the
Trenér line to allow IFR flight and therefore
night flying. To this end, the C-305 also received small lights on the landing gear legs.
These were used for visual inspection from
the ground during final landing approach.
If they were visible, the landing gear was
down, if not, the air traffic controller alerted
the pilot.
The powerplant was again a WM 6-III
six-cylinder engine, which was later replaced by the M-137. The version powered by
the latter was designated Z-236M, then
Z-326MF after the installation of the V-503A
propeller.
The first prototype was taken into the air
by the factory pilot Leopold Brabec for the
first time on August 12, 1957. Ten C-305s
were produced for the air force, most of the
civilian versions were exported. There were
numerous customers in France, Germany,
Spain and in many other countries. Of the
ten military C-305s, nine eventually made
it to civilian service. Five of them are still
flying today, one even in period military livery. It is OK-OTP (originally 0612), while the
second one in this livery, OK-OTE (originally
0610), reached its flight hours limit and is
kept in the Military Historical Institute depository today.
OK-OTP started its service with then
Czechoslovak air force on December 14,
1960 and underwent two overhauls during
its military period of service. The aircraft
was handed over to the Svazarm organiza-
tion on July 29, 1971 and received the civilian
matriculation OK-OTP. It was flown by the
Prievidza Aero Club and on December 29,
1979, was converted to the Z-326M version
by Aerotechnik company. Its last flight was
to be from Prievidza to Dubnica on May 25,
2008. The crew of Jánošík and Chupek transported it to its new owner, who intended to
hang it under the ceiling of a private museum. In green painting it was to represent
a Bf 109. Before the aircraft was irreversibly
damaged, it was discovered by Karel Toman,
who spared this Trener Master from an ignominious fate with desire to restore it to
flying condition again. So, the aircraft was
moved to Prague and in 2012 Milan Mikulecký stepped in and took over the restoration
project. After a complete overhaul by Zlin-Avion Service, the aircraft received some
of the original military equipment again and
also the factory drawing coloring valid for
the military C-305. Due to the installation of
the M-137 engine, it is of course no longer
a genuine C-305, which was powered exclusively by the WM 6-III engine.
The second aircraft in Adam Tooby’s drawing is the Swiss Z-326MF, serial number
925. It is a final production run aircraft that
came to its current owner via France, where it was exported in 1967 and flew as an
F-BORV originally. It was converted to the
MF version by Zlin-Avion Service company
in 2016, after which it returned to its owner
in Yverdon.
October 2022