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