Over the frozen forest lands of Finland, there is an
interesting little single seat sport plane flying in some
numbers that proves you don't need a lot of horsepower
to have fun flying. How about cruising at 105 miles an
hour while sipping just 1.75 US gallons per hour? 60 miles
per US gallon is the same fuel mileage as my Honda Insight
gasoline/electric hybrid car gets, but the Honda doesn't
fly nearly as well!
Designer Kai Mellen spent his 35 year working life as
a project engineer for Finnair, the Finnish national airline.
A graduate of the Technical University in Helsinki (Polyteknikkojen
Ilmailukerho, or PIK in Finnish), Kai has penned a number
of light airplane designs over the last several decades.
One of his earlier design efforts, the PIK-21, was a Volkswagen-powered
Formula Vee racer, shown opposite page.
The PIK-21 and PIK-26 are two of the aeroplanes built
using the numbering system of the Flying Club of the Technical
University of Helsinki, an organisation that has spawned
a large number of aeroplane designs since its inception
in 1931. As a senior member of the flying club, Kai was
given the use of the PIK designation, even though the
design and construction work was done entirely on his
own. The PIK-26, known in Finnish as the "Mini-Sytky"
(nobody seems to be able to translate these words into
English, but it seems to mean something like "Little
Buzzer") was intended as a retirement project for
Kai, to keep him busy and off the streets of Helsinki.
Normally, an aeroplane is designed around the engine.
In this case, the PIK-26 was designed around a Mosler
35 horsepower MMCB engine, (a Volkswagen conversion) that
Kai had lying around the garage, having got a "good
price" on it. Kai's wife, tired of seeing him loafing
around the apartment in a post-retirement funk, suggested
that he activate his drawing board once again and draw
up an aeroplane to use the engine. The price of aviation
fuel in Finland currently runs around $7 US per gallon,
and the low consumption of the Mosler makes it a good
retirement run-about for Kai. Several of the PIK-26 aeroplanes
built subsequently use the VW conversion engineered by
Morry Hummel.
The PIK-26 is attractive despite the designer's use
of flat surfaces.
The Mosler MMCB initially had some oil pressure problems
but now works well.
Two years and 730 hours of labour were necessary to complete
the design work. Kai's skill at the drafting board is
apparent when looking at the hand-drawn plans. In these
days of computer-generated aeroplane designs, it is a
pleasure to see the artistry of a well-done manual drawing!
The designer's hand-drawn sketches and plans are works
of the engineer's art!
The Mosler MMCB, seen above mounted to the prototype,
comes from the Florida machine shop that builds parts
for the Mosler line of kit-built supercars.
How is it built? The PIK-26 uses wood construction,
made largely from pine and from the Finnish birch that
the country is famous for. I was once told that the reason
it is so highly prized as a material is that the short
summers and cold winters make the trees grow slowly, giving
a tight and strong pattern of growth rings. The skins
of the PIK-26 are made of birch plywood, with the thickness
varying from 0.8 mm to 2.4 millimetres. The spars are
made of pine, sawn from planks. Metal parts are made of
2024T3 aluminium and 4130 steel. It is said that if you
can build a wooden model aircraft from plans, the PIK-26
is no problem. The wing ribs are made of 15 mm PVC foam,
and use the GAW-2 profile. The time to complete all the
wing ribs is about 8 hours. The total build time for the
prototype was two years and 2,298 hours, and the 2nd PIK-26
took about 1,500 hours. The construction looks fairly
typical for a light wooden monocoque.
Many of the critical dimensions of the aeroplane were
dictated by the size of Kai Mellen's garage workshop.
When it came time to mate the wing to the fuselage, Kai's
wife was surprised to return home to find that a hole
had been cut in the wall between the garage and her coat
closet, in order to get enough room to put the aeroplane
together!
What's it like to fly? According to builder Panu Mertamo,
the PIK-26 requires a pilot with some experience with
taildraggers. The designer says that "quick feet
action" is required to keep the aeroplane headed
straight down the runway. The controls are very sensitive
at the beginning, but Panu says that the PIK-26 is a very
nice and enjoyable plane to fly after you get familiar
with it. The PIK-26 uses a side stick controller that
requires very small movement. Panu is a fairly tall guy,
at around 6 foot 2 inches, and he fits fine. However,
this is not an airplane for those who make too many visits
to the cheeseburger stand.
The maximum allowed pilot weight is 185 pounds. Kai
Mellen made some modifications to the fuselage cross section,
to accommodate a friend's "more fully developed stature"
for the second example. The Hegy cruise propeller does
not give very rapid acceleration on the take-off run,
which is around 600 feet. Once above 60 miles per hour,
the engine and prop hook up to give a climb rate of around
550 feet per minute. The stall comes at less than 40 miles
per hour (65 kilometres/hour), a requirement under the
Finnish ultralight certification rules.
Builder Panu Mertamo's example of the PIK-26 first flew
in 2002.
The first prototype now has around 148 hours of flying
time and is working well, after some initial oil pressure
problems that led to an engine rebuild shortly after flight
testing began. Four more examples have been built from
Kai's plans and more will surely follow.
Builder Mertamo is enthusiastic enough about the design,
that he is in the process of converting the plans to English,
for those of us who might also enjoy a thrifty but fun
aeroplane. He estimates that the total cost of building
his aeroplane is around 9,000 Euros, or around $12,000
US. This includes the cost of materials, engine, and instruments!
For those of us becoming used to hearing about $80-100,000
US being spent to build a new aeroplane, this is a really
affordable price! Information about availability of plans
can be found at the web site http://gamma.nic.fi/~wilpu/panu2.htm
The specifications are shown below.
All measures are in the metric system.
Top Speed, (kilometres/hour) 190
Cruise @ 3,000 rpm, (kilometres/hour) 170
Fuel Consumption (litres/hour) 7
Stall (km/h) with flaps 63
Rate of Climb, (m/s) 3.2
Take-off Distance, (m) 200
Landing Distance, (m) 250
Engine Used Mosler MMCB
HP 35
Fuel capacity (litres) 27
Empty Weight, (kg) 144
Gross Weight, (kg) 250
Useful Load, (kg) 106
Height, (m) 1.22
Length, (m) 4.33
Wing span, (m) 5.24
Wing area, (sq. m) 6
Wing loading, (kg./sq.m.) 41.6
No. Completed/Flown 4
Load limit, (g) +3.8, -1.5
Airfoil GAW-2
