Agricultural planes constitute a chapter on their own.
These beaten-up work horses are exposed to stressful tasks
and hostile environments with the only purpose of helping us. The Bauhaus
school of design popularized in the 20’s the “form follows function” motto, and
this is especially applicable in the case of the Ag plane.
Surely with a taste for the unorthodox, Mr. Luigi Pellarini
designed the PL-7 cropduster around the product tank located in the center of
the fuselage. To this element the engine support members were bolted as well as
the remaining after part of the fuselage. An array of struts transmitted the
loads from the diverse parts of the airplane to the same central element, the
tank. The lower wing had straight leading edges while the upper wing leading
edges were a bit angled back. The result of such elaborate load distribution
was a very attractive machine that was ready to fly in 1955, a bit out of my
usual subjects’ time envelope but nevertheless strange enough to merit some
extension of boundaries.
Mr. Pellarini continued to surprise and amuse the aeronautic
world with other creations, like the Waitomo / Bennett PL-11 and the Transavia
PL-12 Airtruk, which no doubt I want to model too.
I had the PL-7 project in the back burner for a time; nevertheless
its appearance had me looking at the references I could gather mainly on the
Net and some material sent by the late Jon Noble. His help was instrumental in
materializing many projects. Wherever you are now Jon, thanks.
The model started as a plug that was used to vacuform the
fuselage sides and the canopy transparency. Some internal structure and details
were fabricated before closing the pod. A cowl was made to lodge the Armstrong
Siddeley Cheetah aftermarket resin engine while wheels were selected from the
bin of the white metal bits. A styrene lamination was made to replicate the
Fairey-Reed propeller, which has a particular twist to it (pun intended) being
almost a warped chunk of flat metal.
As the parts were being produced a put-together strategy had
to be devised, a must when the dreaded strut forest is present as in this case,
and even more so given the pod-and-booms configuration. So once the flying
surfaces were made some sub-assemblies were created as per photos to make the
final put-together more manageable. As with almost all front tricycle landing
gear arrangements there is a potential for tail-sitting, so a disk of metal was
added to the firewall just in case.
Isn’t it an interesting twist of faith that a machine
conceived to fight bugs ends up resembling a bug itself?
Mr. Pellarini, what a beautiful and strange thing you
created.
Thanks. I am mucking around finding info on Pellarini and it is interesting as part of the Airtruk development. Tom Lockley, tomlockley@gmail.com January 2018
ReplyDeleteHi Tom
DeleteAnything I may help with?