Let Z-37A-2 Cmelák
The 'bumble-bee'--Czech agplane trainer turned sportplane. By Ernie Hoblyn.
THE FIRST TIME I really sat up and took notice was when I saw this big, imposing aircraft land on Lundy Island, during the PFA Devon Strut's 2000 Fly-in. I really couldn't believe that anything so big could land in such a short distance! Later, owner John Richards and I met at Dunkeswell, so I could discover for myself how this machine would handle.
The Czech-built Cmelák, or 'bumble-bee', is about the size of a Harvard and, how shall I put this, the design is functional in the extreme as befits an aircraft which was originally designed as a crop-duster. Anything they wanted to add to the airframe was simply made out of sturdy material and bolted on, with barely a nod towards aesthetics or aerodynamics. The reinforced step on the wing trailing-edge could have been borrowed from a tractor and the undercarriage seems to defy anyone to break it. The oil cooler is bolted on the side of the engine cowling as if it was an afterthought... "Where shall I put this thing, Chief?" "Can't you see I'm busy, just bolt it on somewhere!" The designer was certainly not aiming for any concours d'élégance. I think it's this victory of substance over spin that I find so appealing.
The walkround reveals an interesting mix of construction methods and materials. The fuselage is of welded steel tube structure (described in Jane's All the World's Aircraft as a fail-safe design), with an aluminium sheet skin, back as far as the rear of the cockpit, and fabric thereafter. The wings are covered in corrugated aluminium, reminiscent of a Ju 52, and are built in three pieces, a flat centre-section constructed as part of the fuselage and outer panels which have marked (7°) dihedral. The leading edges of the outboard panels, ahead of the ailerons, have substantial fixed slats. The flaps are double-slotted aluminium, pneumatically operated, but all the other flight control surfaces are fabric covered and rod operated. The fin and tailplane are aluminium, the tailplane made from the same corrugated material as the wings.