VINTAGE FLYING MACHINES
FLYING MUSEUM
Waco YMF-5
The Waco YMF-3, was introduced to the aircraft market in 1934. It was a refinement of
Waco’s legacy F model design. The company was reluctant to adjust their design, but
sales were dropping off. Waco introduced two F-3 models during the 1934 season.
The Waco YMF-3 equipped with the 7 cylinder Jacobs L-4 engine of 225 hp offered
many aerodynamic refinements, better appearance and more room. Slightly refined for
the 1935 season, the YMF-5 was added to the Waco list of available models. Deep-
chord NACA- type engine cowlings contributed measurably to extra speed. Waco
didn’t build many of the YMF prior to shifting their emphasis to other models, but the
story doesn’t end here.
Vintage Flying Machines YMF-5 was built new in 1991. In 1985, a small group of
airplane enthusiasts in Michigan realized that the Waco type certificates were still valid if
somebody wanted to put the airplanes back into production. The YMF-5 was the
obvious choice because of its beauty and the huge number of Jacobs radial engines
that are available to power the airplane.
It is an oversimplification to say that Waco Classic Aircraft simply set up shop and
started building the YMF just like the original Waco had done 75 years ago. Though the
type certificate is technically still valid, there are many changes that were necessary
either because the same materials were no longer available or because superior
materials and methods had been developed during the intervening decades. So
returning the Waco to production required a series of STCs to the original TC.
One of the primary structural changes was replacing the mild steel tubing used to form
the fuselage frame with high-strength 4130 steel. The steel tubing is now corrosion-
proofed internally and epoxy-coated externally. The mechanical brakes were replaced
by modern-design hydraulic toe brakes. A 28-volt electrical system was installed and
the instrument panels were modified to accept full IFR instrumentation and avionics.
Heaters were added to the forward and aft cockpits. The tailwheel was raised three
inches and made steerable. A new stainless-steel firewall meets current burn-through
standards. And on and on.
While VFM’s was built in 1991, it suffered an accident in 1997 that required a complete
rebuild. Note Waco restorer Jerry Brown undertook the restoration and finished the
aircraft as one of three Waco UMF-3s provided to Cuba in 1937. The original UMF was
powered by Continental R-670-A while VFM’s YMF remains Jacobs powered.