May 2014- It was a rather long road to certification for the airplane which eventually became the Tomahawk, with lots of starts and stops along the way.
Piper began design of a two-seat, low-wing tricycle gear training aircraft in 1958. It was to feature side-by-side seating and be made of fiberglass reinforced plastic with a gross weight of 1,500 pounds.
The first (and as it turned out, only) prototype—N2900M—was completed in spring 1962 and was designated the PA-29 Papoose. It boasted an all-moving horizontal tail, flaperons and a 108 hp Lycoming O-235-C1B engine.
Piper management seems to have been underwhelmed by the plane and initiated a project review to determine the model’s viability.
Concerns were raised about the longevity of the fiberglass material and it was decided that prototypes should be sent to Arizona and Lock Haven to test the material’s ability to withstand summer heat and winter cold.
Other changes were suggested and eventually N2900M received new wings, which met with mixed reviews and added 30 pounds to the empty weight of the plane.
Piper management discussed the future of the PA-29 and considered dropping the project altogether, but really seemed to want a replacement for the PA-22-108 Colt, so they moved forward with the Papoose project. Howard Piper continued to mull over the advisability of committing to fiberglass construction.
Over the next couple of years changes were made to N2900M which included extended wingtips, centering springs on the flaperon system and other fixes. In 1964 a complete redesign was proposed with two possible variations for the canopy, larger wings and a change in material from a paper honeycomb construction to an aluminum honeycomb construction.
None of the proposed changes for the PA-29 were undertaken. Piper had begun production of the two-seat Cherokee 140 in 1964 and it seemed a safer bet to stay with that more tried-and-true design.
Piper’s historian Roger Peperell believes that the Papoose took its last flight on Feb. 22, 1965.
Although Piper executives had dropped the Papoose project, the company continued to look into other possibilities for its training fleet and in 1969 began development of the PA-38. The project was cancelled rather abruptly in July 1970, but Piper continued its market research of the flight training segment by testing competitive aircraft and through market surveys.
In 1972 Piper sent a survey to 10,000 flight instructors throughout the United States asking them what features they would most like in a training aircraft. The top five responses were “handling characteristics,” “performance,” “operating costs,” “cabin comfort” and “price.”
With this information at hand, Piper restarted the Light Trainer program with Richard Kroeger as project director.
Both two- and four-place aircraft were designed, and a wing based on a modified Whitcomb GA (W)-1 airfoil was tested and was fitted to the prototype. It had a conventional low tail and a 100 hp Continental O-200 engine held on by a sheet metal mount rather than the more standard steel tubular mount. Airflow problems created by the sheet metal mount were to be worked out during testing.
Although Kroeger left Piper in 1973*, work continued on the PA-38 for a short time. The prototype received new wheel fairings, wing fences, a new aft fuselage fairing and other changes, but the project was stopped in October 1973 and the prototype was disassembled and stored.
In September 1974 the PA-38 once again resurfaced as the “New” Light Trainer Project. The previous prototype was reassembled with changes; the sheet metal engine mount was scrapped in favor of a tube steel mount used to affix a Lycoming O-234 115 hp engine to its front. It also received sprung-steel landing gear, a new cowl and a change to the fuselage at the door.
Lynn Helms had been hired as Piper’s president in 1974 and he thought T-tails would help to modernize the Piper fleet. The PA-38 received a T-tail in 1976. Despite its modern T-tail, the Piper board would not approve production of the model and the project was once again scrapped on May 25, 1976.
Under the direction Bill Barnhouse, the project was re-re-revived in late 1976. Changes were made to the flaps, wings and ailerons and a 112 hp Lycoming O-235-L2C was fitted to the airframe. A bubble-like cockpit provided exceptional visibility.
Finally the PA-38-112 (now dubbed Tomahawk) was approved for production. It was presented to Piper dealers and training centers in October 1977 to good effect and 1,400 pre-orders were taken. It received its certification on Dec. 20, 1977. Deliveries began in April at a price of $15,280.
Magneto failures caused the FAA to temporarily suspend the Tomahawk’s Airworthiness Certificate in September 1978, but the problem was corrected and production resumed.
Additional stall strips (above what had already been originally certified) became standard equipment on the PA-38 from January 1979 on, and Piper issued a Service Bulletin recommending installation of the additional strips for earlier models. In 1983 AD 83-14-08 was issued and it required (among other things) installation of Piper Flow Strip Installation Kit, Part No. 763-930.
In March 1981 Piper began deliveries of the Tomahawk II. This model came with improved cabin heating and windshield defroster performance, an improved elevator trim system, improved engine thrust vector, better cockpit soundproofing, larger six-inch wheels and tires for greater propeller ground clearance, and improved performance on grass and dirt runways, among other enhancements.
Sales of the Tomahawk II were poor and the model met its final end in 1982.
A total of 2,519 Tomahawks left the Piper production line and about 649 remain on the FAA registry.
The Tomahawk received a reputation for being dangerous in a spin, and in fact in 1997 the NTSB estimated that the Tomahawk’s stall/spin accident rate was three to five times that of the Cessna 150/152.
The AOPA’s Tomahawk Safety Review published in 1997 researched this apparent tendency. The report states, “Looking at the stall/spin scenarios in some detail, we found that the vast majority of them occurred at low altitude where, by our estimate, it would have been difficult—if not impossible—to recover from an incipient spin, regardless of aircraft type.”
It offered this advice for pilots and prospective pilots of the aircraft: “Some Tomahawk critics contend that the aircraft should not be stalled or spun. After looking at hundreds of accidents involving both the PA-38 and comparable aircraft, we note that some caveats are in order.
“No aircraft should be stalled or spun at low altitude, but we would extend the margins a bit in a PA-38. Before going solo, pilots should check out with an instructor who has considerable spin experience in the PA-38 and should have spins demonstrated to them, if circumstances permit, in strict accordance with the POH.”
Designed by a committee of thousands
The Tomahawk was—and is—a unique aircraft. You would think that designing an aircraft to the specifications of its end users would be a winning approach, but the process to get the Tomahawk to market seems remarkably convoluted.
The Tomahawk is nonetheless appreciated by its adherents and with cruise speed ranging from 90 to 110 knots, a fuel flow of about five gph and a range (with reserves) of more than 400 miles, it’s still used today as both a trainer and economical personal transport.
*Roger Peperell tells the story of Richard Kroeger’s post-Piper deeds. He writes, “Richard Kroeger left Piper in September 1973 and went to the University of Michigan, where he refined the design of his ‘light trainer’ in February 1974. Not surprisingly the design looked similar to the Piper ‘light trainer.’ Beech Aircraft [was] offered the design, which they accepted and it became the Beech model 77 Skipper that went on sale in 1979 and explains why the Skipper looks similar to the PA-38.”
“AOPA Tomahawk Safety Review” by Bruce Landsberg