Sliding into N152MP was like meeting an old friend. The bright white Mooney with its bold red, yellow, and blue strips looked like most any other late 1980s Mooney until you looked inside or walked around front. There, the tightly cowled nose gave a clue as to what powered the composite three-blade prop–a Porsche engine.
The airplane showed up in Frederick today as ferry pilot Anthony Eyre of Cross Junction, Virginia, stopped by Landmark Aviation, the local FBO, to get a GPS installed before he took the Porsche-powered Mooney to its new home in Ulm, Germany, near Stuttgart. The Stuttgart name, where Porsche is headquartered, dominated a large Porsche decal on the Mooney’s forward-slanting blue tail. Eyre is flying the airplane for Computaplane in Scotland, delivering it to its new owner in Germany, Uwe Sauter, who happens to be an aircraft mechanic and the owner of a Porsche 911.
The Mooney PFM was familiar to me because shortly after I started working at AOPA in 1988, the association purchased one of the unusual airplanes–only about 45 were built. Several of the editors were checked out in the airplane, including me. It was one of the first high-performance airplanes I’d ever flown. I was soon quite comfortable in the efficient airplane, especially since the engine was so easy to operate. Starting it was car-simple: Turn on the key. No cantankerous mags or balky carburetor or fussy fuel injection system to deal with. A dual electronic ignition system and computers handled the start procedure. Power was managed with a single lever that controlled the prop, mixture, and throttle–the holy grail of engine management that manufacturers attempt to bring to market today; and this was 1988.
The engine was smooth and quiet, but the gearbox necessary to amp the engine rpms down to a rate that could be absorbed the prop added weight–some 200 pounds by some estimates, and complexity. AOPA’s Porsche Mooney suffered numerous cracked and leaky gearboxes. The dual bus electrical system was unheard of in light airplanes in those days. Those of us checking out in the airplane found it a bit intimidating. The large red, guarded “Emergency Crossover” switch was your savior if certain electrical failures occurred; or your nemesis if other failures occurred and you threw the emergency switch tying the two buses together and allowed the failure to take out both systems.
In flight, the Porsche Mooney handled like any other Mooney–aside from the Porsche’s stone-simple engine management. It was quick and efficient. Eyre reports that he sees about 155 knots TAS at 9,000 feet on 9 gph.
So why have you probably never heard of one? Because, like many other products ahead of their time, it wasn’t perfect and the embedded competitive products of the day kept their market acceptance; inertia prevailed. The Porsche airplane was a bit slower and definitely heavier than the Lycoming-powered Mooney 201 of the day. There were a few maintenance issues, like the gearbox. Porsche, who was behind the project in conjunction with Mooney Aircraft, attempted to reassure buyers with guaranteed TBO pricing and other maintenance plans. But in the end, consumers wanted their speed and the Porsche model didn’t quite deliver.
In the end, Porsche bought back most of the airplanes through various programs and re-engined them with Continentals and Lycomings. You may be flying such a modified airplane today and not know that it was once N30MP, the Porsche Mooney that AOPA once owned.
Eyre is hoping to leave Frederick July 15 and make it to Germany within a few days, removing what may well be the last Porsche-powered Mooney from North America.
Certainly one of my most significant memories of my flights in the model was pulling up on a ramp with a few people around. To shut the engine off, you just turned off the key–like a car. At that point, the engine and prop simply thudded to an instant stop rather than winding down the way most conventional airplane engines shut down. The result was frequently curious looks from the crowd wondering what it was that you just broke.
My guess is that with a few tweaks the Porsche engine could have been made to run on high-octane auto fuel. Think what that might be worth today as we scramble to figure out a strategy for moving away from leaded avgas. Back to the future. Fly on N152MP.
- The PFM’s single-lever power control was ahead of its time–and still is.
- The complex dual electrical system was clever but intimidating.
- The Porsche logo on the PFM’s tail
- Tony Eyre with Mooney PFM before delivery to Germany