Aerostar 601P, Superstar, Piper Sequoya, Aerostar 602P, Superstar I, Superstar II, Superstar 650, Aerostar 700P, Superstar 680, Superstar 700, Super 700 Aerostar, Aerostar 702P. Where did all of these names come from, and what do they mean?
by Jim Christy, Vice President of Aerostar Aircraft Corporation
Over the past 32 years there have been several names given to Aerostars to differentiate the various models. Some names came from the manufacturer and some came from modification companies. The Aerostar 601P was developed in 1974 and differed from the turbocharged 601because the cabin was pressurized, hence the P after 601. Machen Inc. developed several conversions and upgrades for Aerostars, and I was the salesman for that company when these conversions were being developed. Machen inc. (pronounced MACH’ en) gave the converted airplanes different names to differentiate them from the standard Aerostar. At that time, around 1978, the Aerostar 601P was the only pressurized Aerostar in production. Machen’s original conversion of an Aerostar consisted of removing the 290-hp. Lycoming engines and installing the 350-hp. counter rotating engines (with some modifications) that were also used on the Navajo Chieftain. In addition to the engines, induction air intercoolers were installed in the wings, and shorter counter rotating propellers were installed. In 1981, Piper Aircraft introduced the Piper Sequoya. An amateur built aircraft was already using the name Sequoya and the designer of that airplane objected, so Piper changed the name to Aerostar 602P. This airplane still had 290-hp. engines and basically the same performance as the 601P but utilized lower compression pistons in the engines and higher manifold pressure to get the same horsepower. Another change was that a lower take-off rpm setting was used to reduce noise. You might ask yourself why the change if the performance was no better. Actually, when the 601P was introduced in 1974 the performance of the turbo system was weak but by 1980 the 601P turbocharger system had evolved and was much more capable of producing high cruise manifold pressures at high altitude. This was good for performance but there were numerous cases of detonation resulting in burned pistons and failed engines during flight testing before the airplane could be delivered to the customer. Something had to be done and Lycoming was hesitant to supply any more 601P engines to Piper. At that time a former Aerostar engineer, Steve Speer, was contacted to discuss intercooling the 601P engines to prevent detonation from occurring. Lycoming had another option, which was to install low compression engines, which were less prone to detonation at altitude. Both were viable options and Piper decided to just switch to low compression engines. The new low compression engines were capable of obtaining the full 290 hp. on take-off, and were therefore slightly more powerful than the 601P engine, which produced about 277 installed HP on a standard sea level day. Because it had slightly more power, the 602P did have some advantage in take-off and full power climb performance and a quieter cabin at full power due to a reduction in take-off rpm from 2575 rpm to 2424 rpm.
From 1981 to 1983, Piper sales people were trying to sell the 602P to 601P owners but with little success. Few owners saw the improvements offered by the 602P to be worth the $250,000. extra dollars required to trade a low time 601P for a new 602P. During that time a 601P owner could upgrade his airplane with two brand new 350 hp. intercooled engines for about $125,000.00 by buying a Superstar conversion from Machen. Inc. Another name was soon introduced when Machen Inc. developed a modification to existing 601P and 602P aircraft to increase the power output of the existing engines from 290 hp. to 325 hp. The cost for this upgrade was $45,000.00 and it became a very successful conversion that gave the Aerostar owner much more performance without the high cost of factory new engines and propellers. It also gave owners an alternative to trading their airplane in on a 602P since they could have the same low compression as the 602P with an additional 35 hp. for a fraction of the cost. We had to come up with a name for this conversion so we decided that we would call this modified airplane the Superstar 1 and renamed the original Superstar the Superstar II. (This by the way is what Piper did with the Cheyenne. They built the 620 hp. airplane first and called it the Cheyenne; then they built a 500 hp version naming it the Cheyenne 1 and renamed the higher powered airplane the Cheyenne II)
In 1982 – 1983 time frame Piper sales people convinced management that they needed a 350- hp. version of the Aerostar. The Piper Aerostar 700P was certified in 1983 and 25 700P’s were delivered as 1984 models. That was the last Aerostar model produced by Piper Aircraft Corp.
About that same time, Machen Inc. sales of the Superstar II were declining but the Superstar I was selling well. We knew that one of the most powerful features of the Superstar II conversion was the induction air intercooling system. Intercoolers gave us the big speed increase at altitude because they allowed us to maintain the horsepower in cruise. (Intercooling the 350-hp. engines resulted in a 20+-knot increase in indicated airspeed at FL250) We decided there might be a good market to increase the performance of the Superstar I by adapting the Superstar II intercooling system to the Superstar I. We knew this would result in even fewer sales of the Superstar II but due to the high cost of the conversion requiring new engines and propellers and with the introduction of the 700P from Piper, our sales of the big conversion were declining rapidly. With the introduction of the intercooled Superstar I we again had a name issue. Since we were going down the road of upgrades that could be installed in stages, we decided to introduce more descriptive names based on the aircraft’s total engine horsepower. At that time in 1985, we renamed the Superstar I the Superstar 650. (2X325 hp= 650) When we added intercoolers to the 650, we certified the engines at 340hp. The Aerostars equipped with those engines were then named the Superstar 680. We later added the shorter quieter propellers and other upgrades to certify the engines at 350 hp. and named that airplane the Superstar 700.
Piper Aircraft acquired the Aerostar Company from Ted Smith’s family in about 1977 and due to hard economic times ceased production of the Aerostar in 1984. From that time until 1991 Piper had three owners and was in financial trouble. That meant Aerostar and other Piper parts were hard to come by, and our sales of Machen products were negatively affected as more and more Aerostars became grounded waiting on parts from Piper. Vendors building parts for Piper weren’t shipping parts because the previous shipment was not yet paid for. In 1991, the owner of Piper was Stuart Milar who owned a 1980 and later a 1984 Aerostar. In the late 1980’s when we first learned Mr. Milar had bought Piper Aircraft and was an Aerostar owner, we approached him about doing development work for him/Piper Aircraft, and he graciously invited us down to his office in California to talk about the possibilities. He knew we had discussions with Piper’s previous owner about buying the Aerostar type certificate before he bought the company. Later in 1991 when he saw that bankruptcy was in Piper’s future he called us and said if we were still interested in buying the Aerostar type certificate, that he would talk to us about it. He agreed to sell us the TC because he said we were probably the only ones who could actually support the aircraft and he didn’t want the Aerostar owners to suffer through years of poor support while the company went through bankruptcy and possibly liquidation. In 1991, Steve Speer and I formed Aerostar Aircraft Corp. and acquired the Aerostar type certificate tooling, and data from Piper, then set about making and selling replacement parts. Word in the aviation community at the time was "you didn't want to buy an Aerostar because you couldn't get parts for them." Interestingly, even today when someone is considering the purchase of an Aerostar I am often told by the prospective buyer that, “I have heard they are hard to get parts for.” In 1991 there were various factory options for the airplane made by other companies such as the air conditioner by JB systems etc. At that time we decided to offer the various Machen STC'ed products also as factory options. In addition regarding names, we gave the name Super 700 Aerostar to those aircraft equipped with 350 hp. TIO-540-U2A engines. Recently we gave the name Aerostar 702P to those 700 hp. Aerostars also equipped with the 700-6 brakes, 5.5 psi pressurization, 6850 gross wt. increase and KFC 225 Autopilot.
Looking through the archives I found a 1972 article from Flying Magazine about Ted Smith. This was after the Aerostar was sold in 1971, and before Ted was able to buy it back. The article talked about the new airplanes he planned to develop. They had a larger cabin, bigger engines and more gross wt. He called them Superstars. There was a piston 400-hp. version and a turbofan version with two 1500 lb. thrust engines. After he was successful in buying the Aerostar design back the Ted Smith Superstars were never produced. There was however an experimental version called the Superstar when I worked at Aerostar in 1973. It was an Aerostar with 350 hp. Lycoming engines, an emergency exit in the overhead and a cruciform tail. Ted built the Superstar by modifying an Aerostar and reportedly used it as leverage (i.e. the Aerostar is obsolete now that I have the Superstar) when buying back the Aerostar design. The Superstar airframe was later used as the prototype Aerostar 800. The prototype 800 was the Superstar airframe with two more seats (due to a 32” extension of the cabin) and featured two 400-hp. Lycoming engines. The 800 was under development when Ted unexpectedly passed on in 1976. Piper continued development of the airplane as a replacement for their P Navajo but never certified it and eventually donated the airframe to Emery Riddle Aeronautical University.
I know it has been difficult for prospective owners to sort through all of the various names and make some sense of it. Hopefully this explanation will be of some assistance. If you see an Aerostar model name not represented above, and there are a few in very small quantities, feel free to call me and I will tell you what I know about it.