What's Your Mission?

by Ken Bacon AOA Executive Director

I am so glad to see the continued interest in the Aerostar almost 40 years after the first 600 rolled out of Ted Smith Aerostar Aircraft Company. Today's interest is a tribute to his expertise in the aviation community.

Our AOA membership changes and grows due to new members who would like to own THE WORLD'S FASTEST PISTON TWIN. The conversation with our new members always turns to "Which Aerostar model is right for me?" I answer their question with a question "What's your mission?" Tell me about what you currently fly, where do you usually go, and how many passengers do you carry.

In an attempt to help AOA members and future members, as well as current Aerostar Owners, I would like give you my opinion on the different Aerostar Models and their benefits. So here goes, please don't get your feelings hurt.

The first production model to roll out of Ted Smith Aerostar Company was the 600. The early models of the 600 didn't have zinc chromate coating on all aluminum parts which later resulted in possible corrosion issues. This problem went away when Ted bought the company back from Butler Aviation in the 1974 model year. The 600s have a light duty crankcase which is susceptible to cracking between cylinders. It is repairable and many have been welded or replaced with heavier crankcases. The good news is the 600 is a 200 knot aircraft which can operate on 30 GPH or less fuel. Also, it is the least expensive to maintain. It has great range but is limited to 5500 lbs. gross wt. I have only heard of one with Known Ice, but the option can be added. The service ceiling is 20K feet, but most owners operate them below 14K. Finding a low time 600 is very difficult because they were very popular as freight haulers.

The next model to come from Ted was the 601. They date back to 1969 and became the 601A in 1974 with an engine change. This is one of my favorite models due to its 30K foot service ceiling. It tends to fly a little nose high in the flight levels, but it is light weight and turbocharged which equates to fast. I have flown in a 1970 601 with intercoolers at 27K feet. The true airspeed was 257 knots burning 32 GPH.

The early 601s used a Lycoming Engine which had a 1400 Hour TBO and had the same corrosion issues as the early 600. The 601A changed to the old reliable IO540S1A5 which was also used in the 601B and 601P. Both 601 and 601A had electric motor driven wastegates which are simple to repair and simple to operate. Another great thing about the 601 is you can operate it with the turbo on or off, your choice. Due to Ted's utilization of the STC process for many of his turbocharger add-ons, you may find a 601 out there which has had the turbos removed via another STC. The early 600 and 601s used a Bendix 810 Autopilot which is very hard to find parts for. Autopilot Central still works on them, but parts are limited. I see many modernized Aerostars updated to the Stec Autopilot.

After Ted purchased the Aerostar back from Butler, he developed the pressurized model 601P. The first models (1974) were STC conversions of the 601A with wing extensions and the Lycoming IO540S1A5 Engines. The service ceiling was limited to 25K feet most likely due to the 4.25 lbs./sq. inch pressurization system which held an 11K foot cabin @ 25K feet. The 601P was the longest production run and the most numerous model existing today. In 1978, after Ted's death, Piper Aircraft Corporation bought the Aerostar rights from Ron Smith (Ted's Son) and Ted's widow. The production was later moved to Vero Beach, FL. Under Piper's ownership the 601P got heavier, but the ventilation system was greatly improved. The fuel burn of the P-model runs 34-36 GPH @ 65% power. Additionally, Piper changed the turbochargers from the RayJay part no. 600574 to the 600575. This change improved the altitude capability of the p-model Aerostar. The majority of the Ted Smith 601P Aerostars used the EDO Mitchell Century IV Autopilot and the Piper version used the King KFC-200.

The Ozone landing gear was used on the early 600, 601, and 601P models until Ozone went broke around 1978. With the Piper 1979 model year, the Weibel landing gear was utilized until the end of production 1985.

The gross weight of the 601P and the 601B is 6000 lbs. Oh yes, in 1976 Ted introduced the 601B, which has the wing extensions and the wastegate actuator system of the 601P, but is not pressurized. There were very few built, but what a payload. Empty, the 601B weight is approximately 4100 lbs. and will carry approximately 1900 lbs. of payload burning 32 GPH. Put the Machen Aux Fuel Tank in this Aerostar and fly 1200 NM non-stop. Top it off with a service ceiling 30K feet.

In 1980, Piper decided the 601P did not have the power it needed for single engine safe operation, so they changed the Lycoming Engine from the S1A5 to the IO540AA1A5. This engine change created the 602P. The AA1A5 was rated at 260HP with the low compression engine (7.3:1) versus 290HP S1A5 (8.7:1). Therefore, the 602P needed more powerful turbochargers to provide the 37 inch boost necessary to provide the 290HP. Piper also added Known Ice to the 602P model. The fuel burn increased due to the low compression motors to approximately 40 GPH. Due to Piper's desire to create a perfect Aerostar, the 602P had a short production life (1980 thru 1983).

Since the initial purchase of the Aerostar, Piper was never happy with the manufacturing methods and parts count for construction of the Aerostar. But, every model of the Aerostar which Piper built took longer to make and required more parts than the Ted Smith Aerostar. Piper had several years experience fixing under-warranty Aerostars, which they thought would help them create the perfect Aerostar.

So, in 1984, they built what they believed was the perfect Aerostar. They produced twenty-five (25) model 700P Aerostars in their last year of Aerostar production. Yes, they did fix a lot of the issues like single engine service ceiling, weight and balance, and better cylinder cooling. What they didn't improve was a higher service ceiling, a significant gross weight increase, and a pressurization system increase.

The 700P utilizes the Lycoming TIO540U2A Engines which are low compression 350HP turbocharged and intercooled. In my opinion, these engines are the best engines Lycoming has produced to date. The crankcases have all the fixes to the design which have caused failure in the previous high horsepower models. They come from the factory with pressurized magnetos and the heaviest crankshaft. The problem Piper and Machen (I will talk about them later) had with the 350HP motors was controlling the high cylinder head temperatures. Piper solved this problem with engine cowl flaps. The 700P POH calls for opening the cowl flaps during take-off and climb. During the summer months the cowl flaps will need to be opened slightly during cruise when operating a 65% power in order to keep the cylinder head temps at or below 400 degrees F.

The 700P single engine service ceiling is the highest of all the models at 15K feet and the best reason for the 700P is the rate of climb on one engine at gross weight. The Aerostar will climb 350 feet per minute from sea level on one engine with flaps up, gear up.

The weight and balance had to be improved due to the additional fuel which you must carry to feed these big motors. The fuel burn at 65% power is 45GPH. The way Piper improved the weight and balance was move the aux hydraulic pump into the nose and the battery from the tail to just behind the luggage compartment. With the 700P full of fuel (approx. 220 gal.) the pilot and co-pilot seats need to be occupied to keep the aircraft in the CG Envelope.

By turning the right engine propeller right and the left engine propeller left they reduced the engine noise in the cabin as well as convincing the FAA the aircraft does not need vortex generators or the water rudder for low speed enhancement. But, by doing the engine thing, the 700P ended up with two critical engines instead of one.

Speaking of the water rudder, this was Piper's answer to low speed handling issues which the FAA was not happy with in the early 1980s. The one nice thing about the water rudder is an improvement in crosswind landings. One of our AOA members has landed his 600 with the rudder in a 36 knot direct crosswind. He says without the rudder it would not be possible.

Even though the 700P is the heaviest of all the Aerostars produced, it is cleanest of all the 700 HP models due to Piper mounting the intercooler aft of each engine to reduce the drag of the air intake of the intercooler. The back of the engine of the 700P is harder to work on due to the location of the intercooler. Well everything in aviation is a trade off!

In the early 1980s Machen Aircraft Corporation comes on the scene with after-market modifications for the Aerostar. The owners of Machen, Jim Christy and Steve Spears, have produced many STCs and additional products for the Aerostar along with several power plant enhancements.

Before Machen modified the Aerostar, they were modifying Bonanzas with Navajo Engines. So naturally they created the Superstar II, doing away with the lighter cased S1A5 engines in favor of the Lycoming TIO540J2BD engines of the Piper Navajo Chieftain. Well this is probably the fastest Aerostar ever created. But, speed in aviation does not come without a tradeoff. The single turbocharger of the J2BD engine cooks the accessories on the back of the engines, as well as the single drive dual magneto, which has been plagued with problems over the years. In my opinion, the maintenance on this aircraft is out of control. Another issue is the tight cowling of the Aerostar and the updraft exhaust system. The TBO of this engine is 1400 hours and costs $50K to overhaul. This installation runs hot no matter how you operate it. But, if you are hell bent on owning one of these speedsters, then you need to know Eric Krueger at Krueger Aviation in Olivehurst, CA. Eric is the Superstar II expert and has developed several STCs for the Superstar II to help reduce the cost of ownership.

The second power enhancement was the Superstar I which took the IO540S1A5 (290Hp) engine of the 601P and increased the power to 325HP per engine with low compression pistons and higher volume turbochargers. The manifold pressure increased to 42 inches. Additionally, they added intercoolers and low noise propellers to produce the 700 HP. By increasing the power of these Lycoming motors the internal pressures increased and case cracking increased in the older design crankcases.

The 602P was easier to convert to a Superstar 700 because the AA1A5 engines had a newer stronger case and already had low compression pistons. By changing the turbochargers, adding low noise propellers, and intercoolers "Voila" 700HP. As I said before, Piper didn't make many 602Ps so the candidates for this enhancement were limited.

Machen was very successful in marketing the Superstar program due to the increase in safety related to single engine rate of climb at takeoff and single engine service ceiling increase. Due to the heat created by the higher horsepower engines, the speed in cruise is approximately 8 to 10 knots over the 601P and 4 to 5 knots over the stock 602P. So, in 4 hours of flight, a Superstar 700 is no more than 40 NM ahead of a 601P. The 700 is burning 45GPH the 601P is burning 36GPH.

Many of the Machen products can be added to any of the models, such as the low speed enhancement mod (vortex generators) which satisfies an AD or the aux hydraulic pump. By the way, I would not fly an Aerostar without the Aux Hydraulic Pump due to the possibility of losing the right engine on takeoff and needing to raise the gear and flaps.

My favorite modifications are the intercoolers, short propellers, six puck brakes, and oil breather separator system. Known Ice enhancement is available for all models, but is stock on the 602P and the 700P. In my opinion, the Machen Aux Fuel Tank is a better system than the Nyak System of the Piper 700P. The Nyak System is automatic which means you turn it on or off but fuel only transfers when the level in the fuselage tank is below 30 gals. The Machen System is automatic or manual. In the manual mode, you can transfer fuel to the fuselage tank filling it above the main tank filler cap (approx. 18 gals more fuel).

The Machen exhaust system is also a nice enhancement to have on your Aerostar. The system is made of Inconel and can handle the higher exhaust temperatures better than the original stainless steel. Additionally, the Machen Inconel tail pipes do away with the every 50 hour inspection of the stainless steel tail pipes. This system is not available on the Superstar II.

Well, now we have covered the history and all the different models. Which one is right for you? Again, "What's your mission?" You have to ask yourself some questions and answer them honestly.

1. Where do I usually fly? (mountainous areas or flat lands)

2. How many passengers do I usually carry? (my wife and a suitcase or 5 hunters and their gear)

3. How far do I usually fly? (400NM or less, 800NM to 1000NM)

4. Do I fly in all weather conditions? (Known Ice, NEXRAD, on board Radar)

5. How many hours annually? (200 or less, more than 200 per year)

6. What model can I get insurance on? (non-turbocharged or pressurized)

7. How much can I afford to spend on maintenance? (600 is normally the least expensive to maintain)

Okay, if you want to fly 800NM or greater with 3 or four passengers on-board then you need to get a 700. If you are a flatlander or an islander, you can get a good ride with the 600 or a 601. If travel means you and your spouse with a suitcase, a 601P or a 602P is just what you need.

Whatever you decide, remember to get a pre-buy inspection from one our Aerostar Maintenance Facilities. I cannot count the number of horror stories I have heard or witnessed firsthand when the pre-buy was performed by the seller or seller's maintenance provider. Also, take the bird up to altitude!

Don't just fly it around the pattern and buy it. If it is p-model then up to 25K, check the pressurization and the engines ability to perform.

Just one more point, the majority of the Aerostars out there that are FOR SALE have been sitting in their owner's hanger for several years before the owner agrees to sell them. You will understand this once you become an owner. Most Aerostar owners believe their Aerostar is part of the family, so it is a sad day when they agree to sell it. Their love for their Aerostar creates initial maintenance opportunities once you start flying your newly purchased Aerostar. So, as a rule of thumb, you will spend about two years fixing all the little things that did not store well and were not found during the pre-buy inspection.

If you have questions or need assistance, please contact us. We will help you find the support you need flying, maintaining and even shopping for the Aerostar of your dreams.

Fly Safe!

Ken