Pilot report - Piper Aerostar
[Reprinted from Fliteguide / Imperial Aviation]
There is absolutely nothing about the Aerostar to suggest it is a slow aeroplane.
Like so many slingshot general aviation aircraft, it perches uncomfortably on
its stalky undercarriage leaving its swept-back tail, pointy nose and shoulder-height
spinners to announce to any observer that this thing goes like hell.
The Aerostar however, is not without compromise nor does it suffer fools gladly.
But whilst everything is happily turnin' and burnin' the aircraft is one of
the world's greatest handling twins. What is curious is that it represented
a major departure for Piper, indeed the aircraft would have been more at home
if it had been taken over by Mooney because thia is surely what they would have
come up with had they expanded upon their fast single-engined line.
By some twist of fate, in 1978, Piper decided to purchase the design rights
from Theodore R. 'Ted' Smith, The Aerostar's creator. The aeroplane had already
been in production since 1969. Ted Smith set up his company in 1966 after working
for Aero Commander and probably disillusioned by his previous employer's prevarications
on improving their twin-piston and turbine line, decided he could do it better.
It was to be the start of an exceedingly turbulent production history that has
left a profound legacy upon many present Aerostar owners.
The original Aerostar 600 was to only the start of a range consisting of single-engined
models and ultimately a jet-powered version. The singles never left the drawing
board, and only recently the Aerostar has emerged with plans to install two
rear-mounted fanjets. Ted Smith had a clear idea of what he was after. The design
began as it ended using a mid-wing, six-seat, circular-section fuselage layout.
It also featured a jet-like swept tail and an airstair cabin door in front of
the wing - not unlike the Aero Commander's business jet designs.
The prototype model 300/400 first flew in 1966 but was used for certifying the
first production 600 version with a pair of Lycoming IO-540 engines. These engines
were flat rated at 300hp each, hence the '600' name tag given to the first model.
In 1968 Ted Smith sold his business to the American Cement Company who took
over roduction of the 600 with a vision of joining the existing boom in light
aircraft manufacturing. The acquisition wasn't a great success. American Cement
had plenty of money but its lack of aviation expertise led to quick disagreement.
The following years Butler Aviation took over. Butler at the time were the owners
of Mooney and they threw the whole lot together under the name of Aerostar Aircraft
Corp in 1970 with the auspicious intention of moving 600 production to the Mooney
plant at Kerrville in Texas. In a complete reversal, Butler had insufficient
funding. No Aerostars were subsequently built during 1971 and 1972.
Ted Smith bought back his design rights in 1972 after 130 Aerostars had been
completed. Smith then went ahead and built a pressurised model, the 601P. He
also built a prototype 700 Superstar with 350hp Lycoming IO-540M engines, though
this wasn't to see the light of day until some years later.
In 1978 Piper decided to purchase the Aerostar. The company wanted to widen
its high performance product line. This wasn't the first time Piper had flirted
with Ted Smith. In 1949 Piper had approached him whilst he was an engineer at
Douglas. Piper wanted to get into the piston-twin business and they were interested
in Smith's high-wing design. As it turned out a pusher design was purchased,
the Bauman Brigadier B250. This was eventually passed over in favour of the
Apache. The Brigadier ended its days amongst the rafters at Lock Haven and Ted
Smith's design evolved into the Aero Commander.
Piper continued to manufacture the 600A, 601B and 601P in California before
eventually moving production to Vero Beach. The 1977 601B version was identical
to the 'A' but with a thirty inch increase in wingspan. The 'B' version was
also given a useful 300lb gross weight increase and brought the specifications
up to the same level as the pressurised model.
Although the basic design features of all Aerostars have remained unchanged
throughout the years, the late seventies saw a number of other detail modifications.
Amongst them was a deft paperwork exercise in increasing the aeroplane's zero-wing-fuel
limitation from 5,400 pounds to 5,900. Flap extension speed was raised by 18
knots and an improved, automatic wastegate system was introduced to replace
the twn Rayjay turbochargers. The aircraft has also come in for a fair share
of criticism regarding its fuel system. After suffering a number of double engine
failures due to fuel mismanagement, the FAA stepped in in the early eighties
with Ads designed to prevent these incidents.
In 1981, the 602P version was launched. This benefited from Lycoming-developed
turbochargers and although they successfully ended persistent engine-detonation
problems associated with the Rayjays, they also resulted in a lower cruise speed.
In 1984 Piper introduced the long awaited 700P. Unfortunately, the writing was
on the wall for many general aviation manufacturers and only twenty-six were
built before Piper finally suspended Aerostar production later that year.
In 1991 Ted Smith once again bought back the type certificate and thus the design
rights. His intention was to replace the piston engines with two Williams FJ44
turbofans. However, this project has yet to see the light of day. It is rumoured
that the Jet-Aerostar concept has been resurrected again but no details have
yet been released.
Today, Aerostar's have become coveted items and few come on the market for resale.
There is a very enthusiastic owners association in the USA who hold annual fly-ins
and publish a regular magazine. There are currently eight South African Aerostars
and one US-registered example in the region.
The Aerostar is a diminutive aeroplane. Its size and somewhat delicate appearance
belie its huge inherent strength. Ted Smith designed the aircraft to comfortably
exceed sixties Part 23 construction specifications. Whilst many manufacturers
were satisfied in meeting the +3g threshold, the Aerostar was built to withstand
up to +6g. It is one of only two twins in the world specially cleared to perform
airshow aerobatics (the other is the Ted Smith-designed Aero Commander, flown
for years by famous flying personality Bob Hoover). The prototype was flown
to 500 miles per hour in a descent and is said to be capable of 800 miles an
hour without displaying any dangerous flutter characteristics. It was also Smith's
intention to dramatically reduce the aeroplane's component count and the most
striking evidence of this is the commonality of tail surfaces. Both horizontal
stabilisers and the fin share the same part numbers and are all fully interchangeable.
Each wing consists of under 50 'detail parts'. Skin thickness is double that
of more common aircraft. The reason for this was to provide greater stiffness
to the outer structure than the innards. It was estimated that an Aerostar should
take no more than 1800 hours to build - some 400 hours less than a Beech Baron
or Cessna 310. Both the American Cement Company and Butler Aviation were unwilling
to apply Smith's manufacturing doctrine - American Cement simply emloyed too
many people and Butler used unfinished airframes as collateral to borrow capital.
Moreover, American Cement ordered a huge stock of spare wings and tail surfaces
- many of which are still around.
A clamshell door at the front allows access to the cabin. At first sight it
appears that passengers must climb over the front seat in order to get into
the cabin. However, the front seat unlatches and slides forward so that the
squab is underneath the instrument panel. A step is incorporated into the lower
door and entry is perhaps easier on the Aerostar than almost any other light
twin. Once the passengers are installed, the seat slides back again to provide
access for the front occupants. Latching the door closed is a very important
checklist item. It has been said that an opening top clamshell is the easiest
way to kill an Aerostar pilot. This is not because the door is likely to become
detached but because the first instinct is to reach out and pull it closed again.
In this case the airflow takes over and forces your arm into the propellor arc.
Not nice.
N7478S is a short-wing, normally aspirated 600. It is operated by Wonderboom-based
Dirk de Vos, a well known aviation personality and better known as the owner
of clip winged Harvard ZS-WFD. His Aerostar is a standard 1969 model and is
undergoing an interior refurbishment. Dirk also happens to be in the aircraft
sales industry and being partial to high-performance light aircraft, he has
become somewhat of an Aerostar expert and loves to sell them.
The manual recommends starting the right hand engine first as this is where
the hydraulic pump is located. The battery is placed at the far end of the tail
with a ground power plug in the tailcone itself. Instrument panel layout is
almost entirely conventional. However, the panel does have a number of interesting
features. On the right hand side and immediately left of the copilots control
column is an elevator and rudder trim indicator - unusual for a light twin.
The trim adjustment itself consists of of two small rocker switches on the centre
pedestal. Below these is another rocker switch - a horizontal one, used for
steering the nosewheel. It's curious that such an important task is delegated
in such a modest way. Nevertheless the system works well and is easy to get
used to. There is also a minimum fuel warning light (of which more later) and
a similar warning system for cabin heater failure. There are no cowl flaps.
As most Aerostar pilots have discovered at some stage, it is advisable to take
off with flaps. Forgetting to do so can be a frightening experience on a short
strip as the aircraft will seemingly roll forever. Furthemore, the angle of
attack needed to climb away from a flapless takeoff can be alarming. Aerostars
need a positive control movement to raise the nose as the aircraft rests on
the ground with a negative angle of attack. Those familiar with the aeroplane
will know to maintain a partial easing back on the column approaching rotation
speed.
This is to be expected considering the small wing area. With an engine failure
at VMCA, the Aerostar needs to be accelerated to 130 knots for best single engine
rate of climb. Under cruise conditions, owners condsider the aeroplane's single
engined handling to be excellent. This eases the transition to final rotation.
Minumim single engine control speed (VMCA) is a highish 97 knots IAS (or 84
with recommeneded wing vortex generators).
Ted Smith made another major departure from conventional light twin design.
He installed push-rod controls which has bestowed fabulous handling upon the
Aerostar. Similar to a Mooney, the control column trow from full left to right
aileron is a short 180 degrees. Predictably, response is instant. The aeroplane
was designed with minimal dihedral. This also contributes to the handling though
makes the Aerostar demanding in an IMC environment. The aircraft has no aural
nor visual stall warning system, however, at about seven knots over the stall
speed there is a very obvious airframe buffet - enough to provide a clear reminder
that things are about to unwind. The stall itself is benign provided all the
controls are neutralised, however, add some rudder or aileron and the Aerostar
will drop a wing.
Owners report performance figures close to what the pilots operating manual
advertises. Speed is the aeroplane's biggest attraction. A normally aspirated
600 will cruise at a little over 210 knots at 7,500 feet on an ISA day. The
combined fuel burn under these conditions is 33.4 gallons per hour giving a
range of just over 1,000 nautical miles. This makes Cape Town an easy hop from
Durban or Johannesburg.
The Aerostar's fuel system has been the subject of some criticism over the years.
The aircraft has three tanks - one in each wing and a central fuselage tank
mounted mid-way up behind the rear cabin bulkhead. The system holds 165.5 gallons
of useable fuel. The intention was to use tank vents to maintain an equal level
of fuel throughout the system. As the wing tanks depleted however, fuel feed
would come from the fuselage. It is important to always have fuel in the central
tank and although the system is designed to accommodate this, a number of accidents
have followed simultaneous engine failure caused by uneven feeding. The number
of Aerostar incidents caught the attention of the FAA who issued an airworthiness
directive mandating the use of a low fuel warning light for the central tank.
In 1979, the FAA issued a further AD forcing owners to install a triple fuel
gauge - one for each tank. The AD also called for fuel cap inspections as it
was suspected that negative pressure was responsible for restricting fuel flow
causing premature depletion of the fuselage tank. All these important ADs are
a feature of the past - however, insurance companies cast a nervous eye at low-time
pilots wanting to fly an Aerostar. It is very important to understand the aeroplane's
systems and handling idiosyncrasies when one of them fails - including the engines.
The good news is that training schemes have need set up for the aircraft, including
a course run by Flight Safety. In many cases the insurance companies are reluctant
to provide cover unless one of these programs has been completed by the owner
or pilot.
In flight, the view from the front seats is spectacular. Being ahead of the
engines, pilots can see directly downwards and upwards through the eyebrow windows
making circuit work and map reading a delight.
Passengers are not quite so lucky as they are seated next to the wing roots
but the big windows provide lots of light. Although a six-seat club layout was
never offered as a factory option, some owners chose a five-seat club setup
with one of the central seats removed and a fold-out table installed.
Landing the Aerostar is straightforward provided it's remembered how small the
wings are. Cut the throttles too early and the aircraft will settle instantly.
This makes it easy to place on the numbers - but only if it's done at the correct
height. The aircraft is more sensitive to thrittle setting on approach rather
than pitch input, so early attention to speed is a good way of handling most
approaches.
There is little doubt that the Aerostar is both challenging and an enormously
satisfying aircraft to fly. The light twin business was notoriously fickle and
the 1.089 Aerostars built must surely be one of Ted Smith's highest accolades.
As a twin, it has something to suit most - turbocharging, pressurisation and
the availability of even more speed by adopting a small but significant number
of modifications. The potential for greater speed has been harnessed by modification
specialist Machen Conversions in the USA. For Aerostar owners wanting something
a little extra, Machen manages to push the cruise speed up to 270 knots using
a pair of 325 or 350hp Lycomings and calling the aircraft 'Superstar'. Piper
themselves ended production with their own 700P version using contra-rotating
350hp engines. If this doesn't thrill pilots sufficiently there's always the
new jet-powered version.
[END OF REPORT]
Note: PlaneCheck often has some nice Piper Aerostars for sale