PA-30 & PA-39 series, including:
PA-30 (1963 to 1965)
PA-30B (1966 to 1968) &Turbo
PA-30C (1969)
PA-39-C/R (1970 to 1972) & Turbo
The original PA-30 Twin Comanche was the first of the line, and it had a
sort of minimalist appeal. It was an immediate success, and 931 of this first
four-seat model were sold. Total sales of all PA-30 models came to 2,000 airplanes.
The big draw - as with all the Twin Comanches - was the airplane's ability
to extract maximum speed from minimum horsepower and fuel consumption. The
PA-30's 160-hp, Lycoming IO-320-BlA engines let a PA-30 cruise at 170 knots
(that's 200-mph) while burning a total of a mere 17 gph. The engines have
TBOs of 2,000 hours and are highly regarded for their simplicity and durability.
The airplane has a maximum gross weight of 3,600 pounds, and typical empty
weights run 2,210 pounds. Twin-engine rate of climb is listed as 1,460 fpm;
single-engine rate of climb is 260 fpm. Standard fuel capacity is 90 gallons;
an optional fuel system has 120 gallons. IFR range with standard tanks is
770 nm, assuming 75-percent power and a cruise altitude of 8,000 feet. With
optional tanks and an economy (45 percent) power setting, fuel burns drop
to 11.2 gph (both engines) and range with 45 minute reserves rises to 1,000
nm. Bare-bones PA-30s came with only one generator and one vacuum pump, but
the "Professional" model was equipped with DME, an IFR panel, a two-axis
autopilot, and a "Palm Beach" paint scheme. New, PA-30s cost $41,190.
The PA-30B was a step-up variant. It marked the first appearance of third
side windows in the Twin Comanche series. Six seats and wing-tip fuel tanks
were offered as options, as well as a heated windshield and wing and propeller
ice protection equipment. Performance and weights are virtually the same
as the PA-30. New, typically equipped PA-30Bs ran from $42,925 to $46,060.
The PA-30B Turbo has the same IO-320 engine as the other Twin Comanches
but comes with the same manually controlled Rajay turbochargers mentioned
in the description of the PA-260TC single-engine Comanche. In this application,
however, there are, of course, two manual wastegate vernier knobs below
the power quadrant. The same cautions regarding over enthusiastic use of
the turbo levers and inadvertent over boosting of the engines applies. As
with the 260TC, the PA-30B Turbo's Rajays offer no automatic controls and
minimal over-boost protection; there is nothing to prevent a careless pilot
from destroying an engine (or engines, in this case) on a single takeoff
or descent. Recommended TBO for these engines is 1,800 hours, a reflection
of the extra wear and potential damage caused by the higher cylinder temperatures
and manifold pressures created by the turbochargers. That said, the turbos
did make the Twin Comanche go faster and higher. At 75-percent power, true
airspeeds hit 194 knots. At low altitudes and with power set to the maximum,
the PA-30B Turbo could reach 209 knots. At economy power settings, range
with 45-minute reserves is approximately 1,100 nm. Twin-engine service ceiling
is 30,000 feet; single-engine service ceiling is 19,000 feet. Maximum gross
weight is 3,725 pounds, and empty weight is typically 2,408 pounds. Rates
of climb are published at 1,460 (twin engine) and 260 (single engine) fpm.
All turbos come with built-in oxygen systems, six seats, and a 120-gallon
fuel system with wing-tip fuel tanks as standard equipment. New, they ran
for between $51,145 and $54,355.
The PA-30C Twin Comanche came next. It, too, has the third side windows
and six seats. Better soundproofing and more standard features give this
airplane a 60-pound empty weight increase over the earlier non-turbocharged
Twin Comanches. The C model also brought with it a more modern panel design
and the first appearance of the standard-T presentation of flight instruments.
The 120-gallon fuel system with tip tanks was an option. New, the Cs sold
for $52,725.
The PA-30C Turbo is the fastest Twin Comanche. It uses the Rajay manual
turbocharging system, and has 75-percent power cruise true airspeeds of
209 knots. At 24,000 feet, Piper claimed 214 knots as possible. With the
standard turbo package (oxygen and tip tanks) and expanded avionics as standard
features, these Turbo models had the highest typical empty weights: about
2,416 pounds. Climb rates are down from previous models (twin engine, 1,290
fpm; single engine, 225 fpm), and takeoff and landing distances are longer.
Single-engine service ceiling is 17,000 feet - 2,000 feet lower than the
PA-30B Turbo. In 1969, the PA-30C Turbo typically sold for $62,174.
The PA-39 C/R Twin Comanches were attempts to address the perceived safety
problems of the PA-30 series. The 39s, therefore, come with counter-rotating
propellers (thus the "C/R" designation). By having the left propeller rotate
clockwise and the right propeller rotate counterclockwise, the control problems
usually associated with the failure of the critical (left) engine at slow
airspeeds and high angles of attack are minimized.
The critical engine is so named because a failure of this engine at airspeeds
at or below Vmc can result in the most dangerous levels of asymmetric thrust.
(This is because descending propeller blades produce more thrust, the right
engine's descending propeller is farthest from the airplane's center of
gravity, and its comparatively greater arm creates a more asymmetric-ergo,
critical-condition in the case of a power loss in the left engine.)
With 155 total sales, the PA-39s were the end of the Twin Comanche line.
Owners of PA-30s can, under the terms of a modification described in Piper
Service Letter 552, dated May 1, 1970, install a new right engine with a counterclockwise-rotating
propeller in their airplanes. This, in effect, transforms a PA-30 into a
PA-39.
The PA-39 Twin Comanche's cruise and load-hauling performance is virtually
identical to that of the PA-30C. Takeoff and landing distances are slightly
less than the PA-30C's. New, an average equipped PA-39 was priced between
$57,190 and $66,715.
Similarly, the PA-39 Turbo Twin Comanche's specifications resemble those
of the PA-30C Turbo's. These models cost an average of between $67,440 (1970
model) and $77,565 (1972 model).