Piper AZTEC D PA-23-250 User guide

A ZTEC D
OWNER'S HANDBOOK

AZTEC 'D'
PA-23-250 {Six Place) ·
Owner's Handboo"' ;
Piper Aircraft Corporation, Lock Haven, Pa.
U. 5. A.

Assurance that the airplane is in an airworthy
condition is the responsibility of the owner. The
pilot in command is responsible for determining that
the airplane is safe for flight. The pilot is also
responsible for remaining within the operating limita-
tions outlined by the Flight Manual, instrument
markings and placards.
If an inconsistency of information exists be-
tween this handbook and the Flight Manual approved
by the FAA, the Flight Manual shall be the authority.
Additional copies of this manual, Part
No. 753 772 may be obtained from your
Piper Dealer.
Published by
PUB LI CA TIO NS DEPARTMENT
Piper Aircraft Corporation
753 772
Issued: May 1968
Revised: May 1972

Perfonnance
Weights . •
Power Plant
Fuel and Oil
Baggage
Dimensions
Landing Gear
680501
SECTION I
SPECIFICATIONS
1
2
2
3
3
3
4

THE PIPER AZTEC "D"
SECTION I
SECTION I
SPECIFICATIONS
PERFORMANCE
Performance figures are for airplanes equipped for cross-
country transportation and flown at gross weight under standard
conditions at sea level or stated altitude. Any changes in equip-
ment may result in changes in performance.
Take-off Run (max effort, ft)
Take-off Distance Over 50-ft Barrier (max effcrt, ft)
Accelerate-Stop Distance (ft)
Minimum Controllable Single Engine Speed (mph)
Stalling Speed (gear down, flaps down 50°, power
off, mph)
Stalling Speed (gear and flaps up, power off, mph)
Best Rate of Climb (ft per min)
Best Rate of Climb Speed (mph)
Best Angle of Climb Speed (mph)
Single Engine Rate of Climb (ft per min)
Best Single Engine Rate of Climb Speed (mph)
Best Single Engine Angle of Climb Speed (mph)
Absolute Ceiling (ft)
Service Ceiling (ft)
Single Engine Absolute Ceiling (ft)
Single Engine Service Ceiling (ft)
Altitude Cruising Speeds (mph)
MP RPM
26.0" 2400
24.0" 2400
24.0" 2200
20.0" 2200
680501
Normal
Intermediate
Economy
Long Range
Altitude
4000
6000
6400
10,200
820
1250
2220
80
68
74
1490
120
107
240
102
97
21;100
19,800
6,400
5,000
Speed
210
208
204
195

SECTIONJ
THE PIPER AZTEC "D"
SPECIFICA!IONS (cont):
PERFORMANCE
Altitude Cruising Range (No Reserve)
MP :· RPM Altitude
26.0" 2400 4000
24.0" 2400 6000
24.0
11
2200 6400
20.0" 2200 10,200
Fuel Consumption (both engines, gph)
MP RPM GPH
26.0"
24.0"
2400
2400
34.0 .
27.0
24.0
11
. 2200 25.0
20.0" . 2200 21.0
Range
830
1080
1110
1210
Top Speed (mph) 216
Landing Roll (flaps down, max effort, ft) 850
Landing Distance Over 50-ft Barrier (flaps down, ft) 1620
WEIGHTS
Gross Weight (lbs)
Maximum Landing Weight (lbs)
Zero Fuel Gross Weight (ll~s)
Empty Weight (Standard, lbs)
USEFUL LOAD (Standard, lbs)
POWER PLANT
2
.Engine (Lycoming)
Rated Horsepower
Rated Speed (rpm)
Bore (inches)
5200
4940
4400
3006'
2194
I0-540-C4B5
250
2575
5-1/8
690505

THE PIPER AZTEC "D"
SECTION I
SPECIFICATIONS (cont):
POWER PLANT
Stroke (inches)
Displacement (cubic inches)
Compression Ratio
Dry Weight (pounds)
FUEL AND OIL
Fuel Capacity (U.S. gal)
Fuel, Aviation Grade (octane)
Oil Capacity (U.S. qts, each engine)
*140 gallons usable
BAGGAGE
4-3/8
54i.5
8.5:1
402
144*
91/96
12
Maximum Baggage (lbs) Forward Compartment 150
Maximum Baggage (lbs) Rear Compartment 150
With oxygen installed 105
Baggage Space (cubic ft) Forward Compartment 17.4
Baggage Space (cubic ft) Rear Compartment 23 .2
Baggage Door Size (in) Fcrward Compartment 19.-5 x 30.5
Baggage Door Size (in) Rear Compartment 30 x 31
DIMENSIONS
Wing Span (ft)
Wing Area (sq ft)
Length (ft)
Height (ft)
Wing Loading (lbs per sq ft)
680501
37.2
207.56
30.2
10.3
25.05
3

SECTION I THE
PIPER AZTEC "D"
SPECIFICATIONS (cont):
DIMENSIONS
Power Loading (lbs per hp)
Propeller Diameter (maximum, in)
LANDING GEAR
·4
Wheel Base (ft)
Wheel Tread
Tire Pressure
Tire Size
Nose
Main
Nose (four ply rating)
Main (eight ply rating)
10.4
77
7.5
11.3
27
46
600 x 6
700 x 6
680501

THE PIPER AZTEC "D"
SECTION I
----150" ----..
I& 9/l&"TO 112 ..
1
0
----- ---- 4453/4 "- -- -----
5° OIHEllRAJ.
------ - 3&25/I"- - - --___.
680501 5

SECTION II
DESIGN INFORM.A TION
Engine and Propeller
Fuel Injection . •
Fuselage and Wing Structures .
Landing Gear •
Hydraulic System .
Cootrol System and Surfaces
Fuel System
Electrical System
Finish .
Instrument Panel
Radio Equipment
Seats
Baggage Compartments
Cabin Features
Heating and Ventilating System
680501
6
7
9
10
12
14
15
19
22
23
23
25
26
26
26

THE PIPER AZTEC "D" SECTION II
SECTION II
DESIGM IMFORMATIOM
ENGINE AND PROPELLER
The Lycoming I0-540-C4B5 engines in the Aztec are rated at 250
HP at 2575 RPM. These engines have a compression ratio of 8.5:1 and
use 91196 minimum octane aviation fuel.
Both engines on the Aztec are equipped with a geared starter,
alternator, vacuum pum ·p, fuel injectors, two magnetos, shielded
ignition system, diaphragm fuel pump, propeller governor and an oil
thermostat. The left engine is equipped with a hydraulic pump.
Engine mounts are of steel tubing construction and incorporate
vibration absorbing Lord mounts. Engine cowls are cantilever
structures, attached at the firewall. Side panels are quickly removable
by means of quick release fasteners. The nose section is split for quick
removal.
The exhaust system is a crossover type with exhaust gases directed
outboard at the the bottom of the nacelles in the area of the cowl flaps.
The cowl flaps, located on the bottom of the engine nacelles provide
additional cooling for ground operation or high temperature conditions.
Manual push-pull controls for the cowl flaps are located on the fuel
control panel.
An efficient aluminum oil cooler is mounted on a rear baffle of
each engine. Engine oil drainage is accomplished with quick oil drain
valves located on the inboard rear corner of the engine crankcases.
The "Compact" Hartzell HC-E2YK-2RB, HC-E2YR-2RB,
HC-E2YK·2RBS, or HC-E2YR-2RBS propellers are constant speed, full
feathering units which represent new concepts in basic design. They are
low in weight with simplicity of design and ruggedly constructed.
The propellers with designations ending in "S" contain springs, to
safeguard against an overspeed due to loss of the air charge. This spring
701015 6

SECTION II THE PIPER AZTEC
"D"
produces sufficient force to control propeller rpm, within normal
operating range, provided airspeed is reduced and power is applied
slowly. The propellers are controlled by the levers in the center of the
control quadrant. Feathering of the propellers, which takes
approximately three to ten seconds, is accomplished by moving the
controls fully aft through the low RPM <Jetent into the feathering
position. A propeller is unfeathered by moving the prop control ahead
and engaging the starter. (See Section III, for complete feathering and
unfeathering instructions.)
FUEL INJECTION
The Bendix RSA-5 Type Fuel Injection System installed in
the Aztec is based on the principle of measuring airflow and
using the airflow signals to operate a servo valve. The accu-
rately regulated fuel pressure established by the servo valve,
when applied across a fuel control Getting system), makes fuel
flow proportional to airflow.
Fuel pressure regulation, by means of a servo valve, neces-
sitates only a minimum fuel pressure drop through the entire
metering system. This makes it possible to maintain metering
pressure above vapor forming conditions, and at the same time
does not require a high inlet fuel pressure. An inherent feature
of the Servo System is self-purging, which eliminates any possi-
bility of vapor lock and the associated problem of difficult
starting.
The Airflow Sensing System, which is incorporated in the
Servo Regulator, consists of the throttle body containing the
throttle valve and venturi. The differential pressure between the
entrance and the throat of the venturi is a measurement of air
entering the engine. These pressures are applied to an air
diaphragm in the Servo Regulator to create a force across the
diaphragm. A change in power will change the airflow to the en-
gine which in turn will change the force across the air diaphragm
in the Servo Regulator.
The air diaphragm in the Servo Regulator converts the
7
701015

THE PIPER AZTEC "D"
SECTION II
airflow measuring signals into an air metering force. Fuel inlet
pressure is applied to one side of the fuel diaphragm and the
pressure of the fuel, after it passes through the fuel control
(metered fuel pressure), is applied to the other side of the dia-
phragm. This creates a force across the diaphragm which is
referred to as fuel metering force. Relatively low airflow signals
develop high fuel metering forces by virtue of the diaphragm
areas selected. The requirement for low airflow signals makes
possible the use of a relatively large venturi which keeps engine
induction system air losses to a minimum. During idle operation,
when air intake is too small to create pressure differential re-
quired for operatioo of the diaphragm, a constant head idle spring
is used to operate the diaphragm and supply the required fuel
for idle.
The fuel control system, which is also incorporated in the
Servo Regulator, consists of an inlet fuel screen, a rotary idle
valve and a rotary mixture control valve. The idle valve is ad-
justable to obtain good idling characteristics without affecting
metering at higher power settings. The mixture control valve
gives fuel rich mixture on one stop and a progressively leaner
mixture as it is moved toward the idle cut-off stop. The setting
incorporated in the fuel control system is worked out to meet
the engine requirement for all power settings without compro-
mise. The full rich stop defines sea level requirements, and
the mixture control provides altitude leaning.
The Flow Divider, which is mounted on top of the engine,
is provided as a fuel distributor point. Six individual lines are
connected to the Flow Divider, then routed to the cylinders. The
Flow Divider contains a spring loaded positive shut-off valve
and is ported to accurately divide fuel flow to the nozzle lines.
Located in each cylinder are the airbleed nozzles. The
cootinuous flow airbleed nozzles incorporate provisions to elim-
inate the adverse effect of low manifold pressure at idle. Through
this, lines can be maintained full of fuel to provide good dis-
tribution and acceleration characteristics. Actual fuel metering
is provided by the Servo Regulator, not the nozzles, which
permits leaner operatioo for economy and longer engine life due
680501
8

SECTION II THE PIPER AZTEC
''D"
to uniform cylinder head temperatures.
Installed in the instrument. panel is a Fuel Flow Indicator.
This instrument is connected to the Flow Divider and monitors
fuel pressure. The instrument converts fuel pressure to an accu-
rate indication of fuel flow in gallons per hour.
NOTE
An increasing or abnormally high fuel flow in-
dication is a possible symptom of restricted
injector lines or nozzles.
Induction air for the engine enters a large air duct at the rear
of the bottom cowl. The air is directed through a filter, and on to
the servo regulator. A heated alternate air source is incorporated
to provide airflow to the engine in case the normal flow of air
through the filter is restricted. The alternate air door is spring
loaded, and will remain closed during normal operation. The
alternate air door will operate automatically, as the normal in-
duction airflow through the filter is restricted, or when the push-
pull control, located on the control pedestal, is placed in the
FULL ON position. The control should be placed in the FULL
ON position prior to entering known or expected icing conditions.
FUSELAGE AND WING STRUCTURE
The Aztec fuselage is a composition of four basic units; the
sheet metal tail cone, cabin section, nose section, and the steel
tubular structure which extends from the tail cone to the nose
wheel. The steel tube unit is intended to withstand the high
loads imposed on the center section region of the airplane, and
provides an extra safety factor in this area.
Finish on the tubular unit, as on all steel tube structures is
zinc chromate primer with synthetic enamel.
9
680501

THE PIPER AZTEC "D"
SECTION II
All windows are double pane except the second window on
the left side which is the emergency exit window. A storm window
located in the forward lower section of the pilot's side window
opens downward and in when unlatched.
The wing structure is lightweight but rugged, and consists of
a massive stepped down main spar, a front and rear spar, lateral
stringers, longitudinal ribs, stressed skin sheets, and a readily
detachable wing tip section. The rectangular plan form of the
wing simplifies the construction while providing excellent sta-
bility and performance characteristics.
The wings are attached to the fuselage steel tubular struc-
ture with fittings at the sides and in the center of this structure,
and the main spars are bolted to each other with high strength
butt fittings in the center of the fuselage, giving the affect of a
continuous main spar. This arrangement combines high strength
and lightweight structure.
LANDING GEAR
All three landing gear units on the Aztec incorporate the
same soft acting air-oil struts, and contain many directly inter-
changeable parts. (See Section V, for gear maintenance.)
Main wheels are 600 x 6 Cleveland Aircraft Products units
with disc type brakes with metallic lining and 700 x 6 tires with
an eight ply rating. The nose wheel is a Cleveland 600 x 6 model
fitted with a 600 x 6 tire with a four ply rating. All tires have
tubes. (See Section V, for tire service.)
Main gear brakes are actuated by toe brake pedals on the
left set of rudder pedals. Hydraulic brake cylinders located in
front of the left rudder pedals are readily accessible in the cock-
pit for servicing. Toe brakes for the right side are available as
optional equipment. A brake fluid reservoir, which is connected
to the brake cylinders with flexible lines provides a reserve of
fluid for the brake system, and is mounted on the fuselage
structure inside . the left nose access panel. (See Section V, for
brake service.)
680501
10