Mustang II N727RH
Project Description and System Schematics
Updated November 25, 2010


 Original "Kit" purchased from Bushby Aircraft September, 1983. Serial # M-II-1209
 Firewall forward except for engine mount from [my wind damaged] 1965 Piper Twin Comanche

Features, modifications and deviations from plans:

 T-18 canopy, roll bar originally 2, now 6 inches aft of plans location
 C-150 seats (recovered in light gray leather) on Cessna seat tracks with fore and aft limit locks
 Tailcone baggage compartment (Sta. 114 to 138)
 Upholstered armrests, carpeted interior
 Flap control of July 1980 newsletter design
 Control stick assembly made from rectangular tubing (as in Feb. 1980 newsletter)
 Wet wings, 18 gallons each (plus 25 gallon main tank) Total fuel = 61 gallons
 Sky Sports capacitance fuel quantity system
  (Reads entire wet wing fuel quantity very accurately)
 Fuel selector system to transfer wing fuel to main tank or pump directly to engine
 Redesigned instrument panel layout, two inches aft of plans location
 Dennis Ashby (Comanche) glareshield with integral lighting
 Garmin GNS 430 TSO GPS-Com-Nav / GI-106A GPS / Nav indicator with glideslope
 Narco MK-12D TSO with GS, ID 825 TSO Nav indicator
 King KN-62A TSO DME
 King KT-76A TSO Transponder
 AmeriKing AK350 altitude encoder
 S-Tec 30 autopilot with altitude hold, heading select, VOR / LOC and GPS tracking
 Piper Marker beacons
 PM-2000 stereo intercom
 Stereo CD player (installed on Sta. 114.75 bulkhead)
 AstroTech LC-2 digital chronometer
 Avionics bus circuit breaker / master switch
 Glasair control stick grips with push-to-talk switches
 Piper external power plug
 Heated Piper pitot / static probe
 Piper True Airspeed indicator - remasked with Mustang II speeds in knots
 Piper Twin Comanche cowling (highly modified) with cowl flap
 Oil cooler cowl flap
 Piper Arrow power quadrant
 Lycoming IO-320-B1A (160 HP) engine,
  50 SMOH with new cylinders by Mattituck
 The following ideas from Kent Paser's excellent book Speed with Economy :
     Engine cooling plenum chamber
     Crossover exhaust heat shield
     Exhaust wrapping
     Removable wing tie down rings
     Nav antenna installed inside canopy
     Wing to fuselage fairings
     Gear leg and brake fairings

 Tach, MP, Fuel flow, EGT, CHT, OP, Oil temp, Volts, Amps
 Hartzell HC-E2YL-2 (72") constant speed propeller (from Twin Comanche)
 Modified Hoerner style wing tips with strobe and nav light units
 Landing and taxi lights (rectangular automotive Halogen bulbs -GE H4701)
 Cleveland "super heavy duty" 5.00 X 5 magnesium brakes and wheels
 DuPont VariPrime self-etching primer
 DuPont Prime-N-Seal primer sealer
 DuPont Imron Polyurethane Enamel paint - White
 DuPont ChromaLusion "Absolute Purpleen" stripes and Chameleon
  (appears to change color depending on light angle and viewing angle)
 Mountain High Oxygen XCP 415 oxygen system

Building hours:
                                 Year         Total
                 1983        175          175
                 1984        213          388
                 1985          63          451
                 1986-1989   0          451   (Project in St. Croix )
                 1990        104          555
                 1991          67          622
                 1992          34          656
                 1993        217          863
                 1994        511        1374
                 1995        424        1798
                 1996        615        2413
                 1997        573        2986
                 1998        516        3502
   Estimated modification hours since first flight: 1500

Flight Manual:

Pilot's Handbook and Owner's Manual (p/n 13-16410 from Aircraft Spruce)
Sections modified with Microsoft Word: Limitations, Systems, Procedures.
A Minimum Equipment List chapter was added.  See Flight Manual  web page.

Selected Systems Descriptions:

The following are some edited sections from the Systems Description chapter of the Flight Manual.


 The fuel system consists of three tanks - one in each wing plus a main tank forward of
the instrument panel, two fuel pumps: a full time engine driven pump and an electric pump,
transfer pump, selector panel, three quantity indicators, fuel flow gauge and interconnecting
vent system.

Fuel Tanks and Vent System

 The leading edge of each outboard wing section is a sealed fuel tank with a capacity of
18 gallons, almost all of which is usable. At the inboard rib near the lower wing attach point is the
fuel pickup with a finger strainer. At the low point of each wing tank is a quick drain. Inside
the tank near the filler cap is the vent / overflow tube. All tanks and the fuel quantity
standpipes are interconnected by the vent system. The vents open to outside air at each wingtip
and just aft of the firewall below the copilot's rudder pedals. The main tank is between the
instrument panel and the firewall and has a capacity of 25 gallons, all useable. The main tank
has a finger strainer at it's outlet.

Fuel Selection

 The fuel selector panel is schematically arranged to show how the tanks, selector
valves, transfer pump and electric fuel pump are plumbed. Wing tank fuel first flows through a
"LEFT, RIGHT, BOTH, OFF" selector and then to the "WING FUEL ROUTING" selector. This selector
enables the pilot to route the fuel to the transfer pump to be pumped into the main tank for
normal operation, or directly to the engine if desired.

 Selection of "DIRECT TO ENGINE" may be desired in the event of transfer pump failure, a
problem with the main tank or it's quantity indicator, or possibly for center of gravity
purposes. The main tank has an "ON, OFF" selector valve at it's outlet. After fuel leaves the
selector panel, it flows through a gascolator / drain at the lower left rear of the engine
compartment, the electric fuel pump, the engine driven fuel pump and then into the fuel

Fuel Quantity Indicating System, Transfer Pump

 The fuel quantity in each tank is accurately measured with electronic capacitance type
probes from
Sky Sports ® (now sold by Aircraft Spruce). The main tank's probe in addition to indicating tank quantity, has a calibrated
sensor that triggers the transfer pump relay to activate the transfer pump (if armed) when the main
tank quantity drops to three fourths full. The transfer pump switch light will illuminate when
the transfer pump is operating. The transfer pump and it's relay are located under the copilot's

 The quantity of each wing tank is measured by a probe in a vented standpipe near each
pilot's outboard knee.

Fuel System Schematic

Fuel System schematic
Photo of fuel panel


 Electrical power is supplied by a 12 volt, direct current system. The system includes a
12 volt 45 ampere alternator, regulator and 35 ampere hour battery to produce electrical power.
The battery is located in a sealed box aft of the baggage compartment. On the right side of the
fuselage near the battery is an external power receptacle enabling the use of an automotive
battery or external battery charger assist for starting or charging. The aircraft Master
Switch must be on for the external power relay to be energized to provide power to the aircraft
battery and electrical system.

 A dual volt / amp meter indicates system performance. The gauge is designed so that
normal operation is indicated with both needles at or above level. Charging is indicated by a
positive ammeter reading and a voltage between 13 and 14.5 volts.

 The split BAT / ALT Master switch "BAT" side energizes the master solenoid to provide
power to the main bus and lower row of circuit breakers. The "ALT" side of the switch energizes
the alternator field turning the alternator on to enable it to recharge the battery. The AVIONICS
MASTER switch / circuit breaker energizes the upper row of circuit breakers providing power to
the avionics. This switch is normally off for engine start. The engine starter solenoid is
located near the base of the copilot's control stick and is activated by the magneto key switch.

 The circuit breakers automatically break the electrical circuit if an overload should
occur. To reset the circuit breaker simply push in the reset button. It may be necessary to
allow approximately two minutes for cooling before resetting a circuit breaker. Corrective
action should be taken in the event of continual circuit breaker popping or a circuit breaker
that will not stay reset. It is possible to manually trip a breaker by pulling out on the reset

The alternator is an Air-Tec (Hitachi) Model AM-0053R 45 amp.
The regulator is a V1200 voltage regulator with overvoltage protection,
also from Air-Tec Inc. Orlando, FL (800) 366-4746. Owner: Dick Waters.

Electrical System Schematic

Current schematic with alternator

Electrical System schematic

Former schematic with generator

Electrical System schematic


 Suction for the vacuum operated gyro instruments - the attitude indicator and the
heading indicator is supplied by an engine driven vacuum pump. Air is drawn into the central
air filter located behind the airspeed indicator, drawn through the two instruments, through an
adjustable vacuum regulator located on the firewall forward of the copilot's rudder pedals to
the vacuum pump. Suction is indicated on the suction gauge located immediately beneath the
vacuum operated instruments. Normal operating range is 4.8 to 5.1 inches of mercury.

Vacuum System Schematic

Vacuum System schematic


 Static air and pitot pressure are supplied by the heated pitot head under the left wing.
Pitot pressure is provided to the airspeed indicator and static pressure is provided to the
airspeed indicator, vertical speed indicator and encoding altimeter.

Pitot / Static System Schematic

Pitot System schematic