Cessna 172SP

Overview

The Cessna 172SP project is a full-scale home cockpit build based on the world's most popular training aircraft. The defining feature of this build is a modular Main Instrument Panel (MIP): the entire instrument panel is designed as a self-contained, drop-in module that can be swapped between a classic six-pack steam-gauge layout and the Garmin G1000 glass cockpit variant — without modifying the cockpit frame, seat structure, or any permanent hardware.

This gives full flexibility to fly either the traditional analogue C172SP or its modern glass-panel counterpart, using the same physical cockpit shell.

Modular MIP Design

The MIP is the centrepiece of this build. Rather than committing permanently to one avionics variant, the panel is engineered as a bolt-in module:

• Standard Six-Pack MIP — six analogue flight instruments, an S-TEC 55X autopilot, two GNS 430s with an audio panel and transponder, and classic push-pull engine controls
• G1000 MIP — dual 10.4-inch displays (PFD + MFD), a GFC 700 autopilot glareshield, and a Garmin audio panel

Swapping panels means unbolting the current module, disconnecting a single wiring harness, and bolting in the other. All switches, circuit breakers, throttle quadrant, yoke, and rudder pedals remain in place — only the instrument panel face changes.

Design Goals

• Full-scale cockpit frame with accurate C172SP geometry
• Drop-in panel modules — both variants fit the same cutout and harness connector
• Yoke — Honeycomb Alpha or custom-built with aileron/elevator axis
• Throttle quadrant — real aircraft-style push-pull knobs for throttle and mixture (the 172SP is fuel-injected, so it has no carb heat)
• Rudder pedals with toe brakes
• Full X-Plane 12 integration for both avionics variants

Six-Pack (Standard) Panel

The classic layout replicates the analogue C172SP instrument panel, with a traditional "T" arrangement of flight instruments.

Analogue instruments are driven by ESP32 controllers using servo motors or stepper-driven gauges, with all values sourced from X-Plane 12 datarefs.

G1000 Panel

The glass-panel layout replicates the G1000-equipped C172SP. Most flight data is rendered on-screen, reducing the number of physical instruments needed and making this variant faster to build and iterate.

Both PFD and MFD are driven by 10.4-inch monitors running X-Plane 12 with the Laminar G1000 plugin.

Current Status

The project is in the planning and research phase. Panel dimensions are being sourced from reference photographs and the Cessna 172SP Pilot's Operating Handbook. The MIP module system is being designed in Fusion 360, with a focus on making the swap mechanism clean and repeatable.

Planned Sub-Pages

Documentation for this project will grow to cover:

• MIP Module System — frame design, swap mechanism, wiring harness connector
• Six-Pack Panel — instrument layout, stepper/servo gauge integration, X-Plane dataref mapping
• G1000 Panel — display mounting, bezel fabrication, X-Plane plugin setup
• GFC 700 / S-TEC 55X Autopilot — physical encoder panels and software mapping
• Radio Stack — audio panel and transponder replica
• Yoke & Rudder Pedals — hardware selection and integration

Simulator Integration

Both panel variants integrate with X-Plane 12 through CockpitConnect, and both ship as Official Blueprints in the app's library: Cessna 172 (six-pack) and Cessna 172 G1000. They share the lower panel, throttle quadrant and annunciator boards, so you wire those once and assign them in both. The Bridge runs the G1000 Blueprint whenever a G1000 Skyhawk is loaded, and the six-pack one for the others.

Every path below is what X-Plane 12's default Skyhawk binds to its own cockpit controls. An index like [0] is the first engine's or battery's element of an array.

Lower panel and throttle quadrant (both variants)

# Electrical
sim/cockpit2/electrical/battery_on[0]            Master BAT
sim/cockpit2/electrical/generator_on[0]          Master ALT
sim/cockpit2/switches/avionics_power_on          Avionics master
sim/cockpit2/engine/actuators/fuel_pump_on[0]    Fuel pump
sim/cockpit2/ice/ice_pitot_heat_on_pilot         Pitot heat

# Lights
sim/cockpit2/switches/beacon_on
sim/cockpit2/switches/landing_lights_on
sim/cockpit2/switches/taxi_light_on
sim/cockpit2/switches/navigation_lights_on
sim/cockpit2/switches/strobe_lights_on

# Engine start and fuel
sim/cockpit2/engine/actuators/ignition_key[0]    0 OFF, 1 R, 2 L, 3 BOTH, 4 START
sim/cockpit2/fuel/fuel_tank_selector             1 LEFT, 4 BOTH, 3 RIGHT
sim/starters/shut_down                           Fuel shutoff (the Skyhawk's toggle)
laminar/c172/fuel/fuel_cutoff_selector           Fuel shutoff state, 1 = pulled
laminar/c172/fuel/fuel_quantity_L                Left fuel gauge, kg
laminar/c172/fuel/fuel_quantity_R                Right fuel gauge, kg

# Controls
sim/cockpit2/controls/flap_handle_request_ratio  Flap lever: 0, ⅓, ⅔, 1
sim/flight_controls/pitch_trim_up                Trim wheel
sim/flight_controls/pitch_trim_down
sim/cockpit2/controls/parking_brake_ratio
sim/cockpit2/engine/actuators/throttle_ratio[0]
sim/cockpit2/engine/actuators/mixture_ratio[0]
sim/cockpit2/switches/instrument_brightness_ratio[0]   Panel lights dimmer
sim/cockpit2/switches/instrument_brightness_ratio[1]   Radio lights dimmer

# Annunciators
sim/cockpit2/annunciators/low_voltage
sim/cockpit2/annunciators/oil_pressure
sim/cockpit2/annunciators/low_vacuum
sim/cockpit2/annunciators/fuel_quantity

Six-pack instruments

sim/cockpit2/gauges/indicators/airspeed_kts_pilot
sim/cockpit2/gauges/indicators/altitude_ft_pilot
sim/cockpit2/gauges/indicators/vvi_fpm_pilot
sim/cockpit2/gauges/indicators/heading_vacuum_deg_mag_pilot
sim/cockpit2/gauges/indicators/pitch_vacuum_deg_pilot
sim/cockpit2/gauges/indicators/roll_vacuum_deg_pilot
sim/cockpit2/gauges/indicators/turn_rate_roll_deg_pilot
sim/autopilot/heading_up / heading_down / heading_sync   Heading bug
sim/instruments/DG_sync_up / DG_sync_down                Heading indicator drift
sim/instruments/barometer_up / barometer_down            Altimeter pressure knob
sim/instruments/ah_ref_up / ah_ref_down                  Attitude indicator adjust knob

G1000

The G1000's bezel keys and knobs are X-Plane commands: sim/GPS/g1000n1_* on the PFD and sim/GPS/g1000n3_* on the MFD, for example sim/GPS/g1000n1_softkey1 to softkey12, sim/GPS/g1000n1_fms_inner_up, sim/GPS/g1000n1_hdg_sync. The GFC 700's keys and its HDG and ALT knobs are on the MFD's commands: sim/GPS/g1000n3_ap, _fd, _hdg, _nav, _apr, _vs, _flc, _alt, _vnv, _bc, _nose_up, _nose_down, _hdg_up, _alt_outer_up and their siblings.

What's Next

Start with the MIP Frame & Structure page, where the build begins, or jump to Electronics for a deep dive into the ESP32 wiring.