What is and is not validated
The Model tab opens with the list of open items: known gaps between this model and the real engines that remain unfixed (the V2527-A5 fuel flow and acceleration, the PT6A-42 propeller overspeed that withholds its reverse lesson, the prescribed autorotation, the unmeasured start transients). The Spec tab repeats the one that applies to the selected engine. Treat numbers from an affected preset as illustrative.
Five engine families
Pick the engine in the top bar. Turbofan (CFM56-7B26, LEAP-1B28 of the 737 MAX, V2527-A5 of the A320, or the PW1127G-JM geared turbofan of the A320neo): starter, fuel lever at 25% N2, idle at N1 21% (LEAP: 19%, V2500: 20%). Piston (O-360, or the O-320 of the Cessna 172): mixture rich, 2-3 primer shots cold, magnetos BOTH, crank; mag check at 1,800 rpm. Turboprop (PT6A-114A, or the PT6A-42 of the King Air B200): prop lever full, starter, condition lever to LOW IDLE at 12-15% Ng, starter off at idle. Turbojet (J85-GE-5A of the T-38): starter, throttle out of CUTOFF at ~14% rpm, idle at 48%; the throttle runs idle → MIL → MAX A/B (1.0 → 1.3), the nozzle closes toward MIL and opens when the afterburner lights. Turboshaft (250-C20B of the JetRanger): starter, throttle twist to IDLE at 15% N1, starter off at 58%, then throttle FULL and the N2 governor holds the rotor at 100% Nr while the collective sets the load.
Scenario script
at 0 starter on
at 18 fuel on
when n2 >= 59 note idle reached
at 70 tla 1.0 # 0..1
when n1 >= 95 fault surge
at 100 tla 0
at 120 engine 2 # or 1, all
at 120 fault ignition_fail on
at 18 watch egt < 725 # must hold to the end
at 90 check n1 >= 20 # evaluated when the line fires
at 200 end
Timed lines: at <s> <cmd>. Conditional lines: when <signal> <op> <value> <cmd>, armed at the preceding at time, fire once. Signals: n1, n2, egt, ff, thrust, oilp, oilt, vib, t4, sm_hpc, alt, mach… (any chart channel).
Commands: engine 1|2|all, ctl <control> <value> (any control of the engine: tla, mixture, magnetos, power_lever, prop_lever, condition_lever, carb_heat…), starter, fuel on|off (fuel lever / mixture / condition lever), tla x (main lever), n1 pct|off, alt m, mach x, isa dK, humidity x, running level, antiice, pack, reverser, fault name [value], bottle, log on|off, speed x, note text, screenshot [label] (saves a PNG of the flight deck), check <signal> <op> <value>, watch <signal> <op> <value>, end. Checkpoints are graded: green when passed, red when failed, with the measured value in the status line. Every graded run is kept in the Results tab (score, per-check details, CSV / JSON export). Lessons written for a specific engine preset (starts, takeoffs, hot starts, a surge, a flameout) are listed first in the lesson dropdown.
Faults
starter_inop, starter_weak, starter_early_cutout, ignition_fail, start_fuel_factor (1 = normal), fuel_pump_fail, oil_leak_qt_per_min, fire, n1_governor_fail, compressor_damage_pct, fod, egt_probe_fail, reverser_stuck; one-shots: surge, flameout, fire_bottle.
Parametric sweep
The sweep display unit plots any signal against altitude, Mach, ΔISA or lever position at steady state, with up to six values of a second variable as separate curves. Points are computed on a settled copy of engine 1; the variables not swept stay at the current environment and lever. CSV exports the curves.
Layout
Drag the grip left of the strip charts to resize the charts column, and the grip under the engine indications to resize them: the dials rearrange to make the most of the space. Double-click a grip to go back to the automatic layout. Both positions are remembered in this browser. While a scenario runs, the editor shows the current line in white and armed when lines in amber.
Replay
Load a CSV flight log, map its columns, and the simulator is driven by the logged levers (or follows the logged N1). Logged channels are overlaid on the charts as dashed lines and the errors are tabulated.
Use
Educational tool only. Not a certified training device and not a substitute for the aircraft and engine manuals. MIT licensed; source and model documentation on GitHub.
Offline and install
After the first visit the simulator works offline: a service worker keeps the app, the wasm core and the lessons. The browser's install option (address bar or menu) adds it as an app on a desktop or tablet.
Sharing
Share copies a link that puts the scenario, a modified spec and the settings into the URL fragment: nothing is sent to the server. Scenario and spec edits are also kept in this browser. Screenshot saves a PNG of the whole flight deck, including the part of the centre column scrolled out of view, named after the engine and the simulation time.