What does the TO/GA switch do in a Boeing 737 simulator?

In a Boeing 737 simulator, pressing either TO/GA (take-off/go-around) switch commands the autothrottle and flight directors into take-off or go-around modes. On take-off it targets computed take-off thrust; on approach it commands go-around thrust and climb guidance. It does not automatically retract the gear, select flaps or complete the missed approach.

For our Aviation & Real-World Flying coverage, we use the real 737 automation logic as the baseline. Detailed simulator aircraft usually reproduce most of this behaviour, while simpler models may treat TO/GA as little more than a thrust command.

The 737 has two TO/GA push-buttons on the thrust-lever assembly. They issue the same command and are duplicated for accessibility; they do not control separate engines.

What happens when you press TO/GA for take-off?

For take-off, TO/GA tells the autothrottle to set the programmed take-off N1 limit and gives the flight directors take-off guidance. That limit may include a derate or assumed-temperature reduction, so TO/GA does not necessarily mean maximum thrust.

1. Prepare the automation: enter or verify the take-off N1 limit and V-speeds, switch on both flight directors, arm the autothrottle and set the initial MCP altitude and heading or route mode.
2. Stabilise the engines: advance the thrust levers to about 40% N1 and allow both engines to stabilise before commanding take-off thrust.
3. Press either TO/GA switch: with the autothrottle armed, the thrust levers should advance towards the calculated N1 target.
4. Check the flight mode annunciator: verify the expected thrust mode and TO/GA flight-director modes. The FMA, not lever movement or engine sound, confirms what the automation actually accepted.
5. Continue the take-off: monitor both engines, rotate at VR, follow the flight director and retract the gear after a positive climb is established.

Later in the take-off roll, the autothrottle mode normally changes from N1 to THR HLD. THR HLD releases the thrust-lever servos so accidental movement is less likely to fight the pilot; it does not mean that take-off thrust has been reduced.

What does TO/GA do during a go-around?

During an approach, TO/GA commands go-around thrust and climb guidance, normally producing an initial pitch command near 15 degrees before adjusting guidance towards the selected speed. If the decision point is unclear, our walk-through of ILS capture, minima and landing places the switch in context.

1. Press TO/GA once: verify increasing thrust and the expected TO/GA or go-around indications on the FMA.
2. Follow the pitch guidance: establish the climb without chasing the flight-director bars or allowing speed to decay.
3. Select go-around flap: from a normal Flaps 30 or 40 landing configuration, call for and select Flaps 15. A non-normal landing configuration may require a different schedule.
4. Retract the gear: select gear up only after confirming a positive rate of climb.
5. Fly the missed approach: at the appropriate height, select the required lateral mode, accelerate and retract the remaining flaps on schedule.

Does pressing TO/GA twice give more thrust?

On faithfully modelled 737 systems, the first go-around press normally commands reduced go-around thrust for a controlled climb; a second press commands full go-around thrust. Do not double-tap the switch automatically—the extra thrust can produce a steep pitch demand at low weight. Simplified simulator aircraft may command full thrust on the first press or ignore the second.

Does TO/GA fly the missed approach automatically?

No. TO/GA starts the go-around, but the crew must still manage pitch, gear, flaps, speed, MCP altitude and the missed-approach route. Its initial roll guidance does not guarantee that the aircraft will follow every turn coded in the FMC.

The missed-approach altitude should already be prepared as part of the 737 descent and approach set-up sequence. Select LNAV, heading or another suitable lateral mode only when required; if the route modes refuse to arm, use our diagnosis for LNAV and VNAV engagement problems.

Do not assume that an engaged autopilot will remain engaged. Autopilot go-around behaviour varies with the 737 variant, approach status and add-on fidelity, so watch the FMA and autopilot status and be ready to hand-fly.

Why is the TO/GA switch not working in my simulator?

A non-responsive TO/GA switch usually results from an incorrect control assignment, an unarmed autothrottle, a hardware throttle override or simplified aircraft systems. Check the cockpit indications rather than repeatedly pressing the switch.

• Wrong command: assign the simulator's dedicated take-off/go-around command, not autothrottle arm, disconnect or generic maximum thrust. Command names differ between simulators and aircraft.
• Autothrottle not armed: TO/GA may provide flight-director guidance without moving the levers. Arm the autothrottle and verify that a valid N1 limit is available, or set thrust manually.
• Throttle axis interference: a noisy or moved hardware throttle can override the virtual servos. Leave the physical levers steady once the autothrottle takes control and correct any axis noise or conflicting assignments.
• Mode not accepted: airborne go-around logic can depend on radio altitude, flap position, glideslope status and aircraft phase. The add-on's FMA and manual should show which conditions it models.
• Simplified aircraft: some default or basic 737 models do not reproduce reduced go-around thrust, the second-press logic or accurate flight-director modes.

The reliable habit is simple: press TO/GA once, then look immediately at the FMA, engine indications and aircraft response. If the expected modes are absent, take manual control rather than waiting for automation that never engaged.