Learn how to use the PMDG 737 autopilot in MSFS: set the MCP, engage CMD, fly LNAV/VNAV, manage descents and fix common mode errors.
To use the PMDG 737 autopilot in Microsoft Flight Simulator, configure the FMC and MCP, switch both flight directors on, then engage CMD A at or above 400 feet AGL once the aircraft is stable and trimmed. Select LNAV/VNAV or heading and vertical modes, and confirm every capture on the PFD flight-mode annunciator.
How do you engage the PMDG 737 autopilot?
- Prepare the FMC if required. An executed route and completed performance data are needed for LNAV and VNAV. They are not required if you intend to fly with heading, speed and vertical-speed selections.
- Set the MCP before take-off. Enter the initial cleared altitude, runway or departure heading and selected speed, normally V2 for take-off.
- Switch on both flight directors. Arm the autothrottle if you plan to use it. Autothrottle and autopilot are separate systems; one can operate without the other.
- Take off using the flight director. Activate the take-off guidance with TO/GA and hand-fly the aircraft through at least 400 feet AGL.
- Stabilise and trim the aircraft. Centre the controls without holding substantial pressure, then press
CMD A. CMD B may be used instead, but only one autopilot is normally engaged outside a dual-channel approach. - Select the required modes. Use LNAV and VNAV for an FMC-managed flight, or combine HDG SEL with LVL CHG, V/S or ALT HOLD for direct MCP control.
- Read the FMA. Check the top of the primary flight display after every selection. Green modes are active and white modes are armed; the FMA, not the illuminated MCP button, tells you what the aircraft is actually doing.
The PMDG 737 variants use the same basic Boeing MCP logic, although individual airline equipment options and cockpit configurations can differ.
Which MCP modes should I use?
| Control or mode | What it does | Main gotcha |
|---|---|---|
CMD A/B | Engages an autopilot channel and follows the active flight-director modes. | It will not choose a route or altitude mode for you. |
HDG SEL | Turns towards and holds the heading selected on the MCP. | Check the heading bug before pressing it. |
LNAV | Tracks the active FMC route laterally. | The route must be executed and have a valid active leg. |
VNAV | Uses FMC speed, altitude constraints and vertical-path data. | Incomplete performance data or a restrictive MCP altitude can prevent the expected climb or descent. |
LVL CHG | Climbs or descends while pitch maintains the MCP speed. | It normally commands climb thrust when climbing and idle thrust when descending. |
V/S | Maintains the selected vertical speed. | A large climb rate can let airspeed decay even with autothrottle operating. |
ALT HOLD | Holds the altitude at which the mode is engaged. | Changing the altitude selector alone does not leave ALT HOLD. |
VOR/LOC and APP | Capture an ILS localiser and, with APP, its glideslope. | The ILS, course and intercept must be set up correctly. |
A simple way to remember the division is that LNAV or HDG SEL controls the lateral path, while VNAV, LVL CHG, V/S or ALT HOLD controls the vertical path. The MCP altitude acts as a clearance limit rather than an instruction to climb or descend by itself.
What do LNAV and VNAV need before they will work?
LNAV needs an executed route, a sensible active leg and suitable intercept geometry; VNAV additionally needs completed performance and cruise-altitude data. Remove unintended route discontinuities and confirm that the first active leg is the one you expect.
Before a VNAV descent, set the MCP altitude to the next cleared lower altitude. VNAV should remain at cruise until its calculated top of descent, then descend only if the selected altitude permits it. For an immediate ATC descent, use LVL CHG or V/S rather than expecting the altitude knob alone to start the descent.
Our focused guide to setting up and troubleshooting 737 LNAV and VNAV covers route activation, FMC performance entries, altitude constraints and unexpected mode reversions.
Why will CMD A not engage or stay engaged?
CMD A normally refuses to engage because the aircraft is below the take-off engagement height, badly out of trim, receiving a conflicting control input or has an invalid system state. Check these items in order:
- The aircraft is at or above 400 feet AGL after take-off.
- The MCP autopilot-disengage bar is in its normal raised position.
- The aircraft is stable, trimmed and not being forced away from the flight-director commands.
- Electrical power, hydraulics, flight controls and IRS operation are normal.
- No joystick axis, trim wheel, keyboard command or controller button is repeatedly sending an autopilot-disconnect or trim input.
- MSFS piloting assistance is not fighting the PMDG aircraft.
- You selected
CMD, not CWS. Control Wheel Steering responds differently and is not the normal route-tracking mode.
A mistake we see constantly is a noisy pitch, roll or trim binding that disconnects the autopilot immediately after engagement. Centre the controls, increase only enough dead zone to remove jitter, and clear duplicate bindings across every connected controller. For broader fault isolation, use our autopilot engagement troubleshooting checklist.
How do you descend and level off correctly?
Set the cleared altitude first, then choose a vertical mode that will take the aircraft there. LVL CHG is usually the clearest choice for an unrestricted climb or descent because pitch controls speed; V/S is useful when ATC assigns a specific rate, but it requires closer airspeed monitoring.
As the selected altitude approaches, the FMA should change to ALT ACQ and then ALT HOLD. If the 737 remains level after you turn the altitude knob, it is usually still in ALT HOLD or waiting for the VNAV top of descent—not malfunctioning.
Can the PMDG 737 autopilot fly an ILS landing?
The PMDG 737 can fly an ILS approach and, when all dual-channel requirements are met, perform an autoland. Tune or verify the ILS, set the inbound course, establish a suitable intercept, select VOR/LOC or APP as required, and verify localiser and glideslope capture on the FMA.
A dual-channel autoland requires a suitable ILS and both autopilot channels engaged under the correct APP-mode conditions. Do not engage both CMD channels merely for redundancy during normal cruise. Our detailed 737 ILS and autoland procedure explains the capture sequence and approach-mode checks.
The autopilot does not lower the landing gear, select flaps, arm the speedbrake or configure the brakes. For a manual landing, disconnect it at the planned height using the yoke autopilot-disconnect switch or a correctly mapped equivalent; press the switch again to cancel the disconnect warning, then continue hand-flying.