FDM-037Cruise

Unexpected autopilot disconnect in cruise

Autopilot disengagement occurs outside a planned manual-flight, system-test, or procedure context.

4Signal groups
1Flight phases
5Safety topics
12Reading links

What the profile screens for

Autopilot disengagement occurs outside a planned manual-flight, system-test, or procedure context.

Why it matters

An unexpected disconnect can increase workload and may indicate system, sensor, turbulence, or control-input effects.

Flight-phase contextCruise
Risk lensesAircraft upset / loss of controlAirborne collisionAirworthiness / system limit

Build the event around relationships—not one number.

01 · Gate

Define the operating context

Identify the cruise state, aircraft configuration, location, and any required external data before applying logic.

02 · Detect

Screen the signal relationship

Use validated combinations of autopilot status, disconnect warning, flight-director mode; avoid treating one isolated value as the whole event.

03 · Validate

Confirm it is a genuine event

Check polarity, units, source, recording rate, dropouts, air/ground logic, persistence, and false-positive mechanisms.

04 · Contextualise

Connect data to the safety question

Review procedures, reports, weather, airport and traffic context, exposure, recurrence, and the strength of the related barriers.

Recorded signals that may help explain the event.

autopilot statusdisconnect warningflight-director modecontrol input

Questions before conclusions

  1. Q1

    Are autopilot status, disconnect warning, flight-director mode valid, correctly decoded, time-aligned, and sampled well enough for this event?

  2. Q2

    What changed immediately before, during, and after the unexpected autopilot disconnect in cruise indication?

  3. Q3

    How do aircraft configuration, weather, airport geometry, automation state, and crew reports change the interpretation?

  4. Q4

    Which current flight manual, SOP, maintenance, or operator event definition controls the final conclusion?

Safety topics that broaden the event review.

Topic atlas2 operational connections
Deep briefs3 detailed research guides

12 useful starting points

Terminology and topic relationships select these links; the publisher source remains authoritative.

No copied report filesSearch all related records →
U.S. Federal Aviation AdministrationEvent-context match

SAFO 14002 — SAFO 14002, Global Positioning System ( GPS )/Global Navigation Satellite System ( GNSS ) Navigator/Autopilot Compatibility

Official U.S. Federal Aviation Administration material indexed for flight controls and automation and navigation and surveillance. Open the publisher source for the complete document, scope, and current status.

Open official source
U.S. Federal Aviation AdministrationEvent-context match

SAFO 08005 — Preflight of helicopter hydraulic systems to include validation of control movement smoothness and identification of adverse flight control “stick-jump.”

Official U.S. Federal Aviation Administration material indexed for flight controls and automation and airworthiness and systems. Open the publisher source for the complete document, scope, and current status.

Open official source
U.S. Federal Aviation AdministrationEvent-context match

SAFO 08015 — Preflight check of helicopter hydraulic systems to include validation of control movement smoothness and identification of adverse flight control “stick-jump”

Official U.S. Federal Aviation Administration material indexed for flight controls and automation and airworthiness and systems. Open the publisher source for the complete document, scope, and current status.

Open official source
U.S. Federal Aviation AdministrationEvent-context match

SAFO 06017 — Equipment Training and Checking for Helicopter Operators on the SPZ-7000 or SPZ-7600 Dual Digital Automatic Flight Control Systems

Official U.S. Federal Aviation Administration material indexed for flight controls and automation and human factors. Open the publisher source for the complete document, scope, and current status.

Open official source
U.S. Federal Aviation AdministrationEvent-context match

SAFO 05002 — Multiple full deflection, alternating flight control inputs

Official U.S. Federal Aviation Administration material indexed for flight controls and automation. Open the publisher source for the complete document, scope, and current status.

Open official source
Airbus Safety FirstEvent-context match

A380 Development of the Flight Controls

Official Airbus Safety First material indexed for aviation safety. Open the publisher source for the complete document, scope, and current status.

Open official source
Airbus Safety FirstEvent-context match

Dual Side Stick Inputs

Official Airbus Safety First material indexed for flight controls and automation. Open the publisher source for the complete document, scope, and current status.

Open official source
Airbus Safety FirstEvent-context match

Inadvertent Autopilot Engagement during Takeoff on A220 Aircraft

Official Airbus Safety First material indexed for takeoff and flight controls and automation. Open the publisher source for the complete document, scope, and current status.

Open official source
Airbus Safety FirstEvent-context match

Inappropriate V/S Target during Autoflight Mode Reversion

Official Airbus Safety First material indexed for flight controls and automation. Open the publisher source for the complete document, scope, and current status.

Open official source
Airbus Safety FirstEvent-context match

System Reset: Use With Caution

Official Airbus Safety First material indexed for airworthiness and systems. Open the publisher source for the complete document, scope, and current status.

Open official source
Airbus Safety FirstEvent-context match

The importance of the pre-flight flight controls check

Official Airbus Safety First material indexed for aviation safety. Open the publisher source for the complete document, scope, and current status.

Open official source
U.S. National Transportation Safety BoardEvent-context match

NTSB Safety Alert SA-048 — Flight Control Locks: Overlooking the Obvious

Official U.S. National Transportation Safety Board material indexed for flight controls and automation. Open the publisher source for the complete document, scope, and current status.

Open official source
EASA

Easy Access Rules for Air Operations — ORO.AOC.130

Official source
EASA / EOFDM

European Operators Flight Data Monitoring forum

Official source
FAA

AC 120-82 — Flight Operational Quality Assurance

Official source
UK CAA

CAP 739 — Flight Data Monitoring

Official source
ICAO

Doc 10000 — Manual on Flight Data Analysis Programmes

Official source