Operations and Maintenance Manual

Summary¶

After reading this manual, the operator can fly libdrone safely under EASA Open A2, respond correctly to in-flight failures, maintain the platform to its design specification, and document operations in a way that supports continued airworthiness. This is the 3.0.0 replacement for the V2.4.6 Maintenance and Operations Manual (DMOM).

Concept¶

The operator's contract with the platform¶

A built drone is not a finished product. It is a machine under continuous maintenance. The arm shafts are designed to fracture in crashes — they need to be inspected after every rough landing and replaced when they do fracture. The O-rings degrade with heat cycles and UV exposure. The LiPo cells age with every charge/discharge cycle. A drone that was airworthy at 10 flight hours may not be airworthy at 50 flight hours if maintenance was skipped.

The operator's contract is simple: inspect before every flight, maintain on interval, repair after every damage event, and document everything. The platform holds its end of the contract by being field-repairable in under 10 minutes for the most common failure modes.

Before every flight¶

→ preflight-checklist is non-negotiable. It covers four areas: site assessment (airspace, obstacles, weather, people), aircraft structure (props, arms, T-locks, sandwich bolts, payload connectors), electronics verification (GPS fix, battery voltage, Blackbox enabled), and pilot readiness.

The regulatory requirements that precede any operation in Czech Republic are in → easa-open-category: operator registration, A2 CoC, insurance, and the airspace check that must happen before arriving at the site. → risk-assessment provides the site-specific assessment framework.

Low-speed mode must be calibrated before every deployment with a new payload weight — → betaflight-profiles explains why and how.

After every flight¶

→ post-flight-check runs immediately after landing, before battery removal. It catches damage while the flight context is fresh and ensures the battery is handled correctly before it is warm. The 15-minute window between landing and safe battery handling is the inspection window — use it.

Log every flight in the maintenance logbook: date, site, flight count, battery cycles used, duration, anomalies. Without this log, maintenance intervals become guesses.

Scheduled maintenance¶

→ scheduled-maintenance defines what must be done and when. The critical intervals: - Every flight: prop inspection, T-lock check - Every 10 flights: motor mount O-ring visual, motor mount screw re-torque - Every 20–30 flight hours: motor mount O-ring set replacement - After every crash: full post-crash inspection sequence

The O-ring replacement is the most important interval. Degraded O-rings transmit vibration to the gyroscope — the first symptom is elevated noise in the Blackbox spectrum, not visible mechanical failure. By the time the O-rings are visibly cracked, they have already been failing functionally.

Corrective maintenance¶

→ corrective-maintenance is triggered by a finding — not a schedule. The post-crash triage sequence runs in order from most to least likely damaged: props, arm shafts, motor mount O-rings, CF rods (acoustic ping), T-slot walls, electronics.

Arm shaft replacement is the most common corrective task: → arm-shaft contains the geometry; corrective-maintenance contains the procedure. Field replacement kit: two spare arm shafts, an M2 hex key, four spare props, four M5 prop nuts. Under 10 minutes.

Emergency procedures¶

→ emergency-procedures covers the three most likely in-flight failures and the correct responses. The critical insight: GPS Rescue is a known and trusted behaviour only if it has been deliberately triggered in controlled conditions before the first uncontrolled activation. Practice GPS Rescue at low altitude over a clear area on every new deployment.

Winter operations require the winter protocol — → winter-protocol covers the LiPo behaviour changes below 5°C, the elevated voltage thresholds, and the reduced flight time planning.

Flight modes and when they apply¶

Understanding what the flight controller does in each mode is not optional for safe operation. → flight-modes explains the sensor dependency chain: GPS position hold requires GPS + compass + barometer + accelerometer + gyro. Losing GPS drops to angle mode — the correct response is manual correction, not confusion. Losing video is handled the same way as losing GPS: remove the goggles, locate the drone visually, fly home manually.

ArduPilot platform operations (Bandit, Ghost, Wing)¶

The operations above apply to Pro and Core (Betaflight). Bandit, Ghost, and Wing run ArduPilot — a different operational model. The full ArduPilot workflow is in → sk-ardupilot-operator-guide. Key differences the operator must be aware of:

Commissioning: ArduPilot requires a strict sequential setup — ELRS MAVLink mode first, then GPS/compass, then sensor calibration, then failsafe. → ardupilot-commissioning has the exact parameter values and sequence.

Failsafe: ArduPilot failsafe has three independent triggers (RC loss, battery, GCS link), each with configurable responses. → ardupilot-failsafe contrasts this with Betaflight GPS Rescue and provides the standard Bandit/Ghost parameter set.

Speed compliance for A2: The Betaflight Profile 2 low-speed calibration described in → betaflight-profiles applies to Pro and Core. ArduPilot platforms enforce speed limits differently — set via PILOT_SPEED_MAX and WP_SPEED parameters. → a2-throttle-compliance covers both approaches.

Reference¶

Operator quick reference¶

Situation	Article
Before every flight	preflight-checklist
After every flight	post-flight-check
Flight mode sensor dependencies	flight-modes
RC link loss / GPS Rescue	betaflight-gps-rescue, emergency-procedures
Video loss	emergency-procedures
Low battery	emergency-procedures
Scheduled maintenance intervals	scheduled-maintenance
Post-crash inspection	corrective-maintenance
Arm shaft replacement	corrective-maintenance, arm-shaft
O-ring replacement	scheduled-maintenance
Winter operations	winter-protocol
ArduPilot operations	sk-ardupilot-operator-guide
ArduPilot failsafe	ardupilot-failsafe
A2 speed compliance	a2-throttle-compliance

Procedure¶

First deployment at a new site¶

Run site risk assessment → risk-assessment
Check airspace → easa-open-category
Set GPS Rescue return altitude for local terrain → betaflight-gps-rescue
Calibrate low-speed profile for payload weight → betaflight-profiles
Complete pre-flight checklist → preflight-checklist
Test GPS Rescue manually at low altitude before operational use

Rationale¶

The DMOM (V2.4.6) combined maintenance planning, maintenance procedures, and technical log guidance in a single document. This skeleton separates the procedures (in atoms) from the navigation (here). An operator who needs the O-ring replacement procedure finds it in scheduled-maintenance. An operator who needs to understand when to do it finds that context in this skeleton. Neither document carries the other's content.