A standardized inspection methodology for assessing the operational, optical, geometric, mechanical, electrical, structural, environmental, calibration, and photometric condition of Precision Approach Path Indicator (PAPI) and Abbreviated PAPI (APAPI) systems. Covers unit identification and spacing, azimuth and elevation alignment, beam setting, lamp/LED operation, optical window and lens condition, housing and mounting, foundation stability, cable and connector interfaces, heater and environmental protection, calibration/alignment records, and photometric performance.
Important control — A PAPI/APAPI unit being illuminated does not by itself confirm that the system is correctly aligned or providing the required visual guidance. Inspection must distinguish between operational condition, physical condition, alignment condition, calibration condition, and photometric condition. Any suspected change in azimuth, elevation, beam setting, unit spacing, foundation stability, optical condition, or system calibration status should be referred for the appropriate technical verification.
Inspection of the complete PAPI/APAPI unit for operational availability, abnormal indications, damaged units, physical deterioration, and visible defects.
Inspection of the horizontal orientation of the PAPI/APAPI units, including individual unit azimuth and the overall array's relationship to the runway centreline.
Inspection of the elevation setting of individual PAPI/APAPI units and the relative elevation relationship between units.
Inspection of the optical beam setting and visible condition of the PAPI/APAPI beam, including transition, colour boundary, output evenness, and obstruction of the optical path.
Inspection of lamps or LED modules for normal operation, including brightness, colour condition, replacement compatibility, and driver/power module condition.
Inspection of optical windows and lenses for cracking, clouding, scratching, contamination, moisture, physical damage, displacement, and seal condition.
Inspection of the PAPI/APAPI housing for structural integrity, physical damage, corrosion, coating deterioration, and seal/access-panel condition.
Inspection of foundations for cracks, settlement, movement, deterioration, and structural instability, and verification that foundation condition has not caused unit displacement or alignment deviation.
Inspection of cable-entry points for sealing, mechanical protection, strain relief, and water ingress, including the condition of cable glands and seal arrangements.
Inspection of connectors for security, corrosion, contamination, moisture, and physical damage, including applicable L-823 plug/receptacle assemblies and other electrical interface points.
Verification that the PAPI/APAPI system has valid calibration/alignment status as required by the applicable maintenance program, with supporting documentation and history.
Assessment of surrounding environmental conditions affecting PAPI/APAPI operation, including vegetation encroachment, obstructions, FOD, water accumulation, and contamination.
The component-level checklist spine underlying all 12 topics above — every applicable PAPI/APAPI unit should be assessed, where relevant, against each of the following areas.
Status values recorded against each detailed inspection area, common across all 12 topics above.
| Parameter | Inspection Status |
|---|---|
| System Status | Normal / Abnormal |
| Unit Identification | Correct / Incorrect / Missing |
| Unit Spacing | Correct / Deviation |
| Azimuth | Correct / Deviated |
| Elevation | Correct / Deviated |
| Beam Setting | Correct / Abnormal |
| Lamp/LED | Normal / Weak / Failed |
| Illumination | Normal / Reduced / Abnormal |
| Colour | Correct / Abnormal |
| Optical Window | Clean / Contaminated / Damaged |
| Lens | Good / Damaged |
| Housing | Good / Damaged / Corroded |
| Mounting | Secure / Loose / Damaged |
| Foundation | Stable / Settled / Cracked / Damaged |
| Cable | Good / Damaged |
| Cable Entry | Sealed / Damaged |
| Connector | Good / Damaged / Corroded |
| Heater | Normal / Abnormal / N/A |
| Environmental Condition | Good / Deficient |
| Vegetation | Clear / Encroaching |
| Water Ingress | None / Suspected / Confirmed |
| Calibration Status | Valid / Due / Overdue / Not Available |
| Alignment Record | Available / Missing / Requires Update |
| Photometric Condition | Acceptable / Deficient |
| Defect Status | Normal / Defective / Unserviceable / Immediate Action Required |
Every observation should be assigned an appropriate status:
NormalEquipment/condition satisfactory and operating as expected.
DefectiveAbnormality or defect identified but equipment remains operational or condition does not require immediate withdrawal.
UnserviceableEquipment or system is not available for its intended function.
Immediate Action RequiredCondition presents an operational, electrical, safety, or airside risk requiring immediate escalation/action.
Each PAPI/APAPI inspection record should include:
Quick answers about papi / apapi inspection in the AGL Inspection Handbook.
Division 05 contains 12 published topics giving a standardized inspection methodology for the operational, optical, geometric, mechanical, electrical, structural, environmental, calibration and photometric condition of Precision Approach Path Indicator (PAPI) and Abbreviated PAPI (APAPI) systems.
The component-level checklist covers unit identification, unit spacing, azimuth, elevation, optical window, housing, mounting, foundation, cable, connector, heater where applicable, photometric condition and alignment record.
The parameters include beam setting, calibration status (Valid, Due, Overdue or Not Available) and alignment record (Available, Missing or Requires Update), and the minimum record includes a re-alignment or re-calibration reference where applicable.
Every observation is assigned one of four statuses. Normal means the equipment or condition is satisfactory and operating as expected. Defective means an abnormality or defect exists but the equipment remains operational or the condition does not require immediate withdrawal. Unserviceable means the equipment or system is not available for its intended function. Immediate Action Required means the condition presents an operational, electrical, safety or airside risk requiring immediate escalation and action.
The record includes the date and time, inspector name and designation, runway and PAPI/APAPI location, unit numbers inspected, observations, status per parameter, defect description where applicable, immediate action taken, the person or department notified, the corrective-action reference, any re-alignment or re-calibration reference, and closure date and time with sign-off.
It starts by reviewing approved data, then verifying identification, checking spacing, inspecting azimuth and verifying elevation, before moving on to the remaining optical, mechanical and photometric checks.
Yes. This handbook is an uncontrolled educational reference, not an approved procedure. The airport's approved inspection schedule, SMS procedures, ATC instructions, NOTAM procedures and local aerodrome regulations always take precedence, and the current revision of any official document should be verified before use.
Yes. Each inspection topic has a Download as Word option that produces an uncontrolled Word checklist template (description, a tick-box inspection table and an inspector sign-off block) for personal reference and internal training, to be reviewed and adopted under the user’s own document control.
PAPI/APAPI inspection is where glide-path signal condition awareness begins. Go beyond identifying defects and build the technical knowledge to understand why abnormalities occur, how they affect system serviceability, and when further testing, troubleshooting, maintenance or corrective action is required.
Develop structured knowledge across:
Learn to connect the inspection process with the wider AGL engineering lifecycle.
Inspect with purpose. Understand the system. Act with technical confidence.
Please read before relying on any content on this page or on any record downloaded from it.