Staff Instruction (SI) No. 300-002

Precision Approach Path Indicator Flight Check

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Issuing Office: Standards Document No.: SI 300-002
File Classification No.: Z 5000-32 Issue No.: 02
RDIMS No.: 11010599-V8 Effective Date: 2015-11-10
  1. 1.0 INTRODUCTION
    1. 1.1 Purpose
    2. 1.2 Applicability
    3. 1.3 Description of Changes
  2. 2.0 REFERENCES AND REQUIREMENTS
    1. 2.1 Reference Documents
    2. 2.2 Cancelled Documents
    3. 2.3 Definitions and Abbreviations
  3. 3.0 BACKGROUND
  4. 4.0 RESPONSIBILITIES
  5. 5.0 TRANSPORT CANADA CIVIL AVIATION IN-FLIGHT INSPECTION PROCEDURE
  6. 6.0 SUMMARY
  7. 7.0 DOCUMENT HISTORY
  8. 8.0 CONTACT OFFICE

1.0 INTRODUCTION

1.1 Purpose

  1. The purpose of this document is to provide guidance for conducting a flight check of Precision Approach Path Indicator (PAPI) and Abbreviated Precision Approach Path Indicator (APAPI) lighting systems.

1.2 Applicability

  1. This document applies to all Transport Canada Civil Aviation (TCCA) Inspectors. This information is also available to the aviation industry for information purposes.

1.3 Description of Changes

  1. This second edition updates the SI and corrects the locations of the distances "d" in Figure 1 to match the calculations in the table below.

2.0 REFERENCES AND REQUIREMENTS

2.1 Reference Documents

  1. (1) It is intended that the following reference materials be used in conjunction with this document:
    1. Part III, Subpart 2 of the Canadian Aviation Regulations (CARs)Airports;
    2. Transport Canada publication, TP 312 – Aerodrome Standards and Recommended Practices – 4th ed.;
    3. Transport Canada publication, TP 312 – Aerodrome Standards and Recommended Practices – 5th ed. (effective 09/2015); and
    4. Advisory Circular (AC) No. 302-009 - Precision Approach Path Indicator Harmonization with Instrument Landing System.

    2.2 Cancelled Documents

    1. Not applicable.

    2.3 Definitions and Abbreviations

    1. The following abbreviations are used in this document:

      1. AC: Advisory Circular;
      2. APAPI: Abbreviated Precision Approach Path Indicator;
      3. CARs: Canadian Aviation Regulations;
      4. OPS: Obstacle Protection Surface;
      5. PAPI: Precision Approach Path Indicator;
      6. PVI: Program Validation Inspection
      7. TCCA: Transport Canada Civil Aviation;
      8. TP: Transport Canada Publication.

    3.0 BACKGROUND

    1. The PAPI/APAPI lighting systems specified in TP 312, section 5.3, are designed to provide visual vertical guidance to pilots for use in the operation of their aircraft safely in all variable weather conditions, by day and by night. To maintain a proper presentation of the on course section to approaching aircraft, the angle settings of the individual lights units of the system needs to be monitored and always properly maintained. Failure to maintain the specified angle settings could result in compromising the obstacle clearance provided to approaching aircraft.

    2. Periodic measurement of the PAPI / APAPI should be conducted by the aerodrome operator to verify that the lights are operating to applicable standards and manufacturers' recommendations as described within their aerodrome's preventive maintenance program.

    4.0 RESPONSIBILITIES

    1. Regulatory roles: It is airport operators' responsibility as per Part III of the CAR to ensure that their airside lighting is correctly installed, inspected and maintained in accordance with published specifications of TP 312, manufacturers' specifications and recommended maintenance procedures; including the verification of the angle settings for the individual PAPI / APAPI light units. TCCA has the mandate to verify that the certificate holder is operating in accordance with their airport certificate, including all applicable standards.

    2. Verification - A flight check of PAPI / APAPI is not required for calibration purposes. An aircraft is not a suitable platform to determine the compliance of the system to the accuracy level required by the standards. Only a field calibration with manufacturer's tools/procedures can establish/determine proper setting of the light beam angles.

    3. (3) Site visits by TCCA should include verification that the installation is in accordance with relevant standards. In the case of PAPI / APAPI installations, this requires demonstration (documentation) by the certificate holder that the units are installed in accordance with standards, and calibrated/maintained in accordance with manufacturer's procedures. Regular/ongoing verifications (PVIs) should focus on the demonstration of proper maintenance procedures/activities to capture any misalignment before these become gross alignment errors.

    4. (4) Failure to maintain the specified angle settings could result in compromising visual presentation of the on course sector to approaching aircraft, and having the aircraft approach at a shallower slope, thereby being closer than desired to obstacles. Periodic verification of the Obstacle Protection Surface (OPS) should also form part of the airport operators' preventive maintenance program to ensure the surface is clear of all obstacles.

    5. (5) As part of normal oversight activities, when TCCA aircraft are utilized to travel to/from the site, an in-flight assessment may be performed to detect any gross alignment errors in the system. Should any such errors be detected, the airport operator should be requested to immediately assess the alignment and correct as required, or remove system from service pending correction.

    5.0 TRANSPORT CANADA CIVIL AVIATION IN-FLIGHT INSPECTION PROCEDURE

    1. Where the decision is to proceed with an in-flight assessment of the system to identify any gross alignment errors, the assessment should be conducted as follows;

      1. Input the PAPI / APAPI coordinates (degrees/minutes/seconds) into the aircraft navigation system;

      2. Establish and maintain the aircraft at an altitude of 1 000 feet AGL at the PAPI / APAPI location;

      3. Track inbound (at 1 000' AGL) on an extended final starting at a distance greater than 4 NM. The PAPI / APAPI system should be operating at maximum intensity;

      4. Note the distance at which the system becomes visible for use, and where the colour transitions are observed. Observed colour changes should be near the distances presented in the table below. Colour transition time between the boxes should be consistent throughout all light units. Repeat the sequence as required to confirm any observed significant differences; and

      5. Where there is a significant difference in distances observed, the airport operator should be requested to immediately assess the alignment and correct as required, or remove system from service pending correction

      Figure 1: Flight Path through light beams

      Colour Change Point (Target Distance) PAPI / APAPI
      1000 feet above ground elevation at PAPI / APAPI position
      1 foot = 0.0001646 NM
      d = 0.1646/tan(ρ)
      The unit angle ρ = the setting angle

      for PAPI 3.0° A = 2° 30', B = 2° 50', C = 2° 10', D = 3° 30'
      for APAPI 3.0° A = 2° 45', B = 3° 15''
      PAPI APAPI
      Note : Distance (NM) is from PAPI / APAPI position.
      Slope
      (degrees)
      Unit A
      (d1)
      Unit B
      (d2)
      Unit C
      (d3)
      Unit D
      (d4)
      Slope
      (degrees)
      Unit A
      (d1)
      Unit B
      (d2)
      3.0° 3.77 NM 3.33 NM 2.98 NM 2.69 NM 3.0° 3.43 NM 2.90 NM
      3.5° 3.14 NM 2.83 NM 2.57 NM 2.35 NM 3.5° 2.90 NM 2.51 NM
      4.0° 2.69 NM 2.46 NM 2.26 NM 2.09 NM 4.0° 2.51 NM 2.21 NM
      4.5° 2.35 NM 2.17 NM 2.02 NM 1.88 NM 4.5° 2.21 NM 1.98 NM
    2. Other subjective in-flight assessment elements are:

      1. Range (normally 4NM or greater);

        Possible issues: weak or misaligned lamps, dirty filters or lenses;

      2. Colour transition sharpness;

        Possible issues: weak or misaligned lamps, dirty filters or lenses;

      3. PAPI – ILS harmonization (where applicable)

        Possible issues: angle settings, PAPI / APAPI location;

        Note: See Advisory Circular 302-009 - Precision Approach Path Indicator Harmonization with Instrument Landing System for guidance on ILS harmonization.

      4. Symmetry of displays on both sides of runway (where provided);

        Possible issues: angle settings, installation distance from threshold not the same on both sides.

    3. When performing an in-flight assessment, care should be taken to time the flight check so to minimize the glare the pilot could see from the position of the sun relative to the PAPI units.
  2. 6.0 SUMMARY

    1. Airport operators are responsible for ensuring the continued compliance of the PAPI/APAPI systems to the stipulated requirements in accordance with Part III of the CARsAerodromes, Airports, and Heliports, and associated standards in TP 312 - Aerodrome Standards and Recommended Practices.

    2. Site visits by TCCA should include verification that the installation is in accordance with relevant standards. In the case of PAPI / APAPI installations, this requires demonstration (documentation) by the certificate holder that the units are installed in accordance with standards, and calibrated/maintained in accordance with manufacturer's procedures. Regular/ongoing verifications (PVIs) should focus on the demonstration of proper maintenance procedures/activities to capture any misalignment before these become gross alignment errors.

    3. An in-flight assessment may be performed by TCCA to detect any gross alignment errors in the system.  Should any such errors be detected, the airport operator should be requested to immediately assess the alignment and correct as required, or remove system from service pending correction.

    7.0 DOCUMENT HISTORY

    1. Staff Instruction SI 300-002 Issue 01, dated 2012-09-21, RDIMS 7291044 (E), 7335526 (F) – Precision Approach Path Indicator Flight Check.

    8.0 CONTACT OFFICE

    For more information, please contact the appropriate TCCA Regional Office listed at the following address: 
    http://www.tc.gc.ca/eng/regions.htm

    Suggestions for amendment to this document are invited, and should be submitted via:

    AARTinfodoc@tc.gc.ca

    [Original signed by]

    David White
    Acting Director, Standards
    Civil Aviation 

    Transport Canada documents or intranet pages mentioned in this document are available upon request.

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