Differential settings for Precision Approach Path Indicator (PAPI) - Civil Aviation Safety Alert (CASA) No. 2020-02


Airport Operators Transport Canada Civil Aviation Safety Inspectors - Aerodromes

File Classification No.: Z 5000-35
RDIMS No.: 16118665
Document No.: CASA 2020-02
Issue No.: 01
Effective Date: 2020-12-15


This Safety Alert is issued to advise Airport operators that Table in TP312 – Aerodrome Standards and Recommended Practices, 5th edition, contains errors in the differential settings for PAPI Unit A to the Obstacle Protection Surface (OPS) when the PAPI is harmonized with an Instrument Landing system (ILS) or when the PAPI approach slope is 4° or greater.


TP312 (5th edition) introduced provisions for PAPI setting angles where the PAPI is to be harmonized with an ILS or for PAPI approach slopes greater than 3°. Unfortunately, the differential setting angles between PAPI Unit A and the OPS for those two conditions were published as 29 minutes of arc and 24 minutes of arc respectively when they should have been kept at 34 minutes of arc.

Recommended action:

Table in TP312 will be rectified with the next amendment. Meanwhile, Airport operators are advised to use 34 minutes of arc for all differential setting angles between PAPI Unit A and the OPS. The differential setting angle for APAPI Unit A to OPS remains at 54 minutes of arc.

Contact office:

For more information concerning this issue, contact a Transport Canada Centre; or contact Marc Juneau, Aerodromes Standards in Ottawa, by telephone at 613-991-2219, by fax at 613-952-3298 or by e-mail at marc.juneau@tc.gc.ca.

Original signed by

Félix Meunier
Standards Branch

The Transport Canada Civil Aviation Safety Alert (CASA) is used to convey important safety information and contains recommended action items. The CASA strives to assist the aviation industry's efforts to provide a service with the highest possible degree of safety. The information contained herein is often critical and must be conveyed to the appropriate office in a timely manner. The CASA may be changed or amended should new information become available.