2.8. FMS/GPS/INS/RNAV Initialization and Programming

[If the aircraft type that these SOPs refers to is not equipped with an RNAV system do not include this section.]

INS) is specified in areas of the CARs Standards other than those that pertain to the SOPs. However, the safe and effective use of Area Navigation Systems invariably requires crew coordination. Therefore, RNAV will be discussed in several areas of these SOPs.]

[If it is necessary to carry out FMS/GPS/INS/RNAV initialization and programming after engine start include the relevant information in the "Normal Flight Procedures Departure" chapter instead of this chapter.]

[Depending on the type of RNAV equipment and company procedures, the depth of guidance presented in this section will vary considerably. Some recommended practises are contained in the documentation that pertains to the specific equipment. Additional general guidance is available from your regional office. The following is a very general indication of some of the types of crew coordination that may be appropriate with a dual linked RNAV system.]

  1. RNAV Designation - The Number 1 RNAV is located adjacent to the pilot's seat. The Number 2 RNAV is located adjacent to the co-pilot's seat. [Or, insert the relevant designations for your aircraft.]
  2. Initialization - The pilot should initialize the No. 1 RNAV and the Co-pilot should initialize the No. 2 RNAV. During initialization it is important to enter the coordinates of the start position with as much accuracy as possible. Each pilot shall insert the start coordinates individually and silently. The track and distance to the first waypoint will later be used to verify correct initialization. This procedure is designed to reduce the risk of both pilots agreeing on an incorrect initial position and inserting it in the navigation system. In the event that only one RNAV system is operational, one pilot will obtain start coordinates from the applicable document and then type them into the RNAV. Prior to accepting the data, the other pilot will look at the coordinates displayed on the CDU then compare them to the document. Use of this reverse path checking technique should reduce the risk of incorrect data entry.
  3. Route Programming - The reverse path checking procedure that is described in this paragraph is similar to that used for single RNAV initialization. It is also intended to reduce the risk of incorrect typing of data into an RNAV system. One pilot is to obtain route/waypoint information from the appropriate document then silently enter it into either one of the RNAV systems. When complete, the other pilot will read the route/waypoint data from the CDU of the recently programmed system and check it against the applicable document. If the second pilot finds an error, that pilot will now insert correct data. The other pilot will check it by looking at the CDU and comparing it to the document. Once the correction is confirmed the second pilot will continue the verification process to completion. For use of Waypoints that are extracted from a database that is integral to the RNAV system, the individual waypoint component data shall be verified for accuracy against an external document. The data checking is required any time when it can not be positively determined that the waypoint has been verified since the last database update. Unfortunately, database information has on occasion been reported to have errors.
  4. Pre-programmed Routes - Pre-programmed routes need be checked by only one pilot unless an error is found. Errors are to be corrected as described in the preceding paragraph. Pre-programmed routes need only be checked if the database has been updated.
  5. Data transfer - To further reduce typing errors, the flight plan information entered or selected on the first RNAV should be electronically transferred to the other unit using the data link. Information should only be typed into the second system in the event of unserviceability.
  6. RNAV System Comparison - The bearing and distance to the first waypoint as displayed by the two RNAV systems is to be compared. They should be the same. If a discrepancy is found it must be corrected. If one of the systems can be determined to be faulty it must not be used. If the discrepancy can not be accounted for neither system is to be used.

Date modified: