B737 IRS Alignment Messages

[B737NG_Pilot]

As per the FCOM

When the Position information is contradictory IRS POS/ORIGIN DISAGREE is displayed.

If an entered latitude/longitude position is not within 4 NM of the origin airport, the CDU scratchpad message VERIFY POSITION is displayed.


During line operations have only seen the IRS POS/ORIGIN DISAGREE. Any examples when VERIFY POSITION can be seen.

[CaptainSandL]

From U10.7 the VERIFY POSITION message was changed to specify the source that needed verifying, as in your example. So I think the old VERIFY POSITION message no longer exists as it has been enhanced.

Your second FCOM quote has probably not been updated to reflect the change.

[B737NG_Pilot]

From U10.7 the VERIFY POSITION message was changed to specify the source that needed verifying, as in your example. So I think the old VERIFY POSITION message no longer exists as it has been enhanced.

Your second FCOM quote has probably not been updated to reflect the change.

Thanks Captain...

VERIFY POSITION is still being mentioned in the FCOM along with IRS POS/ORIGIN DISAGREE. This is on the B737MAX and B737NG FMCU14.0. With U10.7 VERIFY POSITION message has been enhanced as you mentioned. The enhancements include

VERIFY POS: FMC-FMC
VERIFY POS: FMC-GPS
VERIFY POS: FMC-RADIO
VERIFY POS: IRS-FMC
VERIFY POS: IRS-IRS
VERIFY POS: IRS-RADIO
VERIFY POS (On GND Only)

Both IRS POS/ORIGIN DISAGREE and VERIFY POSITION appear on GND as per FCOM. Then what's the difference ?