777 Polar Operations
Thread Starter
Joined: Jun 2002
Posts: 4
Likes: 0
From: ATX
777 Polar Operations
Hello,
I operate the 777F, though our current Ops Spec does not include Polar operations. I would appreciate clarification on your airline’s procedure for transitioning from magnetic to true heading using the HDG REF switch when entering Polar regions.
From my research, the 777’s primary and preferred roll mode for Polar operations is LNAV, which can be used with the heading reference switch in the NORM position. However, when using HDG SEL or HDG HOLD, a manual selection of TRUE for the heading reference is required.
I’d appreciate any insights you can share regarding your airline’s s procedures.
Thank you!
I operate the 777F, though our current Ops Spec does not include Polar operations. I would appreciate clarification on your airline’s procedure for transitioning from magnetic to true heading using the HDG REF switch when entering Polar regions.
From my research, the 777’s primary and preferred roll mode for Polar operations is LNAV, which can be used with the heading reference switch in the NORM position. However, when using HDG SEL or HDG HOLD, a manual selection of TRUE for the heading reference is required.
I’d appreciate any insights you can share regarding your airline’s s procedures.
Thank you!
N4790P
Joined: Jun 2002
Posts: 2,558
Likes: 233
From: Asia
With apologies to the OP but this has triggered an age old memory.
When I joined BOAC in the last 60s, one of the initial courses I went on was the VC10 Polar Path Compass.
Somewhat advanced for those times.
i haven't thought of this decades.
When I joined BOAC in the last 60s, one of the initial courses I went on was the VC10 Polar Path Compass.
Somewhat advanced for those times.
i haven't thought of this decades.
Joined: Jul 2012
Aviation Qualifications: ATPL
Posts: 189
Likes: 29
From: Aus
Joined: Feb 2000
Posts: 70
Likes: 0
From: Sand-Land
I've done a fair few Polar flights, although non recently. It was rare to change from LNAV to HDG/TRK SEL - (generally no weather to avoid that far North), so LNAV was used 99% of the time. That said, if there was a requirement to change modes, then the procedure was as you mentioned. TRUE needed to manually selected prior to engaging HDG SEL.
Joined: Sep 2010
Aviation Qualifications: ATPL
Posts: 886
Likes: 235
From: by the seaside
Not the answer you require but I was operating the first dc10 flight across the North Pole; we were not allowed to to take the autopilot out of NAV but passing overhead the pole our NAV displays showed a 30 odd degree split - above 65? North each display was powered by a separate INS rather than the mean of the three.
Direct to on each side still left different tracks (next waypoint 326nm iirc).
We were planned Fairfax with enroute diversion to our destination ANC so we couldn’t afford mistakes as fuel was limited.
Fortunately we had a good moon so taking nav mode and watching the lat long readout we managed to intercept the correct longitude after 50 or 60 miles.
After a month or so the aircraft manufacturer came back that there was some sort of software issue which had now been rectified.
PS as you know all directions from the North Pole are south. Our Topo was courtesy of National geographic magazine circa 1985.
PPS I wasn’t quite old enough to have done a Nav course.
Direct to on each side still left different tracks (next waypoint 326nm iirc).
We were planned Fairfax with enroute diversion to our destination ANC so we couldn’t afford mistakes as fuel was limited.
Fortunately we had a good moon so taking nav mode and watching the lat long readout we managed to intercept the correct longitude after 50 or 60 miles.
After a month or so the aircraft manufacturer came back that there was some sort of software issue which had now been rectified.
PS as you know all directions from the North Pole are south. Our Topo was courtesy of National geographic magazine circa 1985.
PPS I wasn’t quite old enough to have done a Nav course.
Joined: Nov 2004
Posts: 1,324
Likes: 156
From: Here, there, and everywhere
I think he has the answers now.
Went up there in a Twin Otter on skis. Landed on the closest suitable ice location about a mile from the actual pole. but we did fly directly overhead and then did a 360 degree turn to the right. 24 time zones in 2 minutes. All primary navigation with a GPS.
Went up there in a Twin Otter on skis. Landed on the closest suitable ice location about a mile from the actual pole. but we did fly directly overhead and then did a 360 degree turn to the right. 24 time zones in 2 minutes. All primary navigation with a GPS.
Joined: Feb 2025
Posts: 1
Likes: 1
From: London
As straight & level has said, Polar operations on the 777 is very easy. In fact, off the top of my head I can’t think of one example where I needed to make the transfer in flight.
Just leave the Hdg ref in norm and leave LNAV to take care of the rest. The system is clever enough to switch between true and magnetic as required so no crew intervention is needed at any stage of flight.
Writing an SOP to force crews to manually switch between the two is in my opinion asking for trouble due to crew forgetting to switch back to norm and is actual dumbing down a very clever aircraft.
Just leave the Hdg ref in norm and leave LNAV to take care of the rest. The system is clever enough to switch between true and magnetic as required so no crew intervention is needed at any stage of flight.
Writing an SOP to force crews to manually switch between the two is in my opinion asking for trouble due to crew forgetting to switch back to norm and is actual dumbing down a very clever aircraft.
