Using 'Fix' properly in 777 & 787

[BWBriscoe 116]

Hi,

I'm currently flying the 777 and 787 and I want to more realistically use the 'Fix' function of the FMC to show distances from en route alternates.

Is it as simple as just adding the alternate airfields into the Fix section?

Thanks,

Ben

[jon b 2,047]

Basically yes.

There’s usually no set procedures so it’s up to your own preference what  distance you use with the range rings. If you use them.

Some people use 1 hour flying time , so something like 475nm , personally when able I like to arrange the ring ring circles From different airports  so they just touch each other for situational awareness. You get to know the distances between airports after a while, for example heading west across the Atlantic a 400nm range ring around EINN and BIKF will make the circles just touch.
 

Another thing I sometimes do is put a bearing into the fix which represents the inbound final approach track to the current runway in use at that alternate. So for example if runway 05 is in use you’d enter 230 as the bearing radial.

The 787 and 777 also have an alternates page in the FMC, displaying that will show you the instantaneous eta at each of 4 alternates in chronological order for orientation 

Edited October 25, 2020 by jon b

[scottsware 69]

5 hours ago, jon b said:

The 787 and 777 also have an alternates page in the FMC, displaying that will show you the instantaneous eta at each of 4 alternates in chronological order for orientation 

This is what we do in real life.  We monitor the alternates from this page.  I fly the 787 and we insert the two closest ETOPS airport on that page.  It doesn't look like you can manually set the airports on the the QW787, not sure about the PMDG 777 but the Alternates pages does correctly show the closest four airports.

The only time we use the fix page for alternates is to mark the entry and exit points of the ETOPS area of operations.

[jon b 2,047]

Good info Scott thanks. I’m not that familiar with ETOPS operations yet, I’ll be doing the training shortly as I move onto the 787.

I’ve not had to consider  it previously. As the old joke goes: why do you fly a four engined jet across The Atlantic  ? ... because I can’t find a five engined jet !

[scottsware 69]

Here is a bit more detail on the use of the fix page and ETOPS. We load the entry and exit airports in the fix page then put a 453 ring around them. As an example on a KDEN to PHNL flight you might load KSFO and PHTO.  The 453 ring is roughly 60 minutes away from the airport you load in the fix page.  As you pass over KSFO headed West you want to know when you are in the ETOPS zone.  You have make sure you have the latest weather forecast and that the weather is still legal.  You may need to have tested some of the aircraft systems. An example might be the APU might need to be started to make sure it will run.  This is rare for but sometimes required for maintenance reasons. In general, you have to make sure it’s still legal to proceed into the ETOPS area.  I think, but not 100% sure the 737 has to start it’s APU prior to entering the ETOPS area.  The 787 two electric generators per engine but the 737 only has one. I think they must run the APU so it’s generator is available during that period. The 453 ring on the other end, in this case the one around PHTO let’s you know when you leave ETOPS.  In the 787 we don’t really care but I think in the 737, they would shut down the APU. 
 

From a pilot standpoint ETOPS is not a big deal, there is very little to do.  All the hard work and record keeping is on the shoulders of maintenance and dispatch.    

[Samaritano 304]

The reason they start the APU on a 737 ETOPS segment is because the 737 does not have a RAT (Ram Air Turbine) to provide electrical power in case of an engine failure. 

[scottsware 69]

Thanks, that makes perfect sense.  
 

I also could have RATS, I should have thought of that 🤪

Edited October 26, 2020 by scottsware
Thought of something funnier.