I prefer tuning my own nav frequencies in the sim but I was wondering about real airline procedures. I know you have to tune your own ILS freg but how about en route NAVAIDS? Is it a matter of pilot preference to let the FMC  tune for itself to cross check itself or maybe this varies with company policy? Any hints from real life jet jocks would be interesting. Thanks in advance.

The VOR receivers in the NG do not auto-tune enroute, unlike other Boeing aircraft like the 757,767 and 777.

 

The DME receivers however DO auto-tune (on their secondary channels) while inflight to provide DME/DME position updates to the IRUs. The primary channels of the two DME receivers are coupled to whatever VOR frequencies happen to be manually tuned on the NAV receivers.

 

I assume that SOPs of how the VOR receivers are used in flight depends on the individual airline or crew. in my simulated flights in the NGX, if I am travelling on an airway segment defined between two VORs, I like to keep the number 1 NAV manually tuned to the VOR in front of the aircraft, and the number 2 NAV manually tuned to the VOR to the rear, that way I can immediately use them to navigate in case of an IRU or GPS failure.

in my simulated flights in the NGX, if I am travelling on an airway segment defined between two VORs, I like to keep the number 1 NAV manually tuned to the VOR in front of the aircraft, and the number 2 NAV manually tuned to the VOR to the rear, that way I can immediately use them to navigate in case of an IRU or GPS failure.

 

Oh boy, like in the old days :rolleyes:   I really liked using the two VOR receivers this way in the C172 I flew back in the 90s. Actually this was the only way to navigate (including dead reckoning) because GPS and moving maps were just coming up at the horizon at a reasonable value for money in small GA aircrafts... (Today its even iPad & Co. ...)

But back on topic: I read a Boeing recommendation "somwhere", that includes "every piece of radio NAV aid" (also ADF recievers) to be used for flight preparation of the 737, beginning with DEP/return to field...

 

While nearest VOR bearings (not way point related!) in the A320 are/were shown in principle/automatic, those needle swings though in a B737 may only still be seen on ADF during approaches over an OM/NDB, if there is one installed at all...   (btw. good to have two functioning ADF receivers displayed at the same time in one instrument in "russian ICAO states" for "their NDB approaches"; especially interesting in cross winds...)

 

Would be interesting to know if civil airline B737 SOPs specify the manual operation of NAV radios in general or just under certain conditions...

 

 

Would be interesting to know if civil airline B737 SOPs specify the manual operation of NAV radios in general or just under certain conditions...

 

When I was in the Air Force, atleast one pilot had to tune up radios along the route as a cross check and back up in case you lost FMS data. I've seen where ASCB bus failures take out all FMCs. In the outfit I fly now, we apply the same ops if navaids are along the route. Even during FMS/FMC navaid based approaches, someone one has to tune up green/raw data. Both can have FMC data displayed as long as you have atleast a needle displaying the raw data. This is an FAA thing too.

Even during FMS/FMC navaid based approaches, someone one has to tune up green/raw data. Both can have FMC data displayed as long as you have atleast a needle displaying the raw data. This is an FAA thing too.

 

 

Interesting read, thanks! B)

There is in fact a lot of green data, starting with LOC/GS , that can be used. Although many NDBs are being removed meanwhile, VORs situated at or close to airports bring the needles alive and DMEs are giving at least your distance. And for MAs there might be a VOR in the vicinity that is the Fix for the holding pattern.

For my simulation procedures I tune in the NDB (if only available the "outbound") and if I know that the MA pattern fix/entry is VOR related, I tune it in, too.

So in the future I will also tune in the closest VOR. This way I may have all my radio NAVs in use, just in case that the magenta line disappears...

 

 

 

What got my curiosity is that using Sim Brief to generate a flight plan it depends on what airline format you request as to weather or not it gives you the enroute VOR frequencies. Use a Southwest format you get them, with Delta as well as some others you do not.

Use a Southwest format you get them, with Delta as well as some others you do not.

That really speaks for operators specifying via their SOPs the enroute usage of "traditional" navaids. SIDs, STARS and transitions are a different "story of course"   (pardon the somewhat pun :rolleyes: ) . 

 

Probably there are also other circumstances playing a role in differentiating between the usage of radio NAV versus "RNAV" (EDIT: or GPS/IRS) in general. Probably radar coverage, remote areas, high mountains etc...

 

Who knows? B)

Edited January 8, 201511 yr by vr-pilot

 

 

Use a Southwest format you get them, with Delta as well as some others you do not.

As vr pointed out, some may use RNAV routes that don't follow traditional routes along navaids. Most jet routes still include the navaids. I usually refer back to the American Airlines 757 that crashed in Cali Columbia. One of the contributing factors is that the crew failed to revert back to basic radio navigation. Had they tuned radios to back up the arrival, they would have known that the FMC was taking them some where they didn't want to go. The time spent being heads down trying to rectify the problem led them astray. Just having the route charts up and keeping up with the navaids would have fixed the problem. Sad thing was that there was a navaid on the airfield.

Oh boy, like in the old days :rolleyes:   I really liked using the two VOR receivers this way in the C172 I flew back in the 90s. Actually this was the only way to navigate (including dead reckoning) because GPS and moving maps were just coming up at the horizon at a reasonable value for money in small GA aircrafts... (Today its even iPad & Co. ...)

But back on topic: I read a Boeing recommendation "somwhere", that includes "every piece of radio NAV aid" (also ADF recievers) to be used for flight preparation of the 737, beginning with DEP/return to field...

 

 

Not a real world pilot but don't they say you should be dependent on your VOR/NDB for navigation and the GPS is only used for situation awareness? 

 

Whats the logic in the bigger aircraft for autotune? Does it do so when your xx NM away from the airport and the programmed runway?

If a terminal procedure is based off conventional navaids (i.e. generally speaking does not have 'RNAV' in the title), the law says you must have the appropriate navaids tuned and identified, even if you're using the FMC to navigate.

 

Likewise, common sense (and airline SOPs) dictates that one must ensure the magenta line is in the correct place, particularly before descent or when entering a remote area where you are going to be entirely dependent on the IRS/GPS (i.e. Oceanic areas etc). The way to do this is to compare the FMC position to a tuned and identified navaid, either as you fly over the top of an appropriate navaid or using the bearing and distance information off a navaid with a reasonable intercept angle to the route being flown. As others have mentioned, whether one is required to tune up every navaid enroute will vary between airlines (and, I suspect, between fleets as well).

 

In terms of autotuning VORs, all the B744 book has to say is that "selection is related to the active route and any procedure (SID, STAR, etc.) in the active route" -- which is suitably vague!

 

As for the approach:

 

"Receivers tune and frequency/course display after selecting an ILS, LOC, back course, VOR, runway, or a VFR approach to an ILS/LOC equipped runway and the airplane is within 150 nm of the destination airport, 50 nm of T/D, or in FMC descent."

 

Hope that helps.