Can you fly an ILS app with LNAV/VNAV?
Join Date: Jul 2001
Location: East of West and North of South
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Jeez you guys are making a simple thing complicated. 
Who cares what mode the autopilot is in as long as the raw data (in this case the ILS), is monitored and followed.
We also fly VOR approaches in LNAV/VNAV, same applies: Raw data VOR/DME/Altitude data must be monitored and adhered too.
Of course you can do it for an ILS too. Though why not click the autopilot out and switch the FDs off.
Who cares what mode the autopilot is in as long as the raw data (in this case the ILS), is monitored and followed.
We also fly VOR approaches in LNAV/VNAV, same applies: Raw data VOR/DME/Altitude data must be monitored and adhered too.
Of course you can do it for an ILS too. Though why not click the autopilot out and switch the FDs off.
Join Date: Jun 2012
Location: india
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YOU WILL BE LEGAL PROVIDED in my opinion if YOU HAVE 3 things-
1) you have raw data annunciated for constant monitoring means a valid ILS signal and received without failure on board
2) the LNAV COMING FROM THE FMC IS FROM THE ILS APPROACH SELECTED AND YOUR ANP < RNP and RNP requirements are met
3) VNAV engagement criteria is met from the FMC, as far as Boeing is considered, There must be a defined glide slope angle in FMC matching the Actual G/S or a RWXX Point on the legs page. TCH, ALT and speed constraints can be manually put for A better FMC calculated path.
You are making the approach with FMC cross checked with Raw data should anything go wrong, ready to take over.
so I feel legally you are covered.
VNAV USING TRUE ALT and getting you high on a HOt day, is a good point to introspect before using this kind of approach.
Company SOP may be more restrictive for given a/c type.
Any corrections to above are welcome.
1) you have raw data annunciated for constant monitoring means a valid ILS signal and received without failure on board
2) the LNAV COMING FROM THE FMC IS FROM THE ILS APPROACH SELECTED AND YOUR ANP < RNP and RNP requirements are met
3) VNAV engagement criteria is met from the FMC, as far as Boeing is considered, There must be a defined glide slope angle in FMC matching the Actual G/S or a RWXX Point on the legs page. TCH, ALT and speed constraints can be manually put for A better FMC calculated path.
You are making the approach with FMC cross checked with Raw data should anything go wrong, ready to take over.
so I feel legally you are covered.
VNAV USING TRUE ALT and getting you high on a HOt day, is a good point to introspect before using this kind of approach.
Company SOP may be more restrictive for given a/c type.
Any corrections to above are welcome.
Join Date: Jan 2005
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I think some are missing the point on this topic. There's a big difference between being technically able to do something and being legally capable to do it.
I would be extremely surprised if any airline in the world would allow an ILS to be flown using LNAV/VNAV, coupled or uncoupled.This point in itself makes such an approach illegal.
If the ILS is unavailable for any reason, revert to the next best approach. Usually a non-precision approach. If the minima precludes a landing, go somewhere else!
If I've learned anything in my 40+ years of flying it's CYA and KIS. Cover your ass and keep it simple!
I would be extremely surprised if any airline in the world would allow an ILS to be flown using LNAV/VNAV, coupled or uncoupled.This point in itself makes such an approach illegal.
If the ILS is unavailable for any reason, revert to the next best approach. Usually a non-precision approach. If the minima precludes a landing, go somewhere else!
If I've learned anything in my 40+ years of flying it's CYA and KIS. Cover your ass and keep it simple!
