NAV RAD ILS

[Captain_al]

Hi Hardy:

Couple of questions:

I was doing an RNAV Approach and went to the NAV RAD page to park the ILS by Deleting, and it was an Invalid Delete. The ILS frequency and Front Course should not be locked out, you should be able to Park it when doing an RNAV Approach so you do not have indications for LOC and G/S on the PFD.

Also, on the RNAV approach, do you have any logic that will change the RNP to .3 for the approach at the IAF? It stayed at 1.00, so I put it in manually on POS page 2.

[Hardy Heinlin]

Hi Al,

re park: The logic I implemented is this: Only manual entries can be deleted. And when a manual entry is deleted, it changes to auto. And in auto it autotunes the available backup navaids. If you say this logic is wrong, I need more specific information because it cannot be completely wrong; you must be able to change M to A by deletion. How can the FMC read the pilot's mind as to what the crew wants by the deletion? Do they want park or auto? Also: Are we talking about both NG FMC and legacy?

Re RNP: My FMC gets the RNP number from the nav database. What database are you using?


|-|ardy

[Captain_al]

I am using the database you provide with the product.

This is from the Honeywell FMS Book and it is exactly the same for the NG. It lists the conditions for when the ILS Frequency and Front Course cannot be altered. If you are in Manual Tuning and Delete, it will revert to Autotuning. If you are in Autotuning and Delete, it will revert to PARK, unless you are in one of these conditions and then any change is inhibited. Whenever you pull up an RNAV Approach from the database, it tunes the ILS for that runway. I am guessing that is because there is a Glide Path Angle specified for that approach. In training, to not have the LOC and G/S displayed since we are using LNAV and VNAV for the approach, we routinely PARK the ILS by Deleting it.

From Honeywell, both Legacy and NG

ILS receivers are inhibited from manual or automatic tuning
when any of the following conditions occur:
· An autopilot engaged and either the localizer or glideslope
is captured.
· No autopilot engaged and a flight director engaged, either
localizer or glideslope captured, and the aircraft is below 500
feet RA.
· On the ground and localizer is alive, with airplane heading
within 45 degrees of localizer front course, and groundspeed
greater than 40 knots.
NOTE: Autotuning is inhibited for ten minutes after takeoff.

[Hardy Heinlin]

OK, so the deletion of the auto mode should be valid. That will solve the problem. I thought deletion of auto should be invalid like it is in the VOR fields in line 1. Or should the deletion of auto also be valid in the VOR lines?

[Captain_al]

No, you are correct, VOR (A) is not a valid Delete, but if you manually tune the VOR (M), then Delete it will revert to Auto (A)...

[Hardy Heinlin]

Deletion of autotuned ILS is now valid in PSX update 10.158:

https://aerowinx.com/board/index.php/topic,4191.0.html


|-|ardy

[Captain_al]

Thank you Hardy...