LNAV NDB approach
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And the saddest thing I see is that all the wisdom we (of decrepit age) had beaten into our stupid skulls by not so PC training captains using all manner of rolled up newspapers across the back of the head, etc., to get the message across ... appears to have gone out the window in the current Industry marketplace.
For instance I recall, as a VERY new airline F/O (with not much prior background) having a training captain thrust into my hand his copy of Fate is the Hunter with the admonition that I was to read it prior to the next flight the following day. After reading the book (and, in particular, the match in the face anecdote) I still can recall quite clearly thinking to myself .. no-one had previously told me that THIS is what flying and command is about.
Spoon feeding is for high school kids. Pilots need to be a bit independent and exhibit a bit of initiative.
For instance I recall, as a VERY new airline F/O (with not much prior background) having a training captain thrust into my hand his copy of Fate is the Hunter with the admonition that I was to read it prior to the next flight the following day. After reading the book (and, in particular, the match in the face anecdote) I still can recall quite clearly thinking to myself .. no-one had previously told me that THIS is what flying and command is about.
Spoon feeding is for high school kids. Pilots need to be a bit independent and exhibit a bit of initiative.
Interestingly, for reasons unknown, several NDB approaches are not in the database. Eg, YAYE NDB only has the final section of the approach coded, not the reversal turn.
The mob l work for has announced all new delivered airframes (and there are a lot of them!) will not have an ADF installed.
Hence forth you may fly a line selectable NDB approach using RNAV.
halas
Hence forth you may fly a line selectable NDB approach using RNAV.
halas
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It is fraught with disaster to try to input your own waypint data and/or procedures. Within the navdatabase, you could override the existing data, or worse over-ride an existing waypoint with your custom data.
There is significant coding that goes into a waypoint, and this all predicts the performance..The user has no way to input flyover or flyby, speed restrictions, at or above, or other data that significantly affects how the aircraft will perform.
I know of at least one incident, where as soon as the ac crossed the waypoint, the ac porpoised down the the MDA before the operator could react.
Dont get caught with anything in the box that was generated by your navdatabase provider.
Here are the regulations that specifically and otherwise prohibit an operator from entering their own IFR waypoints.
ICAO Annex 15, Doc 8126
RTCA ED-76, ED77, DO-200A, DO-201A
ARINC 424
FAA AC20-DB
There is significant coding that goes into a waypoint, and this all predicts the performance..The user has no way to input flyover or flyby, speed restrictions, at or above, or other data that significantly affects how the aircraft will perform.
I know of at least one incident, where as soon as the ac crossed the waypoint, the ac porpoised down the the MDA before the operator could react.
Dont get caught with anything in the box that was generated by your navdatabase provider.
Ask them to back that up by reference to the Regulations!
ICAO Annex 15, Doc 8126
RTCA ED-76, ED77, DO-200A, DO-201A
ARINC 424
FAA AC20-DB
OBN, you are getting carried away a bit. We cannot overwrite database waypoints or their stored characteristics. It is possible to create a duplicate but one cannot change a DB waypoint (apart from editing the altitudes and speed once it is in the active flight plan).
Yes, we cannot create a user flyover waypoint (which is a nuisance as it would be handy; have a look at the YPAD RIKAB 6V visual STAR, which is not in the DB, specifically GLOBE.
It is a simple matter to constrain the aircraft at any waypoint to ALT AT, ALT AT or BELOW or ALT AT or ABOVE. Same with speed restrictions (although I am annoyed you can only nominate a speed AT or BELOW; I would like AT or ABOVE as well!
).
Just because an airframe isn't fitted with a navaid doesn't necessarily mean that you are automatically authorised to conduct terrestrial approaches with sole reference to LNAV.
Yes, we cannot create a user flyover waypoint (which is a nuisance as it would be handy; have a look at the YPAD RIKAB 6V visual STAR, which is not in the DB, specifically GLOBE.
It is a simple matter to constrain the aircraft at any waypoint to ALT AT, ALT AT or BELOW or ALT AT or ABOVE. Same with speed restrictions (although I am annoyed you can only nominate a speed AT or BELOW; I would like AT or ABOVE as well!
).
Originally Posted by Halas
The mob l work for has announced all new delivered airframes (and there are a lot of them!) will not have an ADF installed.
Hence forth you may fly a line selectable NDB approach using RNAV.
Hence forth you may fly a line selectable NDB approach using RNAV.
You tell this mob that, Capn Bloggs.
I agree. Although having only done one NDB with this outfit, it was done in LNAV and VNAV. Bottom line is, with autopilot on, the ADF's were superfluous except to "pretty-up" the ND with some blue arrows that funnily enough, lined up with the pink line on the outbound and inbound tracks!
halas
I agree. Although having only done one NDB with this outfit, it was done in LNAV and VNAV. Bottom line is, with autopilot on, the ADF's were superfluous except to "pretty-up" the ND with some blue arrows that funnily enough, lined up with the pink line on the outbound and inbound tracks!
halas
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Hi Halas,
The ADFs were certainly not superfluous if you were conducting the NDB Approach.
However, if you were conducting the RNAV approach - then they were superfluous.
Which one were you doing?
It's explained here:
http://ww1.jeppesen.com/download/aopa/apr00aopa.pdf
e.g. Manchester RW23L has an RNAV Approach, and a VOR Approach. Both have exactly the same track.
the ADF's were superfluous except to "pretty-up" the ND with some blue arrows that funnily enough, lined up with the pink line on the outbound and inbound tracks!
However, if you were conducting the RNAV approach - then they were superfluous.
Which one were you doing?
It's explained here:
http://ww1.jeppesen.com/download/aopa/apr00aopa.pdf
e.g. Manchester RW23L has an RNAV Approach, and a VOR Approach. Both have exactly the same track.
Last edited by rudderrudderrat; 16th Jan 2012 at 10:14. Reason: extra bit about MAN
Bottums Up
An NDB approach in the 71 is typically flown after loading the database approach into the FMS, in NAV & PROF to the minima, with ADF pointers selected on both sides, and usually the PM/PNF/Support Pilot's ND set to APPR, with a pseudo ILS course bar (to aid track keeping).
Part of the command instrument rating test includes demonstrated competency at flying an NDB approach. Flying it in LNAV is not proof that the candidate is competent at that task. For the same reason an autoland is not proof that the candidate can manually land an aeroplane. The autopilot does a sterling job of most LNAV features but the skills test is not of the autopilot but of the person. Therefore the candidate is required to prove he can hand fly using normal tracking skills on an NDB and not the artificial "crutch" of LNAV.
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Yes, JT, bring back the rolled up newspaper. I cannot believe we are still going round in circles here - flying an NDB approach without an ADF fitted? A bit like watching TV on your radio. It has been said many times before - if the approach is an NDB that is how you fly it. If it has 'RNAV' or 'GPS' or whatever, that is how you fly it, but if the 'old' nav beacon info is there on the chart I suggest it is damn fine idea to back it up if you can.
RRR
Thanks for the article. No mention of NDB approaches in my quick glance.
If an NDB approach is line selectable from the FMC then RNAV is to be used with full automatics to be used, as Capt. Claret has mentioned.
This goes for any VOR approach as well.
Centaurus
(Great sounding motor by the way) We are not talking about initial IR ratings. This is in the field regulated and company requirements being met.
BOAC
More like watching TV on your iPhone. Tolerance monitoring is ideal, l agree.
But if there are no ADF's installed, how are you to do that?
The best offer is RNP, which is a minimum requirement on an RNP RNAV approach anyway.
As long as the approach is validated for dist/TRK/GPA and minimum crossing altitudes (plus temp if required) and the minimum RNP is available, then why not?
halas
Thanks for the article. No mention of NDB approaches in my quick glance.
If an NDB approach is line selectable from the FMC then RNAV is to be used with full automatics to be used, as Capt. Claret has mentioned.
This goes for any VOR approach as well.
Centaurus
(Great sounding motor by the way) We are not talking about initial IR ratings. This is in the field regulated and company requirements being met.
BOAC
More like watching TV on your iPhone. Tolerance monitoring is ideal, l agree.
But if there are no ADF's installed, how are you to do that?
The best offer is RNP, which is a minimum requirement on an RNP RNAV approach anyway.
As long as the approach is validated for dist/TRK/GPA and minimum crossing altitudes (plus temp if required) and the minimum RNP is available, then why not?
halas
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More like watching TV on your iPhone
But if there are no ADF's installed, how are you to do that?
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As always Doc8168 to the rescue 
1) naming convention: if the navaid is in the approach chart title, then you need that navaid and a suitable receiver... an NDB approach can not be flown without an ADF.
2) Doc 8168 section General principles, general information:
1) naming convention: if the navaid is in the approach chart title, then you need that navaid and a suitable receiver... an NDB approach can not be flown without an ADF.
2) Doc 8168 section General principles, general information:
USE OF FLIGHT MANAGEMENT SYSTEM (FMS)/
AREA NAVIGATION (RNAV) EQUIPMENT
AREA NAVIGATION (RNAV) EQUIPMENT
1.4.1 Where FMS/RNAV equipment is available, it may be used to fly conventional procedures provided:
a) the procedure is monitored using the basic display normally associated with that procedure; and
b) the tolerances for flight using raw data on the basic display are complied with.a) the procedure is monitored using the basic display normally associated with that procedure; and
Originally Posted by Centaurus
Part of the command instrument rating test includes demonstrated competency at flying an NDB approach. Flying it in LNAV is not proof that the candidate is competent at that task. For the same reason an autoland is not proof that the candidate can manually land an aeroplane. The autopilot does a sterling job of most LNAV features but the skills test is not of the autopilot but of the person. Therefore the candidate is required to prove he can hand fly using normal tracking skills on an NDB and not the artificial "crutch" of LNAV.
From CAO 40.2.1
"An autopilot or a coupled approach may be used in the demonstration of proficiency in instrument approach procedures."
"coupled approach means an ILS approach whereby the aircraft is manoeuvred by the autopilot in response to signals received from the ILS ground installation."
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halas
- But if there are no ADF's installed, how are you to do that?
It seems to me you can't do it without ADF installed or RNAV APCH statement. I mean - to conduct NDB appoach without ADF needles in the minimum at all. It's your own risk.
- But if there are no ADF's installed, how are you to do that?
It seems to me you can't do it without ADF installed or RNAV APCH statement. I mean - to conduct NDB appoach without ADF needles in the minimum at all. It's your own risk.
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Hi halas,
Correct! That's because it's all about RNAV approaches. Clue - it's written in the top right hand corner of the Jep plate.
Using your logic - you could do an ILS without displaying the LOC & GS by flying the RNAV approach.
What limits do you bug when doing the NDB without an ADF?
No mention of NDB approaches in my quick glance.
Using your logic - you could do an ILS without displaying the LOC & GS by flying the RNAV approach.
What limits do you bug when doing the NDB without an ADF?
NDB minima.
And you are correct, you could follow the ILS completely on RNAV. Having both displayed on the PD, the only time they really deviate is at the bottom as the VNAV is using the piano keys as a reference.
With RNP at less than 0.3 or better in approach phase conducting a LOC/VOR/RNAV/GNSS is fine. The last two have no reference aid at all. And the last one is for the Seychelles (CAT C) sliding along the mountain range in a turn on to short finals, or for JFK for 13L/13R to near CAT I minima.
However performing a line-selectable NDB approach without an ADF, but with RNP usually around 0.1 or better seems daunting.
NDB approaches have huge tolerances built in. If there was little room for error then another aid/approach would be there instead.
And it's not my logic. It's the way things are changing toward.
Believe me, if the NAV SYS fell over and the only approach available was an NDB, l would be wanting ADF's there in front of me. But l guess that is a calculated risk by the manufacturer, the company and regulator.
halas
ps: For those not familiar... Line-selectable means the approach that is desired is available in the aircraft nav data base which is updated every 28 days.
This is validated against the chart for the same approach for distances, bearings, speed limits, timing, altitude constraints and temperature.
RNP 0.3 equals 0.3 of one nautical mile before an alert for UNABLE RNP is sounded.
And you are correct, you could follow the ILS completely on RNAV. Having both displayed on the PD, the only time they really deviate is at the bottom as the VNAV is using the piano keys as a reference.
With RNP at less than 0.3 or better in approach phase conducting a LOC/VOR/RNAV/GNSS is fine. The last two have no reference aid at all. And the last one is for the Seychelles (CAT C) sliding along the mountain range in a turn on to short finals, or for JFK for 13L/13R to near CAT I minima.
However performing a line-selectable NDB approach without an ADF, but with RNP usually around 0.1 or better seems daunting.
NDB approaches have huge tolerances built in. If there was little room for error then another aid/approach would be there instead.
And it's not my logic. It's the way things are changing toward.
Believe me, if the NAV SYS fell over and the only approach available was an NDB, l would be wanting ADF's there in front of me. But l guess that is a calculated risk by the manufacturer, the company and regulator.
halas
ps: For those not familiar... Line-selectable means the approach that is desired is available in the aircraft nav data base which is updated every 28 days.
This is validated against the chart for the same approach for distances, bearings, speed limits, timing, altitude constraints and temperature.
RNP 0.3 equals 0.3 of one nautical mile before an alert for UNABLE RNP is sounded.
Last edited by halas; 16th Jan 2012 at 21:23.
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Hi halas,
Your example of JFK 13L/R VOR or RNAV does include "RNAV" in the top right hand corner and may be flown using RNAV only presentation.
Where is the NDB approach which you claim can be flown without an ADF?
Your example of JFK 13L/R VOR or RNAV does include "RNAV" in the top right hand corner and may be flown using RNAV only presentation.
Where is the NDB approach which you claim can be flown without an ADF?
Originally Posted by rudderrudderrat
Where is the NDB approach which you claim can be flown without an ADF?
RRR
I have never stated that l have flown an NDB arrival without an ADF.
The NDB approach l did do was line selected, verified and flown with LNAV and VNAV with the autopilot on with an ANP of around 0.05 with no intervention on the MCP except to slow down as appropriate, down to the NDB minima.
At which point the autopilot was disconnected and a safe landing was conducted. There was no RNAV on the plate however as l mentioned before the ADF needles were present with a continuos monitoring of the beacon and everything worked out well.
Is there a safety issue?
halas
I have never stated that l have flown an NDB arrival without an ADF.
The NDB approach l did do was line selected, verified and flown with LNAV and VNAV with the autopilot on with an ANP of around 0.05 with no intervention on the MCP except to slow down as appropriate, down to the NDB minima.
At which point the autopilot was disconnected and a safe landing was conducted. There was no RNAV on the plate however as l mentioned before the ADF needles were present with a continuos monitoring of the beacon and everything worked out well.
Is there a safety issue?
halas