2 NDB approach
Joined: Jul 1999
Posts: 272
Likes: 5
From: England
FE Hoppy
The minima is still a no go below height on a non-precision approach. This Briefing Bulletin from Jeppesen has some information; take particular note of point c.
it has caused some confusion by calling it a DA(H) but you still cannot go below it.
The minima is still a no go below height on a non-precision approach. This Briefing Bulletin from Jeppesen has some information; take particular note of point c.
it has caused some confusion by calling it a DA(H) but you still cannot go below it.
Joined: Jul 1999
Posts: 272
Likes: 5
From: England
rudderrudderrat
That is correct as your manuals will currently written in accordance with approach calculations based on Appendix 1 (Old) to OPS 1.430; the DA associated with a NPA are calculated in accordance with Appendix 1 (New) to OPS 1.430. The New rules will come into effect by 2011.
Approach chart producers are having to update all minima in accordance with the new rules and for a while you will see minima as JAR-OPS and EU-OPS. The EU-OPS minima are calculated using the new rules.
Your operator should specify that you can only use the old minima (JAR-OPS)until all your approaches are calculated in accordance with Appendix 1 (New) to OPS 1.430. Once that is done, you will only be able to use the new minima; at which point the entry in your Ops manual will be clarified to state that you have to add 50' to all non precision approaches (i.e. MDA & DA) in order to not go below the minima. For precision approaches the DA will be treated as it currently is i.e. you initiate the GA at DA and pass slightly below it.
I apologise that it is all a bit confusing but I do not make the rules!
That is correct as your manuals will currently written in accordance with approach calculations based on Appendix 1 (Old) to OPS 1.430; the DA associated with a NPA are calculated in accordance with Appendix 1 (New) to OPS 1.430. The New rules will come into effect by 2011.
Approach chart producers are having to update all minima in accordance with the new rules and for a while you will see minima as JAR-OPS and EU-OPS. The EU-OPS minima are calculated using the new rules.
Your operator should specify that you can only use the old minima (JAR-OPS)until all your approaches are calculated in accordance with Appendix 1 (New) to OPS 1.430. Once that is done, you will only be able to use the new minima; at which point the entry in your Ops manual will be clarified to state that you have to add 50' to all non precision approaches (i.e. MDA & DA) in order to not go below the minima. For precision approaches the DA will be treated as it currently is i.e. you initiate the GA at DA and pass slightly below it.
I apologise that it is all a bit confusing but I do not make the rules!
Joined: Oct 2009
Posts: 1,270
Likes: 0
From: UK
Hi Don Coyote,
Does this mean that sometime after 2011, we'll be adding 50 ft to all NPA minima (either DA or MDA) again? If so then I'm really confused.
A MDA is a minimum descent Altitude - i.e. don't go below.
A DA is the point I make the decision to continue or not, and since I have a ROD - I'll subsequently sink up to 50 feet below my DA. So what's the point of publishing a NPA DA then?
at which point the entry in your Ops manual will be clarified to state that you have to add 50' to all non precision approaches
A MDA is a minimum descent Altitude - i.e. don't go below.
A DA is the point I make the decision to continue or not, and since I have a ROD - I'll subsequently sink up to 50 feet below my DA. So what's the point of publishing a NPA DA then?
Joined: Jul 1999
Posts: 272
Likes: 5
From: England
Apparently it is down to a misunderstanding by the service providers who produce the charts. Because the minima is based on a continuous descent profile, they call the minima (under the new rules) a DA even though it is a non precision approach. For a non precision approach (under the new rules)you will still be unable to pass below the minima regardless of whether it is a MDA or DA; hence the requirement to add an amount appropriate to your aircraft (nominally 50')
Essentially nothing will change in that currently just add 50' to all minima for non precision approaches (currently only MDA), after the change, just add 50' to all non precision approaches (either MDA or DA).
The important point is to make sure that you are using the correct minima (either JAR-OPS or EU-OPS) dependant on what your operator is currently approved to use. There are no DA minima for JAR-OPS approaches so if your operator has not changed and you have a minima shown as a DA for a non precision approach then you are using the wrong minima.
Essentially nothing will change in that currently just add 50' to all minima for non precision approaches (currently only MDA), after the change, just add 50' to all non precision approaches (either MDA or DA).
The important point is to make sure that you are using the correct minima (either JAR-OPS or EU-OPS) dependant on what your operator is currently approved to use. There are no DA minima for JAR-OPS approaches so if your operator has not changed and you have a minima shown as a DA for a non precision approach then you are using the wrong minima.
Joined: Oct 2009
Posts: 1,270
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From: UK
Hi Don,
This link is for LGW GNSS 26L and is under JAR-OPS, it is a NPA and has both DA and MDA published (depending on whether you have vertical guidance or not).
Can you explain why?
This link is for LGW GNSS 26L and is under JAR-OPS, it is a NPA and has both DA and MDA published (depending on whether you have vertical guidance or not).
Can you explain why?
Joined: Sep 1998
Posts: 1,615
Likes: 1
From: wherever
@Don Coyote,
How do you reconcile this statement from ops 1 (annex 1 (new) to 1.430 c, 2) with your plus 50ft?
How do you reconcile this statement from ops 1 (annex 1 (new) to 1.430 c, 2) with your plus 50ft?
The missed approach, after an approach has been flown using the CDFA technique, shall be executed when reach- ing the decision altitude (height) or the MAPt, whichever occurs first. The lateral part of the missed approach pro- cedure must be flown via the MAPt unless otherwise stated on the approach chart.
Only half a speed-brake
Joined: Apr 2003
Posts: 4,459
Likes: 136
From: Commuting not home
Apparently it is down to a misunderstanding by the service providers who produce the charts. Because the minima is based on a continuous descent profile, they call the minima (under the new rules) a DA even though it is a non precision approach. For a non precision approach (under the new rules)you will still be unable to pass below the minima regardless of whether it is a MDA or DA; hence the requirement to add an amount appropriate to your aircraft (nominally 50')
If, on the other hand, you have the approval, there are two possible solutions. The classical approach/approval that you describe would have you add an increment (i.e. 50 ft) and treat NPA DA as an MDA and there is nothing wrong with that. Other possible approval will allow you to use DA with no additionals and operate with "decison" at DA (and duck under during go around) as opposed to classical "level off" at (M)DA. Extensive reading and good understanding of Doc 8148 both volume I and II is required to find out that the obstacle distance on NPA with DA is in fact still greater than o.d. on an ILS with DA. And nobody disputes DA on ILS, we'll agree to that.
The previous requirement to avoid flight below MDA was based on the situation that you continue towards MAPt after reaching MDA. As long as your operator addition was 0 (common case) MDA = OCA or system minimum and flight below OCA clearly must be avoided. The M.O.C. to calculate OCA on NPA is still greater than the margin used for determine OCA for ILS approaches. Nowdays, level flight to MAPt is about to be prohibited. Ergo, you do not need to treat NPA OCH (or system minimum) as an MDA anymore because the level-off is not an option. So the only remaining problem is the go-around "duck under" called height loss by 8168. The margin for precision approaches allows for go around height loss and more. The minimum obstacle clearance for NPA is greater than margin and also is based on wider protection areas. With regard to obstacle distance (my generic term) a go around on a NPA DA (no additionals) is safer than GA on an ILS as was always the case - Doc 8168 vol I and II reveal. Hence the possibility to use DA for NPAs because level flight towards MAPt (which would put you below OCA and is clearly forbidden) is no longer an allowed manoeuvre.
Sincerely,
FD (the un-real)
Joined: Apr 2010
Posts: 28
Likes: 0
From: Where they speak ICAO Level -2
Polish Tu-154
I know there is a thread on the crash but my question is relating to the NDB approach they were doing.
Read that they were on an NDB approach as there was no VOR or ILS.
And what bewilders me is that haven't they got an MDA and how can you go below it to such an extent.
Read that they were on an NDB approach as there was no VOR or ILS.
And what bewilders me is that haven't they got an MDA and how can you go below it to such an extent.
Thread Starter
Joined: May 2009
Posts: 81
Likes: 0
From: Russia
Thanks everybody a lot for you comments!!!!
.
You obviously have never flown in Russia. In 98% of Russia airports when performing 2NDB approach during descend after the FAF you have the ONLY POINT (inner marker) with hight and distant to check your position. The QDM/QDR accuracy is up to 4deg. to the left and right. And now imagine your position at MDH when weather is munimum for 2NDB appr at night!
P.S.: in addition some airports hasnt PAPI light at all
con respecto!
Use check heights or Rate Of Descents indicated on your Jeppie or Aerad plates to monitor the glide/target profile and get your PNF to call out deviations as you go..
Why worry about NDB approaches.
P.S.: in addition some airports hasnt PAPI light at all
con respecto!
Joined: Jul 2008
Posts: 642
Likes: 203
From: Brisbane
I say Mr Seilfly, you American chaps are awfully spoilt, when you travel outside the goold old US of A you will find lots of twin NDB thingys and even worse. What has always puzzled me is they never seem to line up with the R/W. Melbourne in Aus, R/W 16 is a rare exception. When flying in the US on the 'NAV RAD' page there is no NDB to enter manually, always seems odd to me that you lot never use 'em.
Joined: Mar 2006
Posts: 13
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From: Ormond Beach
Heck yes, we're spoiled. In fact, as an airline pilot, I have NEVER shot a non-precision approach in IMC. It's been either a visual or an ILS. My last NDB approach was back in 2001 and that particular NDB has since been deactivated.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
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From: UK
Visuals in IMC - damn - always knew you yanks were good
Takes me back to RAF Germany low flying days - pulling up at the end to fly an IMC PAR..You would think a country like the US could afford the odd VOR, though?
Twin NDBs procs always used to be a challenge with a single receiver/single pilot.
Takes me back to RAF Germany low flying days - pulling up at the end to fly an IMC PAR..You would think a country like the US could afford the odd VOR, though?Twin NDBs procs always used to be a challenge with a single receiver/single pilot.
Joined: Nov 2005
Posts: 51
Likes: 0
From: Norway
Well I am Norwegian; just happen to live in the US for a couple of years. It must be my excellent languageskills that made you think of me as an American
I am not a knight of the magenta lines/arrows so I do not know what the NAV RAD page does... but taking the IFR charts into account, there are still a lot of NDBs around in the US... It seems like those NDBs are servicing the small airports, and my impression is that they serve the small, old, airports.
New, small airports seem to get the GPS-approaches and/or a VOR/DME approach based on a VOR/DME waaaaay off the field* (nothing wrong with that) instead of setting up a stoneage NDB at the field. The old small airports seem to be getting the GPS-approaches as well, ready to decommission their NDB at the next breakdown or when the NDBs are withdrawn nationwide (whichever occurs first)
* like this one: http://204.108.4.16/d-tpp/1004/05537VDA.PDF - SGR also has an ILS and two GPS approaches
I am not a knight of the magenta lines/arrows so I do not know what the NAV RAD page does... but taking the IFR charts into account, there are still a lot of NDBs around in the US... It seems like those NDBs are servicing the small airports, and my impression is that they serve the small, old, airports.
New, small airports seem to get the GPS-approaches and/or a VOR/DME approach based on a VOR/DME waaaaay off the field* (nothing wrong with that) instead of setting up a stoneage NDB at the field. The old small airports seem to be getting the GPS-approaches as well, ready to decommission their NDB at the next breakdown or when the NDBs are withdrawn nationwide (whichever occurs first)
* like this one: http://204.108.4.16/d-tpp/1004/05537VDA.PDF - SGR also has an ILS and two GPS approaches
Last edited by seilfly; 11th April 2010 at 15:03. Reason: Added the link, and the italic fontstyle :)