Non precision MDA/DA
Thread Starter
Joined: Oct 2005
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From: Hotel
Non precision MDA/DA
Hello Forum,
sorry, but did I miss something the last few month?
I was always the opinion that Non Prec. Apps (talking of NDB now) are MDA based.
Means that I have an altitude which I will not bust.
Bombardier tells you to add 50 to the MDA and call it a DA and perform a GA if you haven't seen the light until then.
But no matter what the Bomabrider procedure is,... have a look to LOWL or LOWS. Check the NDB APPs.
They post a DA there.
Why? What would you do? To be on the save side, as long as I do not know why there is no MDA, I will still add 50 ft and perform GA there. But seems strange for me. If you read strictly the paper you can bust the DAs on those Non Prec. Apps.
What's you opinion?
Thanks for you help.
sorry, but did I miss something the last few month?
I was always the opinion that Non Prec. Apps (talking of NDB now) are MDA based.
Means that I have an altitude which I will not bust.
Bombardier tells you to add 50 to the MDA and call it a DA and perform a GA if you haven't seen the light until then.
But no matter what the Bomabrider procedure is,... have a look to LOWL or LOWS. Check the NDB APPs.
They post a DA there.
Why? What would you do? To be on the save side, as long as I do not know why there is no MDA, I will still add 50 ft and perform GA there. But seems strange for me. If you read strictly the paper you can bust the DAs on those Non Prec. Apps.
What's you opinion?
Thanks for you help.
Joined: Apr 2004
Posts: 509
Likes: 3
From: United States of Europe
Check the side of the plate. It probably says PANS-OPS 5.
PANS-OPS 5 now caters for constant angle non precision approaches.
If it says DA on the chart, use it as an DA. The loss of xx ft after initiation of the G/A has now been taken into account. There are not many procedures which are PANS-OPS 5 now (Europe) so the MDA+50ft is not completely a thing of the past.
Regards
PANS-OPS 5 now caters for constant angle non precision approaches.
If it says DA on the chart, use it as an DA. The loss of xx ft after initiation of the G/A has now been taken into account. There are not many procedures which are PANS-OPS 5 now (Europe) so the MDA+50ft is not completely a thing of the past.
Regards
Guest
Posts: n/a
Its 30' where I work.
The idea is that, lets say MDA is 400', you add your 50' so that gives you 450'.
You do the approach and at 450' you see nothing.
You start to go around but the a/c is still descending.
As you started the GA 50' above MDA, even though it takes a moment or two to arrest your descent, and you lose a bit of height as you do so, you don't go below MDA.
Whereas if you started the GA at MDA, you surely would.
Now, back in the day, you'd level at MDA and then clatter on until you reached the MAP or saw the runway. The so called 'Dive and Drive', so no need for extra height.
Perfectly good, IMHO, but far far too dangerous.
The idea is that, lets say MDA is 400', you add your 50' so that gives you 450'.
You do the approach and at 450' you see nothing.
You start to go around but the a/c is still descending.
As you started the GA 50' above MDA, even though it takes a moment or two to arrest your descent, and you lose a bit of height as you do so, you don't go below MDA.
Whereas if you started the GA at MDA, you surely would.
Now, back in the day, you'd level at MDA and then clatter on until you reached the MAP or saw the runway. The so called 'Dive and Drive', so no need for extra height.
Perfectly good, IMHO, but far far too dangerous.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
Likes: 4
From: UK
Challey - some good stuff here http://www.pprune.org/tech-log/401043-mda-constant-descent-npa.html.
BBF - try not to tread on any squeaky floorboards outside the bedroom or we will have to hear again how great the ?Fokker Tri-motor was it? at 'dive and drive'.
BBF - try not to tread on any squeaky floorboards outside the bedroom or we will have to hear again how great the ?Fokker Tri-motor was it? at 'dive and drive'.
Joined: Jun 2001
Posts: 3,991
Likes: 8
From: UK
BBF - try not to tread on any squeaky floorboards outside the bedroom or we will have to hear again how great the ?Fokker Tri-motor was it? at 'dive and drive'.
Thread Starter
Joined: Oct 2005
Posts: 83
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From: Hotel
@Ken
Thanks, of course that is what the approaches are all about. But check the plates. You will find NDB Apprs with a DA not MDA.
@Open Des
Thanks that was the right answer
found Pan OPS and changed issues on the new plate are minimums an descent angles.
@BOAC
Thanks BOAC thats a good link.
All of you thanks for support.
Cheers
Chally
Thanks, of course that is what the approaches are all about. But check the plates. You will find NDB Apprs with a DA not MDA.
@Open Des
Thanks that was the right answer
found Pan OPS and changed issues on the new plate are minimums an descent angles.@BOAC
Thanks BOAC thats a good link.
All of you thanks for support.
Cheers
Chally
Guest
Posts: n/a
BOAC
Fokker tri-motor????
Am I getting old?
(it was when I was on the Shed.
)
Chally 604.
Re minimums. While you and I all do the old stabilised app stuff,CANPA or whatever it's called.
If you were a dive and drive operator you'd want the 'proper' MDA would you not?
Not everyone has bought the CANPA stuff and non precision apps are as old as it gets in aviation these days.
Fokker tri-motor????
Am I getting old?
(it was when I was on the Shed.
)Chally 604.
Re minimums. While you and I all do the old stabilised app stuff,CANPA or whatever it's called.
If you were a dive and drive operator you'd want the 'proper' MDA would you not?
Not everyone has bought the CANPA stuff and non precision apps are as old as it gets in aviation these days.
Joined: Apr 2004
Posts: 509
Likes: 3
From: United States of Europe
If you were a dive and drive operator you'd want the 'proper' MDA would you not?
CANPA is not much harder on a old-fashioned aircraft. ALT vs. DME using V/S will do the trick just fine.
Regards
Thread Starter
Joined: Oct 2005
Posts: 83
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From: Hotel
Yeah sure. I like it. If you want it basic, HDG + V/S is perfect and works always fine. Adjust your V/S by the altitude deviation at a certain mileage times two and you fly this thing like an ILS.
Take care
Chally
Take care
Chally
Joined: Mar 2001
Posts: 4,563
Likes: 35
From: I wouldn't know.
Flying it like an ILS is done by simply pressing the approach button, even the usual presentation to the pilots nowadays is exactly like an ILS
But yup, it is sometimes good training doing it the old fashioned way with HDG and V/S using the altitude/dme table on the approach chart.
But yup, it is sometimes good training doing it the old fashioned way with HDG and V/S using the altitude/dme table on the approach chart.
Joined: Jan 2007
Posts: 95
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From: Up North UK
Chally
If you are working for a European operator, then EU-OPS 1.430(d)2 says ...
So an NPA flown under these rules is effectively an approach to a DA.
Perhaps some states/airports publish minima including the increment for GA transition, perhaps your Bombardier reference has adopted the terminology; but your company should specify whether to add (50ft) to any NPA minima or not.
If you are working for a European operator, then EU-OPS 1.430(d)2 says ...
(d)2. All non-precision approaches shall be flown using the continuous descent final approaches (CDFA) technique unless otherwise approved by the Authority for a particular approach to a particular runway. When calculating the minima in accordance with Appendix 1 (New), the operator shall ensure that the applicable minimum RVR is increased by 200 metres (m) for Cat A/B aeroplanes and by 400 m for Cat C/D aeroplanes for approaches not flown using the CDFA technique, providing that the resulting RVR/CMV value does not exceed 5 000 m.
Perhaps some states/airports publish minima including the increment for GA transition, perhaps your Bombardier reference has adopted the terminology; but your company should specify whether to add (50ft) to any NPA minima or not.
Joined: Mar 2000
Posts: 8,571
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From: Arizona USA
BBF - try not to tread on any squeaky floorboards outside the bedroom or we will have to hear again how great the ?Fokker Tri-motor was it? at 'dive and drive'.
Nevertheless, we still do a variation of dive and drive...and it seems to work quite nicely...for us, anyway.
I would suggest that dive and drive is not for everyone...only for those that do so regularly...and quite safely, thank you.
Fleet Manager
Joined: Apr 2001
Aviation Qualifications: ATPL
Posts: 7,447
Likes: 310
From: various places .....
411A, for those of us who have been around longer than a week or two, has shown that he is made of much stronger stuff than would see a man tremble in the face of a bit of incoming ...
Joined: Jul 2007
Posts: 374
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From: USA
Fact is, most of the 'pilots' around here seem to know little about flying! Scares the hell out me! I sure hope I won't be learning from some of you guys one day 
Luckily there is always 411A to save the day and remind you of how to fly the thing
411A is the man!
Luckily there is always 411A to save the day and remind you of how to fly the thing
411A is the man!
Joined: Mar 2002
Aviation Qualifications: ATPL
Posts: 9,222
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From: Seat 1A
Flying 100-200ft below the exact 3° profile on an NPA makes a lot of sense (provided the limiting steps allow). You can actually get to the MDA, level off (drive, shock horror), get visual and land, as opposed descending nicely down the precise 3° slope, to getting to the MDA during the level-out but not being able to land because you're now above the PAPI. It's called wriggle room.
Joined: Nov 2007
Posts: 44
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From: London
Bloggs,
The idea is that you DON'T level off! You continue your stabilised approach if you have the required visual references at MDA/DA or you initiate a go-around. There's no mucking around below the profile: you wouldn't do it on a precision approach so why do it on a NPA?
The idea is that you DON'T level off! You continue your stabilised approach if you have the required visual references at MDA/DA or you initiate a go-around. There's no mucking around below the profile: you wouldn't do it on a precision approach so why do it on a NPA?
