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Helicopter Non-Precision Approaches

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Helicopter Non-Precision Approaches

Old 5th Aug 2013, 07:01
  #21 (permalink)  
 
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t seems to me that when using the CDFA procedure. you are not flying the 3.0 angle down to the MAPt, at the MDA. you are flying the angle down to the Threshold. this will put you in a straight line down to the runway when you hit your MDA/DA,
only when the approach is aligned with the runway


however, you will not be anywhere near the MAPt when you hit that target altitude.
so I have to initiate a go around and wait for the MAPt to initiate the MAP...
And if the MAPt or DA is not at the runway I even do net have the time to have a lookout cause I have to initiate the climb immediately...
More complicated than before!

it seems to be the equivalent of shooting an ILS(with no G/S reference)
An ILS holds me aligned with the runway on a glideslope to make a landing from that position. Again, a lot of NPA procedures are not aligned.

but making your DH higher as if you were circling.
So in marginal weather my chance to get visual are reduced!

instead of going missed at Station passage, time, or a given fix, you go missed at the MDA/DH.
Which is always higher / earlier than at the MAPt.
this makes every approach basically the same. you fly the prescribed decent rate based on the angle for the approach and your groundspeed.
THIS is exactly the problem. A precision is NOT the same as a NON Precision! I wait for the first one to confuse the new "DA" as a real DA. There is not much room left on your MAP underneath you!

The price we pay for "making every approach the same" is a higher DA/H or whatever you call it.
If I am IMC and wan't to land there, I want to go as low as possible in the approach to raise my chance to get visual.
Why should I fly a approach which makes it less likely to get out of the clouds?

Sorry, I still don't see the benefit. But maybe I'm just blind!
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Old 5th Aug 2013, 11:03
  #22 (permalink)  
 
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Army_av8r: yes

Stallion: I think the struggle you are having is due to not having flown fixed-wing IFR. Even in the days before CDFA approaches, it was necessary, when flying an airplane, to have at least an awareness of when it was too late to try to land even if you got visual. A calculation was better but depended on navaids and other factors. In my day on jets, we calculated a VDP (visual descent point). It was not uncommon to be IMC at the VDP, visual later in the 'cruise' at MDA, and still be forced to finally O/S at the MAPt.

Getting oneself organized enough to plan a constant descent to arrive at the VDP at MDA set up for the 3 degree app was nice, realizing that going below MDA without being visual first was illegal.

Also, it is always a good idea to remember that legal and practical rarely align completely.

Given the different capabilities of airplanes and helicopters, the same approaches require different considerations.

The OP is just asking about the legality of how approaches must be flown given the current move to CDFA NPA plates. I'm sorry I don't have an answer for you but I strongly suspect, given the regulatory environment, that 'as published' is how they want you to go. Rotary flight is rarely considered when these decisions are made.
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Old 5th Aug 2013, 13:39
  #23 (permalink)  
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I have referred this question to Flight Ops at the UK CAA - I will let you all know if they come back with a definitive answer.
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Old 7th Aug 2013, 09:14
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OK, here's the word from flight ops at the CAA:

The rules have been clearly laid down for aeroplanes in the Part 1 documentation
EASA have not really got round to doing the same properly yet for helicopters in the Part 3.
So - the bottom line legally is the rule that you may only an approach to an airport which has been approved by the State administering that airport.

If you know for certain that the airport where you are landing has a "traditional style" non-precision approach published in the AIP, then of course you can fly it. (Of course you should also have a copy of the corresponding approach chart in your hand!)
If you dont know for sure that the state controlling the airport has specifically authorised it, then dont do it.
As we teach in the simulator to clients from dozens of different countries, and we cant know all the individual differences, the safest option is to say:

1. Make sure you have the correct approach chart.
2. Fly the profile depicted on the chart

Simple, really!

That is the line I am going to take - of course anyone who disagrees should take it up with their flight ops inspector, and see what he says.
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Old 7th Aug 2013, 10:25
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Thanks Plod. Interesting topic actually. I had not noticed the creeping changes from here in the sandbox and your original question prompted me to do some digging.

You don't know what you don't know, until someone brings it up.

HH
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Old 7th Aug 2013, 17:44
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Out of all this I was surprised to see the FAA being willing to follow the lead of European authorities on this.
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Old 14th Sep 2013, 13:55
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Non-PC Plod,

Thanks for asking the question to CAA and sharing their response as that has confirmed my understanding of things from EU Ops 1 subpart E:

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.
Edit: note that EU Ops 1 is fixed wing... still trying to work out the definitive answer for helicopters...

Basically, unless the approach plate specifically states that it is a non-CDFA approach (eg NDB at Norwich and Manston) then you don't get a choice whether to choose to fly the "dive and drive" technique, you must use the CDFA technique, regardless of if the minima for the NPA are depicted as a MDA or DA.

army_av8r makes an important point - you should be planning your descent to the runway threshold, NOT to the beacon, after all you should be planning to continue your approach to land to a long strip of tarmac, not a bunch of aerials!

However I don't agree that this technique is the correct one for use by RW. If I know the weather is a bit rubbish and on the limits then I can reduce my approach speed to 60 kts and normally make an unhurried approach to the far end of the runway if I need to. If the above is CAA's view then they need to have a think about the specific needs of the RW community and not try apply a once size (doesnt) fit all rule.

Last edited by Aynayda Pizaqvick; 15th Sep 2013 at 20:51.
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Old 14th Sep 2013, 22:08
  #28 (permalink)  
 
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Thoroughly agree - this concept has been driven by the FW world (for good reasons) but is wholly unsuited to the more flexible world of RW ops.
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Old 15th Sep 2013, 18:11
  #29 (permalink)  
 
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Some believe that you can still fly this approach in a helicopter in the "traditional" manner, treating the DA as an MDA. Others say that you must fly it as published on the chart. There is debate as to whether there should be a helicopter type allowance to add on before it is acceptable to fly it as a DA.
Just one small fact that I don't think anyone has mentioned yet, NPCP, in UK CDFA was made mandatory for FW in 2011, but not for RW, who are still free to fly non-CDFA. If I were at work, I'd get you the number of the Safety Notice, but I'm on hols soon for a couple of weeks. CAA website, search on S/Ns 2011.
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Old 15th Sep 2013, 22:20
  #30 (permalink)  
 
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Right, armed with Keiths words I've done a bit of digging and... basically got nowhere!

This safety notice http://www.caa.co.uk/docs/33/SafetyNotice201103.pdf states "...Public Transport and Private operators should also use the CDFA technique for NPA operations wherever possible." so would imply we SHOULD use it but may (I would reason such as when doing so might limit our chances of gaining the required visual references) use the dive and drive technique.

http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:296:0001:0148N:PDF this however only references CDFA for aeroplanes (CAT.OP.MPA.115) so would it be reasonable to assume from that the safety notice has been superseded by the newer regulations? I have no idea so have sent another email to CAA asking them to clear it up with some authoritative guidance... I shall share any response I get.
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Old 16th Sep 2013, 12:16
  #31 (permalink)  
 
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Its SN 2011-03 dated 6 May 2011, entitled "Aerodrome Operating Minima".

Refers to "EU-OPS 1" and "aeroplanes", therefore strictly FW.

May well have been subsumed into legislation.

Last edited by keithl; 16th Sep 2013 at 12:17.
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Old 6th Oct 2013, 21:53
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Any joy from the CAA on CDFA?
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Old 7th Oct 2013, 18:08
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Nope, nothing. I seem to have been well and truly ignored!! I may have to try sending it to multiple addresses and see if I get anywhere.
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Old 9th Oct 2013, 20:03
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Ok, got a response following a subsequent email, seems it was an internal email forwarding error rather than them ignoring me! It is only an interim response that ultimately doesn't clear much up so I'll hold off posting it until I have their final word.
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Old 9th Oct 2013, 23:41
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Now that is rich....."The Final Word" from the CAA.
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Old 10th Oct 2013, 14:57
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Here are 2 samples of NP approaches in germany.
You have to fly them as CDFA, because they don´t have a published MAP.





Inbalance
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Old 10th Oct 2013, 18:03
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No MAP?

not sure I understand - you say they have not got a MAP ?

[and I thort MAP and MAPt were different things (Proceedure and Point)]

can a knowing person please clarify for me.

looks to me that those plates have both ?



do you mean they have DA instead of MDA ?
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Old 10th Oct 2013, 18:11
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My mistake,
they don´t have a MAPt.

Inbalance
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Old 10th Oct 2013, 20:22
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The first plate says MAP at RW25 the second MAP at D0.5 MOD if my eyes don't deceive me.

Last edited by RedWhite&Blue; 10th Oct 2013 at 20:22.
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Old 11th Oct 2013, 08:16
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Non-PC Plod

I think 212man had the answer to your original question about the source of the chapter and verse you want, if not the reference itself.

By the way I have included the definition of MAP as some people may be expecting it to be MAPt.

Try

PANS OPS Flight Procedures (Doc 8168)

3.6.1.3
The missed approach point (MAP) in a procedure may be:
a.the point of intersection of an electronic glide path with the applicable DA/H; or
b.a navigational facility; or
c.a fix; or
d.a specified distance from the final approach fix (FAF).
When the MAP is defined by a navigational facility or a fix, the distance from the FAF to the MAP is normally published as well, and may be used for timing to the MAP. In all cases where timing may not be used, the procedure shall be annotated “timing not authorized for defining the MAP”.

1.6.2
Operators may specify two types of approach procedures for non-precision approaches. The first is that described as: “descend immediately to not below the minimum stepdown fix altitude/height or MDA/H as appropriate”. This method is acceptable as long as the achieved descent gradient remains below 15 per cent and the missed approach is initiated at or before the MAP. Alternatively, operators are encouraged to use a stabilized approach technique for non-precision approaches. This technique requires a continuous descent with a rate of descent adjusted to achieve a constant descent gradient to a point 15m (50 ft) above threshold, taking due regard of the minimum crossing altitudes/heights specified for the FAF and any prescribed stepdown fix. If the required visual reference approaching MDA/H is not achieved, or if the MAP is reached before reaching the MDA/H, the missed approach must be initiated. In either case, aircraft are not permitted to go below the MDA/H at any time. The stabilized approach technique is also associated with operator-specified limits of speed, power, configuration and displacement at (a) specified height(s) designed to ensure the stability of the approach path and a requirement for an immediate go-around if these requirements are not met.

Hope that helps.
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