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Part-NCO summarized

Just in addition to the excellent description offered by @Aviathor – basically clearly stating that the instruments required by the rule most clearly indicate this has nothing to do with navigation, but with the ability to fly straight and level and remain in control.

I would prefer a slightly different summary – “If you can’t keep flying straight and level visually, you need …”, over @bookworms (“if there is no visual horizon, you need…”) since it is less prone to lengthy internet debates of what exactly a visual horizon is. For example, below around 3000m visibility there is not much of a horizon, you fly in an “inverted grey bowl”, but as long as you can fly this visually you are ok.

None of the above is criticism of the excellent summary provided by @bookworm .

Last Edited by Cobalt at 29 Aug 08:57
Biggin Hill

Peter wrote:

If the EU law says “Community” then post-Brexit the UK will not be in the “Community” regardless of what they do regarding adopting EASA regs.

That’s certainly not the case. Norway isn’t in the EU, newer was and yet it’s considered part of the Community for the purposes of certain regulations. As was written before, regulations are written for EU MS. If some other state adopts it based on an agreement with the EU, nothing changes in the regulation itself. Which means some parts have to be amended or understood differently for it to make sense. I’m not a fan of this system, but that’s what we have, at least in EFTA/ EEA (i.e. there is a document that lists these changes). Perhaps a bureaucrats wet dream.

Peter wrote:

the default position under the law (of any civilised country; I am not 100% sure that applies to all of what we call “Europe”) has to be like that.

I haven’t seen that principle applied in practice on the continent in this kind of law (contracts are a different matter). What I have seen is application of the spirit of the law. And that doesn’t go against whoever drafted a bad law, but against those who try to abuse the letter of the law when the spirit is sufficiently clear. So if a law calls for underwear of certain colour (because of poor wording), the spirit appears to be to wear underwear and we’re suddenly able to manufacture other colours as well, it should be perfectly acceptable to wear them. Hypothetically speaking (it isn’t state’s business whether and what underwear I wear).

In this case it’s quite clear what they’re trying to achieve. But there are cases which are, shall we say, non-trivial. Consider an EU citizen that doesn’t spend more than a month in any EU MS, operates N-reg and has residence permit outside the EU and his own or rented property there. Where exactly is the line? With most people (just a guess), it’s rather simple – they work and reside in one country in which they spend more then 6 months per year. There is IMHO no way someone like that could avoid being considered a resident for the purposes of aviation regulations.

LeSving wrote:

Please explain, Part NCO is wrong and Bookworm is right? I only sited Part NCO.

I also agree that you’re interpreting it wrong. That part is about keeping control (so it flies where you want). And for that you either need visual reference (to know which way is up) or instrument. This has nothing to do with navigation. That is covered in a different paragraph.

bookworm wrote:

though the cover regulation of 965/2012 includes explicit mention of BR Article 4(1)(c) operators (the established and resident ones) for CAT, but not for NCO/NCC. I wouldn’t rely on that.

That reference to Article 4 is about certification of operators (issuing, revoking, etc. of AOCs) IIRC.

Rwy20 wrote:

And one last thing, I noticed I quoted Part NCC instead of NCO. In non-complex operations, (3) doesn’t apply, so no need for pitot heat. The rest is the same.

The requirement is still there, just as (c) instead of part of (b). NCO.IDE.A.120(c): “Aeroplanes operated in conditions where they cannot be maintained in a desired flight path without reference to one or more additional instruments, shall be, in addition to (a) and (b), equipped with a means of preventing malfunction of the airspeed indicating system required in (a)(4) due to condensation or icing.” The only difference it seems to make is that pitot heat is not required for flight in VMC at night when you have good outside references (can keep it the right side up) – because (b) mentions night VMC explicitly while (c) doesn’t. I’m using the consolidated version linked from EASA’s website.

Rwy20 wrote:

Upon reading the requirements for flight over water again (and again ), I noticed that this may be quite prescriptive as to the functional equipment that you need to have. I have seen planes with three independent artificial horizons, one of which operated by vacuum pumps and the two other on independent electrical circuits. But according to Part NCO, you would still need a turn coordinator on such a plane, right?

I think you again read Part-NCC, but that really doesn’t matter. My interpretation is that you still need it. In the sense that you need the information. The regulation doesn’t require turn coordinator specifically, but something that displays turn and slip (turn coordinator in itself is a different instrument than turn and slip indicator). It doesn’t necessarily have to be a separate instrument but that information must be available to you and the overall solution must be as good as having separate instruments (to put it simply, read the AMC/GM for a little bit more details on integrated solutions).

Aviathor wrote:

It is amazing how you interpret sentences in English in the most creative ways

Aviathor, I know I can be on the “sloppy side” from time to time regarding, what should I say, proper nice and obscure gentleman-like conduct (in lack of a better expression). Some of it is my nature, some of it is probably linguistic “artifacts”, cultural differences. As I said earlier to Rw20, thank you for reminding people to relax. I do not have a personal agenda against anything in Part NCO or anyone here, so let’s stop pretending (and stop posting trolls). I just say things as I see them, it’s nothing more than that. I may be wrong from time to time, but not this time (not until positively proven wrong of course it’s a long way yet though)

Having said that, you clearly haven’t “got” anything of what I am saying. First, you are referring to Part NCC, not part NCO (they are indeed different in this very point, not that it matters though). Second, it is NOT the equipment list I am “concerned with”. it is the “without reference to one or more additional instruments” that makes this regulation difficult to grasp. It is not clear what exactly is meant by it, except perhaps for NVFR, but NVFR is already mentioned before the comma, so it does not count here. However it IS indeed clear that the requirement has nothing to do with “no visual horizon”, the requirement is much broader and is exclusively about your ability to maintain a desired flight path without the use of additional instruments. Those instruments are NOT the additional equipment list (IMO, which include an AH in case you have no visual horizon for instance).

How is this supposed to be interpreted when you use a nav app?

Martin wrote:

I also agree that you’re interpreting it wrong. That part is about keeping control (so it flies where you want). And for that you either need visual reference (to know which way is up) or instrument. This has nothing to do with navigation. That is covered in a different paragraph.

I would say this is wishful thinking at best, because I haven’t interpreted anything, bookworm did. If you believe what you say, then explain: " or in conditions where the aeroplane cannot be maintained in a desired flight path without reference to one or more additional instruments, shall be, in addition to (a), equipped with: " Why use additional instruments in reference to desired flight path ? If the additional instruments are the same as the list, then why mention additional instruments at all? It would be much more natural to write something like: “or in conditions where the aeroplane cannot be maintained in a desired flight path only with the instruments in (a), shall be, in addition to (a), equipped with …”

Thinking about it, it would be nice to be proven wrong here. It would be much simpler. It’s just that it would, IMO, require a misinterpretation of what is actually written, or that it is very poorly written for some reason. What it say is that if you cannot stay on your flight path without additional (navigational) equipment, then you also need the equipment in the list. For instance flying on top is very difficult without VOR or GPS (I guess some are able to without instruments, but I have never met anyone). So, when you need additional instruments, then you also need the list of equipment. That is the natural way to read this, and it fits with normal VFR flying.

It would also be nice if “flight path” was the process of staying on a heading, and staying upright. But then again, why use the word “flight path” if what is meant is simply staying coordinated on one single heading? Aviathor, the Norwegian translation by LT is “flygevei”. It also say you can do that with one additional instrument. There are no one single instrument on that list that enables you to do that. You need at least two, and this is even more explicitly specified in AMC2 NCO.IDE.A.120

The elephant is the circulation
ENVA ENOP ENMO, Norway

LeSving wrote:

If you believe what you say, then explain: " or in conditions where the aeroplane cannot be maintained in a desired flight path without reference to one or more additional instruments, shall be, in addition to (a), equipped with: " Why use additional instruments in reference to desired flight path ? If the additional instruments are the same as the list, then why mention additional instruments at all?

Because they are additional to the basic instruments required for day VFR. In other words, if you need more than what is required for day VFR (additional instruments) to keep the right side up, then you need those specified in (b) as well. I don’t know about much more natural, I’m quite indifferent about this (in conditions where you need additional instruments versus in conditions where instruments listed in (a) aren’t sufficient) – in conversation, I might say something like if that isn’t enough.

LeSving wrote:

What it say is that if you cannot stay on your flight path without additional (navigational) equipment, then you also need the equipment in the list.

As was said, navigation equipment is covered in a different paragraph (195 IIRC). This will just allow you to fly a vector but that’s not enough to navigate. Navigation is about determining how to get where you’re going. Obviously, saying this is just about keeping the right side up is simplification. E.g. time has nothing to do with that. And 120 is titled Operations under VFR — flight and navigational instruments and associated equipment. These instruments are enough to facilitate dead reckoning but that’s it (and you’d still need a map and a starting point, or instructions or something). Equipment like VOR receiver belongs under 195.

Last Edited by Martin at 29 Aug 15:05

Martin wrote:

As was said, navigation equipment is covered in a different paragraph

Specifications for when navigational equipment is needed, yes. But, the headline for Part NCO.IDE.120 is (my emphasis):

NCO.IDE.A.120 Operations under VFR — flight and navigational instruments and associated equipment

IDE.195:

NCO.IDE.A.195 Navigation equipment
(a) Aeroplanes operated over routes that cannot be navigated by reference to visual landmarks shall be equipped with any
navigation equipment necessary to enable them to proceed in accordance with:
(1) the ATS flight plan; if applicable; and
(2) the applicable airspace requirements.
(b) Aeroplanes shall have sufficient navigation equipment to ensure that, in the event of the failure of one item of
equipment at any stage of the flight, the remaining equipment shall allow safe navigation in accordance with (a), or an
appropriate contingency action, to be completed safely.

If you fly so that you have to use (195), then you also need the instruments and equipment according to (120.b and c) This is most probably what “additional instruments” refers to. Which also shuts the door for using non-certified nav apps in those circumstances. The reference to 195 cleared up the whole thing as far as I am concerned.

The elephant is the circulation
ENVA ENOP ENMO, Norway

No. For example – VFR over a solid cloud layer requires navigation equipment, but not the instruments according to 120b.c

Biggin Hill

Care to elaborate how you got to that conclusion?

The elephant is the circulation
ENVA ENOP ENMO, Norway

Fly310 wrote:

2 730 kg is a somewhat obscure limit where I am not entirely sure of its origin, it might be the equivalent of 6000 pounds. The simple reason for Part-M Light being up to 2 730 kg is due to the simple fact that includes a lot more airframes than 2000 kg does.

It does roughly correspond to 6000 pounds. It should be limit for what is called light aeroplane. I don’t know where it comes from, but it’s very old. I saw it in a 40 year old book. I vaguely recall I think de Havilland complaining in some CRD that they pushed Part-M on light aeroplanes up to 2730 kg. One can only speculate what exactly prompted them but this number was used even in the original Part-M I think (and UK CAA had different logbooks I recall).

LeSving wrote:

Specifications for when navigational equipment is needed, yes. But, the headline for Part NCO.IDE.120 is (my emphasis):

I already quoted that. And yes, knowing time, speed and direction allows for primitive navigation and a compass or watch are not instruments needed to keep the right side up. But I feel there is a difference between instrument and equipment. Compass is an instrument, VOR receiver is equipment. And notice that 120 has “navigational instruments” and 195 “navigation equipment”. Don’t know how consistent the use is in the regulation.

Anyway, the navigational aspect of the instruments is already covered in (a). Nothing in (b) is useful for navigation. You have the heading indicator (stabilized heading), but that won’t tell you where north is unless you set it using a compass (magnetic heading) and periodically check against it for drift. If you have ever tried turning without visual reference using a compass, you understand why it’s there. It just enhances capability you already have because compass is not very user friendly in those conditions.

LeSving wrote:

This is most probably what “additional instruments” refers to.

How you get this I can’t fathom. Instead of interpreting it within 120, you somehow connect it to 195 (you previously didn’t know about) which is further down the document and is not referenced at all in 120. Your logic escapes me.

LeSving wrote:

Which also shuts the door for using non-certified nav apps in those circumstances.

What shuts the door on tablets in this case is IMHO 100(a). But there might be a way, I would have to dig into it. If maps fall under 195 (to facilitate dead reckoning), then tablet might be acceptable as EFB displaying a raster version of ICAO map. But one thing is to display a map, another thing is to display a position (and you using that position for navigation).

LeSving wrote:

Care to elaborate how you got to that conclusion?

Well, if you fly above a solid layer of cloud and sky is clear above you, you shouldn’t have trouble controlling the aircraft (you should have nice horizon). It really comes down to whether you can make do with a compass (I think you should; while you can’t navigate using clouds, they’re not that disorienting). But you would still need navigation equipment as per 195 because you can’t navigate visually when all you see are clouds and sky – unless mountains poke out, you won’t be able to identify any landmarks.

Last Edited by Martin at 30 Aug 08:42
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