DIY Instrument Approaches

[fireflybob]

Talking purely from the legal standpoint here:-

If you descend below the Min Ht Rule for IFR (ie you are IMC) on a non published letdown, is this legal? (I have my own views but would be interested to hear others).

[IRRenewal]

This is a wind-up, right?

[Say again s l o w l y]

I can't see how it could possibly be legal. An UNofficial procedure, is just that so it can't be called an approach as such.

Unofficial procedures are fine on a gin-clear day with a student, but I would never use one in anger.

[ATP_Al]

It's a grey area. As far as I understand, there is nothing in the UK ANO that explicitly states such an approach is illegal for UK/JAR licence holders. However, if you make such an approach you will not hear of potential hazards (such as cranes, tethered balloons etc) through the NOTAM system. Furthermore if you do screw up and someone gets hurt you won't have a leg to stand on.

I agree with SAS; fine on a good day but very dangerous if used in anger

Al

[QNH 1013]

If I remember correctly, the old AIP specifically stated that nothing in the IFR rules prevented an "Unpublished" instrument approach being used outside of controlled airspace for non-public transport flights.

Around the time of the JAA changes this paragraph disappeared from the AIP.

From memory, it was a couple of years ago that the CAA proposed changing the ANO to prevent such unpublished approaches being used outside controlled airspace. After a while this idea was fortunately dropped. The ANO already requires the commander of the aircraft to ensure that the flight can be undertaken safely, and I take this to mean that you must check any unpublished instrument approaches yourself before using them.

I know of several unpublished instrument approaches which have been successfully and safely used for many years. However, I would not refer to them as DIY approaches. The criteria for instrument approaches are all published and you should not underestimate the amount of work required to design what may look like a "simple" procedure, whether it is "published" or "unpublished".

Of course, if you are talking about trying to descend to land in IMC using a hand-held GPS, then that is a different subject.....

[fireflybob]

Thanks for the replies.

Here is my take on this. The Minimum Height Rule IFR is 1,000 ft above highest within 5 nm. An exception to this is on a "notified route". I presume (have yet to check) that published (ie in the AIP) approaches are notified for this purpose. Ergo anything else is not published and therefore not "legal" in IMC.

Another issue are the general provisions of Articles 63 and 64 of the ANO:-

Endangering safety of an aircraft

63 A person shall not recklessly or negligently act in a manner likely to endanger an aircraft, or any person therein

Endangering safety of any person or property

64 A person shall not recklessly or negligently cause or permit an aircraft to endanger any person or property.

Its not just a question of the obstacle clearance criteria etc but also the ramifications of not being in receipt of a licensed ATC service etc. Separation also has to be "DIY" ! Lets say two aircraft collide in this situation and wreckage falling to the ground causes injury or loss of life. IMHO this would clearly be in breach of Art 64.

We all know that this goes on but surely we should be discouraging pilots from inventing their own approaches and that such approaches are strictly for practice VFR. If the weather precludes a visual descent beyond the provisions of the Min Ht Rule then pilots should divert and/or fly to a place where there is a published approach, descend on this procedure and, if feasible, proceed VFR to the chosen destination.

Finally another aspect is there is no published weather minima for such an approach and also its highly unlikely that there are trained met observers on the ground at the aerodrome in question.

[hugh flung_dung]

Please don't suggest that it is unacceptable to fly IFR without "licensed ATC service", this has been accepted aviation practice since time immoral.
Even when a service is theoretically available it frequently isn't available in practice due to weather (ironically) or the classic "controller workload" (such as making the tea) :D
What we do not need is more regulation or restrictions where none are justified.

However, anyone trying a home-brewed IF approach using a handheld GPS probably has a limited period left to enjoy their life.

[Say again s l o w l y]

I still don't see a good enough reason for 'home brewed' approaches in actual IMC conditions. In the U.K, how far are you ever away from somewhere with a 'proper' one? Not far I'll wager.

I'm all for using them for training since students find them far more relaxing and less pressured than an full blown procedure at a major airfield, allowing them to concentrate on their flying and awareness rather than worrying about complying with ATC, basically if you stuff up only the IRI will notice!

In this case I whole-heartedly agree with FFB's comments about this.

[fireflybob]

hugh flung_dung

>Please don't suggest that it is unacceptable to fly IFR without "licensed ATC service<

No I was not meaning to make that suggestion but generally in the enroute phase of flight whilst IMC other ATC services are available (radar etc.) although as you say, not always, for the reasons you list. However, usually such a service is never available on the DIY letdown which, I would suggest, carries more risk if other aircraft are around doing the same type of thing.

[NorthSouth]

QNH1013:a couple of years ago that the CAA proposed changing the ANO to prevent such unpublished approaches being used outside controlled airspace. After a while this idea was fortunately dropped.Interesting. I haven't seen any announcement that this has been dropped since the consultation took place. Can you say where your information comes from? This proposal was part of a wider change which would have allowed approved IAPs at airfields with only AFISO.

NS

[FlyingForFun]

The Minimum Height Rule IFR is 1,000 ft above highest within 5 nm. An exception to this is on a "notified route". I presume (have yet to check) that published (ie in the AIP) approaches are notified for this purpose.FFB, that's not correct.

To the best of my knowledge, published approaches are not notified for the purpose of being exempt from the rule. However, a further exemption from the rule applies "as necessary for taking off and landing". There is nothing in this exemption which specifies that you must follow any particular type of approach, published or otherwise.... therefore it is not illegal to to follow a non-published approach.

From a practical point of view, I agree with all the other comments regarding the safety of following such a procedure (both the pros and the cons). And as for lack of ATC... if I were carrying out such an approach, I would expect the local LARS unit to inform me of any traffic in the area of my destination before leaving their frequency. I would then make position reports on the destination's frequency, and expect anyone else to be doing likewise. Have only ever had to do this once (I was a low-hours PPL, flying with an instructor, at the time), but I know people who fly this type of approach regularly and have never heard of any incidents related to the approach as long as suitable care is taken.

FFF
-------------

PS - This has been discussed many times in the Private Flying forum. A search there will reveal that this is another topic where you will not get everyone to agree no matter how long you argue for!

[fireflybob]

>but I know people who fly this type of approach regularly and have never heard of any incidents related to the approach as long as suitable care is taken.<

Statistically that does not mean that its safe - they might have all been lucky!

Flying For Fun, thanks for that - I wonder if there are
any routes which are notified for this purpose then?

The other "unless" for the Min Ht Rule is "..otherwise authorised by the competent authority". The ANO defines "competent authority" (in the UK) as the CAA.

One presumes that published instrument approaches are authorised by the competent authority, ie the CAA. This would also cover items such as the radar vectoring areas where lower heights/altitudes are authorised and indeed radar approaches.

Ergo, DIY approaches are not "authorised by the CAA" and therefore one is not exempt from the Min Ht Rule (assuming not in sight of ground and less the 140 kts IAS). I think its stretching it a bit to use the "take off and landing" exception as a way around the Min Ht Rule - obviously at some stage one has to take off and land and one cannot comply with the Min Ht Rule at this specific time.

By the way, Flying for Fun, I posted the query on this forum because as Instructors and Examiners I was interested to hear from others as to the views and ramifications with respect to what and how we teach. No disrespect to those on the Private Flying forum who are welcome to add their opinions of course.

Yes I know there are many different opinions but all I wanted to know is whether it is strictly legal - I know plenty of people do it but.....!

[bookworm]

The other "unless" for the Min Ht Rule is "..otherwise authorised by the competent authority". The ANO defines "competent authority" (in the UK) as the CAA.

One presumes that published instrument approaches are authorised by the competent authority, ie the CAA.

If you read the Rules of the Air carefully, you'll see that this exemption is for the aircraft, not for the route to be flown.

There are for me three compelling arguments that illustrate that unpublished approaches, while they may undoubtedly be unwise in some circumstances, are not illegal:

1) There is as FFF says no notification of published approaches for the purposes of rule 29. There is therefore no legal distinction between published and unpublished approaches.

2) There are no published departures for airports in uncontrolled airspace in the UK. Thus if exemption (a) to rule 29 must be applied for departure, it seems reasonable to apply it for landing.

3) The CAA has issued an RIA (http://www.caa.co.uk/docs/43/diap_ria_amendment_to_article_90.pdf) that implicitly suggests that unpublished IAPs are not illegal.

[fireflybob]

>If you read the Rules of the Air carefully, you'll see that this exemption is for the aircraft, not for the route to be flown. <

bookworm, thanks - can you please explain ? By the way, I was under the impression that I usually read the Rules of the Air "carefully"!!

Also, we still need to bear in mind Articles 63 and 64 of the ANO.

Thanks for the link - will take a look when time permits!

[bookworm]

bookworm, thanks - can you please explain ? By the way, I was under the impression that I usually read the Rules of the Air "carefully"!!

It wasn't my intention to suggest that you don't FFB.

29 Without prejudice to the provisions of rule 5, in order to comply with the Instrument Flight Rules an aircraft shall not fly at a height of less than 1000 feet above the highest obstacle within a distance of 5 nautical miles of the aircraft unless:
(a) it is necessary for the aircraft to do so in order to take off or land;
(b) the aircraft is flying on a route notified for the purposes of this rule;
(c) the aircraft has been otherwise authorised by the competent authority; or
(d) the aircraft is flying at an altitude not exceeding 3000 feet above mean sea level and remains clear of cloud and in sight of the surface.

The use of exemption (c) would require an explicit authorisation from the CAA for your aircraft. It is not generically applicable to published IAPs.

Also, we still need to bear in mind Articles 63 and 64 of the ANO.

We have to bear in mind those articles every time we fly. But they do not permit you to justify a claim that an activity that is not explicitly approved or published is therefore illegal.

[fireflybob]

>We have to bear in mind those articles every time we fly. But they do not permit you to justify a claim that an activity that is not explicitly approved or published is therefore illegal.<

bookworm - thanks for that - I feel suitable chastised!

I was not saying that it follows that one is in contravention of Articles 63/64 just because one is flying a non published instrument approach. I just think that maybe some pilots need to bear in mind that, generally, such a practice means they may not be enjoying the usual level of safety compared to an approved procedure with full ATC.

Thanks for your interpretation of this Rule wrt "aircraft" - I had not read it that way which shows the advantages of debating such issues - that way we all learn something new.

I will see if I can get Flying Lawyer on the case!

Happy Easter

[bookworm]

bookworm - thanks for that - I feel suitable chastised!

Again, not my intention, but I guess I only get to claim that a couple of times. ;)

I was not saying that it follows that one is in contravention of Articles 63/64 just because one is flying a non published instrument approach. I just think that maybe some pilots need to bear in mind that, generally, such a practice means they may not be enjoying the usual level of safety compared to an approved procedure with full ATC.

I agree that a very careful risk assessment is required.

The risk of collision with other aircraft is probably not very significant. As we've already discussed, uncontrolled IFR outside controlled airspace is standard practice in the UK. Flying over a VOR at a rounded cruise altitude like 2000 ft probably puts you in more danger of encountering another aircraft than when flying an approach in the last 1000 ft down to the surface.

Published IAPs are regularly flown without ATC, but with self-announcement, in countries such as France. The system seems to work well, and the fact that aircraft tell each other what they are doing is important. One of my concerns about the illegality debate is that making DIY IAPs illegal discourages that communication.

The risk of collision with obstacles and terrain on such home-made approaches is surely the dominant risk. There are, unfortunately, too many examples of pilots getting it wrong, of which the most prominent example is probably the crash of Graham Hill's Aztec attempting to find Elstree in 1975.

Published IAPs are produced in accordance with strict specifications that most pilots are unaware of, and they use the information from a survey to assure obstacle clearance. Without an understanding of either of those, the pilot may be in a difficult position to create a safe procedure. There may be an argument however, that it is possible to fly safely with an obstacle clearance less than the arbitrary 1000 ft but rather more than the 250 ft used for non-precision approaches in published procedures.

The flip-side of regulation is usually in the alternative risk-bearing activities that it might promote. If it were made illegal to carry out a carefully assessed DIY IAP, it would leave the law-abiding pilot with the consideration of prolonged scud-running in marginal conditions as the legal alternative to a much safer high altitude cruise and short cloudbreak at destination. It is right and proper to require pilots, via Articles 63 and 64, to exercise appropriate risk-management in every aspect of their flying. The more you narrow the options by regulation, the more difficult you make that job.

[BizJetJock]

I think all the discussion so far has missed a fundamental point, that with the system at present even published approaches are merely advisory. The legal position for public transport flights is that the company must include in its ops manual procedures for every airfield they could use. 99% of times this is covered by adding Aerads or Jepps as an appendix to the ops manual, but there are also plenty of examples of "company" procedures for airfields without approaches, or often where the published approaches are for Cat A & B only.
In the past when getting such approaches scrutinised by the CAA for inclusion in an ops manual they have said that they are only too happy to look at anyone's private procedure as they would prefer to encourage safe procedures than have accidents. This was a few years ago, so they would probably either charge a fortune for the service or mutter about liability now...
The interesting legal point is that the approach ban only applies to published approaches!
Obviously this is all unrelated to off the cuff gps approaches, which are foolishly dangerous.

[BillieBob]

Try Rule 40 of the Rules of the Air Regulations 1996 -

(1) Subject to paragraph (2), the commander of an aircraft shall not make use of any radio navigation aid without complying with such restrictions and appropriate procedures as may be notified in relation to that aid unless authorised by an air traffic control unit.

(2) The commander of an aircraft shall not be required to comply with this rule if he is required to comply with rule 31.

Of course, this does not take account of approaches based on GPS information but, considering that's still not approved as a primary navigation aid in the UK, any approach procedure based solely on GPS is not permitted anyway.

[IO540]

considering that's still not approved as a primary navigation aid in the UK

For private GA (non-AOC) flights, the above is completely untrue, thankfully.

[Cosmic Star]

This multiple fatality accident report discuss exactly what you are talking about, and the legalities of doing it.

S76 (http://www.aaiu.ie/AAIUviewitem.asp?id=4719&lang=ENG&loc=1280)

[IO540]

Page 31 is interesting!

But this accident wasn't caused by a GPS fault.

quote:

Primary Cause
The primary cause of the accident was the loss of situational awareness which prompted the PNF's decision to deviate from the programmed route when he instructed the PF to delay the turn on to the final segment of the approach to the missed approach point, waypoint MAP, by maintaining a heading of south at waypoint WARRN, and his subsequent failure to monitor the aircraft's rate of turn when he initially instructed the PF to execute the turn.

and some other extracts

The flight was conducted using GPS as the prime navigation aid, and in the later portion used GPS as the sole approach aid, in violation of UK Regulations in force at the time of the accident.

.... and then goes on to say ........

3.1.28 The GPS system functioned correctly and accurately on the flight.

[Cosmic Star]

IO540, You are missing some salient points I feel.

The flight was conducted using GPS as the prime navigation aid, and in the later portion used GPS as the sole approach aid, in violation of UK Regulations in force at the time of the accident.

But if they had used INS, Loran or Decca that would have been OK. Thats against IFR flight rules. If we can ignore that for a second, it also says that descending below the MSA's and doing a home made Approach was not illegal.

Yes he was off course, but it sounded like there would have been a very small deflection on the HSI which was coupled to the GPS. The point being that if this had been a properly surveyed approach, this would have been taken into account. You don't tend to see many instrument approaches up valley inlets do you though?

On a seperate note, its scary to see an accident like that happen with the amount of experience on board. Thicker end of Over 10,000 hrs experience between them all.

[reynoldsno1]

To fly a GPS NPA safely and succesfully requires a lttle more preparation than bunging a few waypoints in the box. Designed properly, and coded correctly in a read-only database, the receiver carries out automatic functions other than pure navigation. The CDI (and HSI if integrated) sensitivity changes at critical points in the procedure, as does the RAIM functionality.
If the DIYer does not understand this, then history may well repeat itself.

[squawking 7700]

Using this thread and following on from an 'IMC diary' thread on
the Private Flying Forum, what's the view of instructors and more
specifically examiners on using an-published procedure as part of an IMC test?

7700

Apologies for the finger trouble..........


Using this thread and following on from an \'IMC diary\' thread on
the Private Flying Forum, what\'s the view of instructors and more
specifically examiners on using an un-published procedure as part of an IMC test?

7700