MSA over the sea
DFC,
that accident does not show the error of using a DIY approach; it shows the error of not following a procedure correctly. Every year there are umpteen accidents where aircraft have diverged from published procedures that ARE approved.
For those who asked about helicopter let downs offshore; The procedure is officially approved and published by Aerad. All operators around the N Sea use the same basic procedure, generally known as an ARA (airborne radar approach). It begins with the premise that MSA is 1500 ft, for the reasons given, but once the crew has established that there are no obstacles in the intended let down area, other than their destination rig/platform/ship, the aircraft can be descended on a promulgated profile. Normally it utilises an NDB on the destination along with GPS. Principly, though, it requires the wx radar, which is managed by the PNF to give a 'talk down' to the PF. MDH is 200 ft rad-alt and an offset is flown at 1.5 nm to ensure lateral separation. The descision point is at 0.75 nm.
DIY approaches are fraught with dangers and are not to be taken lightly.
that accident does not show the error of using a DIY approach; it shows the error of not following a procedure correctly. Every year there are umpteen accidents where aircraft have diverged from published procedures that ARE approved.
For those who asked about helicopter let downs offshore; The procedure is officially approved and published by Aerad. All operators around the N Sea use the same basic procedure, generally known as an ARA (airborne radar approach). It begins with the premise that MSA is 1500 ft, for the reasons given, but once the crew has established that there are no obstacles in the intended let down area, other than their destination rig/platform/ship, the aircraft can be descended on a promulgated profile. Normally it utilises an NDB on the destination along with GPS. Principly, though, it requires the wx radar, which is managed by the PNF to give a 'talk down' to the PF. MDH is 200 ft rad-alt and an offset is flown at 1.5 nm to ensure lateral separation. The descision point is at 0.75 nm.
DIY approaches are fraught with dangers and are not to be taken lightly.
Last edited by 212man; 28th Jul 2005 at 07:44.
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"In all cases unless the person in question was in receipt of a radar service Im sure his airmanship would be called into question...and whilst he might not have broken any law would you (given the advice from the authorities) possibly consider his actions to be reckless or negligent given that such advice was for a completely different set of actions? Would you have considered that the commander had placed his aircraft in danger?"
So how would a court have seen our IMC / night letdowns to a 50' hover over the sea? Quite a few more dead folk had we not done it.......
"that accident does not show the error of using a DIY approach; it shows the error of not following a procedure correctly. Every year there are umpteen accidents where aircraft have diverged from published procedures that ARE approved."
I totally agree - once you fail to follow any let-down procedure, home grown or not, you are in uncharted territory and "loss of terrain clearance" is what may follow, even if the MAP is carried out correctly.
So how would a court have seen our IMC / night letdowns to a 50' hover over the sea? Quite a few more dead folk had we not done it.......
"that accident does not show the error of using a DIY approach; it shows the error of not following a procedure correctly. Every year there are umpteen accidents where aircraft have diverged from published procedures that ARE approved."
I totally agree - once you fail to follow any let-down procedure, home grown or not, you are in uncharted territory and "loss of terrain clearance" is what may follow, even if the MAP is carried out correctly.
Last edited by ShyTorque; 28th Jul 2005 at 14:50.
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I wonder what criteria a pilot would use to design a DIY approach? Many years ago I spent several weeks on a Instrument Approach Procedure Design Course. If only we'd realised you could just cuff it with a GPS and the back of a fag packet we wouldn't have had to learn about navaid accuracy, obstacle clearance sectors, acceptable climb and descent rates, weather minimas, missed approach segments etc etc... if only (it was one hell of a course!). Seriously... DIY is for bodgers!
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There is a publication called TERPS. The FAA uses that, AFAIK.
It's easy enough to "design" a DIY IAP for an airfield in flat country.
Doing it among terrain may require a special survey; it's not enough to take the elevations off the local Ordnance Survey map.
It's easy enough to "design" a DIY IAP for an airfield in flat country.
Doing it among terrain may require a special survey; it's not enough to take the elevations off the local Ordnance Survey map.
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I know of at least one "approved" approach (GPS-A PAN) approach in mountainous country (MSA 9300ft) which was designed by an interested GA pilot because the home airfield didn't have an approach. They got the books out, designed and test flew the approach themselves, then got the FAA in to validate it. The FAA came in with their test plane and approved it, cost to the airport/pilots a big fat zero. So it can be done by rank amateurs, but I'd only fly it myself once the "experts" had validated.
No met observer needed on the ground either, what a strange thing to do.
No met observer needed on the ground either, what a strange thing to do.
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TERPS is here:
http://av-info.faa.gov/terps/directives%20page.htm
(warning: 28MB PDF!)
and leaves me in awe of the design process.
Tim
http://av-info.faa.gov/terps/directives%20page.htm
(warning: 28MB PDF!)
and leaves me in awe of the design process.
Tim
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Are you allowed to fly a DIY approach in the UK if you only have an FAA IR? Part 91 says you cannot so you would be doing something your certificate does not authorise.
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Sec. 91.175
Takeoff and landing under IFR.
(a) Instrument approaches to civil airports.
Unless otherwise authorized by the Administrator, when an instrument letdown to a civil airport is necessary, each person operating an aircraft, except a military aircraft of the United States, shall use a standard instrument approach procedure prescribed for the airport in part 97 of this
chapter.
Takeoff and landing under IFR.
(a) Instrument approaches to civil airports.
Unless otherwise authorized by the Administrator, when an instrument letdown to a civil airport is necessary, each person operating an aircraft, except a military aircraft of the United States, shall use a standard instrument approach procedure prescribed for the airport in part 97 of this
chapter.
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IMHO this clearly refers to the official instrument approaches provided - if one is provided, one is supposed to use it and not some home-brew one.
If there isn't one provided, and the airport is in Class G, what does one do?
A DIY IAP could be anything between
a) a synthetic ILS straight onto the runway (like a real ILS), and
b) a descent in IMC under own navigation, a number of miles away, followed by a visual approach
and I cannot see how one can define where the boundary lies between these extremes.
So what you suggest amounts to a ban on any descent in IMC (for the purpose of a landing - and let's face it, every flight is done for the purpose of a landing
) except via an official IAP.
A DIY IAP is rarely going to be a), not least because there could be somebody in the circuit. One would normally descend a few miles away and proceed visually. The sort of MDH which one gets on a non-precision IAP (say 600ft AGL) is generally suitable for flight in VMC.
If there isn't one provided, and the airport is in Class G, what does one do?
A DIY IAP could be anything between
a) a synthetic ILS straight onto the runway (like a real ILS), and
b) a descent in IMC under own navigation, a number of miles away, followed by a visual approach
and I cannot see how one can define where the boundary lies between these extremes.
So what you suggest amounts to a ban on any descent in IMC (for the purpose of a landing - and let's face it, every flight is done for the purpose of a landing
) except via an official IAP.A DIY IAP is rarely going to be a), not least because there could be somebody in the circuit. One would normally descend a few miles away and proceed visually. The sort of MDH which one gets on a non-precision IAP (say 600ft AGL) is generally suitable for flight in VMC.
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IO540,
I accept regulations are open to interpretation but try as I can, there is no way I can interpret 91.175(a) in the same way you do
You do bring up some interesting questions about Class G. Class G is not some lawless zone where the regs don't apply, you just don't need a clearance to fly in class G, IFR rules still apply.
FAA certificate holders are required to immediately climb to MEA which is specified in 91.177 and 91.179. Thats going to be 1000ft above anything within 5 miles, and also teh hemispherical rules apply. Basically no lower than 2000MSL or 3000MSL depending on your course.
You ask when the approach starts. For an airport with no IAP I would say the approach starts when you leave the MEA. What are the requirements? In Class G you need to have VFR minima (91.169(c)(2) ).
VFR mimima in Class G are
<=1200 AGL
during day clear of cloud and 1 miles vis; night 3 miles vis and 500/1000/2000 (91.155).
>=1200 AGL
day 1 miles vis and 500/1000/2000
night 3 miles and 500/1000/2000
This says to me that pilots relying solely on their FAA certicate to fly IFR cannot descend below MEA in class G unless you are clear of clouds by 500/1000/2000 ft.
Sec. 91.177
Minimum altitudes for IFR operations.
(a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, no person may operate an aircraft under IFR below
...
..
(ii) .... an altitude of 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown.
Sec. 91.179
IFR cruising altitude or flight level.
(b) In uncontrolled airspace. Except while in a holding pattern of 2 minutes or less or while turning, each person operating an aircraft under IFR in level cruising flight in uncontrolled airspace shall maintain an appropriate altitude as follows:
(1) When operating below 18,000 feet MSL and--
(i) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude (such as 3,000, 5,000, or 7,000); or
(ii) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude (such as 2,000, 4,000, or 6,000).
91.169(c)(2)
(2) If no instrument approach procedure has been published in part 97 of this chapter and no special instrument approach procedure has been issued by the Administrator to the operator, for the alternate airport, the ceiling and visibility minima are those allowing descent from the MEA, approach, and landing under basic VFR.
However I agree that you don't need any minima to depart in class G. However FAA certificate holders might be interested in ....Careless Reckless (PDF)
So that's my interpretation. Over to you
I accept regulations are open to interpretation but try as I can, there is no way I can interpret 91.175(a) in the same way you do
You do bring up some interesting questions about Class G. Class G is not some lawless zone where the regs don't apply, you just don't need a clearance to fly in class G, IFR rules still apply.
FAA certificate holders are required to immediately climb to MEA which is specified in 91.177 and 91.179. Thats going to be 1000ft above anything within 5 miles, and also teh hemispherical rules apply. Basically no lower than 2000MSL or 3000MSL depending on your course.
You ask when the approach starts. For an airport with no IAP I would say the approach starts when you leave the MEA. What are the requirements? In Class G you need to have VFR minima (91.169(c)(2) ).
VFR mimima in Class G are
<=1200 AGL
during day clear of cloud and 1 miles vis; night 3 miles vis and 500/1000/2000 (91.155).
>=1200 AGL
day 1 miles vis and 500/1000/2000
night 3 miles and 500/1000/2000
This says to me that pilots relying solely on their FAA certicate to fly IFR cannot descend below MEA in class G unless you are clear of clouds by 500/1000/2000 ft.
Sec. 91.177
Minimum altitudes for IFR operations.
(a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, no person may operate an aircraft under IFR below
...
..
(ii) .... an altitude of 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown.
Sec. 91.179
IFR cruising altitude or flight level.
(b) In uncontrolled airspace. Except while in a holding pattern of 2 minutes or less or while turning, each person operating an aircraft under IFR in level cruising flight in uncontrolled airspace shall maintain an appropriate altitude as follows:
(1) When operating below 18,000 feet MSL and--
(i) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude (such as 3,000, 5,000, or 7,000); or
(ii) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude (such as 2,000, 4,000, or 6,000).
91.169(c)(2)
(2) If no instrument approach procedure has been published in part 97 of this chapter and no special instrument approach procedure has been issued by the Administrator to the operator, for the alternate airport, the ceiling and visibility minima are those allowing descent from the MEA, approach, and landing under basic VFR.
However I agree that you don't need any minima to depart in class G. However FAA certificate holders might be interested in ....Careless Reckless (PDF)
So that's my interpretation. Over to you
I think you're missing something, slim_slag. Part 97 describes only approaches to airports in the US. By your interpretation, an N-reg aircraft could never fly an IAP outside the US.
You also misconstrue 91.169(c)(2). 91.169(c) sets out the requirement for filing an alternate airport. 91.169(c)(2) set out the conditions under which an airport without IAP may be used to meet those requirements.
That said, given the airspace structure differences, I don't think the FAA would be nearly as flexible in interpreting the minimum altitude rule in regard to IAPs in the US as the CAA have to be in the UK.
You also misconstrue 91.169(c)(2). 91.169(c) sets out the requirement for filing an alternate airport. 91.169(c)(2) set out the conditions under which an airport without IAP may be used to meet those requirements.
That said, given the airspace structure differences, I don't think the FAA would be nearly as flexible in interpreting the minimum altitude rule in regard to IAPs in the US as the CAA have to be in the UK.
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I would climb down slightly from my earlier position, and concur with bookworm.
Unless one can get a letter from the FAA allowing in an N-reg whatever the CAA allows in a G-reg (which is far from impossible, looking at some written FAA replies I've seen) it may be safer for an N-reg FAA PPL/IR pilot wishing to fly an unofficial IAP to also have a UK PPL with an IMC Rating.
However - what constitutes an "IAP"? One could argue that any descent below what in the UK is called "MSA" i.e. < 1000ft AGL except in mountainous terrain where it is 2000ft. (In fact I don't even know for sure if the 2000ft is just FAA, or ICAO, or CAA).
And one could argue that a 1000ft MDH is reasonable for a DIY IAP, anyway. Which makes all this moot. (Trevor Thom says, in Book 5, it is OK to do a DIY descent TO the MSA so it must be OK )
It's doubly moot since the sort of place where one would be doing a DIY IAP in the UK is unlikely to have an accurate means of determining the cloudbase anyway.
Unless one can get a letter from the FAA allowing in an N-reg whatever the CAA allows in a G-reg (which is far from impossible, looking at some written FAA replies I've seen) it may be safer for an N-reg FAA PPL/IR pilot wishing to fly an unofficial IAP to also have a UK PPL with an IMC Rating.
However - what constitutes an "IAP"? One could argue that any descent below what in the UK is called "MSA" i.e. < 1000ft AGL except in mountainous terrain where it is 2000ft. (In fact I don't even know for sure if the 2000ft is just FAA, or ICAO, or CAA).
And one could argue that a 1000ft MDH is reasonable for a DIY IAP, anyway. Which makes all this moot. (Trevor Thom says, in Book 5, it is OK to do a DIY descent TO the MSA so it must be OK
)It's doubly moot since the sort of place where one would be doing a DIY IAP in the UK is unlikely to have an accurate means of determining the cloudbase anyway.
Are you allowed to fly a DIY approach in the UK if you only have an FAA IR? Part 91 says you cannot so you would be doing something your certificate does not authorise.
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Moreover, FAR Part 91 Subpart H (91.701 etc) - ... US Registered Aircraft outside of the USA ...
states
91.703 (a) (2) When within a foreign country, comply with the regs relating to flight... of aircraft there in force
So an N-reg in UK airspace is required to comply with UK regs, and the main Part 91 does not apply.
states
91.703 (a) (2) When within a foreign country, comply with the regs relating to flight... of aircraft there in force
So an N-reg in UK airspace is required to comply with UK regs, and the main Part 91 does not apply.
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Bookworm,
Looks like you have another different interpretation of the regs. I find it hard to believe you could say that FAA regulations do not apply to an FAA certificate holder flying an FAA registered plane as soon as that plane leaves US airspace.
IO540.
In one breath you are telling me that I have to follow 91.703 (a) (2) when in the UK, the next breath you tell me part 91 does not apply in the UK. By your logic I can just surely ignore 91.703 (a) (2) when in the UK.
Looks like you have another different interpretation of the regs. I find it hard to believe you could say that FAA regulations do not apply to an FAA certificate holder flying an FAA registered plane as soon as that plane leaves US airspace.
IO540.
In one breath you are telling me that I have to follow 91.703 (a) (2) when in the UK, the next breath you tell me part 91 does not apply in the UK. By your logic I can just surely ignore 91.703 (a) (2) when in the UK.
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This can't be settled without reading the entire FAR book and working out the interaction of every clause in there with every other one, and probably never with 100% certainty.
However, if you turn to page 159 in the 2005 FAR/AIM, Subpart A - General, $91.1 Applicability (a)
it states ...........
"within the United States, including the waters within 3nm of the US coast."
This "USA only" qualification extends, as far as I can see, all the way to Subpart H - Foreign Aircraft etc (page 211 of FAR/AIM) where it says
91.703 (a) (2) ... when within a foreign country, comply with the regs relating to the flight ... there in force
and
91.703 (a) (3)
... comply with this part so far as it is not inconsistent with applicable regulations of the foreign country where the aircraft is operated or annex 2 of ICAO...
The bit which one could have fun debating is 91.703 (a) (3) where we could argue the extent to which a regulation prohibiting something in US airspace is applicable to a different country's airspace where the same thing is not prohibited (though not expressly permitted).
It is a fact that N-reg places can legally fly in UK airspace, and it is a fact that the UK has a different airspace structure. The privileges of the IMC Rating are what they are because of our airspace structure - one can see for example why the rest of Europe doesn't have an IMCR also.
However, if you turn to page 159 in the 2005 FAR/AIM, Subpart A - General, $91.1 Applicability (a)
it states ...........
"within the United States, including the waters within 3nm of the US coast."
This "USA only" qualification extends, as far as I can see, all the way to Subpart H - Foreign Aircraft etc (page 211 of FAR/AIM) where it says
91.703 (a) (2) ... when within a foreign country, comply with the regs relating to the flight ... there in force
and
91.703 (a) (3)
... comply with this part so far as it is not inconsistent with applicable regulations of the foreign country where the aircraft is operated or annex 2 of ICAO...
The bit which one could have fun debating is 91.703 (a) (3) where we could argue the extent to which a regulation prohibiting something in US airspace is applicable to a different country's airspace where the same thing is not prohibited (though not expressly permitted).
It is a fact that N-reg places can legally fly in UK airspace, and it is a fact that the UK has a different airspace structure. The privileges of the IMC Rating are what they are because of our airspace structure - one can see for example why the rest of Europe doesn't have an IMCR also.
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Morning IO540,
I am guessing that 91.1 and 91.703 are in there to make sure Chicago Convention stuff are put in the FARs. My understanding of these ICAO regs are that if you are flying in (for example) UK airspace in a US plane with a US pilot certificate, and there is any discrepancy/uncertainty in the regs, the more restrictive will apply.
So, its my interpretation (oh no, not another one!) that the FARS expressly prohibit an instrument letdown to a civil airport unless there is an approved IAP. The UK don't appear to have that restriction. Therefore if you are depending on an FAA certificate, the more restrictive reg applies, and you cannot do an instrument letdown in UK airspace if no CAA approved IAP exists.
If somebody else inteprets differently and wants to do so then that's up to them, but I would not expect the FAA to turn a blind eye if you hurt somebody and survived. So I would not do it without an IMCR, and even then my personal risk/reward calculation would prohibit it for me.
Bookworm,
I quoted 91.169(c)(2) to demonstrate that Class G is not a 'lawless zone' and regulations apply to IFR flight within that airspace and when letting down to an airport within.
cheers
I am guessing that 91.1 and 91.703 are in there to make sure Chicago Convention stuff are put in the FARs. My understanding of these ICAO regs are that if you are flying in (for example) UK airspace in a US plane with a US pilot certificate, and there is any discrepancy/uncertainty in the regs, the more restrictive will apply.
So, its my interpretation (oh no, not another one!) that the FARS expressly prohibit an instrument letdown to a civil airport unless there is an approved IAP. The UK don't appear to have that restriction. Therefore if you are depending on an FAA certificate, the more restrictive reg applies, and you cannot do an instrument letdown in UK airspace if no CAA approved IAP exists.
If somebody else inteprets differently and wants to do so then that's up to them, but I would not expect the FAA to turn a blind eye if you hurt somebody and survived. So I would not do it without an IMCR, and even then my personal risk/reward calculation would prohibit it for me.
Bookworm,
I quoted 91.169(c)(2) to demonstrate that Class G is not a 'lawless zone' and regulations apply to IFR flight within that airspace and when letting down to an airport within.
cheers
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slim_slag
Fair enough, we can leave the FAR v. ICAO v. CAA bit like that for now.
It still means that (UK, Class G) one can descend to the IFR MSA (1000ft above highest obstacle within 5nm I think; the FARs say something slightly different for the MOCA, IIRC, but 5nm is good enough) and provided one is then VMC one can continue with the approach visually.
One can even do a straight-in approach that way, not wisely but legally.
Which amounts to a DIY IAP with an MDH of 1000ft. That's good enough for most requirements.
Do that in say Wales and if your nav is less than 100% you will still get killed.
Why would this be illegal in the USA? It wouldn't be because you can legally fly AT the MOCA (if that's the level in your IFR clearance) and if you are visual then, you can elect to do a visual approach. So the argument is moot.
To re-iterate, there is no practical difference I can see between
a) Flying at MOCA (or MSA if UK/Europe) plus say 10000ft, and then descending to the MOCA 5nm away from the airfield, and if one is visual, doing a visual approach, and
b) Flying AT the MOCA all along and if visual doing a visual approach.
Fair enough, we can leave the FAR v. ICAO v. CAA bit like that for now.
It still means that (UK, Class G) one can descend to the IFR MSA (1000ft above highest obstacle within 5nm I think; the FARs say something slightly different for the MOCA, IIRC, but 5nm is good enough) and provided one is then VMC one can continue with the approach visually.
One can even do a straight-in approach that way, not wisely but legally.
Which amounts to a DIY IAP with an MDH of 1000ft. That's good enough for most requirements.
Do that in say Wales and if your nav is less than 100% you will still get killed.
Why would this be illegal in the USA? It wouldn't be because you can legally fly AT the MOCA (if that's the level in your IFR clearance) and if you are visual then, you can elect to do a visual approach. So the argument is moot.
To re-iterate, there is no practical difference I can see between
a) Flying at MOCA (or MSA if UK/Europe) plus say 10000ft, and then descending to the MOCA 5nm away from the airfield, and if one is visual, doing a visual approach, and
b) Flying AT the MOCA all along and if visual doing a visual approach.
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If there isn't one (an approach procedure) provided, and the airport is in Class G, what does one do?