EASA AND THE IMCR - NEWS
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Nick,
I did read the question - after all, it wasn't me who speared off at a tangent burbling away about flying VC10's using an NDB and a stopwatch....
I'm delighted to hear that you use GPS, but refering to the systems we use in aircraft as "Garmin Wonderbox navigation systems" gives the impression of sneering, rather like the Judge in the "not the nine o'clock news" sketch when confronted with a digital watch...
I did read the question - after all, it wasn't me who speared off at a tangent burbling away about flying VC10's using an NDB and a stopwatch....
I'm delighted to hear that you use GPS, but refering to the systems we use in aircraft as "Garmin Wonderbox navigation systems" gives the impression of sneering, rather like the Judge in the "not the nine o'clock news" sketch when confronted with a digital watch...
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doesn't have to be INS to have DME /DME etc.
Most Turbo props won't have INS and alot of the regional jets won't have either. So no map shift, you can get the difference between GPS position and DME /DME derived if you go through a few pages but the unit bins the gps position if there is a conflict and goes with DME/DME.
...
The idea that the world s commercial aircraft are flying around putting all there trust in GPS is rather stretching it. Its a tool but most of the time it comes down very low on the list of Nav data. Hence why there really isn't that much of a push from commercial operators to have GPS approaches. So there is no one to pay for the surveying and production which is why nothing is really progressing on that front.
Most Turbo props won't have INS and alot of the regional jets won't have either. So no map shift, you can get the difference between GPS position and DME /DME derived if you go through a few pages but the unit bins the gps position if there is a conflict and goes with DME/DME.
...
The idea that the world s commercial aircraft are flying around putting all there trust in GPS is rather stretching it. Its a tool but most of the time it comes down very low on the list of Nav data. Hence why there really isn't that much of a push from commercial operators to have GPS approaches. So there is no one to pay for the surveying and production which is why nothing is really progressing on that front.
However, when the unit bins GPS you Appear to have to have INS or your RNAV capability is degraded (at least in FAA world) and you need to have three DMEs to use it for approaches without GPS. So GPS does seem to be rather higher up the list than you indicate. However, the essence of yournpntnis of course correct, there are DME/DME and DME/VOR FMSs without INS (and not requiring GPS) that will achieve the European BRNAV requirement. (There was an interesting near accident in North Africa where a corrupt VOR signal resulted in a a commercial aircraft being in the wrong location and coming within 59 feet of the ground while maneuvering - without a GPW due to the lack of GPS signal, INS not yet resynched and the corrupt VOR signal)
As an aside, I don't believe there are any GPS approaches - I believe they are all RNAV, GNSS, or RNP. So the issue with a lack of RNAV approaches in Europe is not that commercial operators don't use GPS. It is much more likely that the overlay concept was not approved by the Various NAAs and a rather burndonsome approach to approving new procedures.
PS
I believe that GPS and GLONASS are compatable but not interoperable as they have different bit rates and different (but similar) carrier frequencies. It is unlikely a box designed 15 years ago would support a speculative Russian system.
Last edited by mm_flynn; 7th Feb 2012 at 09:25. Reason: separated answer to GLONASS question
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I don't think he was sneering.
It just that its quite a common point of discussion with examinors and experenced pilots that there is to much heads down and furious button punching for the most simple tasks which the easy solution is just to flick up a NAV beacon and fly the aircraft. Using a 1 in 60 fudge or WAG for an intersection.
Look out suffers as does SA. Some may say SA is improved with moving map etc which I would agree with up to a point as long as the data goes in smoothly. It is quite common though for any interuption due misspelling etc to have the aircraft not being navigated until thats sorted. Where as the old boys/girls will have already turned to a rough heading towards the point in space and by the time the box of tricks have been beaten into submission you will find its only out by < 5 degs.
And to be honest I was going to keep out of this usual hampster wheel about GPS but for Peters incorrect statements about what airliners do and use.
He will never defer away from GPS is King. Any experence that the rest of has that its not quite as golden bollocks as he would have us believe is put down to.
1. We are ****e pilots
2. Our aircraft have some sort of dodgy installation.
3. We are mistaken with what we experence.
4. We arn't using it properly
5. Your just unlucky (well I do over 1800+ flights a year compared to the high end GA usage of what 100?)
6. GPS jamming never occurs, a garmin can defeat the might of the military and can get a decent signal when there mil spek GPS can't get a thing (well I presume they can't get anything as they seem to have the Jammers on whenever there is an exercise)
7. Solar flares and storms don't occur.
8. We know what the USA's intentions are for the next 20 years (maybe N reg owners that use the loophole get a special brief that the rest of us don't) don't )
I use GPS every day but I am glad that there are some cooler heads out there that arn't putting all our eggs in one basket.
Most boxes are DME/DME first and only give you a message when they go to GPS. After giving up on VOR/DME VOR/VOR
There are plenty of RNAV approaches in europe and SIDS and STARS. As you say no GPS ones. And the DME/DME boxes of tricks usually use 6-9 DME's to get the position and when it can't see that many it shiggles the combinations including using VOR/DME to keep the error within limits (not that the pilot would have a clue)
It just that its quite a common point of discussion with examinors and experenced pilots that there is to much heads down and furious button punching for the most simple tasks which the easy solution is just to flick up a NAV beacon and fly the aircraft. Using a 1 in 60 fudge or WAG for an intersection.
Look out suffers as does SA. Some may say SA is improved with moving map etc which I would agree with up to a point as long as the data goes in smoothly. It is quite common though for any interuption due misspelling etc to have the aircraft not being navigated until thats sorted. Where as the old boys/girls will have already turned to a rough heading towards the point in space and by the time the box of tricks have been beaten into submission you will find its only out by < 5 degs.
And to be honest I was going to keep out of this usual hampster wheel about GPS but for Peters incorrect statements about what airliners do and use.
He will never defer away from GPS is King. Any experence that the rest of has that its not quite as golden bollocks as he would have us believe is put down to.
1. We are ****e pilots
2. Our aircraft have some sort of dodgy installation.
3. We are mistaken with what we experence.
4. We arn't using it properly
5. Your just unlucky (well I do over 1800+ flights a year compared to the high end GA usage of what 100?)
6. GPS jamming never occurs, a garmin can defeat the might of the military and can get a decent signal when there mil spek GPS can't get a thing (well I presume they can't get anything as they seem to have the Jammers on whenever there is an exercise)
7. Solar flares and storms don't occur.
8. We know what the USA's intentions are for the next 20 years (maybe N reg owners that use the loophole get a special brief that the rest of us don't) don't )
I use GPS every day but I am glad that there are some cooler heads out there that arn't putting all our eggs in one basket.
Most boxes are DME/DME first and only give you a message when they go to GPS. After giving up on VOR/DME VOR/VOR
There are plenty of RNAV approaches in europe and SIDS and STARS. As you say no GPS ones. And the DME/DME boxes of tricks usually use 6-9 DME's to get the position and when it can't see that many it shiggles the combinations including using VOR/DME to keep the error within limits (not that the pilot would have a clue)
Last edited by mad_jock; 7th Feb 2012 at 09:29.
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A good rant from MJ 
The 430W/530W and all the Garmin IFR ones that came later can use EGNOS.
Whether they can use it today I don't know. EGNOS has been transmitting for years but with a "test" flag active and all IFR approved GPSs were banned from using the signal with that flag set. Only handhelds like the 496 could use it. Then Eurocontrol finally approved EGNOS for "safety of life" ops and that flag should have gone away but due to some Brussels cockup it didn't, and this was quite recently (months ago). It may be sorted now.
EGNOS is not currently operationally relevant, because GPS without SA is easily accurate enough for everything short of LPV. As for LPV approaches, AFAIK the UK has only one of those, in Alderney.
EGNOS is relevant when it comes to integrity checking. I don't know the details but vaguely recall that in the USA if you are receiving WAAS (the US version of EGNOS) then you can proceed with a GPS approach even if a RAIM check does not compute - or something like that. If/when I need to know about this I will check it out; my current GPS (KLN94) is not EGNOS capable anyway.
Re GLONASS, I am not aware of any current IFR GPS which can receive the signals right now. It cannot be hard to do and "should" be possible with just appropriate firmware... unfortunately Galileo and Glonass are not simply extra satellites to supplement the American constellation. They are on slightly different frequencies, etc.
What people also forget is that the Americans are updating their satellites too. The various wild claims for Galileo accuracy and reliability are all based on the Navstar system remaining as it was when originally launched in the 1980s.
Presumably aviation systems track EGNOS in Europe these days?
Whether they can use it today I don't know. EGNOS has been transmitting for years but with a "test" flag active and all IFR approved GPSs were banned from using the signal with that flag set. Only handhelds like the 496 could use it. Then Eurocontrol finally approved EGNOS for "safety of life" ops and that flag should have gone away but due to some Brussels cockup it didn't, and this was quite recently (months ago). It may be sorted now.
EGNOS is not currently operationally relevant, because GPS without SA is easily accurate enough for everything short of LPV. As for LPV approaches, AFAIK the UK has only one of those, in Alderney.
EGNOS is relevant when it comes to integrity checking. I don't know the details but vaguely recall that in the USA if you are receiving WAAS (the US version of EGNOS) then you can proceed with a GPS approach even if a RAIM check does not compute - or something like that. If/when I need to know about this I will check it out; my current GPS (KLN94) is not EGNOS capable anyway.
Re GLONASS, I am not aware of any current IFR GPS which can receive the signals right now. It cannot be hard to do and "should" be possible with just appropriate firmware... unfortunately Galileo and Glonass are not simply extra satellites to supplement the American constellation. They are on slightly different frequencies, etc.
What people also forget is that the Americans are updating their satellites too. The various wild claims for Galileo accuracy and reliability are all based on the Navstar system remaining as it was when originally launched in the 1980s.
Thread Starter
Thanks for the EGNOS information, Peter - that explains a lot. But yes, I also note m_j's point about 'head down' button pecking. It's something we specifically address during training for flying in certain environments.
Given how similar certain intersections both sound and spell quite similar (e.g. in the south of France), if given a direct, you can enter it but confirming the spelling can be awkward - so commonsense and situational awareness to avoid a Gi-Go error is, as you rightly say, of paramount importance. Presumably airlines have SOPs, but if directed to an unfamiliar intersection, it would seem prudent to use HDG rather than NAV until the new point has been confirmed?
Back to the IMCR. One of the current IMCR benefits is that a PPL holder in the UK may fly VFR above cloud, which rather stumps the 'must only use GPS as a back up to visual navigation' luddites at a Certain Aviation Authority who regard it as a tool of Satan. Under EASA, that well-loved SAFETY agency, plain vanilla PPL holders (or LAPL holders) won't be restricted by the ANO criteria applicable to UK PPL (or JAR-FCL) PPL holders without IMCRs / IRs, so assuming they can find suitable holes at both ends, in a couple of years there are likely to be a lot more pilots navigating with non-IFR GPS above cloud than there are at present.
As I understand the TSOs, 'IFR' GPS approval applies to the entire system, including antenna and external feeds, but applies only to en-route IFR cruising and terminal approaches (subject to additional TSO requirements). So if you're flying under VFR and navigating above cloud, you don't actually need an 'IFR' GPS. But what about the IMCR pilot climbing up through cloud to reach a VFR level, or descending below it at the other end? "No, I just note the heading and ignore the GPS until I become visual" Oh really?
As they do with their own SatNavs in hire cars, many pilots are going to prefer to use their portable GPS units in clubs' rental wreckage and the CAA will have to accept that 'VFR' GPS is going to be used more and more often as a primary navigation tool. "Fly and navigate visually, only use the GPS once you have verified its accuracy against something else, and cross-check regularly", as SSL 25 puts it, is going to be observed less and less often in future.
Given how similar certain intersections both sound and spell quite similar (e.g. in the south of France), if given a direct, you can enter it but confirming the spelling can be awkward - so commonsense and situational awareness to avoid a Gi-Go error is, as you rightly say, of paramount importance. Presumably airlines have SOPs, but if directed to an unfamiliar intersection, it would seem prudent to use HDG rather than NAV until the new point has been confirmed?
Back to the IMCR. One of the current IMCR benefits is that a PPL holder in the UK may fly VFR above cloud, which rather stumps the 'must only use GPS as a back up to visual navigation' luddites at a Certain Aviation Authority who regard it as a tool of Satan. Under EASA, that well-loved SAFETY agency, plain vanilla PPL holders (or LAPL holders) won't be restricted by the ANO criteria applicable to UK PPL (or JAR-FCL) PPL holders without IMCRs / IRs, so assuming they can find suitable holes at both ends, in a couple of years there are likely to be a lot more pilots navigating with non-IFR GPS above cloud than there are at present.
As I understand the TSOs, 'IFR' GPS approval applies to the entire system, including antenna and external feeds, but applies only to en-route IFR cruising and terminal approaches (subject to additional TSO requirements). So if you're flying under VFR and navigating above cloud, you don't actually need an 'IFR' GPS. But what about the IMCR pilot climbing up through cloud to reach a VFR level, or descending below it at the other end? "No, I just note the heading and ignore the GPS until I become visual" Oh really?
As they do with their own SatNavs in hire cars, many pilots are going to prefer to use their portable GPS units in clubs' rental wreckage and the CAA will have to accept that 'VFR' GPS is going to be used more and more often as a primary navigation tool. "Fly and navigate visually, only use the GPS once you have verified its accuracy against something else, and cross-check regularly", as SSL 25 puts it, is going to be observed less and less often in future.
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Given how similar certain intersections both sound and spell quite similar (e.g. in the south of France), if given a direct, you can enter it but confirming the spelling can be awkward - so commonsense and situational awareness to avoid a Gi-Go error is, as you rightly say, of paramount importance. Presumably airlines have SOPs, but if directed to an unfamiliar intersection, it would seem prudent to use HDG rather than NAV until the new point has been confirmed?
What happens when it is entered as a DCT depends on the autopilot mode at the time, and the type of HSI. If one is in NAV mode, and the HSI is a mechanical one, the AP will not do anything (much) until you manually turn the course pointer (CP) to the new track as indicated on the GPS. If the HSI is an electronic one (EHSI, or one of the "glass" products) then the CP will flip round by itself and the AP will turn onto the new track automatically, and yes it could be embarrassing if you entered the wrong waypoint
But the track will be obvious on the moving map anyway, where it will appear about the time the AP is turning onto it.It is obviously good practice to always have the HDG bug set to the current heading, even when flying in NAV mode, so you can revert to HDG mode, or even fly manually, immediately, at any time.
In some cases switching over to HDG is highly advisable during track changes. One case if where one is intercepting a track. Most GA autopilots do not do intelligent intercepts. They use the CP as the initial "heading" and then tweak the heading according to the lateral track error, so a lot of intercepts happen slowly, and slowly enough to irritate ATC. The Honeywell APs in particular will not do a clean intercept unless the track error is at least 3 divisions (about 60% HSI full scale) or greater when you press NAV.
So one has to know how to play one's system
I flew up to Coventry the other day and spent about 80% of the flight in HDG, with ATC vectors... The rest of it in HDG without ATC vectors
I also note m_j's point about 'head down' button pecking
As I understand the TSOs, 'IFR' GPS approval applies to the entire system, including antenna and external feeds, but applies only to en-route IFR cruising and terminal approaches (subject to additional TSO requirements).
So if you're flying under VFR and navigating above cloud, you don't actually need an 'IFR' GPS. But what about the IMCR pilot climbing up through cloud to reach a VFR level, or descending below it at the other end? "No, I just note the heading and ignore the GPS until I become visual" Oh really? As they do with their own SatNavs in hire cars, many pilots are going to prefer to use their portable GPS units in clubs' rental wreckage and the CAA will have to accept that 'VFR' GPS is going to be used more and more often as a primary navigation tool.
As they do with their own SatNavs in hire cars, many pilots are going to prefer to use their portable GPS units in clubs' rental wreckage and the CAA will have to accept that 'VFR' GPS is going to be used more and more often as a primary navigation tool.
"Fly and navigate visually, only use the GPS once you have verified its accuracy against something else, and cross-check regularly", as SSL 25 puts it, is going to be observed less and less often in future.
And I support that (with the usual caveats, like backing up with VOR/DME) because GPS is far more reliable than visual nav, dead reckoning, whatever.
I fly 100% on GPS, with VOR/DME backup where possible.
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Mad_Jock
And to be honest I was going to keep out of this usual hampster wheel about GPS but for Peters incorrect statements about what airliners do and use.
He will never defer away from GPS is King. Any experence that the rest of has that its not quite as golden bollocks as he would have us believe is put down to
And to be honest I was going to keep out of this usual hampster wheel about GPS but for Peters incorrect statements about what airliners do and use.
He will never defer away from GPS is King. Any experence that the rest of has that its not quite as golden bollocks as he would have us believe is put down to
