Oceanic Navigation
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Oceanic Navigation
Somebody on another thread mentioned flying off-airways during long oceanic sectors, crossing or paralleling airways. This brought a couple of questions to mind :
1) Am I right in thinking that there is no radar / no ATC out in the middle of the ocean?
2) If so, and you are flying off-airways, how do you make sure that there isn't anything else in the same bit of sky as you?
Thanks,
Steve.
1) Am I right in thinking that there is no radar / no ATC out in the middle of the ocean?
2) If so, and you are flying off-airways, how do you make sure that there isn't anything else in the same bit of sky as you?
Thanks,
Steve.
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Steve
Check out the following, together with the links and come back if you need any clarification.
http://en.wikipedia.org/wiki/Shanwick_Oceanic_Control
Check out the following, together with the links and come back if you need any clarification.
http://en.wikipedia.org/wiki/Shanwick_Oceanic_Control
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Thanks for that. Let me see if I've got it straight. First, as you go westbound into the OCA, you get a clearance from Shanwick Control (at Prestwick), to enter the OCA, and fly a certain pre-planned route (airway or otherwise) which gives you procedural seperation.
You're then handed on to Shanwick Radio (based in Ballygireen), who provide mointoring and traffic information based on the planned routes and reports from traffic in the area.
Presumably a similar thing happens going in the other direction into the Gander area, and the two talk to each other so that they know who's coming.
Is that about right?
Steve.
You're then handed on to Shanwick Radio (based in Ballygireen), who provide mointoring and traffic information based on the planned routes and reports from traffic in the area.
Presumably a similar thing happens going in the other direction into the Gander area, and the two talk to each other so that they know who's coming.
Is that about right?
Steve.
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Steve
You're pretty well there. Take a typical Heathrow-Kennedy flight routing via Shanwick into Gander:
Approx 30-90 minutes before entering the Shanwick Oceanic Control Area the flight will request an Oceanic Clearance. (Shanwick, as with other OCAs, is Class A Airspace above FL55 therefore an ATC clearance is a requirement - with few, usually military, exceptions). The clearance would be requested/issued on a Shanwick Control (Prestwick) VHF frequency or by using an ACARS based system called ORCA. ('Oceanic Route Clearance Authorisation'). If required, a clearance can also be requested/issued via Shanwick Radio (Ballygirreen) on HF.
The requested/cleared route will be either on what is called a 'Random Route' or alternatively follow one of the designated tracks of the North Atlantic (NAT) Organised Track Structure (OTS). The clearance will apply from the Oceanic Entry Point all the way across the ocean to a designated Landfall which falls within a radar environment
Once in receipt of the clearance the flight will arrange to cross the Oceanic Entry Point at a specified time (give or take a couple of minutes) and continue in accordance with the FL, route and speed contained in the clearance, until again coming back into radar cover in a Canadian radar sector. (Changes whilst en-route to the cleared FL, route or speed can be requested by crews at any time however).
Once within the procedural (non-radar) environment of the OCA, ATC plots aircraft positions using actual and estimated times over significant points held on the route, speed calculations taking into account the forcast MET and ensures that safety is maintained by applying horizontal separations which are so large as to make your average radar controller green with envy. (Or cry in despair - one or other!). Vertical separation remains at 1000' up to and including FL410. (Unless you're an A380, in which case you get 2000' between you and the next guy below!)
Communications with ATC are via HF or CPDLC ('Controller-Pilot-Data-Link-Communications') and the flight will make routine Waypoint Position Reports either again via HF or by using ADS at every significant point along the cleared route. (Usually every 10 degrees of Longitude). Once within the Gander OCA the flight will then fall under their jurisdiction and Gander Radio will handle all HF comms and Gander Center the control function.
Oceanic flight data is held in much the same way as flight data at any other ATC centre, although the procedural control aspect makes Oceanic Control a fairly unique ATC environment. (The technology used also being quite different from your typical en-route ATC radar-based centre).
Hope that clarifies things
You're pretty well there. Take a typical Heathrow-Kennedy flight routing via Shanwick into Gander:
Approx 30-90 minutes before entering the Shanwick Oceanic Control Area the flight will request an Oceanic Clearance. (Shanwick, as with other OCAs, is Class A Airspace above FL55 therefore an ATC clearance is a requirement - with few, usually military, exceptions). The clearance would be requested/issued on a Shanwick Control (Prestwick) VHF frequency or by using an ACARS based system called ORCA. ('Oceanic Route Clearance Authorisation'). If required, a clearance can also be requested/issued via Shanwick Radio (Ballygirreen) on HF.
The requested/cleared route will be either on what is called a 'Random Route' or alternatively follow one of the designated tracks of the North Atlantic (NAT) Organised Track Structure (OTS). The clearance will apply from the Oceanic Entry Point all the way across the ocean to a designated Landfall which falls within a radar environment
Once in receipt of the clearance the flight will arrange to cross the Oceanic Entry Point at a specified time (give or take a couple of minutes) and continue in accordance with the FL, route and speed contained in the clearance, until again coming back into radar cover in a Canadian radar sector. (Changes whilst en-route to the cleared FL, route or speed can be requested by crews at any time however).
Once within the procedural (non-radar) environment of the OCA, ATC plots aircraft positions using actual and estimated times over significant points held on the route, speed calculations taking into account the forcast MET and ensures that safety is maintained by applying horizontal separations which are so large as to make your average radar controller green with envy. (Or cry in despair - one or other!). Vertical separation remains at 1000' up to and including FL410. (Unless you're an A380, in which case you get 2000' between you and the next guy below!)
Communications with ATC are via HF or CPDLC ('Controller-Pilot-Data-Link-Communications') and the flight will make routine Waypoint Position Reports either again via HF or by using ADS at every significant point along the cleared route. (Usually every 10 degrees of Longitude). Once within the Gander OCA the flight will then fall under their jurisdiction and Gander Radio will handle all HF comms and Gander Center the control function.
Oceanic flight data is held in much the same way as flight data at any other ATC centre, although the procedural control aspect makes Oceanic Control a fairly unique ATC environment. (The technology used also being quite different from your typical en-route ATC radar-based centre).
Hope that clarifies things
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FOR STRATEGIC LATERAL OFFSET PROCEDURES, CONTINGENCY PROCEDURES RELATED TO OPS IN NATS FLOW, PLEASE REFER TO THE NAT PROGRAMME COORDINATION OFFICE WEBSITE AT WWW.NAT-PCO.ORG 20 DEC 11:13 UNTIL 31 MAR 12:00 2007 ESTIMATED
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All this 'regulation' takes all the fun out of flying in oceanic airspace.
I say, bring back pressure pattern long range navigation...and the professional navigators who positively knew how to do it.
Additionally, anyone for Loran A?
I say, bring back pressure pattern long range navigation...and the professional navigators who positively knew how to do it.
Additionally, anyone for Loran A?
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bring back pressure pattern long range navigation
Additionally, anyone for Loran A?
As a matter of interest, it wasn't so many years ago I used to listen in to this old German U-boat long range navigation aid out in the Atlantic. Transmitted from Quimper, Brest, and I think Vigo, Spain into the 80s I believe. If the Spanish were transmitting this during the war, why didn't it get blown up 'in a mysterious explosion' one night? Anyone know?
'Consol' was the British name for the German 'Sonne' system developed pre WW2. It was a general navigation system but primarily used in WW2 by the German U boats. There were three staions origianlly. One in Spain, one in Quimper, France and one in Stavanger, Norway. It transmitted a series of dots and dashes on 300khz and the beauty of it was that a nav fix could be made by anyone with a radio that could receive that frequency. So an ADF could be tuned and a count done.
To use it, you listened to the series of dots and waited for the dash. The dash related to which 'radial' you were on. You noted what time you got the dash and looked up the time split from the start of the signal on the Consol chart. A 3 position line fix could take some time as I seem to remember that one count sequence could take about a minute.
One of the reasons why it didn't get blown up was that the allies used it as well, although I seem to remember reading that some selective jamming and spoofing took place. It was well known by the allies as it was a commercial facility pre war.
After WW2, it was maintained and additional stations were added. One in Ballykelly, Northern Ireland was blown up by the IRA who thought it was a listening station.
I seem to remember the Stavanger station being in existance up to 1990.
To use it, you listened to the series of dots and waited for the dash. The dash related to which 'radial' you were on. You noted what time you got the dash and looked up the time split from the start of the signal on the Consol chart. A 3 position line fix could take some time as I seem to remember that one count sequence could take about a minute.
One of the reasons why it didn't get blown up was that the allies used it as well, although I seem to remember reading that some selective jamming and spoofing took place. It was well known by the allies as it was a commercial facility pre war.
After WW2, it was maintained and additional stations were added. One in Ballykelly, Northern Ireland was blown up by the IRA who thought it was a listening station.
I seem to remember the Stavanger station being in existance up to 1990.
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Quite fascinating it lasted so long. I recall it being used (in desperation) on transatlantics when the other stuff wasn't working properly and star/sun shots were out because of turbulence or cloud (pre- INS days 411A- I'll tell you all about it one day! None of yer triplicated-autopilot/INS direct-lift-control-Tristar modern rubbish then!).
I didn't use it personally - had a Navigator for that! He would announce "Off intercom - Consol count" at which point the rest of the crew would try and distract him so he would lose his place. Pictures of scantily clad women seemed to work best.
This was on the Victor which had pretty poor Nav kit. Occaisionally we would use it in anger but some of the older crustier Navs would do Consol fixes for nostalgia. Well, that's what they said. Personally I suspected it was because they hadn't worked out how to use the new-fangled Omega!
This was on the Victor which had pretty poor Nav kit. Occaisionally we would use it in anger but some of the older crustier Navs would do Consol fixes for nostalgia. Well, that's what they said. Personally I suspected it was because they hadn't worked out how to use the new-fangled Omega!
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I remember when I joined BA in the late 80's, we used to fly up to Bergen and Stavanger and I heard tales of the Stavanger Consol beacon, which would be tuned in for nostalgic reasons.. I remember listening in to the series of dots and dashes, but never learned how to interpret them, so thanks for that.
IIRC the station was still there until at least 1992 or 93, it may still be, I think I recall seeing the large aerial arrays required just south of Stavanger airport.
Looking at a 2001 Aread European Supplement, it gives Stavanger (Varhaug) NDB 'NEC' on freq 319 with A1A coding - is/was that correct?
IIRC the station was still there until at least 1992 or 93, it may still be, I think I recall seeing the large aerial arrays required just south of Stavanger airport.
Looking at a 2001 Aread European Supplement, it gives Stavanger (Varhaug) NDB 'NEC' on freq 319 with A1A coding - is/was that correct?
I gather the aerial array was large - three tall towers, each half a mile apart. Although the Consol signal could be received by an ADF, it isn't the NDB if that's what you are asking. It's was just an audio signal which was phased to give a different series of tones depending on your bearing from it.
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I remember, in the 60's Transport Command, knowing all about consul but only listening to it out of interest.
We did get friendly in Bermuda with a small yacht crew-a chap and his girl friend-who were about to make their first transatlantic crossing. Not only did we let them use our hotel rooms for a shower but the Nav set up a ground school for them on consul.
They departed with one of Her Majesty's consul charts suitably marked with Ocean Stations and frequencies. I hope that they made it!
We did get friendly in Bermuda with a small yacht crew-a chap and his girl friend-who were about to make their first transatlantic crossing. Not only did we let them use our hotel rooms for a shower but the Nav set up a ground school for them on consul.
They departed with one of Her Majesty's consul charts suitably marked with Ocean Stations and frequencies. I hope that they made it!
Was a young whipper when I learned of consolan. I was in the back seat of an F-100 on a drag to Turkey. The pilot was a ex-nav on KC-97s, he stated we were some miles south of track. He explained consol to me. Then, he told the KC-135 nav of his estimate of position. The nav said, "Right!, Maj". About 30 minutes later, the Santiago VOR showed up 20 degrees left and the formation promptly made a cut at an intercept. Sheepish nav bought a round in Torrejon club that night.
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Young whippersnapper, my foot, Rainboe.
I have actually used pressure pattern nav in a 1649 Connie, trans-Pacific, long ago.
Then it was Bendix (and the occasional Marconi) dopplers in the B707, pre INS, together with the navigator, Loran A...and yes Consol, as this was available on the west coast of the Pacific, stations in Oregon and California, I believe.
And then there were ocean stations, with their big powerful NDB's, the one at 30N140W (half way to HNL) was 1K watts.
At night, this gave a clear signal from PERCH, at 205NM on the LAX 236 radial.
Ah, the good 'ole days...
I have actually used pressure pattern nav in a 1649 Connie, trans-Pacific, long ago.
Then it was Bendix (and the occasional Marconi) dopplers in the B707, pre INS, together with the navigator, Loran A...and yes Consol, as this was available on the west coast of the Pacific, stations in Oregon and California, I believe.
And then there were ocean stations, with their big powerful NDB's, the one at 30N140W (half way to HNL) was 1K watts.
At night, this gave a clear signal from PERCH, at 205NM on the LAX 236 radial.
Ah, the good 'ole days...
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Can anyone remember the Ocean Stations...that is, 'Delta', or 'Charlie', etc? Navigators promised to pass personal messages for operators for a good fix. How many weeks did these people stay out there, stationery, giving fix after fix? How about the olde military ATC callsigns...Fuchu, Elmendorf, Saigon, Loring, McDill, Lajes, etc? How about "Sky King, Sky King, this is Fuchu Fuchu, Break Break"...and then, codes requiring authentication? And...the hope was, no fail-safe message resulted in the 'Pickens ride to Destiny'! Consolan, Loran 'C'; I don't remember 411A's 'A', guess he's that much older, the time when the NAT's went both ways each 12 hours. Times when the nav was, if the Captain was competent, the ACTUAL Commander (They were always the MENSA contingent of the crew anyway). Sam the Whippersnapper
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Ocean stations were Coast Guard cutters which remained on station for six-eight weeks at a time, steamed in a predetermined grid that was reported to the aeroplane for a positive fix, and had NDB's that were very useful.
A lonely job, I would think.
Loran A.
Similar in principle to Loran C, but was a completely manual operation, IE: the operator (pilot or navigator) stared into a CRT, determined a line of position, and plotted it on the Loran chart....and hoped like hell not to have a lane skip.
Come to think of it, the good 'ol days weren't so easy after all....
A lonely job, I would think.
Loran A.
Similar in principle to Loran C, but was a completely manual operation, IE: the operator (pilot or navigator) stared into a CRT, determined a line of position, and plotted it on the Loran chart....and hoped like hell not to have a lane skip.
Come to think of it, the good 'ol days weren't so easy after all....