Thursday, June 25, 2009

NOTAMs of the Day

This is more of a technical how-the-system-works post, than a funny post about me spilling things on myself while flying. But I did knock the leftover remains of my rootbeer float off the desk while editing it.

When I pulled up my flight planning information today, I decided that some of the NOTAMs from the the Edmonton FIR (Flight Information Region) were interesting enough to talk about. Others were boring unlighted tower and closed heliport NOTAMs. I had to read them, but I deleted them for you.

090172 CZEG EDMONTON FIR
CZEG DUE TO TEMPO TELECOMMUNICATIONS SYSTEMS OUTAGES IN THE
ANCHORAGE FIR, EDMONTON ACC WILL BE UNABLE TO ACCOMMODATE REQUESTS
MADE NORTH OF 70N, FOR ALT TRANSITION ON NW BOUND TRACKS ENTERING
THE ANCHORAGE FIR AND DESTINED FOR DEVID, RAMEL, ORVIT OR NIKIN
TIL 0906300400

According to that, until the end of the month (which often means "indefinitely," as they renew and revise it each month) some northern relay transmitters are out of service so Edmonton won't be able to talk to you north of 70N and west of those intersections. Oh and they have to make sure they pass the blame to Anchorage, so you don't blame them. A polar bear ate the power supply or something. No kidding, it's possible. We've had bears nibble on our equipment. Presumably when they get a shock from it that's when they get mad and destroy it.

090187 CZEG EDMONTON ACC
CZEG PAL 265.6 AT CALGARY U/S TIL 0907020900

That means that a UHF frequency out of service at Calgary. I don't thing they can blame that on the Americans.

090281 CZEG EDMONTON FIR
CZEG DESIGNATED PORTIONS WITHIN CZEG AIRSPACE IS STRUCTURED FOR ONE WAY TFC AS FOLLOWS:
1. FL350 AND FL390 ARE STRUCTURED AND AVBL AS WESTBOUND
CRUISING FLT LEVELS BTN 1300/2300 DLY (DST:1200/2200 UTC), WITHIN AN AREA BOUNDED BY A LINE BEGINNING AT DOGGY TO 701520N 12000W TO 6540N 12000W TO 6400N 11700W TO 591133N 992227W THENCE COUNTER CLOCKWISE ALONG THE CTA BOUNDARY TO THE POINT OF BEGINNING.
2. FL310 IS STRUCTURED AND AVBL AS WESTBOUND CRUISING FLT LEVEL BTN 1300/2300 DLY (DST:1200/2200 UTC), WITHIN AN AREA BOUNDED BY A LINE BEGINNING AT 623600N 8500W TO 760131N 8500W TO 701520N 12000W TO 6540N 12000W TO 6400N 11700W TO 591133N 992227W TO 621625N 9000W TO THE POINT OF BEGINNING.
TIL APRX 0907312359

There are default altitudes of flight for traffic going in different directions, just as there are default lanes in the road, but NOTAMs can change that. In this case they are putting extra westbound lanes in to accommodate the rush hour traffic coming in from Europe. You might notice that the extra flight levels are available for westbound traffic between 1300 and 2300 daily, that's Zulu time of course, so you might be taken aback by the (DST:1200/2200 UTC). UTC doesn't have daylight savings time. But the world does, and the westbound tracks are to accommodate the world's needs. Right now the NOTAM only goes to the end of July, but the NOTAM could have started or could extend into the winter. This wording makes sure that it always refers to the hours of 4 a.m. to 2 p.m. Alaska time. That's when the flights that will be landing in North America during reasonable hours are coming through the north.

090288 CZEG EDMONTON FIR
CZEG LO2: PANEL F: V317 BETWEEN FARNS AND HOWZR NOT AUTH TIL APRX 0907291800

090294 CZEG EDMONTON FIR
CZEG LO1 CHART V306 BTN YPE AND YZU MEA 9000 VICE 8000 WITH A 13 NM GAP ABOUT THE MID-POINT TIL APRX 0907301800

090295 CZEG EDMONTON FIR
CZEG HIGH ALTITUDE ENROUTE CHART 2 AND 3: J486 FM YEG TO YSM NOT AUTH TIL APRX 0907301800
090301 CZEG EDMONTON FIR
CZEG V325 BTN YPE AND YMM: MEA GAP TO READ 17NM VICE 13NM TIL APRX 0907301800 090302 CZEG EDMONTON FIR
CZEG J528 BTN YPE AND YSM MEA 24000 VICE 22000 MEA GAP 25 NM APRX MID POINT TIL APRX 0907301800 090303 CZEG EDMONTON FIR
CZEG LO1 CHART: V21 BTN YMM AND YSM: MEA GAP TO READ 15 NM VICE 8 NM TIL APRX 0907301800

There were a whole raft of NOTAMS similar to these. I didn't pull them all out. V21, J528 and V325 are airways, defined by a series of VORs and other waypoints. The MEA is the minimum enroute altitude to receive the nav aids properly, determined by a combination of terrain (reception is line of sight) and distance (the signals attenuate with an inverse square law). So how are a number of VORs temporarily worse until the end of July? I don't know what's going on here.

I noticed that the FSS here doesn't use HJ/HN but has reverted to the old SR/SS for "from sunrise to sunset" as in "ALL ACFT TO REMAIN CLR SR/SS DLY". But come to think about it, SR/SS and HN/HJ should be the same thing. Especially here, la nuit ends well before the sunrise and le jour begins well after the sunset. They're allowed to use either abbreviation.

Oh and if this is an unreadable mess, I apologize. I did put line breaks in it, but Blogger has been ignoring the br tag sometimes lately.

10 comments:

Anonymous said...

Don't be silly someone always seems to find a way to blame it on us Americans. :)

Aviatrix said...

I didn't ask about the calories, just what was the difference between the two. And it wasn't so much a root beer float as half a small pop with a chunk of simulated ice cream in it. The other half I abandoned on the desk and later fed to the carpet. But I suppose that contributed to the longevity of the meal.

Sarah said...

'Trix comment above is a response to dpierce on the previous blog entry. Don't be confused like I was.

Oh and if this is an unreadable mess, I apologize.

What?? O RLY? SRSLY? NOTAMs are supposed to be an unreadable mess. ( Oh. No - your post was fine. ) They're worse than METAR/TAFs because the acronyms are from a larger set and novel by definition. US FAA Notam list

We're supposed to read a long long list of "unlighted obstruction 250' AGL" and pull out the significant ones. Instrument procedures change & minima go up & VORs go up and down & NDBs go up & down ( no, NDBs just go down ) ....

But the fun ones are the odd ones. High altitude amateur rocket launches. Free balloon launches. Airborne trailing wires ( ? ) Mysterious predicted GPS outages over huge anonymous antenna farms. And.. watch out!

!FDC 9/1329 ZME .. SPECIAL NOTICE.. 1300-2100 UTC DLY, EFFECTIVE FROM 0906011300 UTC UNTIL 0906292100 UTC, AIRBORNE LASER OPERATIONS WILL BE CONDUCTED WITHIN 200 NM RADIUS OF 352130N/0973636W OR THE IRW VORTAC,
FROM FL180 TO FL280. THE LASER BEAM MAY BE INJURIOUS TO PILOTS/AIRCREWS AND PASSENGERS EYES FOR A DISTANCE
OF 6000 FEET DIRECTLY BELOW THE AIRCRAFT, NOT EXTENDING BELOW FL180. THIS AREA WILL BE MONITORED BY OBSERVERS AND THE LASER BEAM WILL BE TERMINATED IF NON-PARTICIPATING AIRCRAFT ARE DETECTED THAT MAY ENTER THE AFFECTED AREA. OTHER VISUAL EFFECTS E.G. FLASH BLINDNESS, AFTER IMAGE, GLARE, AND DISTRACTION MAY OCCUR AT GREATER DISTANCES.

Julien said...

I love the way abbreviations in NOTAMs and METARs are a mix of French and English. I can perfectly picture the committee discussion where this kind of trading game is played: we give you smoke and we keep rain. You can have thunderstorms if we have hail. And so on. Examples:

FU - Smoke (Fumée)
GR - Hail (Grêle)
BR - Mist (Brume)

There's a whole list here.

My favorite is UTC. Not Universal Coordinated Time (which would be UCT). Not Temps Universel Coordonné (which would be TUC). A middle-of-the-road mix of the two which, to my knowledge, does not map to anything.

Anonymous said...

My understanding is that UTC stands for "Universal Time, Coordinated".

Marty

Aviatrix said...

Marty, while reversing the words is a fine way to remember what UTC means, it really is Co-ordinated Universal Time, in that order.

I like Julien's image of a negotiation.

Oh and thanks for the redirect, Sarah. This was initially one post and then I decided it should be two.

Frank Van Haste said...

Dear Trix:

Quoth thee: "So how are a number of VORs temporarily worse until the end of July?"

Solar weather?

Frank

Wayne Conrad said...

Frank, The sun is as quiet as it's ever been during our lifetime.

Ed said...

I like Julien's image of a negotiation.

It was: it is an explicitly negotiated compromise between abbreviations of the English (Coordinated Universal Time) and French (Temps Universel Coordonné) names. However, it also fits into the pattern of the names of other UT related timescales like UT0, UT1 and UT2.

Andrew said...

To Frank and Trix:

Quoth thee: "So how are a number of VORs temporarily worse until the end of July?"

Also...how about, substitute transmitter/antenna gear with lower effective power? Perhaps due to maintenance of primary transmitter/antenna gear?