Major Pilots: Oceanic Plots
- Thread starter dasleben
- Start date
We still plot but we don't do post position plots.
We only plot thinks like CRONO 5050N 5040N, ETP's and mid-ocean alternates.
You know, the only use I see for even plotting it is knowing which OCA you're in, but since we no longer do post position plots, even doing it in the first place is largely useless and a waste of effort.
We only plot thinks like CRONO 5050N 5040N, ETP's and mid-ocean alternates.
You know, the only use I see for even plotting it is knowing which OCA you're in, but since we no longer do post position plots, even doing it in the first place is largely useless and a waste of effort.
dasleben
That's just, like, your opinion, man
Cool! Thanks for the info. According to some guys I fly with, you guys do nothing but eat prime rib all the way across, all the while trying not to drip tea with pinky-extended on your Gucci loafers. Just wanted to set the record straight. 
I agree about the plots, by the way. I can see it in the non-GPS aircraft, but GPS-equipped, well, if my plot is off the line it's probably because I did it wrong. Not to say that track busts are a laughing matter, but I figure after we've verified the track message, the next fix name, checked the oceanic waypoint coordinates in the nav data, then cross-checked the track/distance with the flightplan, we're probably fine. I feel like we're piloting a steamboat across the ocean in 1905 some days. But hey, I just work here.
I agree about the plots, by the way. I can see it in the non-GPS aircraft, but GPS-equipped, well, if my plot is off the line it's probably because I did it wrong. Not to say that track busts are a laughing matter, but I figure after we've verified the track message, the next fix name, checked the oceanic waypoint coordinates in the nav data, then cross-checked the track/distance with the flightplan, we're probably fine.
I feel like we're piloting a steamboat across the ocean in 1905 some days. But hey, I just work here.
C150J
Well-Known Member
I'm also interested in answers to Dasleben's question and what the FAA finds acceptable when it comes to "plotting procedures:"
49. PLOTTING AND SYSTEMATIC CROSS-CHECKING OF NAVIGATION INFORMATION. During all phases of flight in Class II navigation the standardized application of disciplined, systematic cross-checking of navigation information shall be required in each operator’s long-range navigation program. Advisory Circular 91-70, as amended, provides amplification of these procedures.
A. Plotting procedures have had a significant impact on the reduction of gross navigational errors. There is a requirement to plot the route of flight on a plotting chart and to plot the computer position, approximately 10 minutes after waypoint passage. Plotting may or may not be required, depending upon the distance between the standard ICAO ground-based NAVAIDs.
(1) Plotting procedures are REQUIRED for all turbojet operations where the route segment between the operational service volume of ICAO standard ground-based navigational aids exceeds 725 nm.
- http://rgl.faa.gov/regulatory_and_guidance_library/rgorders.nsf/0/569707afb7dfd3218625724b00681e57/$FILE/N8000_340.pdf
How many LRNSs do you guys have? We have five, but I'm new the plane and don't know if that's Gulfstream overkill or the norm.
49. PLOTTING AND SYSTEMATIC CROSS-CHECKING OF NAVIGATION INFORMATION. During all phases of flight in Class II navigation the standardized application of disciplined, systematic cross-checking of navigation information shall be required in each operator’s long-range navigation program. Advisory Circular 91-70, as amended, provides amplification of these procedures.
A. Plotting procedures have had a significant impact on the reduction of gross navigational errors. There is a requirement to plot the route of flight on a plotting chart and to plot the computer position, approximately 10 minutes after waypoint passage. Plotting may or may not be required, depending upon the distance between the standard ICAO ground-based NAVAIDs.
(1) Plotting procedures are REQUIRED for all turbojet operations where the route segment between the operational service volume of ICAO standard ground-based navigational aids exceeds 725 nm.
- http://rgl.faa.gov/regulatory_and_guidance_library/rgorders.nsf/0/569707afb7dfd3218625724b00681e57/$FILE/N8000_340.pdf
How many LRNSs do you guys have? We have five, but I'm new the plane and don't know if that's Gulfstream overkill or the norm.
DE727UPS
Well-Known Member
If your talking about plotting inflight (I guess I call it plotting), we plot our lat log at each madatory reporting point while within the etops 90 min area of operations to verify that the magenta line is in the right place. As far as pre-flight plotting, we only do the ETP and EEP as the madatory reporting points are already charted. I only do Pac Rim stuff, so I'm not sure what Atlantic stuff is like. Also, we have GPS updating with our FMC's. No CPDLC yet but they say it's coming....
dasleben
That's just, like, your opinion, man
Three IRUs with GPS updating (VOR/DME or DME/DME if in Class I without the GPS). What exactly constitutes 5 systems on yours? That seems like a lot!
Sounds pretty much identical to us, then. When you say you plot lat/long at each point, is that the post-fix (10-minute) plot?
Dugie8
Well-Known Member
I always plotted, even with dual FMS and indapendent entry of the flight plan on each unit. Sometimes the aviation gods didn't receive their sacrifice of back packs and ipods and things go awry. I simply would plot out where I should be in 10 minutes or so after a fix, then at the allotted time would cross check the LAT/LON I came up with vs the LAT/LON the GPS/FMS/IRU/Sextant showed.
Works great, last long time, kept me doing something on those long legs over shark/iceberg/pirate/pirahna/etc infested waters.
Works great, last long time, kept me doing something on those long legs over shark/iceberg/pirate/pirahna/etc infested waters.
C150J
Well-Known Member
So are you dissing my methods of entertaining myself when I'm out of reading material? Oh it's on... It's ON, son.
dasleben
That's just, like, your opinion, man
Nope, but not all of our planes have GPS. I was over Bulgaria one day and our FMC position updating got some bad info from some eastern bloc VOR. Caused a map shift of about 5 miles. Nothing like cruising along fat, dumb and happy and suddenly the airplane starts turning. Wheeeeeeere yaaaaa gooooooin'?
Doug: Plotting sea serpent sightings may be an effective use for the plotting chart.
pericynthion
Well-Known Member
Can someone explain to the uninitiated what exactly a post position plot is, and what it accomplishes?
dasleben
That's just, like, your opinion, man
10 minutes after you cross an oceanic waypoint (such as 55N 030W), you take the lat/long the aircraft thinks it's at, and you plot that position on your chart. You do this to make sure that where the airplane thinks it is coincides with where it actually should be (i.e., your plotted position is on the course line you drew before you coasted out). This is a very good idea if your sole navigation sources are based on inertial reference (IRUs), but with GPS-equipped airplanes it's borderline unnecessary.
Well if you're not where you should be, the PPP is a certain way of verifying it.
pericynthion
Well-Known Member
Thanks - I understand the first part, but not the second (blue). It seems that this does nothing to detect errors in the navigation system (i.e. the aircraft not being where it thinks it's at), but rather it's helpful to see if the route that the FMS is following differs from the route you had planned on paper (e.g. due to a misentered waypoint). As such, why is it less necessary to do these checks when you have a very accurate navigation source such as GPS? The check wouldn't reveal IRU problems in the first place.
Polar742
All the responsibility none of the authority
There can be any number of errors introduced into the system in multiple ways.
It could be a straight GIGO (you're filed A - B - C, got rerouted A-D-E, entered A - D - C).
It could be that the NAVs aren't updating properly, in that case you get the INS drift and the airplane ACTUALLY isn't where it should be since the INS's mix a position for the ship's position, and if one is particularly bad, you might not be where you wanna be on the course line.
The Airplane might be in the wrong Navigation mode ("oh, just cut 15 right and we'll steer it back on course, then back to LNAV")
...and for the non-GPS pilots, the plane could do the "crazy Ivan" (He's going to turn RIGHT at the bottom of the hour!) when you get a VOR/DME update (Shemya anyone?)
Or, the VOR/DME update could be put out, but it's not correct.
Dugie8
Well-Known Member
So are you dissing my methods of entertaining myself when I'm out of reading material? Oh it's on... It's ON, son.
View attachment 17517
I can't draw stick people, they end up looking like circles and my circles look like straight lines, never could reverse the two??
I would pick random units of measurement and convert my times or fuel to some obscure thing. Temps in kelvin always got a raised eyebrow.
