Delta Hawaiian Routes-how determined?


#1

How are flight plans determined? DL317 seems to be taking the long way today.

Today’s route:
RMBLN2 GAD MEM FSM IRW J6 TCC ACH J231 SJN
J74 LAX C1316 DINTY STEVN BAKON R464 BANDY
R464 BITTA MAGGI3

http://flightaware.com/live/flight/DAL317


#2

DAL511 took a similar path. Routing probably had to do with winds aloft.


#3

DL511
WHWTR5 DEC STL J134 VARNR J134 DRK TNP J10
LAX C1316 DINTY STEVN BAKON R464 BITTA MAGGI3

DL317
RMBLN2 GAD MEM FSM IRW J6 TCC ACH J231 SJN J74
LAX C1316 DINTY STEVN BAKON R464 BANDY R464 BITTA MAGGI3

Why is R464 in the route twice in the 317 plan–error?

DL365
RMBLN2 GAD MEM MLC SPS J166 CME J65 PXR J65 KOFFA J50 YCDIL J74
LAX C1316 DINTY STEVN BAKON R464 BITTA MAGGI3


#4

BANDY is a reporting point along R464, but I’m not sure why one flight plan would mention it when the others don’t. Could just be a personal quirk by whoever filed the plan.


#5

This flight path looks like a normal great circle routing with consideration for winds.


#6

How about tonight’s route?

COKEM2 CARPT BNA FAM ANX MCI LBF CYS J175 LAR
TCH J154 BVL MVA ECA J58 OAK BEBOP R464 BITTA
MAGGI3

http://flightaware.com/live/flight/DAL317

Why are they going over Oakland rather than LAX? Seems like the long way.

Thanks


#7

Go to notams.jcs.mil/ and look for “Pacific Tracks”. That will show you the track in use for crossing the Pacific.

You can also click on “North Atlantic Routes” and see the route to take across the Atlantic.

Usually based on winds. I’m GUESSING a nice tailwind going East and the least headwing going West, but I’m no pilot.


#8

The Oceanic routes always approximate a great circle route and are modified for winds or the avoidance of significant weather.


#9

Now Delta is going over Seattle or Oregon from ATL to HNL.

Adds almost an hour to the flight.


#10

DAL317 (KATL/PHNL) flew over Oregon tonight (2/19). The flight took 8:55 hrs. The shortest flight since 10/20 took 8:43 hrs. It seems to me that it’s hardly adding anything close to an hour to the flight time.

Does anyone have a link to a web site that shows Great Circle routes between any two airports?


#11

tobyz1

I posted my message before the flight ended. The estimated time was 10 hours and the flight has been trending longer the last few days-9:31, 9:20, 9:15, versus the 8:55, 8:50 and faster during early February.

I’ve asked before–please don’t respond to my messages.


#12

“I’ve asked before–please don’t respond to my messages.”

It appears your post was wrong - the exact handle of the person pointing that out should not be a problem.

In any case, the winds over the Pacific the past few days have been blowing from the northeast at 50-70kts over WA/OR and out over the water, so a nice tailwind. The SW US saw 100-140kt winds straight out from the west, so a horrid headwind. I think that explains the slower times and/or reasons for heading north first.


#13

A useful site for calculating distances and great circle routes.

Great Circle Mapper:

http://gc.kls2.com/


#14

Thanks for the Great Circle Mapper site, jphil.

It seems that the Great Circle route KATL/PHNL passes just south of the Great Salt Lake and a bit north of San Francisco. Flight distance is 4275 nm.

The two-segment Great Circle route KATL/KPDX/PHNL, of course, crosses Oregon. Its flight distance is 4353 nm.

The difference between the two routes is just 78 nm. In the absence of wind, at the speed of 485 kts (posted for DAL317), the additional flight time is 9 minutes, 39 seconds. If the more northerly routing avoids a headwind and finds a tailwind, there’s no doubt that that ought to be the way to go.


#15

DL317 on March 20 on FlightAware says 9 hours 3 minutes. I was actually ON that flight. It actually was 10 hours. Why the difference?

RDALE "It appears your post was wrong - the exact handle of the person pointing that out should not be a problem. " Stay out of it; you probably are not aware of the previous problems I had with tobyz1 and you don’t need to be.


#16

It may have accidently been marked as arrived while enroute.


#17

“Stay out of it; you probably are not aware of the previous problems I had with tobyz1 and you don’t need to be”

Then keep it off the public forum. Use a private message.


#18

Great research, tobyz1, but my calculations give slightly different results: KATL-PHNL=3912nm, KATL-KPDX-PHNL=4149nm. Difference of 237nm or 29.3 minutes @ 485 KTAS. (Not sure why I would get a diffferent distance than you using the same GC mapper. Must be continental drift :slight_smile: ) Still, given the possible winds and long distance, this could certainly be the reason for the unusual route. 237 nm is not far out of the way at all when you are travelling 4,000 and even a 25k difference in winds can make a difference of roughly half an hour. Might have also been some other thing there to avoid, like large area of weather, etc.

Computerized flight plan generators are notorious for inconsistencies like this (The same generators responsible for planning trips to PHNL via Oregon.) The desired route is what is described, but the same route can usually be described in many different ways.

Exactly what caused this case is unknown, but it might have been from something like having generated an original plan to join a route at a certain intersection, and then the plan being updated to join at a different point.


#19

In the spirit of reconciliation, I don’t consider there to be a problem between myself and JeffSheets. I’ve not been offended by his postings.

I consider that I am responding to the message and not to the messenger.

Peace to all.


#20

DL317 on March 20 on FlightAware says 9 hours 3 minutes. I was actually ON that flight. It actually was 10 hours. Why the difference?

The 9:03 should be wheels-up to wheels-down. How much taxi time did you have? A combined time of 57 minutes for taxiing to and from the gates doesn’t sound unreasonable to me.