Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Headwinds Question  
User currently offlineFCA787 From United Kingdom, joined Sep 2006, 19 posts, RR: 0
Posted (7 years 8 months 2 weeks 3 hours ago) and read 5864 times:

Hi

I have a question about headwinds.

I have been a flight from JFK-LHR a few months ago and it took approx 8hr30mins as their as alot of headwinds the captain said, but I also have done this flight about 2 yrs ago and it took just over 6hrs?.

Has anyone ever been on a flight that has had to put down and refuel because of headwinds?

How long could headwinds potentially prolong a flight by?

Is their a specific flight that is operated regular that you know has to put down regular because of hadwinds?

Do headwinds vary from times or the year? Is their a particular bad time for them?

Cheers

19 replies: All unread, jump to last
 
User currently offlineFlyboy2001 From Canada, joined May 2005, 186 posts, RR: 0
Reply 1, posted (7 years 8 months 2 weeks 2 hours ago) and read 5845 times:

Well, as a private pilot, I don't deal with those kinds of extremes but my understanding is this... certain routes will nearly always encounter strong headwinds in one direction and a tailwind in the other. Crossing the Atlantic means dealing with the Jetstream but, depending where the Jetstream is flowing that week, one may encounter more or less of it. Flightplans will be made to take advantage of a strong tailwind or avoid a vicious headwind. However, at some point during the year, it is conceiveable that you could find a flight which can't avoid a trans-oceanic track with bad headwinds because of distance/fuel considerations or ETOPS rectrictions.

I've never heard of a flight that had to put down and refuel due to enroute headwinds, most likely because the winds aloft are pretty well predicted and airlines will route their planes around the winds or fuel them for a longer time in the air.

If the flight is long enough, a 100kt headwind can add quite a bit of time to your flight. A simplified example: If your 500kt jet hits a 100kt headwind, the effective forward progress is at 400 kts. Carry that forward, say... 10 hours and you've gone 4000 nm, when you wanted to have done 5000. That's an extra 2.5 hours still to go.

That said, I have never been on any flight that varied as much as your 6 hour vs. 8.5 hour journey!

Hope this helps!  Smile



And you... Revolution, or just resistance?
User currently offlineGoldenshield From United States of America, joined Jan 2001, 5970 posts, RR: 14
Reply 2, posted (7 years 8 months 2 weeks 2 hours ago) and read 5836 times:

Quoting Flyboy2001 (Reply 1):
I've never heard of a flight that had to put down and refuel due to enroute headwinds, most likely because the winds aloft are pretty well predicted and airlines will route their planes around the winds or fuel them for a longer time in the air.

There are times when an enroute diversion is needed when, in the opinion of the PIC or dispatcher, the flight cannot be completed with the fuel remaining. The chance of this happening is pretty rare, but it does happen, and he may, or may not, be correct.

Also, here in the U.S., winds aloft are published twice a day, so when a flight is planned and departs when another chart is due out, planned and actual can very well vary signifigantly.

Quoting Flyboy2001 (Reply 1):
However, at some point during the year, it is conceiveable that you could find a flight which can't avoid a trans-oceanic track with bad headwinds because of distance/fuel considerations or ETOPS rectrictions.

There are times when you just have to suck it up and fight the wind. Case in point, last month, the jet stream pretty much spread itself out over the eastern half of the U.S. There was no avoiding from Atlanta to Maine.

Quoting FCA787 (Thread starter):
Do headwinds vary from times or the year? Is their a particular bad time for them?

In the summer, the jet stream tends to hang out closer to the poles, rarely venturing south (or north, in the Southern hemisphere.) In the winter, the cooler air brings the jetstream out to play for the winter causing all kinds of problems, like bad winds, and CAT, among other things.

Quoting FCA787 (Thread starter):
Is their a specific flight that is operated regular that you know has to put down regular because of hadwinds?

While no airline wants to have a fuel stop, there are times when one may be called for. If the winds are bad enough on a certain route, and the fuel required to depart is greater than the tanks can hold, there is most definately going to be a fuel stop.

[Edited 2006-11-12 11:51:19]


Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
User currently offlineFlyboy2001 From Canada, joined May 2005, 186 posts, RR: 0
Reply 3, posted (7 years 8 months 2 weeks 1 hour ago) and read 5803 times:

Quoting Goldenshield (Reply 2):
There are times when an enroute diversion is needed when, in the opinion of the PIC or dispatcher, the flight cannot be completed with the fuel remaining.

Well how 'bout that... Nice to get a Dispatch POV. How frequent (or infrequent) are these instances?



And you... Revolution, or just resistance?
User currently offlineGoldenshield From United States of America, joined Jan 2001, 5970 posts, RR: 14
Reply 4, posted (7 years 8 months 2 weeks 1 hour ago) and read 5788 times:

Quoting Flyboy2001 (Reply 3):
How frequent (or infrequent) are these instances?

There are too many variables to give an accurate number, but you are looking in the range of 1:500,000+ for unplanned fuel diversions in a commercial operation.



Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 5, posted (7 years 8 months 1 week 6 days 20 hours ago) and read 5702 times:

Quoting FCA787 (Thread starter):
Do headwinds vary from times or the year? Is their a particular bad time for them?

To illustrate what Goldenshield mentioned, here's a prog chart for later today.

As you can see, the heavy green lines indicate the location and orientation of the jetstream winds, and for this specific chart time of 00Z, and where they're anticipated to be at that time. The jetstream is constantly in motion, and the location and orientations change. Two days from now, the jetstream could be blowing on a straight line from LAX-JFK, or oriented some other way.

The green triangle barbs are 50 knots of speed, and the green lines are 10 knots, so if you had 2 triangles and 2 lines, that speed would be 120 knots. The yellow dashed lines indicate areas of turbulence, which we dispatchers seek to avoid, or plan the the flights to stay under.

http://i34.photobucket.com/albums/d143/OPNLguy/HISIGPROG.jpg


User currently offlineFuturecaptain From , joined Dec 1969, posts, RR:
Reply 6, posted (7 years 8 months 1 week 6 days 19 hours ago) and read 5682 times:

So, it looks like a flight from JFK-LHR today could have anywhere from 120-150 knots of tailwind today.
The flights going in the opposite direction will be fighting this same wind. Ouch.

[Edited 2006-11-12 18:16:47]

User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 7, posted (7 years 8 months 1 week 6 days 19 hours ago) and read 5659 times:

Quoting Futurecaptain (Reply 6):
The flights going in the opposite direction will be fighting this same wind. Ouch.

Not necessarily. If they flew that exact opposite direction, sure, but westbound flights are normally planned on routes that take them out of the jetstream as much as possible so they'll save time/fuel...


User currently offlineNcfc99 From United Kingdom, joined May 2005, 738 posts, RR: 0
Reply 8, posted (7 years 8 months 1 week 6 days 17 hours ago) and read 5614 times:

A couple of years ago I flew LGW-SFB. Outbound was 9.5 hours due to weather, northerly routing over southern greenland and down the east coast. Inbound the arriving flight was late, bad weather over the Atlantic again but the captain needed to make up time so we went straight through the weather and encountered bad turbulance. 7 hours to get home. Not nessissarily due to headwinds but a 2.5 hour flight difference due to weather.

User currently offlineTristarSteve From Sweden, joined Nov 2005, 3976 posts, RR: 34
Reply 9, posted (7 years 8 months 1 week 6 days 17 hours ago) and read 5602 times:

Quoting OPNLguy (Reply 7):
Not necessarily. If they flew that exact opposite direction, sure, but westbound flights are normally planned on routes that take them out of the jetstream as much as possible so they'll save time/fuel...

Briefly the North Atlantic tracks are set twice a day. Early morning for Westbound and late afternoon for Eastbound. Specific airlines' flight planning offices calculate the best track for the day, and the Atlantic controllers work out a mean, and then publish the five tracks for the day. Eastbound flights look for the best tailwinds, and Westbound flights look for the smallest headwinds. The Eastbound and Westbound tracks will be hundreds of miles apart.
I am not invloved because the transatlantic track from ARN is North of the tracks and joins them usually over Canada.


User currently offlinePPVRA From Brazil, joined Nov 2004, 8941 posts, RR: 40
Reply 10, posted (7 years 8 months 1 week 6 days 17 hours ago) and read 5596 times:

I've heard that sometimes AR aircraft flying MAD-EZE have to stop at GRU for refuelling due to headwinds. I don't think it hapens very often, however.


"If goods do not cross borders, soldiers will" - Frederic Bastiat
User currently offlineRalgha From United States of America, joined Nov 1999, 1614 posts, RR: 6
Reply 11, posted (7 years 8 months 1 week 6 days 15 hours ago) and read 5523 times:

Quoting Goldenshield (Reply 2):
Also, here in the U.S., winds aloft are published twice a day, so when a flight is planned and departs when another chart is due out, planned and actual can very well vary signifigantly.

The winds aloft forecasts are usually way off. They get the general direction right, but the speed varies widely.



09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
User currently offlineChksix From Sweden, joined Sep 2005, 345 posts, RR: 4
Reply 12, posted (7 years 8 months 1 week 6 days 15 hours ago) and read 5506 times:

Quoting OPNLguy (Reply 5):
o illustrate what Goldenshield mentioned, here's a prog chart for later today.

Would such a map be available online?
I'd like to plan my "virtual" flights better but have not been able to find jetstream info anywhere.



The conveyor belt plane will fly
User currently offlineRalgha From United States of America, joined Nov 1999, 1614 posts, RR: 6
Reply 13, posted (7 years 8 months 1 week 6 days 12 hours ago) and read 5465 times:

http://adds.aviationweather.gov


09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 14, posted (7 years 8 months 1 week 6 days 10 hours ago) and read 5445 times:

Quoting Ralgha (Reply 13):
http://adds.aviationweather.gov

...and click the tab for "Prog Charts"

...and on the right side, click on "Hi Level"

...and go down to "Mercator" and mouse-over the area you want to cover...


User currently offlineChksix From Sweden, joined Sep 2005, 345 posts, RR: 4
Reply 15, posted (7 years 8 months 1 week 6 days 5 hours ago) and read 5405 times:

Thanks!  Smile
That was the page I had missed. Didn't think global data was available there.

A followup question: The jetstreams are labeled with a FL, the question I have is how close to that FL do I have to fly to use the jetstream? If I fly higher, at what level will I leave the jetstream?

In short, how "thick/deep" are the jetstreams?



The conveyor belt plane will fly
User currently offlineGoldenshield From United States of America, joined Jan 2001, 5970 posts, RR: 14
Reply 16, posted (7 years 8 months 1 week 5 days 8 hours ago) and read 5318 times:

Quoting Ralgha (Reply 11):
The winds aloft forecasts are usually way off. They get the general direction right, but the speed varies widely.

And yet, you'd be surprised at just how accurate flight plans made from them can be.

Quoting Chksix (Reply 15):
A followup question: The jetstreams are labeled with a FL, the question I have is how close to that FL do I have to fly to use the jetstream? If I fly higher, at what level will I leave the jetstream?

The green lines on the charts just show the centerline of a projected path of the jetstream. They can in fact be hundreds of miles wide and thousands of feet deep.



Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 17, posted (7 years 8 months 1 week 5 days ago) and read 5273 times:

Quoting Chksix (Reply 15):
In short, how "thick/deep" are the jetstreams?

In my experience, flight planning at FL220, FL240, or FL260 usually gets you under the core of the strongest winds....


User currently offlineBond007 From United States of America, joined Mar 2005, 5395 posts, RR: 8
Reply 18, posted (7 years 8 months 1 week 4 days 23 hours ago) and read 5257 times:

Quoting Goldenshield (Reply 2):
There are times when an enroute diversion is needed when, in the opinion of the PIC or dispatcher, the flight cannot be completed with the fuel remaining. The chance of this happening is pretty rare, but it does happen, and he may, or may not, be correct.

Although a month or two ago, there was a whole bunch of East Coast - West Coast flights over a period of a few days, that had to stop for fuel somewhere on the way. The winds were extremely strong. I seem to remember a few airports getting some unusual visitors!


Jimbo



I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
User currently offlineChksix From Sweden, joined Sep 2005, 345 posts, RR: 4
Reply 19, posted (7 years 8 months 1 week 4 days 20 hours ago) and read 5238 times:

Thanks Goldenshield and OPNLguy  Smile

It'll make the virtual flights a bit more realistic...



The conveyor belt plane will fly
Top Of Page
Forum Index

Reply To This Topic Headwinds Question
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
B767-200 Fuel Consumption Question posted Sun Nov 12 2006 07:06:31 by Jetline
Concorde Gear Question posted Tue Nov 7 2006 18:38:10 by EHHO
Lockheed L-2000 Question posted Sat Nov 4 2006 00:06:17 by Blackbird
SXM Runway Length Question... posted Fri Nov 3 2006 19:51:57 by T7ILS13LatJFK
NonEngineer's Question About Fuel In Ceiling posted Thu Nov 2 2006 18:32:01 by SpeckSpot
Embraer Question posted Sun Oct 29 2006 09:00:35 by Flametech21
US Cabin Crew Question posted Tue Oct 24 2006 10:22:52 by Icelandair
B767 Cargo Hold Question posted Mon Oct 23 2006 09:34:54 by Don
Question For Those That Have Heard Sonic Booms posted Mon Oct 23 2006 04:09:55 by FLY2HMO
ILS Question posted Sun Oct 22 2006 02:46:43 by AirWillie6475
JFK Parallel ILS Approach Question. posted Fri Mar 2 2012 13:23:53 by aquablue
Question On SAS 737NG Delivery Flights posted Wed Feb 29 2012 23:24:03 by uhntissbaby111
IRS Alignment Question posted Mon Feb 27 2012 07:46:26 by SAAFNAV
B737NG Etops Question posted Sat Feb 25 2012 20:29:01 by divemaster08
Fuel Calculation Question Help posted Mon Feb 13 2012 18:29:56 by greenair727
C-47 Fuel System Question posted Sun Feb 5 2012 17:21:02 by L-188
Airbus Engine Pylon Question posted Fri Feb 3 2012 16:55:48 by risingsunfitnes
Noob Question: Rudder Use In Flight posted Sun Jan 29 2012 17:02:29 by bristolflyer
Q400 SPU Question. posted Thu Jan 12 2012 14:16:41 by avt007

Sponsor Message:
Printer friendly format