Chris97

665 ground speed possible with the 77W?

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Hello,

I'm actually flying from NZAA (Auckland) to KLAX (Los Angeles) with the 77W in P3DV4. From Waypoint TATAS to SAMAD I saw a crazy high ground speed of 665 knots... Is that possible in reality? Cost index is very high (2500).

Here is a screenshot

2017-7-11_0-23-49-380c9kcr.jpg

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With a strong enough tailwind, of course - any ground speed is possible. In fact, I'd go so far as to say that 665 is relatively tame: I've seen over 700 before in the Jumbo.

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Well judging how you're doing Mach .863 with a 153 knot tail wind I would say yes what you're seeing is possible. By far the highest I've ever seen, I don't think I've ever gotten better than a 109KT tail wind. I was doing 605 over the ground on that flight.

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Sure, if you catch a good jet stream.  I've been in 150kt tailwinds in the sim and across the Pacific in the real world.  Really shaves off the time.  On the other hand, I wouldn't want to be facing those winds on the way back.  Yikes!

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Very nice thanks for your replies :)

If anyone is interested to fly these route (ANZ2) this is my routing:

SATL1Q DABAS DCT TATAS B200 OSUGA DCT 15S162W DCT OTURI DCT 0500S15706W/M083F330 00N154W 05N150W 10N146W 15N142W/M083F350 20N137W 27N130W ROSIN BUFIE4

Actually you can see very high ground speeds between TATAS to DABAS and DABAS to SAMAD. With the PMDG 744 maybe it's possible to try Mach .089 :)

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I flew back and forth from NZAA to Australia yesterday and right now actually and have 168 kt winds from the SW between NZAA and Australia. AS16/77W/P3Dv4/FL340-360

Bill

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You have 153 knots almost directly on the tail of your aircraft - so yes - this is a possibility. More than likely you were inside of a jet core!

 

ITRW - I have personally have 140 on the tail and had a ground speed over 600kts. Just checked my log book and it was a VHHH to CYVR in a 77W in December of 2013 though.  We generally get amazing pushes from Asia to our North American bases in the winter months due to the strong jet stream

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55 minutes ago, warriorpilot said:

There was a 777 from BAW that made news for breaking the speed of sound. It actually reached 745 and crossed JFK to LHR in under 5 hours. Here is the article. 

https://www.rt.com/news/221559-boeing-supersonic-heathrow-airplane/

 That article is pretty bad reporting. A high ground speed doesn't mean it was close to breaking the speed of sound. They were probably still in the high M0.8's as usual, just with a fantastic push.

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16 minutes ago, Dave_YVR said:

 That article is pretty bad reporting. A high ground speed doesn't mean it was close to breaking the speed of sound. They were probably still in the high M0.8's as usual, just with a fantastic push.

Right, but the OP is posting and referencing to his 655 GS. A real 777 at 745 GS is IMO talking about the same thing. GS

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19 minutes ago, Dave_YVR said:

 That article is pretty bad reporting. A high ground speed doesn't mean it was close to breaking the speed of sound. They were probably still in the high M0.8's as usual, just with a fantastic push.

Thanks for sharing, hate to be traveling opposite direction with that headwind, wonder how much extra fuel they allowed for.

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I'm currently flying from YSSY to KLAX in the PMDG 744ER and I'm getting some great tailwinds too, MAX so far has been 127 knots resulting in a  605 GS. My route is quite a bit further west than yours --- I'm currently over TEPEK at FL330:

( FPL-WDL189-IN
-B744/H
-SDE1FGHIJ1RWXYZ/LB1
-YSSY2345
-N0500F310 MARUB6 DCT MARLN DCT NATLI A579 NN B581 BAXIL/N0510F330 B581
 WOOBY/N0508F350 DCT 00N163W 08N155W/N0504F370 17N145W 25N135W/N0496F390
 30N127W DCT ELKEY RYDRR1
-KLAX1253 KSLI
-PBN/A1B1C1D1L1O1S1 NAV/RNVD1E2A1 DOF/170710 REG/N744ER
 EET/YBBB0022 NFFF0132 NZZO0448 KZAK0536
 KZLA1218 RVR/75 PER/E
-E/1554)
       

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This past winter, I had a 200 kt tailwind in the jet stream from Japan to US and I saw 700 kt GS.... of course the airplane only "sees" the airspeed as far as speeds go since we fly in a moving reference frame.

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IDY02740.png

 

It is normal, if the weather engine is applying actual wind. Basically it is like swimming in a river in the direction of the current, if you are swimming at 5 km/hr and the speed of current is 10km/hr, your speed in relation to the shore is 15km/hr (your "ground" speed). 

 

As you can see from the SIGWX chart above, the jet stream over australia and the southern pacific is forecast to reach ~170kts later in the afternoon today. 

 

Like many others who have pointed out above, I personally have experience over 200kts jet stream in the northern pacific (from the north of NAHA extends all the way out to nearly the middle of the pacific ocean) last winter, which makes a flight from HKG to YVR feels a breeze. 

The downside is going west bound from LAX / SFO to HKG will have a longer flight time than JFK to HKG (which goes over the pole and not quite effected by jet streams) and watching the GS showing at ~320-350kts for 15-16hours is not really fun at all.

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15 minutes ago, Driverab330 said:

IDY02740.png

As you can see from the SIGWX chart above, the jet stream over australia and the southern pacific is forecast to reach ~170kts later in the afternoon today. 

Can you tell the forecasted speed from the chart?

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1 hour ago, PMDG777 said:

Can you tell the forecasted speed from the chart?

Yup. The chart of this type is part of the pre-flight weather package for every crew to review before flight (as well as in the cruise for review, particularly on long haul flights). It provides very good information about en-route weather. although nowadays, there is some ipad weather app which provides even more accurate en-route weather forecast than the old SIGWX, it is still gives pilots a good big picture for the flight. 

One full black triangle = 50kts and one dash line = 10kts and half the dash line = 5kts 

On the chart you can see 3 full black triangles with two dash lines following behind that equals to 50 + 50 + 50 + 10 + 10 = 170kts 

 

For those who are interested, here is the reference document talking about the decode of the SIGWX, which used to be one of the ATPL weather course ground school topics, and I think it is still in the syllabus now.

It will probably be obsoleted in 10-15years time just like astro-navigation, when every one is so used to having the "ipad-like" device with the real time weather update capability. 

https://www.icao.int/safety/meteorology/WAFSOPSG/Guidance Material/Representing WAFS SIGWX Data in BUFR - V4 3 Final.pdf

 

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1 minute ago, Driverab330 said:

Yup. The chart of this type is part of the pre-flight weather package for every crew to review before flight. It provides very good information about en-route weather. although nowadays, there some company weather app which provides even more accurate en-route weather forecast than the old SIGWX, it is still gives pilots a good big picture for the flight. 

One full black triangle = 50kts and one dash line = 10kts and half the dash line = 5kts 

On the chart you can see 3 full black triangles with two dash lines following behind that equals to 50 + 50 + 50 + 10 + 10 = 170kts 

 

Awesome thanks!

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Simbrief also has these when you generate a flight plan and when the flight plan is combined with AS16, AS16 emulates these winds perfectly.

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Skyvector can give you this info too, great for adjusting your route for more favorable winds. The shortest route isn't always the best.

nzaa-klax.jpg

 

 

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Just a quick look at reality ... the web page "Ground Speed Records" shows photos of high ground speeds, as submitted by real life pilots.

Currently, the page is under reconstruction, but archive.org still has a fairly recent snapshot archived:

https://web.archive.org/web/20160323234926/http://groundspeedrecords.com/index.php?option=com_content&view=category&layout=blog&id=20&Itemid=1139

And it turns out ... the ground speed record for the 777-300ER (and -200) on this page ist 735 kts. :biggrin: Unfortunately, the image proving the record is temporarily not available (but I have seen it myself earlier, it was definitely there.)

 

p.s. and Edit

Some of the photos are still on the Facebook page. :cool: Just one ... this 777 is doing 495 kts of TAS with a tailwind of 214 kts. Now just add 30 more knots of true airspeed and you'll be doing some 735-740 kts ground speed. Awesome!

 

 

Edited by ps1flyer
real life photo added

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That's mental. Bet that shaves a heap of time off the flight! Anyone remember the SIA A345 flight between WSSS and KEWR, it used to go either West or East depending on what way had the tailwind (normally East)

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... or via the North Pole. :cool:

But that's exactly the point with long haul flight planning ... so often, the prevailing winds determine the route. (e.g. some months ago, when I flew real-life from Europe to Hong Kong, the European part of the route was as far down as Istanbul, but the return leg from Singapore - being 1500 miles south of VHHH - took me 1000 miles further north almost up to Moscow! :blink:)

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Yes each black triangle is 50kts and each line is 10kts.

EDIT: Sorry didn't see the above post mentioning the same, must the time delay it takes to get down under:biggrin:

I flew back from NZQN to YSSY yesterday ITRW as pax on an A320 and we had 100+kts headwinds and rather rough midway across the Tasman.

A friend sent me a flight radar shot last night of an Qantas 737 from YBRM-YSSY doing 632Kts GS!

 

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If you are interested in winds around Australia and Asia, The Bureau of Meteorology has an Aviation section. It provides Warning, Forecasts, charts of Grid Point Winds, SIGWX and Wind and Temperature. It is good for Route Sector Winds between major airports like Sydney and Melbourne too. 

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