Chuck Dreier

PMDG 777-200LR range????

11 posts in this topic

Delta flies the 77L from KATL-FAOR (JNB) and return with a typical flight time of 15+ hours and a distance of approximately 8450 miles. I'm assuming the typical real-life payload is close to normal. Obviously this is a routine flight. But this is where I'm confused - doesn't a trip of this length place the aircraft close to operational limits in terms of fuel, weight, etc.?  Specifically, when using the PMDG 777-200LR, I can't get a flight plan to work in PFPX.   No matter what, the range/fuel is exceeded.  I'd appreciate it if someone could help me out with this.

One more thing.  I wonder why PMDG set the maximum passenger load at a rather paultry 234 persons?  Delta's 77L for instance, is configured with 291 seats.

 

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First try B343 operations in PFPX.  We redispatch our long haul flights to readjust the reserve fuel needed at our destination.  So don't do US Flag fuel requirements.  

Select B343 and then select re redispatch airport about 2 hours from the destination with a redispatch point maybe at a 45* offset to the redispatch airport.  See what that gives you for required Block Fuel.

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3 hours ago, Chuck Dreier said:

No matter what, the range/fuel is exceeded.

Reduce your payload by about 10000 to 15000 lbs. I have done FAOR-KATL several times using U.S. Flag Jet Fuel Policy several times and this is what I have done.

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I've also done the DAL trip to FAOR several times with the B77L.  I agree with Brian, always try to use redispatch on these long flights otherwise the reserves penalty is punitive.

I'm waiting for NMG to update FAOR for P3Dv4.  Has that happened?

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When I get time.  Probably tomorrow morning I'll plan two flights showing the savings utilizing Flag vs B343.

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I've crossed the Pacific several times in the real world CYVR Vancouver to YSSY Sydney in an Air Canada 772LR. Don't know the distance but its 15 hours.

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Ok so this fuel burn is from a 747 plan (KSEA-VHHH) I just made just to show a comparison of US Flag vs B343.  I tried todo the 777 but something seems corrupt on my 777 climb profiles in the template.  So I'll have to redo it or something.  Anyways.  Both are set to Max Available Payload, Opt Cruise Alt with 2,000ft Steps on an economic CI of 60 and no weather.  Weights are in Kilos.

US Flag   MinFuel is 154341kg (14.01 hrs endurance) with a Payload of 63403kg!  Trip fuel is 136788kg(12.03hrs).  That brings FAR Reserve of 3934kg and 10% Flag reserve of 10977(1.33hrs).

B343   MinFuel is 140557kg (12.54 hrs endurance) with a Payload of 67319kg(Limited by Landing weight)  Trip fuel is 133407kg(12.04hrs  -- Notice the time comparison.  Its the same but less fuel.  Carrying the flag fuel cost over 3000kgs).  That brings FAR Reserve of 3847kg and 10% Flag reserve of 701(0.05hrs).

You could plan this better.  I just kinda slapped it together.  I've seen our dispatchers gain us something like 15k kgs of Payload on a flight not to long ago.  The only reason there wasn't a significant jump in Payload was because of a landing weight limit.  Probably Taipei...idk didn't really feel like digging into it to try and find the weak link.  I think its the Pax bird profile vs the Freighter.  Freighter has anywhere between 18-35k kgs more landing weight than the Pax plane.  That would have turned the payload up to the 90k kg mark for B343.

Anyways hopes this makes sense and convinces some of you guys to start utilizing PFPX to it maximum...it might just get you those extra minutes or range your looking for.

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Thanks for bringing this up Brian.  I've seen mention of the B343 policy in the PFPX forum but I was digging for something else at the time and forgot about it.  I just downloaded and reviewed the FAA policy notice and note that it applies to Part 121 only (is GTI a 121 or 135 operator?), and requires that the company conduct one of two methods of statistical analysis on the fuel burn for a specific route.  The company is also required to report the performance of flights using this policy and maintain redundant means of communicating with the crew.  All of this is very interesting but of little concern to a simulator pilot but I think it is worthwhile to understand how B343 is more restrictive.

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1 hour ago, downscc said:

I just downloaded and reviewed the FAA policy notice and note that it applies to Part 121 only (is GTI a 121 or 135 operator?), and requires that the company conduct one of two methods of statistical analysis on the fuel burn for a specific route. 

Atlas is at this point I'm pretty sure the largest 747 operator in the world.  Thats not even including our 767 flight which is exploding and probably inside the year adding 777 and 737 when Southern merges into our certificate.  There is no way we could be a 135 operator.  If your flying anything bigger than a Saab you wouldn't be a 135 operator really.   But in regards to the statistical analysis...I'm flight crew.  What they do with numbers are not my concern.

The company is also required to report the performance of flights using this policy and maintain redundant means of communicating with the crew. 

As you pointed out.  This is of little concern to a pilot.  What the company is required to tell the feds, I don't care.  I show up and do my job...this is not my job. :cool:

All of this is very interesting but of little concern to a simulator pilot but I think it is worthwhile to understand how B343 is more restrictive.

I wouldn't say its more "restrictive".  I would say the only point of concern (flight simulator wise) is making your redispatch point with the Min Fuel. 

While someone could just load up 100% fuel then payload to Max Gross or whatever to make Max Landing weight it would be HIGHLY unrealistic.  I keep hearing people claim they only like to fly real flights but I wonder how many actually do it with an accurate fuel and payload lay out.  Planes are flown with the minimum fuel required.  B343 allows for the minimum fuel required and thus realistically.  If you leave with 100% fuel you might be landing without even being tank/eng which again isn't realistic.

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FSX 744F GE. Flight from KSKA ( Fairchild AFB) to RKSO (Osan AFB) using B343 as fuel policy and auto re-dispatch per PFPX. Re-dispatch airport was RJCW which is the northern most airport in Japan. Release fuel was 248980 lbs.

Once I completed this flight I ran PFPX again using same route but U. S. Flag Jet fuel policy. Obviouly the weather was different. First flight had an average TL wind of 11 knots and second plan had an average HD wind of 1 knot. Release fuel was 283507. B343 plus auto-redispatch saved 34527 lbs of fuel being carried.

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