Empty weight seems incorrect

[Mark.Gibbons7 1]

Hi,

This may be a very quick and simple question for you all.

I went digging with regards to weights so I could set up SimBrief correctly.  I found the Empty Weight for the 777 to be 344,224 pounds (From the Aircraft.cfg, couldn't find it in the FCOM.) I've never been able to get my ZFW to align with my VAs estimate, and after finding this, I've realised why. Because my empty weight is heavier than their ZFW.

I looked here for a reference: http://www.boeing.com/assets/pdf/commercial/airports/acaps/777_2lr3er.pdf

It states that the empty weight for a Boeing 777-200LR is 320,000. Now this weight would allow me to use the suggested ZFW for my VAs flights and makes sense, so I'm starting to think the Empty Weight for the 777 is incorrect.

So my question is, is the Empty Weight in the .cfg correct and if so, why is it so much heavier than Boeing's documented numbers?

Thanks,

Mark Gibbons.

[Olympic260 415]

51 minutes ago, Mark.Gibbons7 said:

Hi,

This may be a very quick and simple question for you all.

I went digging with regards to weights so I could set up SimBrief correctly.  I found the Empty Weight for the 777 to be 344,224 pounds (From the Aircraft.cfg, couldn't find it in the FCOM.) I've never been able to get my ZFW to align with my VAs estimate, and after finding this, I've realised why. Because my empty weight is heavier than their ZFW.

I looked here for a reference: http://www.boeing.com/assets/pdf/commercial/airports/acaps/777_2lr3er.pdf

It states that the empty weight for a Boeing 777-200LR is 320,000. Now this weight would allow me to use the suggested ZFW for my VAs flights and makes sense, so I'm starting to think the Empty Weight for the 777 is incorrect.

So my question is, is the Empty Weight in the .cfg correct and if so, why is it so much heavier than Boeing's documented numbers?

Thanks,

Mark Gibbons.

Mark,

The empty weight is different per airliner as it includes also the cabin fittings, extra equipment etc. If you see on the document you sent this is mentioned as well. We simulate a plane with Empty weight of 344224 pounds or 156.1tones.

[skelsey 765]

Just to add to Chris' post -- the reason you won't find the empty weight in the FCOM is because it is unique to every airframe. Each specific aircraft in a fleet has a separate document detailing its specific empty weight and CG datum, taking in to account the equipment fitted to that particular airframe. Periodically the airframes are re-weighed and the OEWs updated.

So this is one of those things which cannot be correct or incorrect - it just is. Saying that, your VA must be using exceptionally light loads if your ZFW is consistently less than the OEW of the PMDG model -- are you sure you've not got a lbs/kgs issue going on?

[Mark.Gibbons7 1]

Hi gents,

Perfect, thanks for the response. Just wanted to make sure it was correct, of course I can work with it and ignore the CFP as it's only guidance anyway.

8 minutes ago, skelsey said:

Saying that, your VA must be using exceptionally light loads if your ZFW is consistently less than the OEW of the PMDG model -- are you sure you've not got a lbs/kgs issue going on?

Yes, double checked to make sure. Perhaps they're using the rock bottom 320,000, I don't see how else they could be doing it.

Thanks for your help,

Mark.

 

 

[Mike777 163]

9 hours ago, Olympic260 said:

The empty weight is different per airliner as it includes also the cabin fittings, extra equipment etc. If you see on the document you sent this is mentioned as well. We simulate a plane with Empty weight of 344224 pounds or 156.1tones.

I'm surprised, with all the emphasis on reducing weight and recent use of composite materials, that an extra 24,000 lbs would be acceptable to any airline.  I am curious to know, what adds so much extra weight?

Thanks

[Olympic260 415]

14 hours ago, Mike777 said:

I'm surprised, with all the emphasis on reducing weight and recent use of composite materials, that an extra 24,000 lbs would be acceptable to any airline.  I am curious to know, what adds so much extra weight?

Thanks

Mike,

 

Cabin fttings, ie first class suites etc, galleys, lavatories, extra equipment like satphone, on board internet etc etc etc

[Mike777 163]

6 minutes ago, Olympic260 said:

Mike,

 

Cabin fttings, ie first class suites etc, galleys, lavatories, extra equipment like satphone, on board internet etc etc etc

Thanks.  I would have guessed that galleys & lavatories would be included in the base empty weight.  But not the elaborate furnishings in first class or satphone equipment. 

Mike

[Ephedrin 418]

42 minutes ago, Mike777 said:

Thanks.  I would have guessed that galleys & lavatories would be included in the base empty weight.  But not the elaborate furnishings in first class or satphone equipment. 

Mike

I‘m quite sure the seats on a KLM 738 have a different weight than te seats on a Ryanair 738. 

then the first class suite on an Emirates 777 is pretty different to the seating on an AAL 777... and so on. Boeing gives a factory native weight but that is absolutely empty, nothing in there...

 

edit: I just woke up and didn‘t read your post correctly  that‘s actually what you said...

[skelsey 765]

Also worth noting that Boeing's figures on their website are, I would presume, essentially marketing...

"Our 777 is lighter than ever before - 320,000 lb. (Of course, that's rounded down, with virtually no useful equipment at all on board and the lightest and most basic versions of everything but you'll find that out when you buy it...)"