Dry weight vs Empty weight et al

[gprice2]

Hello all;
I had always assumed that an aircraft's "dry weight" was equal to its "empty weight" minus the fuel load. In other words the "dry weight" plus the weight of the fuel equals the "empty weight"(the weight of the aircraft before loading passengers or cargo).
In my aircraft's .air file there is a 2,180 lb. disparity between these comparative weights(a "dry weight" of 4,524 lbs. and 900 lbs. of fuel, versus an "empty weight" of 7,604 lbs.). Have I been misinformed about the meanings of these flight dynamics terms or is there misinformation in the .air file? Thanx for your help.

[Taliflush]

Dry weight is one way of describing the zero fuel weight. The zero fuel weight is, of course, the weight of the aircraft all loaded up on the ramp (passengers, and/or cargo). Empty weight is the weight of just the aircraft itself plus whatever (minus fuel) it would take in order for the aircraft to be operational.

Now for the interesting part. Near as I can tell, in the config file for the aircraft there are two weights listed: max takeoff weight and empty weight. What I have been doing is figuring a zero fuel weight (ZFW) and plugging this into the empty weight column. This seems to work properly for me, but if someone else knows another way to edit the ZFW I'm all ears to hear it.

Cheers

[AirToob]

Here's a somewhat tortuous path to answering your question, but it might take you past other info that you might be interested in.

OK, go to "The FS2002 Pilot's Assistant" Flight Procedures Section, at:

http://www.tooby.demon.co.uk/FS2002/...tml#Pre-Flight

and take a look at the rows in the table that start with "Weight / Fuel Planning".

The most direct answer to your question (that I know about) is in the last row called "Load Fuel". You'll find quite a bit of related info in that hints & tips file.

You could also have reached the same info by looking up "weight" in the page's A-Z index at:

http://www.tooby.demon.co.uk/FS2002/...stant.html#A-Z


HTH...

Regards,

--
Brian Tooby
TCA Pilot #2658

Pilot's Assistant Home Page:
http://www.tooby.demon.co.uk/P_Assist_Home.html

[gprice2]

> Dry weight is
>one way of describing the
>zero fuel weight. The zero
>fuel weight is, of course,
>the weight of the aircraft
>all loaded up on the
>ramp (passengers, and/or cargo). Empty
>weight is the weight of
>just the aircraft itself plus
>whatever (minus fuel) it would
>take in order for the
>aircraft to be operational.
>
> Now for the
>interesting part. Near as I
>can tell, in the config
>file for the aircraft there
>are two weights listed: max
>takeoff weight and empty weight.
>What I have been doing
>is figuring a zero fuel
>weight (ZFW) and plugging this
>into the empty weight column.
>This seems to work properly
>for me, but if someone
>else knows another way to
>edit the ZFW I'm all
>ears to hear it.
>
>Cheers

Taliflush:
Thanks for your remarks. Your suggestion about calculating the ZFW and plugging that number into the aircraft config file's empty weight column sounds logical to me because I had already been thinking along that track and was looking for some confirmation. My aircraft is hopping around on the runway around like an electrocuted frog and I needed the proper "dry" weight value in order to try curing the condition using Tom Goodrick's "Stopping Hopping" tutorial.

[gprice2]

Brian;
Thanx for the valuable links you provided in your reply to my "Dry weight vs Empty weight" question. I would have never found such rich sources of information without your help. Thanx again.
Gprice2

[AirToob]

You're welcome! :-)

Glad it was useful.

Best regards,

--
Brian Tooby
TCA Pilot #2658

Pilot's Assistant Home Page:
http://www.tooby.demon.co.uk/P_Assist_Home.html

[27general]

Empty Weight: The weight of the airplane with nothing (fuel and payload (passengrs and cargo)) in it. Some airlines and Boeing use the term Operational Empty Weight (OEM) which includes pilots, attendants, water, food i.e. things that are usually standard for the flight. This weight is entered in the configuration file under empty_weight.

Dry Weight (the maximum is called Maximum Zero Fuel Weight MZFW): The weight of the airplane with everything (pilots, attendants, cargo, passengers etc.) but not fuel in it. The difference between dry weight and empty weight is called, in FS2002, station load. Station load is entered into the configuration file under station_load.0=. You can enter up to I think 50 station load points. Dry Weight can not exceed a weight established by manufacture which is Maximum Zero Fuel Weight (MZFW). The difference between Dry Weight and Empty Weight is called payload. MZFW less OEM gives the maximum payload the structure of the airplane is capable off holding.

Maximum Take Off Weight (MTOW) is dry weight plus fuel. Fuel quantity/weight is entered in FS2002 under menu Aircraft/fuel. Maximum fuel load is weight of fuel with all the tanks filled,
In most aircraft, OEM + maximum payload + maximum fuel will exceed MTOW. MTOW is entered in the congregation file under max_gross_weight I have been told that Microsoft uses MTOW only as a reference number..

Summary: The three things you can enter are empty weigh, payload and fuel as long as you do not exceed the absolutes established by the manufacture. The absolutes are OEM, MZFW and MTOW. I have found most weight entries, including those of Microsoft and well established add on companies often using incorrect numbers. This is the first thing I look at and correct in a new download are the empty_weight, station_load and max_gross_weight entries in the configuration file. The aircraft will then fly much better.

[gprice2]

Thanx for the in depth explaination of the various "weight" definitions. You could not have made it more plain. At first the information was a bit mind boggling, but that was probably because of my unfamiliarity with editing the aircraft.cfg and .air files. I am studying your message carefully and each time I read it again it becomes increasingly more understandable to me. Thanx again for your helpful help!
>>Gprice2

[rossevenil]

Just to let you know the dry weight is actually whats called the Dry Operating Weight or DOW which is the weight of the aircraft including the standard crew and things like catering trolleys etc
Never heard of empty weight unless this is what I would know as Basic Weight which is purely the weight of the aircraft with nothing else on it at all.
MZFW is the Maximum Zero Fuel Weight which is the structural max weight of the aircraft,crew,catering,pax,bags,cargo and mail while MTOW is all of the above plus the aircrafts take off fuel added on.
Hope this helps you understand.