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Robi77

PMDG MD-11 Load Manager Question

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I purchased the MD-11 program from PMDG and am about to study the tutorial flightLondon to Zuerich.In the weight and balance there are a few terms which I do not understand.( but would like to )1) ZFW = Zero Fuel Weight This is obvious the weight of the aircraft without any fuel.2) ZFWCG What does this mean ? It seems a percentage of something.3) TOGW What does this mean ?4) TOCG Whay does this mean ?5) I noticed that the cargo weight is more than the weight of the passengers.Is this also true in the real world ? I appreciate your explanations. Robi77

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1) ZFW = Zero Fuel Weight This is obvious the weight of the aircraft without any fuel. Aircraft+Passengers+Cargo2) ZFWCG What does this mean ? It seems a percentage of something. 3) TOGW What does this mean ?4) TOCG Whay does this mean ?CG is Center of GravityGW is Gross WeightTO is TakeoffAll very important values when programming FMC.5) I noticed that the cargo weight is more than the weight of the passengers.Is this also true in the real world ? Don't know.

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2) ZFWCG What does this mean ? It seems a percentage of something. The "Zero Fuel Weight Center of Gravity". This is where the aircraft's Center of Gravity sits without fuel, but with pax & cargo. It is expressed as a percentage of the Mean Aerodynamic Chord (MAC) of the wing. A straight - parallel leading/trailing edge - wing is easiest to picture, and so we can say that for a chord (distance between the LE and the TE) of say, 12 feet - with a CG of 25% - the aircraft physically balances at a point 3 feet back from the leading edge - ok? At 33% it will balance around 4 feet back. As the pax move back down the aircraft - so the CG moves back with them. This "point" is critical in how the aircraft will respond in the pitch axis. In practice commercial aircraft will generally have a load manager calculate this for the aircrew, and it may also be modified at the Captains discretion.3) TOGW What does this mean ? Take-off Gross Weight. This is the loaded aircraft weight as you're turning onto the runway; i.e. aircraft empty weight + pax + cargo + fuel left in the tanks after the taxy to the hold point. 4) TOCG What does this mean ? Take-off CG. This reflects the new CG, compared to the ZFWCG, and accounts for the addition of the fuel load. It is possible for the CG to change - or to be changed dependent upon 1). which tank(s) contain fuel, and 2). changed as a result of the taxy fuel being burnt. A large aircraft might not even notice 300lbs being burnt, but a smaller aircraft - particularly if held for a while - might well notice 100lbs.5) I noticed that the cargo weight is more than the weight of the passengers.Is this also true in the real world ? Sometimes.Have fun! :(

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1) ZFW = Zero Fuel Weight This is obvious the weight of the aircraft without any fuel. Aircraft+Passengers+Cargo2) ZFWCG What does this mean ? It seems a percentage of something. 3) TOGW What does this mean ?4) TOCG Whay does this mean ?CG is Center of GravityGW is Gross WeightTO is TakeoffAll very important values when programming FMC.5) I noticed that the cargo weight is more than the weight of the passengers.Is this also true in the real world ? Don't know.
ThanksRobi7
2) ZFWCG What does this mean ? It seems a percentage of something. The "Zero Fuel Weight Center of Gravity". This is where the aircraft's Center of Gravity sits without fuel, but with pax & cargo. It is expressed as a percentage of the Mean Aerodynamic Chord (MAC) of the wing. A straight - parallel leading/trailing edge - wing is easiest to picture, and so we can say that for a chord (distance between the LE and the TE) of say, 12 feet - with a CG of 25% - the aircraft physically balances at a point 3 feet back from the leading edge - ok? At 33% it will balance around 4 feet back. As the pax move back down the aircraft - so the CG moves back with them. This "point" is critical in how the aircraft will respond in the pitch axis. In practice commercial aircraft will generally have a load manager calculate this for the aircrew, and it may also be modified at the Captains discretion.3) TOGW What does this mean ? Take-off Gross Weight. This is the loaded aircraft weight as you're turning onto the runway; i.e. aircraft empty weight + pax + cargo + fuel left in the tanks after the taxy to the hold point. 4) TOCG What does this mean ? Take-off CG. This reflects the new CG, compared to the ZFWCG, and accounts for the addition of the fuel load. It is possible for the CG to change - or to be changed dependent upon 1). which tank(s) contain fuel, and 2). changed as a result of the taxy fuel being burnt. A large aircraft might not even notice 300lbs being burnt, but a smaller aircraft - particularly if held for a while - might well notice 100lbs.5) I noticed that the cargo weight is more than the weight of the passengers.Is this also true in the real world ? Sometimes.Have fun! :( Thanks for you detailed answer.I am sure I will have fun and more questions in the future as I am new to thisgame.Robi77

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