Post by SEAN ZARELLA on Oct 26th, 2015 at 6:43pm
Ok so first of all, You have to realise that Captain sim. other, Ect never assign payload along the longtitudinal axis of the plane there fore assigning all the weight at station 0.0 thus giving an incorrect empty weight CG% and the empty weight is incorrect
What MSFS does is go by OEW or operating empty weight,
but it is incorrect.
Another thing is that CS .air file shows static thrust closer to the rating of PW2040 Engines rather than 2037 engines increasing its range, MTOW and MLW.
in the .air file shows 40177 lbs of static thrust
the PW2040 is 40100 Lbs instead of 36600 of the PW2037 that shows in the FMC, so this changes and if you see this from boeing youll see the change in MTOW and MLW
Engines``````````````````` Thrust
Pratt & Whitney PW2037 36600 lb st (162.8 kN)
Pratt & Whitney PW2040 40100 lb st (178.4 kN)
Rolls Royce RB211-535C 37400 lb st (166.0 kN)
Rolls Royce RB211-535E4 40200 lb st (178.8 kN)
Rolls Royce RB211-535E4-B 43500 lb st (193.5 kN)
Fuel capacity 42684 liters (11276 US gallons)
and you know what that means??
operating weight empty---- 57840 - 57075 kg (passenger version) / 50475 - 50605 kg (freighter)
freighter revenue load----- 32755 kg (72,212 lb)
freighter payload 757-200 SF---- 27215 kg (59,998 lb)
max take-off weight (PW2037 & RB211-535E4) 99790 kg (220,000 lb
max take-off weight (PW2040 & RB211-535E4--B) 115665 kg (255,000 lb)
max landing weight (PW2037 & RB211-535E4) 89815 kg (198,000 lb)
max landing weight (PW2040 & RB211-535E4-B) 95255 kg (210,000 lb)
max ramp weight (PW2037 & RB211-535E4) 100245 kg (221,000 lb)
max ramp weight (PW2040 & RB211-535E4-B 116120 kg (256,000 lb)
So this means that our CS757 with PW2040 engines have a new MTOW of 255,000 Lbs and MLW of 210,000 Lbs.
Now that we know that Here is how we calculate CG%
Before we Begin, These are some specifications we must know before we begin, involving the Boeing 757-200
Empty Weight: 125,750 lbs // Weight of the aircraft empty without any fuel, Passengers, crew, catering, and cargo.
Dry Operating Weight: 130,875 lbs // Weight of aircraft with Crew, Crew bags, Unusable fuel, Galley Equipment.
Zero Fuel Weight: -------- // Weight of aircraft with crew, passengers, and cargo. Without Fuel.
I will start with the basics on the fundamentals before I go into the actual math involved in determining your planes CG% or %mach can also be called.
All Center of gravity is based upon the starting point which we call DATUM.
DATUM is referred as the starting point of the line which the manufacturer determines for each plane they make, and for the B752 that line starts 159 inches in front of the nose.
You draw that line linear from that point to the start of a small window of balance which we call MAC. which is mostly located at the wings ( center Of plane)
Here is an illustration
So you start with your Datum and a line is drawn from there to the start of the MAC and measure that distance in inches. , the start of the MAC line we call LEMAC or leading edge MAC.
and for the B752 LEMAC is @ 991.9 inches from the datum. The mac line starts from there and is 199.7 inches long,. we refer MAC as 199.7 inches.
So drawing that line from Datum to the LEMAC point and if you add up the point of LEMAC 991.9 + your mac 199.7 = 1191.6
0% mac is 991.9 inches. where it starts, 100% mac is 1191.6 inches.
Here is a image of what we are talking about, I illustrated where the datum line starts and where lemac is and 0 - 100 % MAC.
Between 0%MAC and 100% MAC is the window of CG we need the plane to be balanced. But that isn't the balance point. Per aircraft each is different based on Weight and
placement of Objects forward and aft of the LEMAC line. For instance, For the B752 The CG window envelope is 7% - 39% CG and that depends on your Gross Weight.
This can be found in the 757 - 200 weight and balance handbook.
Finally, where the Cg is located within that window is called BALANCE ARM or the distance from CG% to datum. measured in inches.
ARM is measured by balance point when the airplane is at DRY OPERATIING WEIGHT or EMPTY WEIGHT, and changes from aircraft to aircraft because of seating configurations
forward and Aft Lemac. I found out that per the 757-200 Delta Flies is called. DAL 75X PER delta seating specification that can hold 184 PAX.
The Balance Arm or distance from datum to the EMPTY WEIGHT CG is 1037.8 inches. This is How you determine your planes EMPTY CG%
````````````distance aft of LEMAC
`` cg%mac = ___________________
```````````````````` MAC
Distance aft OF LEMAC is easy to figure out now, if our LEMAC is 991.9 inches and the balance arm is 1038.7 inches. we take 1038.7 -991.9 = 46.8 inches.
````````46.8
CG%=____________ = 23.43%
```````1.997
if you just had your CG% and needed your ARM ( to compute DOI )
~~~~~~~~~~~~~~~~~~%MAC
Balance Arm = LEMAC + ( ----------------× MAC )
~~~~~~~~~~~~~~~~~~ 100
SO
``````````````` 23.43%
ARM = 991.7 + ( ----------------- x MAC ) = 1038.68971 or 1038.7
`````````````````100
Next is Computing the planes Dry Operating Index empty weight.
Formula for this is for the B752 for its BASE DOI before LMC
DOI = Weight x (Arm - 1037.8) + 50
````````````````75000
Since balance arm base before LMC is 1037.8. that zeros out the equation and you add 50. so our DOI is 50.
refer to the actual LOAD SHEET to find CG% and Trim values.
Now that we Know how to compute CG% and Trim. Follow the instructions below to edit your plane to match Deltas, 75X 184 pax.
I have discovered that The planes OEW CG% is 23.47% and 130875 LBS.
In order in MSFS to match this was to navigate to my Aircraft.cfg and change the following
[WEIGHT_AND_BALANCE]
max_gross_weight = 256000 // (pounds)
empty_weight = 127520 // (pounds)
reference_datum_position = 2.3, 0, 0 // (feet) distance from FlightSim Reference position: (1/4 chord, centerline, waterline)
empty_weight_CG_position = 2.5,[/color][/color][/color][/color] 0, 0 // (feet) longitudinal, lateral, vertical distance from specified datum
max_number_of_stations =12
station_load.0 ="460, 70, 0, 0, Flight Crew"
station_load.1 ="920, 0, 0, 0, Cabin Crew"
;Moments of Inertia
empty_weight_pitch_MOI = 7040000
empty_weight_roll_MOI = 1960000
empty_weight_yaw_MOI = 7500000
empty_weight_coupled_MOI = 1000
station_load.2=5970, 25, 1, 0, F/C Row 1-7
station_load.3=15612, 14, 1, 0, E/C ECON Row 20-30
station_load.4=12398, -13, 0, 0, ECON Row 31-39
station_load.5=8265, -33, 0, 0, ECON Row 40-45
station_load.6=888, 25, -1, -2, FWD Cargo Bay 1
station_load.7=0, 12, -1, -2, FWD Cargo Bay 2
station_load.8=8312, -12, -1, -2, AFT Cargo Bay 3
station_load.9=0, -25, -1, -2, AFT Cargo Bay 4
station_load.10=1975, 0, 0, 0, OPERATIONAL ITEMS
station_load.11=0, 0, 0, 0, ADDITIONAL WEIGHT
This load station data will give you a fully loaded 757 X version of 184 passengers, and 9200lbs cargo. and a ZFW of 182,320 LBS
This station load data also Matches Simbrief.com for all your planning needs. And this is how these numbers came from.
Simbrief uses 229.59 per passenger/with baggage, per each row. and section. for instance we get this weights from how many pax in a row and section,
first class holds 26 pax, so 26 x 229.59 = 5969
so you see where i am getting the station load data from. 26 first class 68 is economy comfort with a few rows of economy 54 is economy and 36 per last row of economy,
So this accounts with simbrief without adding cargo. just 184 pax. we still have to add 50 lbs per pax per baggage thats checked in. x 184 = 9200lbs.
The Above Configuration will give your 757-200 an accurate weight of ZFW of 182,320 lbs @ 29% CG
To match Simbrief you will need to edit your 757. Follow below.
Max Passengers: 184
OEW (Empty Weight):130.8 (in thousands of pounds)
MZFW (Max Zero Fuel Weight):184.0 (in thousands of pounds)
MTOW (Max Takeoff Weight):240.0 (in thousands of pounds)
MLW (Max Landing Weight): 198.0 (in thousands of pounds)
Max Fuel Capacity:75.6 (in thousands of pounds)
When you are plotting your dispatch on Simbrief, Select Passengers to FULL, Cargo to 9200 and ZFW to AUTO
Your plane will always come out to 182,320 LBS as designed to match your loaded 757-200.
I know this has been long and exhausting but I Know all there is to CG% and load balance data on this bird :)
Any questions let me know
here is the real Load balance sheet for the PW2040 757-200
What I do , belonging to Delta Virtual Airlines, Is we have an acars program for dispatch and flight tracking, I manually set my flights through the aircraft.CFG and always have a full flight with 184 pax, and 50lbs bags per pax 9200lbs,
What MSFS does is go by OEW or operating empty weight,
but it is incorrect.
Another thing is that CS .air file shows static thrust closer to the rating of PW2040 Engines rather than 2037 engines increasing its range, MTOW and MLW.
in the .air file shows 40177 lbs of static thrust
the PW2040 is 40100 Lbs instead of 36600 of the PW2037 that shows in the FMC, so this changes and if you see this from boeing youll see the change in MTOW and MLW
Engines``````````````````` Thrust
Pratt & Whitney PW2037 36600 lb st (162.8 kN)
Pratt & Whitney PW2040 40100 lb st (178.4 kN)
Rolls Royce RB211-535C 37400 lb st (166.0 kN)
Rolls Royce RB211-535E4 40200 lb st (178.8 kN)
Rolls Royce RB211-535E4-B 43500 lb st (193.5 kN)
Fuel capacity 42684 liters (11276 US gallons)
and you know what that means??
operating weight empty---- 57840 - 57075 kg (passenger version) / 50475 - 50605 kg (freighter)
freighter revenue load----- 32755 kg (72,212 lb)
freighter payload 757-200 SF---- 27215 kg (59,998 lb)
max take-off weight (PW2037 & RB211-535E4) 99790 kg (220,000 lb
max take-off weight (PW2040 & RB211-535E4--B) 115665 kg (255,000 lb)
max landing weight (PW2037 & RB211-535E4) 89815 kg (198,000 lb)
max landing weight (PW2040 & RB211-535E4-B) 95255 kg (210,000 lb)
max ramp weight (PW2037 & RB211-535E4) 100245 kg (221,000 lb)
max ramp weight (PW2040 & RB211-535E4-B 116120 kg (256,000 lb)
So this means that our CS757 with PW2040 engines have a new MTOW of 255,000 Lbs and MLW of 210,000 Lbs.
Now that we know that Here is how we calculate CG%
Before we Begin, These are some specifications we must know before we begin, involving the Boeing 757-200
Empty Weight: 125,750 lbs // Weight of the aircraft empty without any fuel, Passengers, crew, catering, and cargo.
Dry Operating Weight: 130,875 lbs // Weight of aircraft with Crew, Crew bags, Unusable fuel, Galley Equipment.
Zero Fuel Weight: -------- // Weight of aircraft with crew, passengers, and cargo. Without Fuel.
I will start with the basics on the fundamentals before I go into the actual math involved in determining your planes CG% or %mach can also be called.
All Center of gravity is based upon the starting point which we call DATUM.
DATUM is referred as the starting point of the line which the manufacturer determines for each plane they make, and for the B752 that line starts 159 inches in front of the nose.
You draw that line linear from that point to the start of a small window of balance which we call MAC. which is mostly located at the wings ( center Of plane)
Here is an illustration
So you start with your Datum and a line is drawn from there to the start of the MAC and measure that distance in inches. , the start of the MAC line we call LEMAC or leading edge MAC.
and for the B752 LEMAC is @ 991.9 inches from the datum. The mac line starts from there and is 199.7 inches long,. we refer MAC as 199.7 inches.
So drawing that line from Datum to the LEMAC point and if you add up the point of LEMAC 991.9 + your mac 199.7 = 1191.6
0% mac is 991.9 inches. where it starts, 100% mac is 1191.6 inches.
Here is a image of what we are talking about, I illustrated where the datum line starts and where lemac is and 0 - 100 % MAC.
Between 0%MAC and 100% MAC is the window of CG we need the plane to be balanced. But that isn't the balance point. Per aircraft each is different based on Weight and
placement of Objects forward and aft of the LEMAC line. For instance, For the B752 The CG window envelope is 7% - 39% CG and that depends on your Gross Weight.
This can be found in the 757 - 200 weight and balance handbook.
Finally, where the Cg is located within that window is called BALANCE ARM or the distance from CG% to datum. measured in inches.
ARM is measured by balance point when the airplane is at DRY OPERATIING WEIGHT or EMPTY WEIGHT, and changes from aircraft to aircraft because of seating configurations
forward and Aft Lemac. I found out that per the 757-200 Delta Flies is called. DAL 75X PER delta seating specification that can hold 184 PAX.
The Balance Arm or distance from datum to the EMPTY WEIGHT CG is 1037.8 inches. This is How you determine your planes EMPTY CG%
````````````distance aft of LEMAC
`` cg%mac = ___________________
```````````````````` MAC
Distance aft OF LEMAC is easy to figure out now, if our LEMAC is 991.9 inches and the balance arm is 1038.7 inches. we take 1038.7 -991.9 = 46.8 inches.
````````46.8
CG%=____________ = 23.43%
```````1.997
if you just had your CG% and needed your ARM ( to compute DOI )
~~~~~~~~~~~~~~~~~~%MAC
Balance Arm = LEMAC + ( ----------------× MAC )
~~~~~~~~~~~~~~~~~~ 100
SO
``````````````` 23.43%
ARM = 991.7 + ( ----------------- x MAC ) = 1038.68971 or 1038.7
`````````````````100
Next is Computing the planes Dry Operating Index empty weight.
Formula for this is for the B752 for its BASE DOI before LMC
DOI = Weight x (Arm - 1037.8) + 50
````````````````75000
Since balance arm base before LMC is 1037.8. that zeros out the equation and you add 50. so our DOI is 50.
refer to the actual LOAD SHEET to find CG% and Trim values.
Now that we Know how to compute CG% and Trim. Follow the instructions below to edit your plane to match Deltas, 75X 184 pax.
I have discovered that The planes OEW CG% is 23.47% and 130875 LBS.
In order in MSFS to match this was to navigate to my Aircraft.cfg and change the following
[WEIGHT_AND_BALANCE]
max_gross_weight = 256000 // (pounds)
empty_weight = 127520 // (pounds)
reference_datum_position = 2.3, 0, 0 // (feet) distance from FlightSim Reference position: (1/4 chord, centerline, waterline)
empty_weight_CG_position = 2.5,[/color][/color][/color][/color] 0, 0 // (feet) longitudinal, lateral, vertical distance from specified datum
max_number_of_stations =12
station_load.0 ="460, 70, 0, 0, Flight Crew"
station_load.1 ="920, 0, 0, 0, Cabin Crew"
;Moments of Inertia
empty_weight_pitch_MOI = 7040000
empty_weight_roll_MOI = 1960000
empty_weight_yaw_MOI = 7500000
empty_weight_coupled_MOI = 1000
station_load.2=5970, 25, 1, 0, F/C Row 1-7
station_load.3=15612, 14, 1, 0, E/C ECON Row 20-30
station_load.4=12398, -13, 0, 0, ECON Row 31-39
station_load.5=8265, -33, 0, 0, ECON Row 40-45
station_load.6=888, 25, -1, -2, FWD Cargo Bay 1
station_load.7=0, 12, -1, -2, FWD Cargo Bay 2
station_load.8=8312, -12, -1, -2, AFT Cargo Bay 3
station_load.9=0, -25, -1, -2, AFT Cargo Bay 4
station_load.10=1975, 0, 0, 0, OPERATIONAL ITEMS
station_load.11=0, 0, 0, 0, ADDITIONAL WEIGHT
This load station data will give you a fully loaded 757 X version of 184 passengers, and 9200lbs cargo. and a ZFW of 182,320 LBS
This station load data also Matches Simbrief.com for all your planning needs. And this is how these numbers came from.
Simbrief uses 229.59 per passenger/with baggage, per each row. and section. for instance we get this weights from how many pax in a row and section,
first class holds 26 pax, so 26 x 229.59 = 5969
so you see where i am getting the station load data from. 26 first class 68 is economy comfort with a few rows of economy 54 is economy and 36 per last row of economy,
So this accounts with simbrief without adding cargo. just 184 pax. we still have to add 50 lbs per pax per baggage thats checked in. x 184 = 9200lbs.
The Above Configuration will give your 757-200 an accurate weight of ZFW of 182,320 lbs @ 29% CG
To match Simbrief you will need to edit your 757. Follow below.
Max Passengers: 184
OEW (Empty Weight):130.8 (in thousands of pounds)
MZFW (Max Zero Fuel Weight):184.0 (in thousands of pounds)
MTOW (Max Takeoff Weight):240.0 (in thousands of pounds)
MLW (Max Landing Weight): 198.0 (in thousands of pounds)
Max Fuel Capacity:75.6 (in thousands of pounds)
When you are plotting your dispatch on Simbrief, Select Passengers to FULL, Cargo to 9200 and ZFW to AUTO
Your plane will always come out to 182,320 LBS as designed to match your loaded 757-200.
I know this has been long and exhausting but I Know all there is to CG% and load balance data on this bird :)
Any questions let me know
here is the real Load balance sheet for the PW2040 757-200
What I do , belonging to Delta Virtual Airlines, Is we have an acars program for dispatch and flight tracking, I manually set my flights through the aircraft.CFG and always have a full flight with 184 pax, and 50lbs bags per pax 9200lbs,