How to read this chart
1 Attachment(s)
Really simple, can someone help explain this chart to me and how to read it?
3.2 PAYLOAD/RANGE FOR LONG RANGE CRUISE FOR 0.84 MACH CRUISE 3.2.1 Payload/Range for 0.84 Mach Cruise: Model 777-200LR (GE90-100 Series Engines) |
Hi AirlineTycoon
You start at the bottom of the chart with your OEW (which is Operating Empty Weight) plus the Payload (which is passengers, baggage and / or freight). If you are calculating in Tons, (kg * 1000), you take the very bottom line, if you have lbs (*1000) you take the other line. From there you follow the thin vertical lines vertically up the page, until you hit the diagonal line that is labelled with "Brake release gross weight" (which is sometimes also referred to as "ramp weight"). If you are calculating in pounds (*1000) you look at the numbers without brackets, and if you are referring to tons, the figure in the bracket. The difference between the two ("OEW+Payload" and "Brake release gross weight") is basically the fuel weight, so now the range can be calculated. The chart does that calculation for you - so now you have found the intersection point between the OEW+Payload (also called "Zero fuel weight") and the "Brake release gross weight", you now follow the thin horizontal line from that point horizontally to the right of the page. There you can now read the range in NM (nautical miles) *1000. At the very left of the chart you see the left vertical line labelled "Max zero fuel weight = 461'000lbs", which is a structural limit. Therefore if your weight would end up to the left of that line, you would be out of limits and therefore out of the chart. At the top of the chart the lines end depending on your version (more tanks = more fuel capacity = higher possible Brake-release-gross-weight = higher range). Anytime you fall out of the chart at the top, you have to either reduce the payload or the fuel, and thus reducing your range. You can also use the chart "backwards", if you have a given range, you can figure out how much payload you can take with your OEW and required fuel for the range. Hope that helps! Cheers, Moswey |
So if I have a OEW of 380,000lbs how do I know which curved line to look at which will ultimately tell me my range.
That line is the zero fuel weight? what is that? |
Zero Fuel Weight is everything without the fuel, as the name says. The bottom line (OEW + Payload) is the Zero Fuel Weight.
The diagonal line is the full weight, it is the figure of the bottom line + the fuel weight. |
Actually I understand you, if I have 380,000lbs of OEW then I can do a max of 9,000NM without AUX tanks?
The brake release gross weight is then 7,000lbs? Or to get out to 10,000NM I would need 3 AUX tanks and take a max of 375,000lbs of OEW |
Originally Posted by AirlineTycoon
(Post 10126816)
Actually I understand you, if I have 380,000lbs of OEW then I can do a max of 9,000NM without AUX tanks?
Originally Posted by AirlineTycoon
(Post 10126816)
The brake release gross weight is then 7,000lbs?
Originally Posted by AirlineTycoon
(Post 10126816)
to get out to 10,000NM I would need 3 AUX tanks and take a max of 375,000lbs of OEW
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One small point. "Brake release" is the beginning of the takeoff roll and not ramp weight. There is a planning chart for the 744 for determining trip time and fuel that says "from brake release to touchdown. APU usage, taxi, inflight flaps down maneuvering (other than a straight in approach) and reserve fuel should be added..."
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I sincerely hope you’re NOT a real airline tycoon.
GF |
Originally Posted by MarkerInbound
(Post 10127735)
One small point. "Brake release" is the beginning of the takeoff roll and not ramp weight. There is a planning chart for the 744 for determining trip time and fuel that says "from brake release to touchdown. APU usage, taxi, inflight flaps down maneuvering (other than a straight in approach) and reserve fuel should be added..."
|
Originally Posted by moswey4a
(Post 10126536)
Hi AirlineTycoon
You start at the bottom of the chart with your OEW (which is Operating Empty Weight) plus the Payload (which is passengers, baggage and / or freight). If you are calculating in Tons, (kg * 1000), you take the very bottom line, if you have lbs (*1000) you take the other line. From there you follow the thin vertical lines vertically up the page, until you hit the diagonal line that is labelled with "Brake release gross weight" (which is sometimes also referred to as "ramp weight"). If you are calculating in pounds (*1000) you look at the numbers without brackets, and if you are referring to tons, the figure in the bracket. The difference between the two ("OEW+Payload" and "Brake release gross weight") is basically the fuel weight, so now the range can be calculated. The chart does that calculation for you - so now you have found the intersection point between the OEW+Payload (also called "Zero fuel weight") and the "Brake release gross weight", you now follow the thin horizontal line from that point horizontally to the right of the page. There you can now read the range in NM (nautical miles) *1000. At the very left of the chart you see the left vertical line labelled "Max zero fuel weight = 461'000lbs", which is a structural limit. Therefore if your weight would end up to the left of that line, you would be out of limits and therefore out of the chart. At the top of the chart the lines end depending on your version (more tanks = more fuel capacity = higher possible Brake-release-gross-weight = higher range). Anytime you fall out of the chart at the top, you have to either reduce the payload or the fuel, and thus reducing your range. You can also use the chart "backwards", if you have a given range, you can figure out how much payload you can take with your OEW and required fuel for the range. Hope that helps! Cheers, Moswey Question, to get the OEW you need aircraft weight plus payload. Wiki lists the 77L as 330,000lbs - what's the 'standard' weight given for each pax including bags? Assume if you add 330,000Lbs + (Bag/Pax weight * Number of Pax) leaves you with cargo weight until you reach MTOW.. |
I'm glad you found my description useful.
The standard weights for passengers, hand luggage and cargo hold bags depend on the company. Typical is for example 200 lbs per passenger (including hand luggage) and 50 lbs for hold luggage. Some airlines make a difference between male and female standard weights. |
On Page 161 of this, it's got Payload.
So the 31,000Kg at the 325 passenger mark is just for passengers (the chart says 95kg per pax including baggage). Therefore the very right of the X-axis is by default the OEW? There is no cargo in this scenario. https://www.airbus.com/content/dam/c...0-900-1000.pdf |
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