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JumboJet

I needed some answers Wink

Can anyone tell how much does passenger weight influence fuel consumption on a typical Boeing or Airbus flights?

Is there a formula used to estimate the total passenger weight based on how many seats are filled?

Is there a per-person fuel allotment?

Is there a formula to estimate carry-on baggage weight?

How carefully do carriers measure cargo weight?
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I love the smell of Jet Fuel in the morning.

stealthpilot · Member Joined: 19 Dec 2006 Posts: 2325 Location: BLR, DXB

Don’t know about fuel consumption vs. passenger weight on an Airbus or Boeing,hopefully Boeing7xx or iflytb20? or someone can help you out there?

On the CRJ (and I assume other flights) in America they use standard weights to calculate the a/c weights. Please note that I forget the exact weights so the info below might be inaccurate. From what I can remember a passenger is 175 pounds in winter, 30 lbs per check in bag (something else if it’s heavy) and 15 lbs per carry on. The airline obviously knows how many people and bags are checked in, they probably just estimate the carry on luggage.
There are separate weights for children

I don’t believe there is ever a per-person fuel allotment.

How carefully do carriers measure cargo weight? Hmmmm D-ABTH?. I would imagine pretty carefully Smile

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eP007

ssbmat · Member Joined: 20 Dec 2006 Posts: 1710

I think apart from the passenger load, particularly on the smaller planes like the CRJ, greater importance is given to the CG (Center of Gravity).
Of course, CG is important for ALL airplanes, but there is a greater tendency to compensate the pasenger distribution inside a CRJ or ERJ than, lets say, a B737 or A320.

I have myself been shunted to the rear in an ERJ flight once (Embraer) before take off and I am not more than 180lb !

But I dont think they work on a fuel-per-passenger formula for the flightplan-they work on the gross numbers.
The cargo-other than baggage is weighed carefully and even more important, placed appropriately in the cargo areas to balance the plane out.
There are several photos of planes on A.NET where planes have tipped over on the tail or nose because of incorrect loading!

In general, the amount of fuel loaded depends on a combination of factors , including (but not limited to)
- Distance of the journey
- weather (headwinds/tailwinds)
- traffic pattern (holding etc)
-diversion fuel for alternate airport
-ETOPS restrictions if any (ETOPS is a whole topic on its own)
-passenger and cargo (payload)

Pilots calculate the estimated cruise speeds ( usually Mach decimal numbers) based on the CPI (Cost performance index) which factors in all this.