Min ZFW
Do a Hover - it avoids G
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Min ZFW
I have been asked why a minimum zero fuel weight should be specified/required
I could not come up with any answer that I believed.
Anybody know ?
I could not come up with any answer that I believed.
Anybody know ?
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We asked this question of Airbus - they said it was part of the bending load calculation across the wing with reference to where the tanks are.
Max ZFM - all the punters on and max downward load pivotting on the gear
Min ZFM - no one on or even in a stripped out condition, max upward load pivotting on the gear.
Seemed to make some sense at the time.
Max ZFM - all the punters on and max downward load pivotting on the gear
Min ZFM - no one on or even in a stripped out condition, max upward load pivotting on the gear.
Seemed to make some sense at the time.
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Zero Fuel Weight:
MEW - manufacturers empty Weight
OEW - Operators empty weight
OEW + Payload is a function - the delta you looking for is the max mass allowable, ipso Max ZFW (fuel that can be up loaded)
MEW is the A/C mass (static) as produced by OEM
OEW is MEW + customer add ons (customization)
OEW changes based on customer requirements - not a military problem as slinging a few missiles on an fast jet is not the problem that confronts an Ops manager for a civil operation
OEW - ZFW = total fuel load max allowable based on A/c allowables
structure moments and bending are more to do with repairs and static nominal zero for stress jacking ( it's more complicated than that but I can't be bothered going into it)
So, in summary - ZFW is the derived sum of available mass after all optional operational considerations are allowed for i.e how much fuel can I upload for this operational sector is one option, but in general mass and loading are derivatives of commercial Ops
MEW - manufacturers empty Weight
OEW - Operators empty weight
OEW + Payload is a function - the delta you looking for is the max mass allowable, ipso Max ZFW (fuel that can be up loaded)
MEW is the A/C mass (static) as produced by OEM
OEW is MEW + customer add ons (customization)
OEW changes based on customer requirements - not a military problem as slinging a few missiles on an fast jet is not the problem that confronts an Ops manager for a civil operation
OEW - ZFW = total fuel load max allowable based on A/c allowables
structure moments and bending are more to do with repairs and static nominal zero for stress jacking ( it's more complicated than that but I can't be bothered going into it)
So, in summary - ZFW is the derived sum of available mass after all optional operational considerations are allowed for i.e how much fuel can I upload for this operational sector is one option, but in general mass and loading are derivatives of commercial Ops
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On the aeroplane I fly (Embraer 145), the line for minimum zero fuel weight is the bottom of the C of G envelope and is co-incident with the line for lowest aircraft weight.
I reckon that there isn't techincally a minimum zero fuel weight for the aeroplane, merely a minimum FLIGHT weight. I imagine this is something that was defined during testing when determining Va and generating that graph that you see which plots g loading against speed for a given gust if you know the one I mean???
Not sure if this is a load of old pants though, but I did some research into this too a while ago and couldn't get anywhere.
I reckon that there isn't techincally a minimum zero fuel weight for the aeroplane, merely a minimum FLIGHT weight. I imagine this is something that was defined during testing when determining Va and generating that graph that you see which plots g loading against speed for a given gust if you know the one I mean???
Not sure if this is a load of old pants though, but I did some research into this too a while ago and couldn't get anywhere.
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There are several design cases which infer min weight restrictions .. right up MFS' alley I suggest .. I have no doubt he will wade into the discussion in due course. I shan't exert myself by flicking through Part 25 to list the likely contenders but I located one not too ancient thread which has some relevant commentary ...
