Granny fuel
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granny fuel...never heard the expression...but I have heard of the practice
it is wrong
weight is weight. if you need extra fuel, take it...leave cargo/payload/passengers behind.
report this practice to the FAA or whatevercountry you fly in.
it is wrong
weight is weight. if you need extra fuel, take it...leave cargo/payload/passengers behind.
report this practice to the FAA or whatevercountry you fly in.
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Never heard of the expression but I like it! Anyway, on the 737NG this 'granny' error is defined as 2.5% of full scale reading of the fuel quantity indicators. So you can quickly figure out what your 'granny fuel' would be. And that will be my excuse from here onwards. 
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So when you are fretting over the weight of the Evil Granny Gas, do you also consider all the dirt, dust, dead bugs, dead birds, live birds, bird guano, bird nests, lost pens, wrenches, coffee mugs, nudie mags, water, etc. that your "large", twin-engine turboprop 19 seat airplane has acquired since it was last weighed? And do you weigh every person, including the pilots, and everything they bring onboard the airplane before departing? Or does your airline use standard weights? So how much does that add to the official numbers?
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'Standard' Weights
When I was an undergraduate engineer, I spent a summer vacation working in the stress office at BAC, Hurn, helping with the final stress of the BAC 1-11 500 series. We were all hoping that we were not going to find too many reserve factors less than one, as the first aircraft was flying already... co-incidentally, the last flight in the U.K. of a 1-11, ZH763, on Friday is noted on the Military Aircrew blog.
The standard weights that were used were 150 lbs for aircrew, and 140 lbs for passengers; that included carry-on baggage, Jepperson bibles, the lot.
Given the current propensity for SLF to take as carry-on sufficient baggage to see them through a fortnight's holiday, to say nothing of the ever widening girths of our fellow human beings, what are the standard weights that you use in your operation? I can remember an occasion in the mid-90s when all the pax, with their hand baggage, were weighed at the bottom of the air bridge just prior to boarding a BA LHR-NRT service. I wonder what happened to the data? I was slightly embarrassed at the time, as I had a complete mini hi-fi, with speakers, about my person, as I was heading back to a part of the world where they were unobtainable, and needed something on which to play CDs.
The standard weights that were used were 150 lbs for aircrew, and 140 lbs for passengers; that included carry-on baggage, Jepperson bibles, the lot.
Given the current propensity for SLF to take as carry-on sufficient baggage to see them through a fortnight's holiday, to say nothing of the ever widening girths of our fellow human beings, what are the standard weights that you use in your operation? I can remember an occasion in the mid-90s when all the pax, with their hand baggage, were weighed at the bottom of the air bridge just prior to boarding a BA LHR-NRT service. I wonder what happened to the data? I was slightly embarrassed at the time, as I had a complete mini hi-fi, with speakers, about my person, as I was heading back to a part of the world where they were unobtainable, and needed something on which to play CDs.
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Its 86kg for a male 68kg for a female and 35kg for a child.
They tend to weigh both carry on and checked in bags.
If its the 19 seater which I think it is its not even designed to a civilian spec.
Someone planted one on the runway recording 5.6g, it split the main spar and a pax commented it felt like a normal landing nobody hurt. Recently though there was one which had a leg come off on landing under 2g due to a fatigue crack in the gear.
They tend to weigh both carry on and checked in bags.
If its the 19 seater which I think it is its not even designed to a civilian spec.
Someone planted one on the runway recording 5.6g, it split the main spar and a pax commented it felt like a normal landing nobody hurt. Recently though there was one which had a leg come off on landing under 2g due to a fatigue crack in the gear.
Last edited by mad_jock; 28th Apr 2013 at 07:34.
Fuel from Nana
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So when you are fretting over the weight of the Evil Granny Gas, do you also consider all the dirt, dust, dead bugs, dead birds, live birds, bird guano, bird nests, lost pens, wrenches, coffee mugs, nudie mags, water, etc. that your "large", twin-engine turboprop 19 seat airplane has acquired since it was last weighed?
I could list a number of fallacies from here that would apply to your logic - Common fallacies
They tend to weigh both carry on and checked in bags.
The only time an aircraft has too much fuel is when it is on fire.
Your quote might be correct if fuel didn't weigh anything. Unfortunately, it does. I can think of many cases where having less weight would be better - engine failure on takeoff, for one.
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We try and train commercial pilots out of that crap.
The other time is when an engine goes bang then you discover that there is not enough runway infront of you to stop.
Then of course just as your rotate maybe you can't climb and hit a hill or a mast.
Then you might go for struggling round the circuit in the wrong direction and forget that Vmca goes through the roof if you start banking towards the dead engine and while your struggling to hold height you suddenly run out of rudder and loose it and spin in.
But hey engines very rarely fail on takeoff do they thank goodness.
The guys that seem to not care and take the piss the most tend to be the ones with a fair bit of experience with single engine GA work when its never really made much difference if they were over weight. They are also the ones that seem to think height is safety in a twin and go for V2+10 climbs all the time. Try and explain to them speed is safety and terrain separation is assured if you follow the performance sheets in a twin and its just alien to them.
The other time is when an engine goes bang then you discover that there is not enough runway infront of you to stop.
Then of course just as your rotate maybe you can't climb and hit a hill or a mast.
Then you might go for struggling round the circuit in the wrong direction and forget that Vmca goes through the roof if you start banking towards the dead engine and while your struggling to hold height you suddenly run out of rudder and loose it and spin in.
But hey engines very rarely fail on takeoff do they thank goodness.
The guys that seem to not care and take the piss the most tend to be the ones with a fair bit of experience with single engine GA work when its never really made much difference if they were over weight. They are also the ones that seem to think height is safety in a twin and go for V2+10 climbs all the time. Try and explain to them speed is safety and terrain separation is assured if you follow the performance sheets in a twin and its just alien to them.
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+1 to that, mad_jock.
I'm surprised to hear the logic of some pilots I fly with. I had a pilot (Captain) within the last week tell me that if there wasn't a usable altimeter setting available at the airport you were flying an instrument approach at, you could use the altimeter setting from another airplane on 126.7 that's nearby. I tried explaining that it firstly isn't safe and that it also isn't legal but that had no effect.
I'm surprised to hear the logic of some pilots I fly with. I had a pilot (Captain) within the last week tell me that if there wasn't a usable altimeter setting available at the airport you were flying an instrument approach at, you could use the altimeter setting from another airplane on 126.7 that's nearby. I tried explaining that it firstly isn't safe and that it also isn't legal but that had no effect.
Last edited by Virtus; 28th Apr 2013 at 22:47.
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I notice its those cheap and nasty low cost outfits
who make a real song and dance about ordering a
"good" level of fuel.
One would swear blind an extra 100kg on a 737 or
320 is literally bankrupting 'em. They also make a
huge bloody stink about actual arrival fuel too so
I'm told, if its more than 200kg over CFP.
who make a real song and dance about ordering a
"good" level of fuel.
One would swear blind an extra 100kg on a 737 or
320 is literally bankrupting 'em. They also make a
huge bloody stink about actual arrival fuel too so
I'm told, if its more than 200kg over CFP.
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To be fair Slasher I have never been given stick about even taking full tanks.
Its when you bang on min and offload that the pillocks come out the wood work.
I have learn't though that if you don't even engage them in discussion eventually they don't bother even trying to bully you which is what it is.
Its when you bang on min and offload that the pillocks come out the wood work.
I have learn't though that if you don't even engage them in discussion eventually they don't bother even trying to bully you which is what it is.
