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 A 747's Instrument Panel Question?
 Mr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 8Posted Wed Jul 24 2002 19:25:51 UTC (13 years 10 months 1 week 5 days 11 hours ago) and read 6783 times:

 Hi guys. I have a great poster at home of the cockpit of KLM's 747 named "Wilbur Wright" (PH-BUI). I was looking at it today, and started wondering about the gauge in the middle of the panel that's titled "FF". What does it stand for? My amateur educated guess tells me it means Fuel Flow, but I would like to know for sure. Here's some photos...the first one is very interesting because of the #4 engine failure. View Large View MediumPhoto © Mulder View Large View MediumPhoto © Patrick Lutz Chris
 "Just a minute while I re-invent myself"
 FDXmech From United States of America, joined Mar 2000, 3251 posts, RR: 30 Reply 1, posted Wed Jul 24 2002 19:44:39 UTC (13 years 10 months 1 week 5 days 11 hours ago) and read 6759 times:

 Correct! FF stands for Fuel Flow in Pounds Per Hour (PPH)X 1,000. In other words the 1 = 1,000 pounds per hour or 12 = 12,000 PPH. 1 gallon of jet A weighs approx 6.7 lbs. I've seen this vary from 6.7 - 6.8 lbs per gallon. FF can also be measured in Kgs.
 You're only as good as your last departure.
 B747skipper From , joined Dec 1969, posts, RR: Reply 2, posted Wed Jul 24 2002 19:47:32 UTC (13 years 10 months 1 week 5 days 11 hours ago) and read 6761 times:

 Dear Spaceman - FF means fuel flow, calibrated in lbs/hour or kg/hour (airline option)... KLM uses kg for weight and fuel units... The picture shows the "tape gages option" as well as was found in airplanes of the KSS group (KLM, SAS and Swissair) which agreed on common equipment and configurations for their aircraft. The "standard configuration" of the 747 is quite different (i.e. "round gages")... (s) Skipper
 Mr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 8 Reply 3, posted Wed Jul 24 2002 19:59:43 UTC (13 years 10 months 1 week 5 days 10 hours ago) and read 6754 times:

 Thank You Gentlemen. I've had this poster of PH-BUI's cockpit since I was 14 and now I'm almost 36. I figured it was about time I asked what those letters "FF" stood for. Thanks Again. PS, How's the weather in your part of the world? Here in Toronto it's +25 C, with a nice sunny sky dotted with broken heap clouds. It's a beautiful day today. Chris
 "Just a minute while I re-invent myself"
 B747skipper From , joined Dec 1969, posts, RR: Reply 4, posted Thu Jul 25 2002 09:08:48 UTC (13 years 10 months 1 week 4 days 21 hours ago) and read 6697 times:

 Hi Spaceman - Weather here Argentina is winter, drizzle and wind, near freezing at night... but we revenge ourselves from DEC through MAR, we have barbecues at the beaches for Xmas... Since you are a metric guy obviously, the weight of a liter of jet fuel is 815 grams at the temperature of 15C. We never think about fuel in terms of gallons or liters, except when I sign the fuel bill from the supplier, we think about it as weight (kilos outside USA)... (s) Skipper
 Wardialer From United States of America, joined Sep 2001, 1201 posts, RR: 0 Reply 5, posted Wed Jul 31 2002 06:09:22 UTC (13 years 10 months 6 days ago) and read 6612 times:

 Let's say I filled my car to 10.5 Gal. of gasoline, how many pounds would that be? But I think gasoline differs in weight compared to jet fuel though. But I just want to be sure.
 B747skipper From , joined Dec 1969, posts, RR: Reply 6, posted Wed Jul 31 2002 08:07:37 UTC (13 years 10 months 5 days 22 hours ago) and read 6598 times:

 Dear Wardialer - Each liquid or solid (or gas) has a specific gravity... Water is 1... some liquids are heavier, some are lighter than water... Jet fuel (Jet A, Jet A-1) has specific gravity of .813... meaning that the weight of jet fuel is lighter than water... .813 % of the weight of water... Gasoline, aviation or car gasoline has specific gravity of .69... so, it is lighter than water, and jet fuel... Since you ask me for lbs and gallons (the above is easier with metric units), a gallon of gasoline is 6 lbs, and a gallon of jet fuel is 6.75 lbs... So if you put 10.5 gallons of gasoline in a car or airplane, it weighs about 63 lbs... xxx The cooler the gasoline (or jet fuel gets) the heavier it becomes for that gallon of volume... and the warmer it gets, the lighter it gets as well... As an example, jet fuel weighs only some 6.68 or 6.7 lbs per gallon when hot on a summer day... xxx An advise to you and all those who read this... you buy gas by volume (litre or gallons) but your engine only knows its weight... so buy fuel when it is cold such as early in the morning... you will save, a little, if you do so... xxx A 747 may need a lot of fuel (we think by weight, we burn it by weight) yet, we pay the bill by volume, can make a difference when we get the fuel... All the best... (s) Skipper
 PW4084 From United States of America, joined Mar 2001, 291 posts, RR: 0 Reply 7, posted Wed Jul 31 2002 08:15:00 UTC (13 years 10 months 5 days 22 hours ago) and read 6592 times:

 Gasoline is lighter than kerosene (Jet Fuel)... the general relationship is 6 LB/Gallon. So I'd say you have 63 Lb of Gasoline PW4084
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