B744 Oil Quantity
Thread Starter
Joined: Mar 2007
Posts: 11
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From: England
B744 Oil Quantity
From the FCOM - "The oil quantity indication changes color to magenta if low oil quantity is detected or if the oil quantity differential is exceeded."
Can any engineers shed any light on what this differential is?
Thanks
Durango
Thanks
Durango
Joined: May 2005
Posts: 187
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From: Standing at P37
Your answer in Magenta has "popped-up" from the -400 manual below;
Difference Quantity
Oil Quantity Difference Monitoring begins when;
•At least 2 Engines are running within 2% N1 RPM, and
•The change in altitude of the Airplane is less than 200 feet/min or the aircraft is on the ground motionless.
An automatic pop-up of all oil parameters occurs when the difference in oil quantity between the high and low quantity Engine is 7 Litres
for greater than 180 seconds;
•The indication, which represents the low quantity Engine, will turn magenta in colour at the differential limit.
.
Difference Quantity
Oil Quantity Difference Monitoring begins when;
•At least 2 Engines are running within 2% N1 RPM, and
•The change in altitude of the Airplane is less than 200 feet/min or the aircraft is on the ground motionless.
An automatic pop-up of all oil parameters occurs when the difference in oil quantity between the high and low quantity Engine is 7 Litres
for greater than 180 seconds;
•The indication, which represents the low quantity Engine, will turn magenta in colour at the differential limit.
.
Joined: Aug 2007
Posts: 118
Likes: 0
From: Seattle KBFI
"During cruise, oil quantity displays on EICAS whenever oil quantity on one
engine differs from any other engine by a predetermined amount. When this
occurs, the lowest oil quantity is shown in magenta. If there is an increase in oil
quantity during cruise (indicator malfunction or leaking fuel/oil heat exchanger),
the EICAS oil partial engine indications display may appear. However, for this
condition the low quantity displays in magenta, even though that oil quantity may
be normal."
I thought the quantity difference was 5 quarts, but they have removed the number from the FHB. Perhaps a customer specific option?
engine differs from any other engine by a predetermined amount. When this
occurs, the lowest oil quantity is shown in magenta. If there is an increase in oil
quantity during cruise (indicator malfunction or leaking fuel/oil heat exchanger),
the EICAS oil partial engine indications display may appear. However, for this
condition the low quantity displays in magenta, even though that oil quantity may
be normal."
I thought the quantity difference was 5 quarts, but they have removed the number from the FHB. Perhaps a customer specific option?
