Here's the fuel sequence, taken from B-52H Stratofortress Flight Manual.
STEP 1 - TAKEOFF
-aft body tank to engine 1 & 2
-No 2 main tank to engine 3 & 4
-No 3 main tank to engine 5 & 6
-center wing tank to engine 7 & 8
note: for takeoff with main tank No 1 & No 4 above green band and center wing and aft body tank containing 2,000 lbs or more each
or
-mains to all engines (respective)
Note: for takeoff with main tank 1 & 4 above green band and either center wing or aft body tank less than 2,000 lbs
or
-mains to all engines (crossfeed valves open)
note: for takeoff with main tank 1 or 4 in green band. Open all crossfeed valves (9, 10, 11, 12)
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STEP 2
-aft body tank to engine 1, 2, 3 & 4
-center wing tank to engine 5, 6, 7 & 8
Note: maintain until center wing tank empty
STEP 3
-aft body tank to engine 1, 2, 3 & 4
-forward body tank to engine 5, 6, 7 & 8
Note:retain 3,000 lbs forward body fuel (ballast) if operating weight center gravity aft of 23% MAC, otherwise fwd body until empty
STEP 4
-mid body to all engines
Note:maintain until mid body empty
STEP 5
-aft body to all engines
Note: maintain until 6,000 lbs left in tank
STEP 6
-aft body tank to engine 1, 2, 7, 8
-No 2 main tank to engine 3 & 4
-No 3 main tank to engine 5 & 6
Note: maintain until aft body tank empty
STEP 7
-mains to all engines (understand each main tank feeds its respective engines)
Note:mains No 1 and No 4 to green band. After this step, mains No 2 and No 3 will be in green band area
STEP 8
-left external to engine 1 & 2
-No 2 main to engine 3 & 4
-No 3 main to engine 5 & 6
-right external to engine 7 & 8
Note: maintain until external tanks empty
STEP 9
-left outboard to engine 1 & 2
-No 2 main to engine 3 & 4
-No 3 main to engine 5 & 6
-right outboard to engine 7 & 8
Note:use 5,000 lbs from each tank
STEP 10
-left outboard to engine 1, 2, 3 & 4
-right outboard to engine 5, 6, 7 & 8
Note:maintain until outboard tanks empty
STEP 11
-forward body tank (ballast) to all engines (not through main tanks, use main manifold)
Note: maintain until forward body tank empty
STEP 12
-mains to all respective engines
Note: when any main is down to 5,000 lbs, open all crossfeed valves (9, 10, 11 & 12)
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ALL LANDINGS, TRANSITION AND LOW APPROCHES
-mains to all engines
Note:with main No1 and No4 above green band area, close all crossfeed valves (9, 10, 11 & 12)
or
-mains to all engines (crossfeed valves open)
Note:with main No1 or No4 in green band area, open all crossfeed valves (9, 10, 11 & 12)
Note:with any main down to 5,000 lbs, open all crossfeed valves (9, 10, 11 & 12)
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General note
In the fuel sequence above, fuel from auxiliary tanks is transfered directly to the engines through the main manifold and not through the main tanks. During the entire fuel sequence, fuel level control valves switches (19, 20, 21, 22 on fuel panel) are kept closed at all time.
When auxiliary fuel is being used, main tank boost pump switches remain ON. The boost pump in the auxiliary tanks are of higher capacity than boost pumps in the main tanks thus allowing a pressure override condition to exist. When an auxiliary tank runs dry, the main tank boost pumps take over fuel supply to the engines with no interruption in fuel flow.
External tanks when full, act as wing tips oscillation/vibration damper. So make sure before you leave that they are filled up to capacity, even for a short distance flight.
Thanks