(8)  
Position flap control lever in 1-unit detent. Check that leading edge devices do not move.

(9)  
Position flap control lever in FLAP UP detent.

(a)  
Check that respective EXT green light extinguishes and respective amber TRANSIT light illuminates as each flap or slat unlocks and starts to retract.

(b)  
Check that when each flap and slat is in up and faired position the respective amber light extinguishes and no green lights are illuminated.

(c)  
On center instrument panel, check that all lights extinguish as last flap or slat locks in up position.

(10)
Check normal leading edge flap and slat operating time.

(a)  
Close hydraulic ground interconnect valve and turn OFF hydraulic system B pumps No. 1 and 2.

(b)  
Provide system A hydraulic power using hydraulic service cart set at 20 gpm and 3000 psi or using at least one engine-driven pump. Refer to 29-11-0, Hydraulic System A – Maintenance Practice.

(c)  
If service cart is used for pressurizing, ensure parking brake is set, then open hydraulic ground interconnect valve.

(d)  
Position flap control lever in 1-unit detent position.

(e)  
Check that leading edge flaps are fully extended and locked and slats are in intermediate position and locked within 6 seconds after unlocking from up position.

(f)  
Position flap control lever in 10-unit detent.

(g)  
Check that all slats are fully extended and locked within 1.6 seconds after unlocking from intermediate position.

(h)  
Position flap control lever in 40-unit detent position, then return flap control lever to 10-unit detent. No change in leading edge flap or slat position or indicator light illumination shall occur.

(i)  
Position flap control lever in 1-unit detent position.

(j)  
Check that all slats are locked in intermediate position within 4 seconds after unlocking from down position.

(k)  
Position flap control lever in FLAP UP detent.

(l)  
Check that leading edge flaps and slats retract within 9 seconds after unlocking from down and intermediate position.

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NOTE:  If lights function properly with hydraulic pressure applied, disregard amber light indications which may occur if hydraulic pressure is removed.
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27-81-0  Feb 15/73
Page 520
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

(11) Check leading edge flap and slat alternate system operation: 
(a)  
Ensure hydraulic system A is pressurized and flap control lever is in FLAP UP detent.

(b)  
Actuate alternate flap arming switch to ARM position. 1) Check that STANDBY HYD LOW PRESSURE light comes on. 2) Check that standby hydraulic pump starts and that STANDBY HYD LOW

PRESSURE light is off. 3) Check that trailing edge flap bypass valve moves to position 2. 4) Check that leading edge flaps and slats do not extend.
NOTE:  This verifies that leading edge standby drive shutoff valve is in correct position.
(c)  
Position flap control lever to 40-unit detent. Check that leading edge flaps and slats do not respond.

NOTE:  Flap control lever is moved to 40-unit detent as a standard procedure to minimize load on flap hydraulic motor when hydraulic system A is pressurized.

(d)  
Actuate alternate flap drive control switch to DOWN position.

CAUTION:  DO NOT OPERATE ALTERNATE FLAPS DRIVE MOTOR FOR MORE THAN 4 MINUTES IN A 25-MINUTE TIME SPAN. DRIVE MOTOR MAY OVERHEAT.
1)  Check that leading edge flaps and slats are fully extended in 15 +4 seconds from time flaps start to move.
(e)  
Position alternate flap drive control switch to OFF position.
1) Check that the leading edge flaps and slats do not move.

(f)  
Position flap control lever to FLAP UP detent. Check that leading edge flaps and slats do not respond.

(g)  
Position alternate flap arming switch to OFF position.
1) Check that standby hydraulic pump stops.
2) Check that trailing edge flap bypass valve moves to position 1.
3) Check that leading edge flaps and slats fully retract.

NOTE: Retraction is due to hydraulic system A being pressurized.

(h)  
Depressurize system A hydraulic system and system B hydraulic system (Ref 27-81-00 MP).