Engine Start
ENGINE START
Engine No. 3 may be started before, during, or after pushback. Engine 1 and 2 may be started only after tow bar has been disconnected and visually confirmed to be clear of the aircraft.
At start clearance, the engineer places pack switches to CLOSE and checks that pack pressure increases to manifold pressure. Place selector switch to MANIFOLD. If pressure is low, or if R and L are different, verify that bleed switches are OPEN and wing anti-ice valves are closed.
Normal start sequence is 3, 1, 2, unless conditions dictate otherwise.
The captain ensures the beacon light is on.
The pilot non flying holds number 3 start switch to GROUND, notes time, checks the STARTER VALVE OPEN light on, and observes N2 rotation within 10 seconds.
The engineer monitors manifold pressure for proper indications and oil pressure within 30 seconds of rotation.
When N2 reaches 20% and N1 is increasing, the pilot flying moves start lever to IDLE and observes fuel flow meter.
After lightoff, verify that EGT and RPM increase steadily until the engine attains idle speed.
Release start switch when engine reaches 40% N2. Check that STARTER VALVE OPEN light is out.
As engine reaches idle speed the engineer.
Checks CSD low oil pressure light out.
Checks manifold pressure increases after start switch is released.
Checks generator voltage and frequency are within limits.
Records engine start time on the fuel log.
Use the same procedure to start the other engines. When starting engines 1 and 2, engineer checks system A hydraulic pressure increases and pump low pressure light goes out.
TRANSITION FROM EXTERNAL OR APU POWER TO AIRPLANE POWER
To automatically parallel a generator,
Position the AC METERS selector to the generator to be paralleld.
Observe the sync lights.
Adjust the generator frequency to obtain greatest interval between flashes.
Hold the generator GB switch to CLOSE.
Repeat that for all 3 generators before shutting down the APU.
TAXI
All engines must be used for taxi if:
One or two-engine taxi is prohibited.
Temperature at or below freezing and visible moisture present.
Ramp areas or taxiways are slippery.
ALL ENGINE TAXI
ELECTRICAL POWER CHANGEOVER
Check voltage and frequency of generator No. 3. Select essential power to generator No. 3 and close its main generator relay. Close the remaining main generator relays after checking the generator voltage and frequency.
After all generators are operating, check essential power to generator No. 1 and No. 2 to confirm speed switch and essential relay operation. Return essential selector to No. 3 position.
BLEED AIR
After all engines are at idle, place engine 2 bleed switches to CLOSE.
Place one pack switch to OPEN, and verify pack cooling fan operation by KW load increase. When electrical load stabilizes, place the other pack switch to OPEN and verify pack cooling fan operation.
TWO-ENGINE TAXI
Start all engines if heavy weight, slope or tight maneuvering requires excessive thrust to leave the gate area. Shut down No. 3 engine when clear of the gate area.
Engine No. 3 may be started before, during or after pushback. Start engine No. 1 only after tow bar has been disconnected. Engines 1 and 3 must be utilized to commence taxi.
ELECTRICAL POWER CHANGEOVER
Check voltage and frequency of generator No. 3. Select essential power to generator No. 3 and close its main generator relay
Close No. 1 main generator relay. Monitor electrical loads and reduce if necessary.
BLEED AIR
Leave engine No. 2 bleed switches open and use the APU for pack air.
Place one pack switch to OPEN, and verify pack cooling fan operation by KW load increase. When electrical load stabilizes, place the other pack switch to OPEN and verify pack cooling fan operation.
TAXI
Turn on both hydraulic system B pumps.
Limit thrust to 45% N1 or 1.1 EPR in the gate area and allow additional time for the aircraft to begin moving.
Leave one boost pump on in each tank and crossfeed as necessary to maintain fuel load limits.
START ENGINE 2
When ready to start engine No. 2, close both pack switches and ensure that engine No. 2 bleed switches are open. The APU is preferred for starting engines.
When voltage and frequency on generator No. 2 are within limits, close its main generator relay. Move essential power selector switch to generators No. 1 and No. 2, then to generator No. 3 position.
After all engines are at idle, place engine 2 bleed switches to CLOSE.
Place one pack switch to OPEN, and verify pack cooling fan operation by KW load increase. When electrical load stabilizes, place the other pack switch to OPEN and verify pack cooling fan operation.
Complete the Delayed Engine Start checklist.
ONE-ENGINE TAXI
Start all engines if heavy weight, slope, or tight maneuvering requires excessive thrust to leave the gate area. Shut down engine No. 3 when cleared of the gate area. Shut down engine No. 2 when desired.
ENGINE START
Engine No. 3 may be started before, during or after pushback. Start engine No. 1 only after tow bar has been disconnected.
ELECTRICAL POWER CHANGEOVER
Check voltage and frequency of generator No. 1. Select essential power to generator No. 1. Use the APU generator to power the main AC busses.
BLEED AIR
Leave engine No. 2 bleed switches open, and operate both air conditioning packs using APU air.
Place one pack switch to OPEN and verify pack cooling fan operation by APU amperes load increase. When electrical load stabilizes, place the other pack switch to OPEN and verify pack cooling fan operation.
TAXI
Open brake interconnect.
Turn on both hydraulic system B pumps.
Limit thrust to 45% N1 or 1.1 EPR in the gate area and allow additional time for the aircraft to begin moving.
Leave one boost pump on in each tank and crossfeed as necessary to maintain fuel load limits.
START REMAINING ENGINES
When ready to start engines 2 and 3, close both pack switches and ensure that all bleed switches are open. The APU is preferred for starting engines, but the Cross Start procedure may be used.
After all engines are at idle, place engine No. 2 bleed switches to CLOSE.
Place one pack switch to OPEN and verify pack cooling fan operation by KW load increase. When electrical load stabilizes, place the other pack switch to OPEN and verify pack cooling fan operation.
Complete the Delayed Engine Start checklist.
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