H. N1 Tach Signal Test
NOTE: Two alternate N1 tach signal procedures are provided:
1 - using the Quantum Dynamics Simulator [Ref. par. 2.G.(1)] 2 - using a signal generator [Ref par. 2.G.(2) connected at the engines]
(1) N1 tach signal test using Quantum Dynamics Simulator
(a)
For each engine, disconnect the N1 Tach Generator by disconnecting D546 located inside the engine nose dome.
(b)
Connect N1 simulator adapter cable to simulator and each of the two engines.
(c)
Engage the autothrottle.
(d)
Set N1 simulator to 3600 ± 180 rpm.
(e)
On the Captain's Mach/Airspeed indicator, set the bug to 340 knots and check that all thrust levers drive forward.
(f)
Restrain the thrust levers near mid-position, maintaining less than 8 degrees thrust lever split to prevent autothrottle disengagement.
(g)
Increase indicated rpm to 4800 rpm. Check that the autothrottle trips at approximately 4380 rpm and both thrust levers retard.
(h)
Remove N1 simulator and reconnect the connectors disconnected in step (a).
(a)
Remove and disconnect the N1 Tach Indicators N34 and N35 on the center instrument panel.
(b)
For each engine, disconnect the N1 Tach Generator by disconnecting D546 located inside the engine nose dome.
(c)
Connect signal generator to connector D546P such that the output signal is applied between Pin A and the aircraft structure.
(d)
Engage the autothrottle and set both F/D switches to ON. Verify that the IAS/MACH window on the AFCS control panel indicates 325 knots. Verify that SPEED is annunciated on the FMA's.
(e)
Set signal generator (N1 Tach Simulator) to provide 60 +5 Hz for the engine being tested and no tach signal for the other engine.
NOTE: The signal must be greater than 10 VAC (RMS) and less than 26 VAC (RMS).
(f)
Select 340 knots on AFCS control panel and check that both thrust levers drive forward. Restrain the thrust levers near the mid-position.
(g)
Increase the frequency of the simulated N1 Tach Signal to 80 +4 Hz for the engine being tested and check that the thrust lever for the engine being tested drives aft while the other thrust lever continues to drive forward. Restrain the thrust levers near the mid-position.
NOTE: The signal shall be greater than 10 VAC (RMS) and less than 26 VAC (RMS).
(h)
Decrease the frequency of the simulated N1 Tach Signal to 60 +5 Hz for the engine being tested and check that both thrust levers drive forward. Restrain the thrust levers near mid-position.
(i)
Select 325 knots on the AFCS control panel.
(j)
Repeat steps (c) thru (h) for second engine.
(k)
Disengage the autothrottle and reset the lights.
(l)
Return landing gear handle to DOWN position.
(m)
Disconnect N1 Tach Signal Simulator and reconnect connector D546P to its mating connector for each engine. Lockwire these connectors.
(n)
Reinstall the N1 tach indicators.
NOTE: Run engines to check N1 indicators prior to next flight.
5B8
Oct 20/84 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 22-31-01 Page 517
NOTE: Run engines to check N1 readings before flight.
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22-31-01 Page 518 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Jan 20/83
I. Flare Retard and Go-Around (GA) Engage Test
(1)
Establish the following initial conditions:
(a)
Simulated airspeed: 150 knots
(b)
Radio altitude: 1800 feet
(c)
Flap position: 25 degrees
(2)
Verify that angle-of-airflow sensor vane is set at 2 degrees trailing edge up.
(3)
Engage one channel of the autopilot.
(4)
Adjust the localizer and glide slope deviations to zero.
(5)
Press APP ON on AFCS Control panel.
(6)
Set A/T ARM switch to ARM on AFCS control panel.
(7)
Place thrust levers at mid-position (half way forward).
(8)
Verify that SPEED is annunciated on FMA's in A/T section.
(9)
Slowly reduce the radio altimeter towards zero starting at 40 feet altitude. As the altitude is reduced thru 27 ±3 feet, verify that autothrottle annunciation changes from SPEED to RETARD.
(10)
Press the Go-Around switches on thrust levers. Verify that thrust levers drive forward. Verify that EPR is annunciated on FMA's and that RETARD drops out and that autopilot disengages.
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