Service Bulletin

18 October 2013 340–27–116

Page 1 of 22

ATA CHAPTER: 27

FLIGHT CONTROLS – STALL WARNING/IDENTIFICATION SYSTEM – TEMPORARY

DEACTIVATION OF STALL WARNING ICE SPEED CURVES

Mod No. 3522

1. PLANNING INFORMATION

A. EFFECTIVITY

(1) Aircraft:

Aircraft Mfg. Serial No’s SAAB SF340A – 004–159.

Aircraft Mfg. Serial No’s SAAB 340B – 160–169, 171–341, 343–361, 364–366, 368–371, 373–378,

380–384, 386–394, 396–404, 406–408, 410–430, 432–454, 456–459.

NOTE: This Service Bulletin is only applicable for A/C POST Service Bulletin SAAB

340–27–098 (Mod No 3312) or POST Service Bulletin SAAB 340–27–099 (Mod No

3313).

(2) Spares: Not affected.

B. REASON

After implementation of the new stall warning computer with increased stall warning levels (stick shaker

at higher aircraft speed) with Engine Anti Ice selected ON, Saab has received several reports of

premature activation of the increased stall warning level. In the reported cases the activation has been

initiated during takeoff prior to the intended time delay of 6 minutes after lift–off.

The increase in stall warning level is inhibited for the first 6 minutes after lift–off. This is the segment

when the aircraft is operating at low speed and there is no ”ice” speed increment. Too early initiation

is a potential unsafe condition since the failure rate has been greater than predicted.

The implementation of the new stall warning computers are mandated by EASA AD 2011–0219 and

FAA AD 2012–24–06 based on Saab SB 340–27–097 (MOD 3311) for provision and SB 340–27–098

(MOD 3312) or SB 340–27–099 (MOD 3313) for activation.

At this stage, Saab, together with the supplier of the Stall Warning Computer, is investigating the reason

for the premature activation and until the investigation is finished, no permanent action has been

defined.

This SB provides the instructions for temporary deactivation of the increased stall warnings level.

The non–icing stall warning (stick shaker) and stall indent (stick pusher) functions remains unchanged

after deactivation.

The deactivation of the system is temporary and when the reason for the deficiency is identified and

a corrective action has been determined the system should be reactivated by instructions from Saab.

No additional limitations or procedures for operating in icing conditions are imposed after the

deactivation and the aircraft shall be operated in accordance with the recommendations for an

unmodified aircraft, i.e. pre Saab Service Bulletin 340–27–098 (MOD 3312) or 340–27–099 (MOD

3313).
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C. DESCRIPTION

This Service Bulletin gives instructions for:

– parking of wires at the stall warning computers and at the circuit breaker panel 10VU

– open and safening of circuit breaker ”SW ICE IND” at 12VU

– installation of a ”INOP” sign at the ICE SPEED push–button switch at the instrument panel 1VU

– functional test of the stall warning/identification system.

D. COMPLIANCE

Mandatory

To be performed within 28 days from first release date of this Service Bulletin.

This Service Bulletin is under EASA consideration for an Airworthiness Directive.

The final compliance terms will be set by the EASA Airworthiness Directive when issued.

E. APPROVAL

This Service Bulletin is developed and approved under the authority of DOA nr. EASA.21J.066. 

The change addressed in the bulletin is classified as ”Major” in accordance with EC regulation

1702/2003 Part 21A.91 and is approved by the European Aviation Safety Agency, 

Ref. EASA No. 10046621.

F. MANPOWER

Estimated time to complete this Service Bulletin is:

2 person required.

NOTE: 2 persons required during the test procedure

Total manhours: 6

Elapsed time (hours): 4

Labour cost at operators expense.

G. MATERIAL – COST AND AVAILABILITY

Local supply.

H. TOOLING

(1) Insert/Removal tool M81969/14–01 (for removal of contacts/wires from 3WH–P1 and 4WH–P1).

(2) Angle of attack (AOA) calibration tools:

– TES–4054332–001 (LH)

– TES–4054332–002 (RH).

(3) Weight on wheels (WOW) switches operating tool, TDO 5–4650224.

I. WEIGHT AND BALANCE

None.
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J. ELECTRICAL LOAD DATA

RH Bat Bus: –170 mA when Engine Anti Ice is set to ON.

RH Bat Bus: –50 mA when lamps are in DIM mode.

RH Bat Bus: –60 mA when weight on wheel is true.

K. REFERENCES

Aircraft Maintenance Manual (AMM) 06–30–00 Description / Operation

12–00–00 Servicing

24–00–00 Maintenance practices

25–11–05 Removal/Installation

Wiring Manual (WM) 20–00–00 Standard practices

L. OTHER PUBLICATIONS AFFECTED

Not affected.

2. ACCOMPLISHMENT INSTRUCTIONS

CAUTION: BE CAREFUL WHEN YOU DO THE MODIFICATION OF THE HARNESS. MAKE SURE

THAT YOU DO NOT DAMAGE THE EXISTING WIRES. CLEAN AND INSPECT THE

AFFECTED HARNESS WHEN THE MODIFICATION IS COMPLETED. DAMAGES TO

THE WIRES CAN CAUSE SYSTEM MALFUNCTION.

NOTE: All wiring changes are to be performed in accordance with the procedures in the WM

20–00–00.

A. JOB SET–UP

(1) Before you start the SB, make sure:

– The local supply items listed in the Service Bulletin are available

– The documentation is available

– The special tools are available.

(2) Make the aircraft safe for maintenance:

(a) Isolate the electrical power (Ref. AMM 24–00–00, maintenance practices).

(3) Open for access (Ref. AMM 06–30–00)

FOR A/C 004–078

(a) Remove the LH flight crew seat (Ref. AMM 25–11–05).

(b) At the avionics rack, remove the fwd access panel 210AZ (Ref. AMM 06–30–00).

FOR A/C 079–459

(c) At the avionics rack, remove the aft access panel 220AZ (Ref. AMM 06–30–00).

FOR A/C ALL

(d) Loosen the screws that attach the circuit breaker panel 10VU to the structure and lower the

panel.
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B. MODIFICATION

REF. FIG. 1

(1) At the circuit breaker panel 12VU position S–28:

(a) Open the circuit breaker ”SW ICE IND” 2WHC.

(b) Use a cable–tie to safety the circuit breaker ”SW ICE IND” 2WHC in open position.

(2) At the circuit breaker panel 10VU, locate the circuit breaker 36WH.

(a) Disconnect, park and stow the wire WHC36–16:

REF. FIG. 2 and 3

Wire No: Class: From: Contact: To: Contact: Remarks:

WHC36–16 A 36WH:L/1 36WH:911

(b) Use shrink sleeve RNF–100 to insulate the terminal lug and park the wire.

(3) At the stall warning computers 3WH and 4WH, disconnect the connectors 3WH–P1 and 4WH–P1.

FOR A/C 004–078

(a) Disconnect, park and stow these wires:

REF. FIG. 2

Wire No: Class: From: Contact: To: Contact: Remarks:

WHC16–24 A 4WH–P1:7 4WH–P1:911

WHC17–24 A 3WH–P1:7 3WH–P1:911

WHC18–24 A 4WH–P1:15 4WH–P1:911

WHC39–24 A 3WH–P1:15 3WH–P1:911

(b) Use shrink sleeve RNF–100 to insulate the contacts and park the wires.

FOR A/C 079–459

(c) Disconnect, park and stow these wires:

REF. FIG. 3

Wire No: Class: From: Contact: To: Contact: Remarks:

WHC44–24 A 4WH–P1:15 4WH–P1:911

WHC45–24 A 4WH–P1:7 4WH–P1:911

WHC46–24 A 3WH–P1:15 3WH–P1:911

WHC47–24 A 3WH–P1:7 3WH–P1:911

(d) Use shrink sleeve RNF–100 to insulate the contacts and park the wires.

FOR A/C ALL

(4) Connect the connectors 3WH–P1 and 4WH–P1 to the stall warning computers 3WH and 4WH.

C. INSTALLATION

REF. FIG. 1

(1) Make a label with the text ”INOP” and install on top of the existing label ”ICE SPD CANCEL” to

cover the existing label. (At 1VU adjacent to the ICE SPEED push–button switch).
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D. FUNCTIONAL TEST

FOR A/C POST Service Bulletin SAAB 340–27–098 (Mod No 3312)

(1) Prepare the aircraft for test:

CAUTION: BE CAREFUL WHEN YOU MOVE THE VANES. MOVE THE VANES IN A

GENTLY WAY. DAMAGE TO THE VANES CAN OCCUR IF YOU PUSH THEM

HARD TO THE OUTER POSITIONS.

(a) Fasten the Angle of Attack (AOA) calibration tools to the LH and the RH AOA transmitters:

– (LH) TES–4054332–001

– (RH) TES–4054332–002.

(b) Turn the LH AOA vane fully clockwise.

(c) Turn the RH AOA vane fully counter–clockwise.

(d) Make sure the flaps are at 0.

(e) On the LH circuit breaker panel 11VU, close the circuit breaker:

LABEL POS C/B

STAB & WING AUT CTL K–21 1HP

(f) On the overhead panel STAB & WING 18VU, set the switch AUTO CYCLING to OFF.

(g) On the overhead panel ENGINE 42VU, set the L and R Engine Anti–Ice to OFF.

(h) On the LH circuit breaker panel 9VU, open the circuit breaker:

LABEL POS C/B

STALL WARN CHAN 1 E–7 13WH

(i) On the RH circuit breaker panel 10VU, open these circuit breakers:

LABEL POS C/B

STALL WARN CHAN 2 L–6 2WH

STICK PUSHER L–4 36WH

(j) Supply the 28 VDC external power (Ref. AMM 12–00–00, servicing).

(k) At 1VU, make sure that the blue indication light in the ICE SPEED push–button switch is OFF.

(2) Do the test of the stall warning functions, flap 0and non–icing condition:

(a) On the CWP, make sure the amber caution–lights L STALL FAIL and R STALL FAIL are

illuminated.

(b) On the RH circuit breaker panel 10VU, close the circuit breaker:

LABEL POS C/B

STICK PUSHER L–4 36WH

(c) On the CWP, make sure the amber caution–lights L STALL FAIL and R STALL FAIL remains

ON.

(d) On the RH circuit breaker panel 10VU, open the circuit breaker:

LABEL POS C/B

STICK PUSHER L–4 36WH
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(e) On the LH circuit breaker panel 9VU, close the circuit breaker:

LABEL POS C/B

STALL WARN CHAN 1 E–7 13WH

(f) On the CWP, make sure the L STALL FAIL amber caution–light goes off.

(g) On the RH circuit breaker panel 10VU, close the circuit breakers:

LABEL POS C/B

STALL WARN CHAN 2 L–6 2WH

(h) On the CWP, make sure the R STALL FAIL amber caution–light goes off.

(i) At the LH and the RH main landing–gear, install the WOW operating tool (TDO 5–4650224)

on the WOW switches 5GA and 6GA in flight position.

(j) Turn the LH AOA vane counter–clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the LH and the RH control columns

– the aural warning (continuous clacker).

(k) Make sure the measured angle from the LH calibration tool is 12.5 ± 1.

(l) Turn the LH AOA vane clockwise until the stall warning stops.

(m) Turn the RH AOA vane clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the RH and the LH control columns

– the aural warning (continuous clacker).

(n) Make sure the measured angle from the RH calibration tool is 12.5 ± 1.

(o) Turn the RH AOA vane counter–clockwise until the stall warning stops.

(3) Do the test of the stall identification functions, flap 0and non–icing condition:

(a) On the RH circuit breaker panel 10VU, close the circuit breaker:

LABEL POS C/B

STICK PUSHER L–4 36WH

(b) Make sure the PUSHER DISARM switch lights (31WH and 32WH) on the LH and RH side

panels 5VU and 6VU do not come on. 

If the PUSHER DISARM switch lights (31WH and 32WH) come on, proceed as follows:

1 Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical

center 306VU to the ACTIVE position and release it. Make sure the PUSHER DISARM

lights goes off.

(c) Turn the RH AOA vane slowly clockwise until the PUSH 2 lights of the indicator lights (1WH

and 6WH) on the LH and RH instrument panels 3VU and 4VU come on. 

Make sure the PUSHER SYSTEM amber caution–light on the CWP (3WW) comes on.

(d) Make sure the measured angle from the RH calibration tool is 19± 1.

(e) Turn back the RH AOA vane slowly until the PUSH 2 lights goes off.

(f) Pull the control column fully aft.
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CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(g) Turn the LH AOA vane slowly counter–clockwise until the stick pusher is operated. Make sure

the PUSH 1 and the PUSH 2 lights come on at the same time.

(h) Make sure the measured angle from the LH calibration tool is 19± 1.

(i) Turn back the LH AOA vane to an angle between the stall warning and the stall identification,

e.g. 16. Make sure the PUSH 1 and the PUSH 2 lights are on.

(j) Turn the RH AOA vane fully counter–clockwise. Make sure the stick pusher is deactivated

and the PUSH 1 and the PUSH 2 lights goes off.

CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(k) Turn the RH AOA vane slowly clockwise until the PUSH 1 and the PUSH 2 lights come on

and the pusher is operated.

(l) Turn the RH AOA vane back to, e.g. 16and make sure the PUSH 1 and the PUSH 2 lights

are still on and the pusher is operated.

(m) Turn the LH AOA vane fully clockwise and make sure the PUSH 1 and the PUSH 2 lights goes

off and the pusher is deactivated.

(n) Turn the RH AOA vane fully counter–clockwise.

(4) Do the test of the stall identification functions, flap 35and non–icing condition:

(a) Set the flap selector to 35.

(b) Make sure that the PUSHER DISARM switch lights (31WH and 32WH) on the left and the

right side panels 5VU and 6VU not are on. 

If the PUSHER DISARM switch lights (31WH and 32WH) are on, proceed as follows:

1 Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical

center 306VU to the ACTIVATE position and release it. Make sure the PUSHER

DISARM lights goes off.

(c) Turn the RH AOA vane slowly clockwise until the PUSH 2 lights of the indicator lights (1WH

and 6WH) on the left and right instrument panels 3VU and 4VU come on. 

Make sure the PUSHER SYSTEM amber caution–light on the CWP (3WW) comes on.

(d) Make sure the measured angle from the RH calibration tool is 20° ± 1°.

(e) Turn back the RH AOA vane slowly until the PUSH 2 lights goes off.

(f) Pull the control column fully aft.

CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(g) Turn the LH AOA vane slowly counter–clockwise until the stick pusher is operated. Make sure

the PUSH 1 and PUSH 2 lights come on at the same time.
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(h) Make sure the measured angle from the LH calibration tool is 20° ± 1°.

(i) Turn back the LH AOA vane to an angle between the stall warning and the stall identification,

e.g. 16°. Make sure the PUSH 1 and the PUSH 2 lights are on.

(j) Turn the RH AOA vane fully counter–clockwise. Make sure the stick pusher is deactivated

and the PUSH 1 and PUSH 2 lights goes off.

CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(k) Turn the RH AOA vane slowly clockwise until the PUSH 1 and the PUSH 2 lights come on

and the pusher is operated.

(l) Turn the RH AOA vane back to, e.g. 16and make sure the PUSH 1 and the PUSH 2 lights

are still on and the pusher is operated.

(m) Turn the LH AOA vane fully clockwise and make sure the PUSH 1 and the PUSH 2 lights goes

off and the pusher is deactivated.

(n) Turn the RH AOA vane fully counter–clockwise.

(5) Do the test of the stall warning functions, flap 0and Engine Anti Ice selected ON:

(a) Set the flap selector to 0.

(b) Make sure that a minimum of 6 minutes has passed after weight off wheel and after power

up. On the overhead panel ENGINE 42VU, set the Left Engine Anti Ice to ON.

Make sure that the blue indication light in the push–button switch ICE SPEED on the

instrument panel 1VU not come on.

(c) Turn the LH AOA vane counter–clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the LH and the RH control columns

– the aural warning (continuous clacker).

(d) Make sure the measured angle from the LH calibration tool is 12.5 ± 1.

(e) Turn the LH AOA vane clockwise until the stall warning stops.

(f) Turn the RH AOA vane clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the RH and the LH control columns

– the aural warning (continuous clacker).

(g) Make sure the measured angle from the RH calibration tool is 12.5 ± 1.

(h) Turn the RH AOA vane counter–clockwise until the stall warning stops.

(i) On the overhead panel ENGINE 42VU, set the Left Engine Anti Ice to OFF.

(6) Do the test of the test functions:

(a) Remove the WOW operating tool from the LH and the RH WOW switches 5GA and 6GA. (to

make the aircraft in ground configuration).

(b) Set and hold the STALL 1 switch on the TEST 1 panel (19VU) to the up position for at least

6 seconds:

– make sure that the aural warning starts and the two stick shakers start to operate

– make sure that the PUSH 1 lights and the PUSHER SYSTEM caution light come on.

(c) Set and hold the STALL 2 switch on the TEST 1 panel (19VU) to the up position for at least

6 seconds:
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– make sure that the aural warning starts and the two stick shakers start to operate

– make sure that the PUSH 2 lights and the PUSHER SYSTEM caution light come on.

(d) Pull the control column aft and, at the same time, set the STALL 1 and the STALL 2 switches

on the TEST 1 panel to the up position:

– make sure that the aural warning starts and the two stick shakers start to operate

– make sure that the PUSH 1 and PUSH 2 lights come on

– make sure that the pusher starts to operate the control columns forward.

NOTE: PUSHER SYSTEM caution light may come on during this test depending on the

pusher actuator. This does not indicate a failure.

(e) Pull the control column aft and, at the same time, set the STALL 1 and the STALL 2 switches

on the TEST 1 panel to their lower position.

– make sure that the aural warning starts and the two stick shakers start to operate

(In this mode, the servo–actuator internal G–switch is tested, the operation of the stick pusher

is not started.)

NOTE: PUSHER SYSTEM caution light may come on during this test depending on the

pusher actuator. This does not indicate a failure.

(7) Do the test of the pusher disarm function:

(a) Push the PUSHER DISARM switch light (31WH) on the left side panel 5VU. 

Make sure the LH and the RH PUSHER DISARM switch lights (31WH and 32WH) on the left

and the right side panels 5VU and 6VU come on.

(b) Set the STALL 1 and the STALL 2 switches (29WH and 30WH) on the TEST 1 panel 19VU

to the up position. 

Make sure there is no PUSH 1 or PUSH 2 indication on the left and the right instrument panels

3VU and 4VU.

(c) Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical center

306VU to the ACTIVATE position and release it. 

Make sure the PUSHER DISARM lights goes off.

(d) Push the PUSHER DISARM switch light (32WH) on the right side panel 6VU. 

Make sure the LH and the RH PUSHER DISARM switch lights (31WH and 32WH) on the left

and the right side panels 5VU and 6VU come on.

(e) Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical center

306VU to the ACTIVATE position and release it. 

Make sure the PUSHER DISARM lights goes off.

(8) Do the test of the ICE SPEED push–button lamp:

(a) On the TEST 1 panel 19VU, set the lamp test switch to the LWR position and make sure that

the blue indication light in the ICE SPEED push–button switch not come on.
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FOR A/C POST Service Bulletin SAAB 340–27–099 (Mod No 3313)

(9) Prepare the aircraft for test:

CAUTION: BE CAREFUL WHEN YOU MOVE THE VANES. MOVE THE VANES IN A

GENTLY WAY. DAMAGE TO THE VANES CAN OCCUR IF YOU PUSH THEM

HARD TO THE OUTER POSITIONS.

(a) Fasten the Angle of Attack (AOA) calibration tools to the LH and the RH AOA transmitters:

– (LH) TES–4054332–001

– (RH) TES–4054332–002.

(b) Turn the LH AOA vane fully clockwise.

(c) Turn the RH AOA vane fully counter–clockwise.

(d) Make sure the flaps are at 0.

(e) On the LH circuit breaker panel 11VU, close the circuit breaker:

LABEL POS C/B

STAB & WING AUT CTL K–21 1HP

(f) On the overhead panel STAB & WING 18VU, set the switch AUTO CYCLING to OFF.

(g) On the overhead panel ENGINE 42VU, set the L and R Engine Anti–Ice to OFF.

(h) On the LH circuit breaker panel 9VU, open the circuit breaker:

LABEL POS C/B

STALL WARN CHAN 1 E–7 13WH

(i) On the RH circuit breaker panel 10VU, open these circuit breakers:

LABEL POS C/B

STALL WARN CHAN 2 L–6 2WH

STICK PUSHER L–4 36WH

(j) Supply the 28 VDC external power (Ref. AMM 12–00–00, servicing).

(k) At 1VU, make sure that the blue indication light in the ICE SPEED push–button switch is OFF.

(10) Do the test of the stall warning functions, flap 0and non–icing condition:

(a) On the CWP, make sure the amber caution–lights L STALL FAIL and R STALL FAIL are

illuminated.

(b) On the RH circuit breaker panel 10VU, close the circuit breaker:

LABEL POS C/B

STICK PUSHER L–4 36WH

(c) On the CWP, make sure the amber caution–lights L STALL FAIL and R STALL FAIL remains

ON.

(d) On the RH circuit breaker panel 10VU, open the circuit breaker:

LABEL POS C/B

STICK PUSHER L–4 36WH
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(e) On the LH circuit breaker panel 9VU, close the circuit breaker:

LABEL POS C/B

STALL WARN CHAN 1 E–7 13WH

(f) On the CWP, make sure the L STALL FAIL amber caution–light goes off.

(g) On the RH circuit breaker panel 10VU, close the circuit breakers:

LABEL POS C/B

STALL WARN CHAN 2 L–6 2WH

(h) On the CWP, make sure the R STALL FAIL amber caution–light goes off.

(i) At the LH and the RH main landing–gear, install the WOW operating tool (TDO 5–4650224)

on the WOW switches 5GA and 6GA in flight position.

(j) Turn the LH AOA vane counter–clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the LH and the RH control columns

– the aural warning (continuous clacker).

(k) Make sure the measured angle from the LH calibration tool is 14.5 ± 1.

(l) Turn the LH AOA vane clockwise until the stall warning stops.

(m) Turn the RH AOA vane clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the RH and the LH control columns

– the aural warning (continuous clacker).

(n) Make sure the measured angle from the RH calibration tool is 14.5 ± 1.

(o) Turn the RH AOA vane counter–clockwise until the stall warning stops.

(11) Do the test of the stall identification functions, flap 0and non–icing condition:

(a) On the RH circuit breaker panel 10VU, close the circuit breaker:

LABEL POS C/B

STICK PUSHER L–4 36WH

(b) Make sure the PUSHER DISARM switch lights (31WH and 32WH) on the LH and RH side

panels 5VU and 6VU do not come on. 

If the PUSHER DISARM switch lights (31WH and 32WH) come on, proceed as follows:

1 Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical

center 306VU to the ACTIVE position and release it. Make sure the PUSHER DISARM

lights goes off.

(c) Turn the RH AOA vane slowly clockwise until the PUSH 2 lights of the indicator lights (1WH

and 6WH) on the LH and RH instrument panels 3VU and 4VU come on. 

Make sure the PUSHER SYSTEM amber caution–light on the CWP (3WW) comes on.

(d) Make sure the measured angle from the RH calibration tool is 19± 1.

(e) Turn back the RH AOA vane slowly until the PUSH 2 lights goes off.

(f) Pull the control column fully aft.
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CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(g) Turn the LH AOA vane slowly counter–clockwise until the stick pusher is operated. Make sure

the PUSH 1 and the PUSH 2 lights come on at the same time.

(h) Make sure the measured angle from the LH calibration tool is 19± 1.

(i) Turn back the LH AOA vane to an angle between the stall warning and the stall identification,

e.g. 16. Make sure the PUSH 1 and the PUSH 2 lights are on.

(j) Turn the RH AOA vane fully counter–clockwise. Make sure the stick pusher is deactivated

and the PUSH 1 and the PUSH 2 lights goes off.

CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(k) Turn the RH AOA vane slowly clockwise until the PUSH 1 and the PUSH 2 lights come on

and the pusher is operated.

(l) Turn the RH AOA vane back to, e.g. 16and make sure the PUSH 1 and the PUSH 2 lights

are still on and the pusher is operated.

(m) Turn the LH AOA vane fully clockwise and make sure the PUSH 1 and the PUSH 2 lights goes

off and the pusher is deactivated.

(n) Turn the RH AOA vane fully counter–clockwise.

(12) Do the test of the stall identification functions, flap 35and non–icing condition:

(a) Set the flap selector to 35.

(b) Make sure that the PUSHER DISARM switch lights (31WH and 32WH) on the left and the

right side panels 5VU and 6VU not are on. 

If the PUSHER DISARM switch lights (31WH and 32WH) are on, proceed as follows:

1 Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical

center 306VU to the ACTIVATE position and release it. Make sure the PUSHER

DISARM lights goes off.

(c) Turn the RH AOA vane slowly clockwise until the PUSH 2 lights of the indicator lights (1WH

and 6WH) on the left and right instrument panels 3VU and 4VU come on. 

Make sure the PUSHER SYSTEM amber caution–light on the CWP (3WW) comes on.

(d) Make sure the measured angle from the RH calibration tool is 20° ± 1°.

(e) Turn back the RH AOA vane slowly until the PUSH 2 lights goes off.

(f) Pull the control column fully aft.

CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(g) Turn the LH AOA vane slowly counter–clockwise until the stick pusher is operated. Make sure

the PUSH 1 and PUSH 2 lights come on at the same time.
Service Bulletin

18 October 2013 340–27–116

Page 13 of 22

(h) Make sure the measured angle from the LH calibration tool is 20° ± 1°.

(i) Turn back the LH AOA vane to an angle between the stall warning and the stall identification,

e.g. 16°. Make sure the PUSH 1 and the PUSH 2 lights are on.

(j) Turn the RH AOA vane fully counter–clockwise. Make sure the stick pusher is deactivated

and the PUSH 1 and PUSH 2 lights goes off.

CAUTION: DO NOT OPERATE THE STALL WARNING PUSHER SYSTEM FOR MORE

THAN A MAXIMUM OF 10 SECONDS CONTINUOUSLY. ALLOW THE

SYSTEM A MINIMUM OF 1 MINUTE OF NON–OPERATION BEFORE YOU

CONTINUE THE TEST. IF YOU RUN THE PUSHER SYSTEM FOR MORE

THAN 10 SECONDS, THE PUSHER SERVO ACTUATORS CAN

OVERHEAT.

(k) Turn the RH AOA vane slowly clockwise until the PUSH 1 and the PUSH 2 lights come on

and the pusher is operated.

(l) Turn the RH AOA vane back to, e.g. 16and make sure the PUSH 1 and the PUSH 2 lights

are still on and the pusher is operated.

(m) Turn the LH AOA vane fully clockwise and make sure the PUSH 1 and the PUSH 2 lights goes

off and the pusher is deactivated.

(n) Turn the RH AOA vane fully counter–clockwise.

(13) Do the test of the stall warning functions, flap 0and Engine Anti Ice selected ON:

(a) Set the flap selector to 0.

(b) Make sure that a minimum of 6 minutes has passed after weight off wheel and after power

up. On the overhead panel ENGINE 42VU, set the Left Engine Anti Ice to ON.

Make sure that the blue indication light in the push–button switch ICE SPEED on the

instrument panel 1VU not come on.

(c) Turn the LH AOA vane counter–clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the LH and the RH control columns

– the aural warning (continuous clacker).

(d) Make sure the measured angle from the LH calibration tool is 14.5 ± 1.

(e) Turn the LH AOA vane clockwise until the stall warning stops.

(f) Turn the RH AOA vane clockwise until the stall warning is activated. Make sure these

warnings and cautions operate:

– the stick shaker on the RH and the LH control columns

– the aural warning (continuous clacker).

(g) Make sure the measured angle from the RH calibration tool is 14.5 ± 1.

(h) Turn the RH AOA vane counter–clockwise until the stall warning stops.

(i) On the overhead panel ENGINE 42VU, set the Left Engine Anti Ice to OFF.

(14) Do the test of the test functions:

(a) Remove the WOW operating tool from the LH and the RH WOW switches 5GA and 6GA. (to

make the aircraft in ground configuration).

(b) Set and hold the STALL 1 switch on the TEST 1 panel (19VU) to the up position for at least

6 seconds:

– make sure that the aural warning starts and the two stick shakers start to operate

– make sure that the PUSH 1 lights and the PUSHER SYSTEM caution light come on.

(c) Set and hold the STALL 2 switch on the TEST 1 panel (19VU) to the up position for at least

6 seconds:
Service Bulletin

18 October 2013 340–27–116

Page 14 of 22

– make sure that the aural warning starts and the two stick shakers start to operate

– make sure that the PUSH 2 lights and the PUSHER SYSTEM caution light come on.

(d) Pull the control column aft and, at the same time, set the STALL 1 and the STALL 2 switches

on the TEST 1 panel to the up position:

– make sure that the aural warning starts and the two stick shakers start to operate

– make sure that the PUSH 1 and PUSH 2 lights come on

– make sure that the pusher starts to operate the control columns forward.

NOTE: PUSHER SYSTEM caution light may come on during this test depending on the

pusher actuator. This does not indicate a failure.

(e) Pull the control column aft and, at the same time, set the STALL 1 and the STALL 2 switches

on the TEST 1 panel to their lower position.

– make sure that the aural warning starts and the two stick shakers start to operate

(In this mode, the servo–actuator internal G–switch is tested, the operation of the stick pusher

is not started.)

NOTE: PUSHER SYSTEM caution light may come on during this test depending on the

pusher actuator. This does not indicate a failure.

(15) Do the test of the pusher disarm function:

(a) Push the PUSHER DISARM switch light (31WH) on the left side panel 5VU. 

Make sure the LH and the RH PUSHER DISARM switch lights (31WH and 32WH) on the left

and the right side panels 5VU and 6VU come on.

(b) Set the STALL 1 and the STALL 2 switches (29WH and 30WH) on the TEST 1 panel 19VU

to the up position. 

Make sure there is no PUSH 1 or PUSH 2 indication on the left and the right instrument panels

3VU and 4VU.

(c) Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical center

306VU to the ACTIVATE position and release it. 

Make sure the PUSHER DISARM lights goes off.

(d) Push the PUSHER DISARM switch light (32WH) on the right side panel 6VU. 

Make sure the LH and the RH PUSHER DISARM switch lights (31WH and 32WH) on the left

and the right side panels 5VU and 6VU come on.

(e) Set the spring–loaded STICK PUSHER RESET switch (27WH) on the RH electrical center

306VU to the ACTIVATE position and release it. 

Make sure the PUSHER DISARM lights goes off.

(16) Do the test of the ICE SPEED push–button lamp:

(a) On the TEST 1 panel 19VU, set the lamp test switch to the LWR position and make sure that

the blue indication light in the ICE SPEED push–button switch not come on.
Service Bulletin

18 October 2013 340–27–116

Page 15 of 22

FOR A/C ALL

E. JOB CLOSE–UP

(1) Remove the electrical power (Ref. AMM 12–00–00).

(2) Remove the AOA calibration tools from the LH and the RH AOA transmitters.

(3) Close the access:

(a) Remove all the tools and equipment from the work area. Make sure the work area is clean.

(b) Put the circuit breaker panel 10VU in position at the structure and tighten the screws.

FOR A/C 004–078

(c) At the avionics rack, install the fwd access panel 210AZ (Ref. AMM 06–30–00).

(d) Install the LH flight crew seat (Ref. AMM 25–11–05).

FOR A/C 079–459

(e) At the avionics rack, install the aft access panel 220AZ (Ref. AMM 06–30–00).

FOR A/C ALL

(4) Remove all the tools and equipment from the work area. Make sure the work area is clean.

(5) Restore the electrical power (Ref. AMM 24–00–00, maintenance practices).

3. MATERIAL INFORMATION

A. Local supply

Item Part Number Qty Nomenclature Designation Remarks

– RNF–100 AR Shrink sleeve – For parking of

wires.

– – 1 “INOP” sign – To cover label

“ICE SPD CANCEL” at 1VU.
Service Bulletin

18 October 2013 340–27–116

Page 16 of 22

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Service Bulletin

18 October 2013 340–27–116

Page 17/18 of 22

A31445

Flight Compartment – Component Location

FIG. 1
Service Bulletin

Date Month Year

Revison X, Date Month Year

340–XX–XXX

Page 18
Service Bulletin

18 October 2013 340–27–116

Page 19/20 of 22

A31446





 	

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Wiring Diagram – POST MOD for A/C 004–078

FIG. 2
Service Bulletin

Date Month Year

Revison X, Date Month Year

340–XX–XXX

Page 20
Service Bulletin

18 October 2013 340–27–116

Page 21/22 of 22

A31447





 	







 

 

  







 



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Wiring Diagram – POST MOD for A/C 079–459

FIG. 3
Service Bulletin

Date Month Year

Revison X, Date Month Year

340–XX–XXX

Page 22