88-16-51 R1 EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER): Amendment 39-6053. Applies to all Model EMB-120 series airplanes, certificated in any category. Compliance required within 24 hours after the effective date of this AD, unless previously accomplished.
To prevent an overspeed occurrence, accomplish the following:
A. Insert the following into the FAA-approved Airplane Flight Manual (AFM) and alert all flight crews. This may be accomplished by inserting a copy of this airworthiness directive (AD) into the appropriate section of the AFM.
1. LIMITATIONS:
POWERPLANT
- INFLIGHT OPERATIONS AT POWER SETTINGS BELOW FLT IDLE NOT APPROVED.
2. EMERGENCY PROCEDURES IN CASE OF PROPELLER OVERSPEED:
- POWER LEVER (AFFECTED ENGINE) FLT IDLE
- CONDITION LEVER (AFFECTED ENGINE) FEATHER
- SYNCHROPHASING OFF
- POWER LEVER (OPERATIVE ENGINE)
......FLT IDLE (ALTITUDE PERMITTING)
- FLAPS..................15 DEGREES (AIRSPEED PERMITTING)
- AIRSPEED..........................................125 KIAS MINIMUM
NOTE
POWER REDUCTION ON THE OPERATIVE ENGINE WILL INCREASE DECEL RATE
TO 125 KIAS AND WILL PREVENT ADVERSE AIRCRAFT HANDLING QUALITIES
ASSOCIATED WITH Vmc. OPERATIVE ENGINE MAY BE USED AS NECESSARY TO
MAINTAIN ALTITUDE AIRSPEED.
NOTE
WITH Np ABOVE 120 PERCENT, BOTH MECHANICAL AND ELECTRICAL AUXILIARY FEATHER SYSTEMS MAY NOT HAVE SUFFICIENT AUTHORITY TO FEATHER THE
PROPELLER. THEREFORE, IT IS NECESSARY TO REDUCE THE Np BELOW 120 PERCENT IN ORDER TO OBTAIN SATISFACTORY FEATHERING ACTION.
- IF Np IS BELOW 120 PERCENT:
o ELECTRIC FEATHERING SWITCH ON
- IF Np IS ABOVE 120 PERCENT:
o AIRSPEED/FLAPS REDUCE AIRSPEED
EXTEND FLAPS PER
TABLE BELOW TO
REDUCE Np BELOW
120 PERCENT:
MINIMUM AIRSPEED FLAPS
125 KIAS 15 DEGREES
120 KIAS 25 DEGREES
115 KIAS 45 DEGREES
o POWER LEVER (OPERATIVE ENGINE) AS REQUIRED
(SEE TABLE ABOVE)
NOTE
WITH FLAPS LOWERED PAST 15 DEGREES, THE LANDING GEAR WARNING WILL SOUND.
o ELECTRICAL FEATHER SWITCH ON
NOTE
THE ELECTRICAL AUXILIARY FEATHERING PUMP IS AUTOMATICALLY TURNED
OFF AFTER 20 SECONDS. THEREFORE, FOR FURTHER PUMP OPERATION, IT IS
NECESSARY TO TURN THE SWITCH OFF, THEN ON. THE PUMP IS CAPABLE OF
SIX CONSECUTIVE OPERATIONS.
- IF PROPELLER DOES NOT FEATHER:
WARNING!
DO NOT SHUT DOWN THE AFFECTED ENGINE UNLESS ADDITIONAL FAILURES
WARRANT SHUTDOWN.
o AIRSPEED 25 KIAS (MIN)
o FLAPS 15 DEGREES
o LAND AS SOON AS POSSIBLE USE PROCEDURES FOR A
ONE ENGINE
INOPERATIVE
APPROACH AND LANDING.
MAINTAIN Vref +10 UNTIL
LANDING ASSURED.
- WHEN PROPELLER IS FEATHERED:
o CONDITION LEVER FUEL CUT OFF
o COMPLETE PRECAUTIONARY ENGINE SHUTDOWN IF PROPELLER IS
FEATHERED PRIOR TO LANDING.
B. An alternate means of compliance which provides an acceptable level of safety may be used when approved by the Manager, Atlanta Aircraft Certification Office, FAA, Central Region.
NOTE: The request should be forwarded through an FAA Principal Operations Inspector (POI), who may add any comments and then send it to the Manager, Atlanta Aircraft Certification Office.
All persons affected by this directive who have not already received the appropriate service documents from the manufacturer, may obtain copies upon request to Embraer, 276 S.W. 34th Street, Fort Lauderdale, Florida 33315. This information may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or at FAA, Central Region, Atlanta Aircraft Certification Office, 1669 Phoenix Parkway, Suite 210C, Atlanta, Georgia.
This amendment, 39-6053, revises Telegraphic AD 88-16-51 issued August 5, 1988.
This amendment, 39-6053 (AD 88-16-51 R1), becomes effective November 7, 1988.