# AD 88-16-51 R1: AFM Changes-Overspeed - Type: Airworthiness directive - Status: Current - Products: Embraer - Empresa Brasileira de Aeronautica EMB-120 and EMB-120RT - Effective: November 7, 1988 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-6053 - Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/35850A0859839B12862569ED006A3A38.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/88-16-51-R1 ## The airworthiness directive 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. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A31SO](https://openairdocs.org/tcds/A31SO): Embraer S.A.; names 2 of 5 models: EMB-120, EMB-120RT ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 3 (3 by airframe model, 0 by engine model) - Makers: Embraer 3 Models with the most aircraft: - [Embraer EMB-120](https://openairdocs.org/model/embraer-emb-120): 3 aircraft (airframe model) All 1 models: https://openairdocs.org/ad/88-16-51-R1/models.md Every aircraft: https://openairdocs.org/ad/88-16-51-R1/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.