AD 88-16-51 R1

final rule

Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes

AD Number
88-16-51 R1
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft propeller assembly
Problem area Propeller

Applicability

TypeManufacturerModelDetails
aircraft Embraer - Empresa Brasileira de Aeronautica S.A. EMB-120 Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes
aircraft Embraer - Empresa Brasileira de Aeronautica S.A. EMB-120RT Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes

Unsafe Condition

An overspeed occurrence could lead to insufficient authority of mechanical and electrical auxiliary feather systems to feather the propeller when Np exceeds 120 percent, resulting in adverse aircraft handling qualities and potential loss of control.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Insert specified limitations and emergency procedures into the FAA-approved AFM, alert flight crews, and consider alternate compliance methods approved by the FAA Manager. Actions include setting power levers to FLT IDLE, feathering the affected engine, adjusting flaps and airspeed as per tables, and following shutdown procedures if feathered prior to landing.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

within 24 hours after the effective date of this AD

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

All Model EMB-120 series airplanes, certificated in any category.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

AFM Changes-Overspeed

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_88-16-51_R.html
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AD Number:
88-16-51 R1
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes
Subject:
AFM Changes-Overspeed
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
11/07/1988
Make:
Embraer - Empresa Brasileira de Aeronautica S.A.
Model:
EMB-120 | EMB-120RT
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
Updated RGL applicability to match AD applicability; CAR C-11-185
AIRWORTHINESS DIRECTIVES FINAL RULES: 88-16-51 R1
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-6053

AD NUMBER:   88-16-51 R1

SUBJECT HEADING:   Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective November 7, 1988.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   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.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_88-16-51_R.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
88-16-51 R1
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes
Subject:
AFM Changes-Overspeed
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
11/07/1988
Make:
Embraer - Empresa Brasileira de Aeronautica S.A.
Model:
EMB-120 | EMB-120RT
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
Updated RGL applicability to match AD applicability; CAR C-11-185
AIRWORTHINESS DIRECTIVES FINAL RULES: 88-16-51 R1
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-6053

AD NUMBER:   88-16-51 R1

SUBJECT HEADING:   Airworthiness Directives; EMPRESA BRASILEIRA DE AERONAUTICA S.A. (EMBRAER) Model EMB-120 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective November 7, 1988.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   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.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.