AD 81-22-51

final rule

BOEING Model 747 Series Airplanes

AD Number
81-22-51
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 747-100 Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-100B Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-100B SUD Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-200B Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-200C Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-200F Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-300 Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-400 Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-400D Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747-400F Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747SP Series BOEING Model 747 Series Airplanes
aircraft The Boeing Company 747SR Series BOEING Model 747 Series Airplanes

Unsafe Condition

Failure of the Airborne Vibration Monitor (AVM) system or engine oil system could lead to engine failure or other engine malfunction without timely crew awareness.

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

Required Actions

Revise the Airplane Flight Manual (AFM) to include AVM system operational requirements and emergency procedures, install an amber repeater light for vibration meter alarm lights within 60 days, and perform specified maintenance actions on engines after specific AVM or oil indications.

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

Compliance Time

Within 25 hours time in service after the receipt of this AD, or within 3 calendar days, whichever occurs later for AFM revision; within 60 days calendar time after effective date for installing the repeater light.

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

Affected Aircraft

Boeing Model 747 series airplanes with Rolls Royce RB.211 engines, including 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, and other 747-200 series models.

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

Federal Register Abstract

AFM Revision

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_81-22-51.html
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AD Number:
81-22-51
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
BOEING Model 747 Series Airplanes
Subject:
AFM Revision
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
01/11/1982
Make:
The Boeing Company
Model:
747-100 Series | 747-100B Series | 747-100B SUD Series | 747-200B Series | 747-200C Series | 747-200...Show more
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:
AIRWORTHINESS DIRECTIVES FINAL RULES: 81-22-51
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4291

AD NUMBER:   81-22-51

SUBJECT HEADING:   BOEING Model 747 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 11, 1982.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-22-51 BOEING: Amendment 39-4291. Applies to all Boeing Model 747 series airplanes certificated in all categories with Rolls Royce RB.211 engines. To alert the flight crew to conditions which may precede engine failure, perform the following, unless previously accomplished:

A. Within 25 hours time in service after the receipt of this AD, or within 3 calendar days, whichever occurs later, revise the Boeing 747 FAA approved Airplane Flight Manual to add the following and provide to the flight crew:

SECTION 1 - LIMITATIONS

Powerplant Limitations

Airborne Vibration Monitor (AVM) System

o At least one channel (A or B) of the AVM system must be operative for each engine for all flight operations.
o The operative AVM channel (A or B) must be the same for all engines.
o When both channels of the AVM system are operative, select channel A. If this channel becomes inoperative (indication goes to zero) in flight, select B.
o The AVM filter selector must be set to the norm position at all times except during routine AVM monitoring checks.

SECTION 2 - EMERGENCIES

Engine Abnormal Vibration Indication

During steady running conditions, if an airborne vibration monitor (AVM) system channel indicates a sudden increase of 1 (one) unit or more, or if the AVM warning light activates, even if the indicator returns to normal:

IMMEDIATE ACTION
THRUST LEVER	CLOSE
START LEVER	CUT OFF

NOTE: During takeoff roll, a momentary fluctuation of the AVM indicator with no other indication of engine malfunction is not cause for shutdown.

NOTE: When holding or descending in severe icing conditions, the AVM indication may gradually increase to above 2.5 units (warning light setting). This condition can be alleviated by increasing N1 to 90% for 5 seconds when ice accumulation (gradual vibration increase) is first detected. AVM indications may exceed 2.5 units during shedding. No action is required unless other indications of engine malfunction are observed.

SECTION 2 - EMERGENCIES
Engine Oil Light Illuminated
If the engine oil light illuminates steadily or filter blockage is indicated:

IMMEDIATE ACTION
THRUST LEVER	CLOSE
START LEVER	CUT OFF

B. Within 60 days calendar time after effective date of this AD, install an amber repeater light (annunciator) for the vibration meter alarm lights on the pilot's panel in accordance with Boeing Service Bulletin 747-77-2061 dated November 4, 1981, or later revision approved by the Chief, Seattle Area Aircraft Certification Office, FAA Northwest Mountain Region.

C. When the indications specified in paragraph A above occur, engines must undergo the following maintenance actions prior to further engine operation for flight:

1. Rolls Royce RB.211-77-A6424, Rev. 1, dated October 14, 1981, paragraph D.(4) for oil pressure and/or AVM indications.
2. Boeing Maintenance Manual Chapter 71-00-47, High Indicated Vibration.

D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

E. Alternate methods of compliance with this AD may be used when approved by the Chief, Seattle Area Aircraft Certification Office, FAA, Northwest Mountain Region.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to the address listed above. These documents may also be examined at FAA Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington 98108.

This amendment becomes effective January 11, 1982, and was effective earlier to those recipients of telegraphic AD T81-22-51 dated October 16, 1981.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_81-22-51.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
81-22-51
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
BOEING Model 747 Series Airplanes
Subject:
AFM Revision
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
01/11/1982
Make:
The Boeing Company
Model:
747-100 Series | 747-100B Series | 747-100B SUD Series | 747-200B Series | 747-200C Series | 747-200...Show more
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:
AIRWORTHINESS DIRECTIVES FINAL RULES: 81-22-51
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-4291

AD NUMBER:   81-22-51

SUBJECT HEADING:   BOEING Model 747 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective January 11, 1982.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
81-22-51 BOEING: Amendment 39-4291. Applies to all Boeing Model 747 series airplanes certificated in all categories with Rolls Royce RB.211 engines. To alert the flight crew to conditions which may precede engine failure, perform the following, unless previously accomplished:

A. Within 25 hours time in service after the receipt of this AD, or within 3 calendar days, whichever occurs later, revise the Boeing 747 FAA approved Airplane Flight Manual to add the following and provide to the flight crew:

SECTION 1 - LIMITATIONS

Powerplant Limitations

Airborne Vibration Monitor (AVM) System

o At least one channel (A or B) of the AVM system must be operative for each engine for all flight operations.
o The operative AVM channel (A or B) must be the same for all engines.
o When both channels of the AVM system are operative, select channel A. If this channel becomes inoperative (indication goes to zero) in flight, select B.
o The AVM filter selector must be set to the norm position at all times except during routine AVM monitoring checks.

SECTION 2 - EMERGENCIES

Engine Abnormal Vibration Indication

During steady running conditions, if an airborne vibration monitor (AVM) system channel indicates a sudden increase of 1 (one) unit or more, or if the AVM warning light activates, even if the indicator returns to normal:

IMMEDIATE ACTION
THRUST LEVER	CLOSE
START LEVER	CUT OFF

NOTE: During takeoff roll, a momentary fluctuation of the AVM indicator with no other indication of engine malfunction is not cause for shutdown.

NOTE: When holding or descending in severe icing conditions, the AVM indication may gradually increase to above 2.5 units (warning light setting). This condition can be alleviated by increasing N1 to 90% for 5 seconds when ice accumulation (gradual vibration increase) is first detected. AVM indications may exceed 2.5 units during shedding. No action is required unless other indications of engine malfunction are observed.

SECTION 2 - EMERGENCIES
Engine Oil Light Illuminated
If the engine oil light illuminates steadily or filter blockage is indicated:

IMMEDIATE ACTION
THRUST LEVER	CLOSE
START LEVER	CUT OFF

B. Within 60 days calendar time after effective date of this AD, install an amber repeater light (annunciator) for the vibration meter alarm lights on the pilot's panel in accordance with Boeing Service Bulletin 747-77-2061 dated November 4, 1981, or later revision approved by the Chief, Seattle Area Aircraft Certification Office, FAA Northwest Mountain Region.

C. When the indications specified in paragraph A above occur, engines must undergo the following maintenance actions prior to further engine operation for flight:

1. Rolls Royce RB.211-77-A6424, Rev. 1, dated October 14, 1981, paragraph D.(4) for oil pressure and/or AVM indications.
2. Boeing Maintenance Manual Chapter 71-00-47, High Indicated Vibration.

D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

E. Alternate methods of compliance with this AD may be used when approved by the Chief, Seattle Area Aircraft Certification Office, FAA, Northwest Mountain Region.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to the address listed above. These documents may also be examined at FAA Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington 98108.

This amendment becomes effective January 11, 1982, and was effective earlier to those recipients of telegraphic AD T81-22-51 dated October 16, 1981.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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