AD 67-26-01

final rule

Airworthiness Directives; BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes

AD Number
67-26-01
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.
Technical illustration of an aircraft flight control surface and actuator
Problem area Flight controls

Applicability

TypeManufacturerModelDetails
aircraft Airbus SAS BAC 1-11 200 Series Airworthiness Directives; BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes

Unsafe Condition

Yaw damper control valve drift when electrically deenergized could cause unwanted rudder actuation.

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

Required Actions

Install a placard near the yaw-damper control switch, deactivate the yaw damper with FAA-approved methods, or adjust/modify the yaw-damper control per specified service bulletins. Compliance must be completed within 10 hours' time in service after the effective date.

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

Compliance Time

within the next 10 hours' time in-service after the effective date of this AD

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

Affected Aircraft

BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes

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

Federal Register Abstract

Yaw Damper Control Valve Drift

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_67-26-01.html
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AD Number:
67-26-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes
Subject:
Yaw Damper Control Valve Drift
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/05/1967
Make:
Airbus SAS
Model:
BAC 1-11 200 Series
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Superseded AD: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Superseded By: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: 67-26-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-482

AD NUMBER:   67-26-01

SUBJECT HEADING:   Airworthiness Directives; BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 5, 1967.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
67-26-01 BRITISH AIRCRAFT: Amdt. 39-482 Part 39, Federal Register September 15, 1967. Applies to Model BAC 1-11 200 Series Airplanes.

Compliance required within the next 10 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent unwanted rudder actuation as a result of yaw-damper control valve drift when electrically deenergized, comply with either paragraph (a), (b), or (c).

(a) Install a placard as near as practicable to the yaw-damper control switch, reading as follows: "Yaw Damper must be operating at the time of takeoff and at all times during flight." In the event of failure of the yaw damper during flight, the flight may continue only to the next scheduled stop. Repair yaw damper or comply with paragraph (b) before further flight, except that the airplane may be flown in accordance with FAR 21.197 to a base where the repair can be performed.

(b) Positively deactivate the yaw damper in accordance with British Aircraft Corporation Instruction SS316 or an FAA-approved equivalent, and install placard to indicate that the yaw damper is deactivated

(c) Adjust and modify the yaw-damper control as follows:

(1) Adjust the yaw-damper actuator Boulton Paul Part No. P185-45-10 to provide one degree bias between the torque motor and the rotary hydraulic control valve of the unit in accordance with BAC 1-11 Service Bulletin 27-PM 3291, or later ARB-approved issue, or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.

(2) Modify the Elliotts Company torque motor type 130/6P to incorporate Boulton Paul Modification Nos. P185/11 or P185/15, in accordance with BAC 1-11 Service Bulletin No. 27-PM 3191 or later ARB-approved issue or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.

(3) Apply sealant, Midlands Silicones LTD, cold-cure silastromer K9160, or an FAA-approved equivalent, to the inside surfaces of the torque motor mounting access plates on final assembly and plug the 5/32 inch diameter dowel access hole, if present in the mounting, with a suitable aluminum alloy plug, in accordance with BAC 1-11 Service Bulletin No. 27-PM 3193 or later ARB-approved issue, or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.

(d) When the adjustments and modifications set forth in paragraph (c) are accomplished, any placards installed in accordance with paragraphs (a) and (b) may be removed.

This amendment effective December 5, 1967.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_67-26-01.html
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Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
67-26-01
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes
Subject:
Yaw Damper Control Valve Drift
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/05/1967
Make:
Airbus SAS
Model:
BAC 1-11 200 Series
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: 67-26-01
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-482

AD NUMBER:   67-26-01

SUBJECT HEADING:   Airworthiness Directives; BRITISH AIRCRAFT Model BAC 1-11 200 Series Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective December 5, 1967.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
67-26-01 BRITISH AIRCRAFT: Amdt. 39-482 Part 39, Federal Register September 15, 1967. Applies to Model BAC 1-11 200 Series Airplanes.

Compliance required within the next 10 hours' time in service after the effective date of this AD, unless already accomplished.

To prevent unwanted rudder actuation as a result of yaw-damper control valve drift when electrically deenergized, comply with either paragraph (a), (b), or (c).

(a) Install a placard as near as practicable to the yaw-damper control switch, reading as follows: "Yaw Damper must be operating at the time of takeoff and at all times during flight." In the event of failure of the yaw damper during flight, the flight may continue only to the next scheduled stop. Repair yaw damper or comply with paragraph (b) before further flight, except that the airplane may be flown in accordance with FAR 21.197 to a base where the repair can be performed.

(b) Positively deactivate the yaw damper in accordance with British Aircraft Corporation Instruction SS316 or an FAA-approved equivalent, and install placard to indicate that the yaw damper is deactivated

(c) Adjust and modify the yaw-damper control as follows:

(1) Adjust the yaw-damper actuator Boulton Paul Part No. P185-45-10 to provide one degree bias between the torque motor and the rotary hydraulic control valve of the unit in accordance with BAC 1-11 Service Bulletin 27-PM 3291, or later ARB-approved issue, or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.

(2) Modify the Elliotts Company torque motor type 130/6P to incorporate Boulton Paul Modification Nos. P185/11 or P185/15, in accordance with BAC 1-11 Service Bulletin No. 27-PM 3191 or later ARB-approved issue or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.

(3) Apply sealant, Midlands Silicones LTD, cold-cure silastromer K9160, or an FAA-approved equivalent, to the inside surfaces of the torque motor mounting access plates on final assembly and plug the 5/32 inch diameter dowel access hole, if present in the mounting, with a suitable aluminum alloy plug, in accordance with BAC 1-11 Service Bulletin No. 27-PM 3193 or later ARB-approved issue, or an equivalent approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa and Middle East Region.

(d) When the adjustments and modifications set forth in paragraph (c) are accomplished, any placards installed in accordance with paragraphs (a) and (b) may be removed.

This amendment effective December 5, 1967.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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