AD 74-24-13

final rule

Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft

AD Number
74-24-13
Status
final_rule
Effective Date
Product Category
appliance
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft United Instruments, Inc. Altimeters Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft
appliance United Instruments, Inc. Altimeters Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft

Unsafe Condition

Altimeters may be deprived of readings during certain aircraft operating conditions.

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

Required Actions

Within 10 hours' time in service after the effective date, check each altimeter or maintenance record to determine if it falls within specified part and serial numbers. If applicable, prior to further flight, either comply with paragraph C or install a placard restricting operation to day VFR only. By November 30, 1976, replace or modify the altimeter as specified.

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; prior to further flight; on or before November 30, 1976

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

Affected Aircraft

United Instruments, Inc. altimeters with P/N 5932 (Serial Numbers 47851-69000) and P/N 5934 (Serial Numbers 70,000-102,000, A1-A9999, B1-B9999, C1-C2860), installed on various aircraft including Piper, Beech, Cessna, Bell, Aero Commander, Schweizer, Enstrom, Helio, American Aviation, Bellanca.

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

Federal Register Abstract

Altimeters

Applicability Source Text

Show captured applicability text from the source AD
AD Final Rules - DRS_74-24-13.html
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AD Number:
74-24-13
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft
Subject:
Altimeters
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/05/1974
Make:
United Instruments, Inc.
Model:
Altimeters
Product Type:
Appliance
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 74-24-13
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2028

AD NUMBER:   74-24-13

SUBJECT HEADING:   Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft

ACTION:  

SUMMARY:  

DATES:   Effective December 5, 1974.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
74-24-13 UNITED INSTRUMENTS, INC.: Amendment 39-2028. Applies to P/N 5932 ( ) (Serial Numbers 47851 thru 69000) and P/N 5934 ( ) (Serial Numbers 70,000 thru 102,000, A1 thru A9999, B1 thru B9999, and C1 thru C2860) altimeters installed on various aircraft, such as Piper, Beech, Cessna, Bell, Aero Commander, Schweizer, Enstrom, Helio, American Aviation, Bellanca, et al.

Note 1: United Instruments P/N 5932 ( ) altimeters may be additionally identified as TKK Model LA 4 TSO C-10b. United Instrument P/N 5934 ( ) altimeters may be additionally identified as TKK Model LA 7 TSO C-10b.

Note 2: These altimeters may also be identified by various aircraft manufacturer's part numbers. Some but not all are:

Beech: P/N 50-380094-( ), 50-384119-( ), 58-380011-( ), 58-380012-( ), 58-380041-( ), 100-324056-( ), 169-380073-( )

Cessna: P/N C661011-( ), C661071-( ), C661025-( ), C661014-( )

Piper: P/N 99009-( ), 450-611-( ), 450-694-( ), PS50008-( )-( ), 550-488-( ), 550-489-( ), 550-490-( ), 550-491-( ), 550-492-( ), 550-493-( ), 322-81-03, 322-81-04

Bell: P/N 206-070-263-( ), 47-711-303-( ) Compliance: Required as indicated, unless already accomplished.

To prevent being deprived of altimeter readings during certain aircraft operating conditions, accomplish the following:

A) Within the next 10 hours' time in service after the effective date of this AD, check each altimeter installed in all aircraft or check the aircraft's permanent maintenance record to determine if the altimeter falls within the Part Number and Serial Number designations set forth in the applicability statement. The owner/operator of the aircraft may make these checks.

B) If, as a result of the determinations required by Paragraph A, an altimeter falls within the Part Number and Serial Number designations in the applicability statement, prior to further flight, either comply with Paragraph C or install a placard on the instrument panel in clear view of the pilot which states:

"AIRCRAFT APPROVED FOR DAY VFR FLIGHT ONLY"

and operate the aircraft in accordance with this limitation.

C) On or before November 30, 1976, on any altimeter which falls within the Part Number and Serial Number designations set forth in the applicability statement, either replace the altimeter with an approved replacement part, an altimeter from outside the applicable Serial Numbers, or modify the existing altimeter in accordance with the United Instruments, Inc., Service Bulletin No. 1, dated September 19, 1974, or subsequent approved revisions. A modified altimeter will be identified by a 1/4-inch white dot painted alongside the nameplate on the back of the case. Upon compliance with this paragraph, the requirements of Paragraph B are no longer applicable.

D) Any alternate means of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

E) Compliance with Paragraph B of this AD is not required if the aircraft has two sensitive altimeters installed. In the event of failure of one of the altimeters, where both altimeters are noted in the applicability statement, compliance with Paragraph B and/or C is required.

This amendment becomes effective December 5, 1974.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_74-24-13.html
Copy URL
Print/Save as PDF
Document Versions
 Feedback
Details
AD Number:
74-24-13
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft
Subject:
Altimeters
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
12/05/1974
Make:
United Instruments, Inc.
Model:
Altimeters
Product Type:
Appliance
Product Subtype:
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 74-24-13
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:   39-2028

AD NUMBER:   74-24-13

SUBJECT HEADING:   Airworthiness Directives; UNITED INSTRUMENTS, INC.: Altimeters Installed On Various Aircraft

ACTION:  

SUMMARY:  

DATES:   Effective December 5, 1974.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
74-24-13 UNITED INSTRUMENTS, INC.: Amendment 39-2028. Applies to P/N 5932 ( ) (Serial Numbers 47851 thru 69000) and P/N 5934 ( ) (Serial Numbers 70,000 thru 102,000, A1 thru A9999, B1 thru B9999, and C1 thru C2860) altimeters installed on various aircraft, such as Piper, Beech, Cessna, Bell, Aero Commander, Schweizer, Enstrom, Helio, American Aviation, Bellanca, et al.

Note 1: United Instruments P/N 5932 ( ) altimeters may be additionally identified as TKK Model LA 4 TSO C-10b. United Instrument P/N 5934 ( ) altimeters may be additionally identified as TKK Model LA 7 TSO C-10b.

Note 2: These altimeters may also be identified by various aircraft manufacturer's part numbers. Some but not all are:

Beech: P/N 50-380094-( ), 50-384119-( ), 58-380011-( ), 58-380012-( ), 58-380041-( ), 100-324056-( ), 169-380073-( )

Cessna: P/N C661011-( ), C661071-( ), C661025-( ), C661014-( )

Piper: P/N 99009-( ), 450-611-( ), 450-694-( ), PS50008-( )-( ), 550-488-( ), 550-489-( ), 550-490-( ), 550-491-( ), 550-492-( ), 550-493-( ), 322-81-03, 322-81-04

Bell: P/N 206-070-263-( ), 47-711-303-( ) Compliance: Required as indicated, unless already accomplished.

To prevent being deprived of altimeter readings during certain aircraft operating conditions, accomplish the following:

A) Within the next 10 hours' time in service after the effective date of this AD, check each altimeter installed in all aircraft or check the aircraft's permanent maintenance record to determine if the altimeter falls within the Part Number and Serial Number designations set forth in the applicability statement. The owner/operator of the aircraft may make these checks.

B) If, as a result of the determinations required by Paragraph A, an altimeter falls within the Part Number and Serial Number designations in the applicability statement, prior to further flight, either comply with Paragraph C or install a placard on the instrument panel in clear view of the pilot which states:

"AIRCRAFT APPROVED FOR DAY VFR FLIGHT ONLY"

and operate the aircraft in accordance with this limitation.

C) On or before November 30, 1976, on any altimeter which falls within the Part Number and Serial Number designations set forth in the applicability statement, either replace the altimeter with an approved replacement part, an altimeter from outside the applicable Serial Numbers, or modify the existing altimeter in accordance with the United Instruments, Inc., Service Bulletin No. 1, dated September 19, 1974, or subsequent approved revisions. A modified altimeter will be identified by a 1/4-inch white dot painted alongside the nameplate on the back of the case. Upon compliance with this paragraph, the requirements of Paragraph B are no longer applicable.

D) Any alternate means of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

E) Compliance with Paragraph B of this AD is not required if the aircraft has two sensitive altimeters installed. In the event of failure of one of the altimeters, where both altimeters are noted in the applicability statement, compliance with Paragraph B and/or C is required.

This amendment becomes effective December 5, 1974.

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.