AD 47-16-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | C54-DC | DOUGLAS Model C-54 and DC-4 Aircraft |
| aircraft | The Boeing Company | C54A-DC | DOUGLAS Model C-54 and DC-4 Aircraft |
| aircraft | The Boeing Company | C54B-DC | DOUGLAS Model C-54 and DC-4 Aircraft |
| aircraft | The Boeing Company | C54D-DC | DOUGLAS Model C-54 and DC-4 Aircraft |
| aircraft | The Boeing Company | C54E-DC | DOUGLAS Model C-54 and DC-4 Aircraft |
| aircraft | The Boeing Company | C54G-DC | DOUGLAS Model C-54 and DC-4 Aircraft |
| aircraft | The Boeing Company | DC-4 | DOUGLAS Model C-54 and DC-4 Aircraft |
Unsafe Condition
Failure of the ammeter shunts, voltmeter circuit, or generator field circuit protection could result in electrical circuit overloads, leading to potential fire hazards or loss of electrical system functionality.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install two 10-ampere non-automatic-reset circuit breakers in each nacelle junction box for ammeter leads. Install a 10-ampere non-automatic-reset circuit breaker in the main junction box for the voltmeter circuit wire PJ-34. Install 15-ampere circuit breaker switches at the regulator location for wires PA-530, PA-531, PA-730, and PA-731, using non-thermal types as standard fuses do not provide sufficient protection.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
not later than September 1, 1947
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Douglas Model C-54 and DC-4 aircraft with ammeter shunts in the positive generator leads, including models C54-DC, C54A-DC, C54B-DC, C54D-DC, C54E-DC, C54G-DC, and DC-4
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Circuit Breaker Switches in Each Nacelle Junction Box
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_47-16-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-16-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: DOUGLAS Model C-54 and DC-4 Aircraft Subject: Circuit Breaker Switches in Each Nacelle Junction Box Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: C54-DC | C54A-DC | C54B-DC | C54D-DC | C54E-DC | C54G-DC | DC-4 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: 47-16-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-16-01 SUBJECT HEADING: DOUGLAS Model C-54 and DC-4 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-16-01 DOUGLAS: (Was Mandatory Note 16 AD-762-7.) Applies to C-54 and DC-4 Aircraft. To be complied with not later than September 1, 1947. A. In those aircraft having the ammeter shunts in the positive generator leads, install two circuit breakers or circuit breaker switches in each nacelle junction box and reconnect each ammeter lead through one of these circuit breakers. Any type or variety of 10-ampere circuit break may be used, with the exception of the automatic-reset type. B. Install a circuit breaker or circuit breaker switch in the main junction box and connect in series with the voltmeter circuit wire PJ-34 at the (d.c.) buss. Any type or variety of 10-ampere circuit breaker may be used, with the exception of the automatic-reset type. The nonoverride variety of circuit breaker is preferable. C. Install for Heinemann type AM 1614-15-28-2 or equivalent, 15-ampere circuit breaker switches or circuit breakers, at the regulator location, in the leads to the B terminal of the voltage regulators; wires PA-530, PA-531, PA-730, and PA-731. The usual thermal circuit breaker or fuse does not provide sufficient protection to meet the peculiar requirements of a protective device for a generator field circuit application. Additional information on the foregoing changes are described by Douglas Drawing No. 4350951 entitled "Rework of Generator Field Lead and Volt-Ammeter Lead Circuit Protection". A Douglas Aircraft Service Bulletin on this subject is also being issued. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_47-16-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 47-16-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: DOUGLAS Model C-54 and DC-4 Aircraft Subject: Circuit Breaker Switches in Each Nacelle Junction Box Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: The Boeing Company Model: C54-DC | C54A-DC | C54B-DC | C54D-DC | C54E-DC | C54G-DC | DC-4 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: 47-16-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 47-16-01 SUBJECT HEADING: DOUGLAS Model C-54 and DC-4 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 47-16-01 DOUGLAS: (Was Mandatory Note 16 AD-762-7.) Applies to C-54 and DC-4 Aircraft. To be complied with not later than September 1, 1947. A. In those aircraft having the ammeter shunts in the positive generator leads, install two circuit breakers or circuit breaker switches in each nacelle junction box and reconnect each ammeter lead through one of these circuit breakers. Any type or variety of 10-ampere circuit break may be used, with the exception of the automatic-reset type. B. Install a circuit breaker or circuit breaker switch in the main junction box and connect in series with the voltmeter circuit wire PJ-34 at the (d.c.) buss. Any type or variety of 10-ampere circuit breaker may be used, with the exception of the automatic-reset type. The nonoverride variety of circuit breaker is preferable. C. Install for Heinemann type AM 1614-15-28-2 or equivalent, 15-ampere circuit breaker switches or circuit breakers, at the regulator location, in the leads to the B terminal of the voltage regulators; wires PA-530, PA-531, PA-730, and PA-731. The usual thermal circuit breaker or fuse does not provide sufficient protection to meet the peculiar requirements of a protective device for a generator field circuit application. Additional information on the foregoing changes are described by Douglas Drawing No. 4350951 entitled "Rework of Generator Field Lead and Volt-Ammeter Lead Circuit Protection". A Douglas Aircraft Service Bulletin on this subject is also being issued. 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.
Related Airworthiness Directives
2023-10-02
final ruleAirworthiness Directives; Transport and Commuter Category Airplanes
Unsafe Condition: Radio altimeter anomalies that are undetected by the automation or pilot, particularly close to the ground (e.g., landing flare), could lead to loss of continued safe flight and landing. Additional...
2011-12-01
final ruleAirworthiness Directives; Koito Industries, Ltd., Seats and Seating Systems Approved Under Technical Standard Order (TSO) TSO-C39b, TSO-C39c, or TSO-C127a
Unsafe Condition: Seats and seating systems may not meet certain flammability, static strength, and dynamic strength criteria. Failure to meet static and dynamic strength criteria could result in injuries during eme...
93-14-12
final ruleAirworthiness Directives; ESSEX PB&R CORPORATION (formerly E.I. DuPont de Nemours and Company \\nIncorporated) PELS Model 4566M37B Crewmember Protective Breathing Equipment (PBE) Units
Unsafe Condition: Leakage of the PBE neck seal could compromise the crew's ability to combat an aircraft fire.
85-23-04
final ruleAirworthiness Directives; McDONNELL DOUGLAS DC-4 and C54-DC Series, and all C54 Military
Unsafe Condition: Loss of the elevator trim tab control in flight due to cracks in the left-hand and right-hand elevator trim tab spars at station 81.5.
