AD 59-05-04

final rule

Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.

AD Number
59-05-04
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Univair Aircraft Corporation 415-C Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.
aircraft Univair Aircraft Corporation 415-CD Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.
aircraft Univair Aircraft Corporation 415-D Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.
aircraft Univair Aircraft Corporation 415-E Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.
aircraft Univair Aircraft Corporation 415-G Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.

Unsafe Condition

Frequent failures of the rear spar center section due to cracking of the upper flange at the intersection with the fuselage side, progressing into the spar web despite field repairs with gusset plates. Failures are attributed to rough landings with insufficient oleo strut fluid, high-speed taxiing over rough terrain, and corrosion from lack of protective coating.

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

Required Actions

Inspect the rear spar for damage or cracks. Reinforce with stiffener angle P/N F-13109 or equivalent if no damage. If damage/cracks exist but not in the spar web, add stiffener and inspect every 100 hours; replace spar if damage progresses or extends into the web. Install new spar and stiffener if required, eliminating subsequent 100-hour inspections.

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

Compliance Time

within the next 100 hours of operation

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

Affected Aircraft

Univair Aircraft Corporation models 415-C, 415-CD, 415-D, 415-E, and 415-G

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

Federal Register Abstract

Rear spar reinforcement

Applicability Source Text

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AD Final Rules - DRS_59-05-04.html
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AD Number:
59-05-04
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.
Subject:
Rear spar reinforcement
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
05/09/1959
Effective Date:
Make:
Univair Aircraft Corporation
Model:
415-C | 415-CD | 415-D | 415-E | 415-G
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
AIR-700: Compliance & Airworthiness Division
Office of Primary Responsibility:
AIR-770: West Certification Branch
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 59-05-04
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   59-05-04

SUBJECT HEADING:   Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   59-05-04 ERCOUPE: Applies to All Models 415-C, 415-CD, 415-D, E and G.
Compliance to be accomplished within the next 100 hours of operation.
Frequent failures of the rear spar center section have been found on Ercoupe Model aircraft. These failures follow the same pattern in that the rear spar P/N 415-13048 L/R failed due to cracking of the upper flange in the area of the intersection of the rear spar with the fuselage side on either the right or left spar assembly. Repairs made in the field with gusset plates have been found to be only partially satisfactory and in most instances did not keep the crack from progressing into the spar web. This damage to the spar has been attributed to the following:
(1) Rough landings coupled with a lack of fluid in the oleo struts.
(2) Taxiing at high speeds over rough terrain.
(3) A combination of (1) and (2) with the structure weakened by corrosion due to no protective coating of the spar.
In view of the above, it is mandatory that the rear spar on Forney (Ercoupe) aircraft be inspected and action taken as follows:
(1) If no damage or cracks are found, the spar must be reinforced by stiffener angle P/N F-13109 or equivalent. The spar may be considered satisfactory if previously reinforced with P/N 415-13108 or equivalent.
(2) If damage or crack exists but does not extend into the spar web, a repair may be made by the addition of stiffener P/N F-13109 or equivalent provided an inspection every 100 hours of service life thereafter discloses no further progressive damage. If damage is found to progress, then a new spar and stiffener must be installed. If damage or crack extends into the spar web, the spar must be replaced.
(3) If a new spar and stiffener is installed, the 100-hour inspection requirement in (2) above may be eliminated.
(Forney Manufacturing Company, Aviation Division, Fort Collins, Colorado, Service Memorandum 53A supersedes Service Memorandum 53 and covers this same subject.)
This supersedes AD 57-13-03.

FOOTER:

Document Text

Show stored source text (verify against official source)
AD Final Rules - DRS_59-05-04.html
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Print/Save as PDF
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 Feedback
Details
AD Number:
59-05-04
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.
Subject:
Rear spar reinforcement
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
05/09/1959
Effective Date:
Make:
Univair Aircraft Corporation
Model:
415-C | 415-CD | 415-D | 415-E | 415-G
Product Type:
Aircraft
Product Subtype:
Small Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
AIR-700: Compliance & Airworthiness Division
Office of Primary Responsibility:
AIR-770: West Certification Branch
CFR Part Reference:
Part 39
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 59-05-04
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   59-05-04

SUBJECT HEADING:   Airworthiness Directives; ERCOUPE All Models 415-C, 415-CD, 415-D, E and G.

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:   59-05-04 ERCOUPE: Applies to All Models 415-C, 415-CD, 415-D, E and G.
Compliance to be accomplished within the next 100 hours of operation.
Frequent failures of the rear spar center section have been found on Ercoupe Model aircraft. These failures follow the same pattern in that the rear spar P/N 415-13048 L/R failed due to cracking of the upper flange in the area of the intersection of the rear spar with the fuselage side on either the right or left spar assembly. Repairs made in the field with gusset plates have been found to be only partially satisfactory and in most instances did not keep the crack from progressing into the spar web. This damage to the spar has been attributed to the following:
(1) Rough landings coupled with a lack of fluid in the oleo struts.
(2) Taxiing at high speeds over rough terrain.
(3) A combination of (1) and (2) with the structure weakened by corrosion due to no protective coating of the spar.
In view of the above, it is mandatory that the rear spar on Forney (Ercoupe) aircraft be inspected and action taken as follows:
(1) If no damage or cracks are found, the spar must be reinforced by stiffener angle P/N F-13109 or equivalent. The spar may be considered satisfactory if previously reinforced with P/N 415-13108 or equivalent.
(2) If damage or crack exists but does not extend into the spar web, a repair may be made by the addition of stiffener P/N F-13109 or equivalent provided an inspection every 100 hours of service life thereafter discloses no further progressive damage. If damage is found to progress, then a new spar and stiffener must be installed. If damage or crack extends into the spar web, the spar must be replaced.
(3) If a new spar and stiffener is installed, the 100-hour inspection requirement in (2) above may be eliminated.
(Forney Manufacturing Company, Aviation Division, Fort Collins, Colorado, Service Memorandum 53A supersedes Service Memorandum 53 and covers this same subject.)
This supersedes AD 57-13-03.

FOOTER:

Source: Official FAA Source ↗

Retrieved: Apr 8, 2026

Rights: U.S. Government Public Domain

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