AD 56-27-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Kelowna Flightcraft R & D Ltd. | 340 | CONVAIR Models 340 and 440 Aircraft |
| aircraft | Kelowna Flightcraft R & D Ltd. | 440 | CONVAIR Models 340 and 440 Aircraft |
Unsafe Condition
Failure of the elevator servo tab rod due to loose rivets attaching rod ends to rods and relative movement between rod and rod ends, leading to serious flutter condition and critical accident risk.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect tab rods and rod ends for loose rivets and relative movement; replace defective parts. Replace elevator tab rods and rod ends with improved heavier versions for Models 340 and 440, and install symmetrical idler link on Model 340 right-hand elevator tab.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Compliance required at every 110 hours of operation or regular scheduled inspection closest thereto, not later than November 30, 1957.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
CONVAIR Models 340 and 440 Aircraft, all serial numbers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Elevator Servo Tab Rod
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_56-27-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-27-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: CONVAIR Models 340 and 440 Aircraft Subject: Elevator Servo Tab Rod Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Kelowna Flightcraft R & D Ltd. Model: 340 | 440 Product Type: Aircraft Product Subtype: Large Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 56-27-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-27-01 SUBJECT HEADING: CONVAIR Models 340 and 440 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-27-01 CONVAIR: Applies to All Models 340 and 440 Aircraft. Compliance required as noted below. A report has been received concerning the failure of the elevator servo tab rod on a version of the Model 340 aircraft. Since the tabs on the subject model aircraft are unbalanced, a serious flutter condition resulted and a critical accident was narrowly avoided. In view of the fact that the tab rods and tab rod ends on the subject models aircraft are identical in design, hence susceptible to a similar type of failure, the following inspections and tab rod replacements or equivalent measures are required. Compliance required at every 110 hours of operation or regular scheduled inspection closest thereto. 1. (a) Inspect the tab rods and rod ends on the elevator, for looseness in the rivets which attach the rod ends to the rods, and for any relative movement between the rod and the rod ends. Parts which exhibit these defects shall be replaced with satisfactory parts. Upon completion of the tab rod replacement program or equivalent noted in items 2 (a), and 2 (b) below, this 110-hour inspection may be discontinued. Compliance required not later than November 30, 1957. 2. (a) Model 340 replacement of all elevator tab rods with improved, heavier rods and rod ends, and replacement of the right-hand elevator tab idler link with symmetrical idler link. (Convair Service Bulletin Nos. 340-207 and 340-150A cover this same subject.) 2. (b) Model 440 replacement of the right-hand elevator tab rods and tab rod ends with improved heavier tab rods and tab rod ends. (Convair Service Bulletin No. 440-27A covers this same subject.) FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_56-27-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 56-27-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: CONVAIR Models 340 and 440 Aircraft Subject: Elevator Servo Tab Rod Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Kelowna Flightcraft R & D Ltd. Model: 340 | 440 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: 56-27-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 56-27-01 SUBJECT HEADING: CONVAIR Models 340 and 440 Aircraft ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 56-27-01 CONVAIR: Applies to All Models 340 and 440 Aircraft. Compliance required as noted below. A report has been received concerning the failure of the elevator servo tab rod on a version of the Model 340 aircraft. Since the tabs on the subject model aircraft are unbalanced, a serious flutter condition resulted and a critical accident was narrowly avoided. In view of the fact that the tab rods and tab rod ends on the subject models aircraft are identical in design, hence susceptible to a similar type of failure, the following inspections and tab rod replacements or equivalent measures are required. Compliance required at every 110 hours of operation or regular scheduled inspection closest thereto. 1. (a) Inspect the tab rods and rod ends on the elevator, for looseness in the rivets which attach the rod ends to the rods, and for any relative movement between the rod and the rod ends. Parts which exhibit these defects shall be replaced with satisfactory parts. Upon completion of the tab rod replacement program or equivalent noted in items 2 (a), and 2 (b) below, this 110-hour inspection may be discontinued. Compliance required not later than November 30, 1957. 2. (a) Model 340 replacement of all elevator tab rods with improved, heavier rods and rod ends, and replacement of the right-hand elevator tab idler link with symmetrical idler link. (Convair Service Bulletin Nos. 340-207 and 340-150A cover this same subject.) 2. (b) Model 440 replacement of the right-hand elevator tab rods and tab rod ends with improved heavier tab rods and tab rod ends. (Convair Service Bulletin No. 440-27A covers this same subject.) 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.