AD 49-44-02

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AD Number:
49-44-02
Document Type:
AD Final Rules
Docket Number:
Unknown
Subject Heading:
CONVAIR Model 240 Series Aircraft
Subject:
Horizontal Tail
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
Make:
Kelowna Flightcraft R & D Ltd.
Model:
240 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Superseded AD: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Superseded By: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: 49-44-02
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   Unknown

AMENDMENT:  

AD NUMBER:   49-44-02

SUBJECT HEADING:   CONVAIR Model 240 Series Aircraft

ACTION:  

SUMMARY:  

DATES:  

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
49-44-02 CONVAIR: Applies to All Model 240 Series Aircraft.

To be accomplished not later than August 1, 1950.

Due to difficulties being located during the special inspections of the horizontal tail presently required by Airworthiness Directive 48-51-02, mandatory corrective action is now considered to be necessary. These difficulties include cracking of the left elevator leading edge ribs, cracking of the left elevator structure at the elevator flight tab hinge brackets, excessive wearing of the tab hinge pins, and loosening of the balance weights on the elevators and rudder. If allowed to progress, these difficulties could result in tail flutter or other hazardous conditions; therefore, it is considered necessary that the following rework be accomplished on all individual Convair Model 240 Series aircraft:

1. Install the revised elevator flight tab assembly, CVAC P/N 240-2210401-78.

(CVAC Service Bulletin No. 240-56A covers this same subject.)

2. Reinforce the left elevator leading edge ribs outboard of Station 111.6, and strengthen the means of attaching the rudder and both left and right elevator balance weights.

(CVAC Service Bulletin No. 340-176A covers this same subject.)

3. Replace the present tab hinge pins and bushings with close tolerance bolts and bushings.

(CVAC Service Bulletin No. 240-205 covers this same subject.)

4. Reinforce the left elevator ribs at the flight tab hinge points.

(CVAC Service Bulletin No. 240-225 covers this same subject.)

5. Reinforce the left elevator leading edge ribs and the carry-through structure from leading edge ribs to the corresponding ribs aft of the spar, at Station 111.6 and inboard.

(CVAC Service Bulletin No. 240-268 covers reinforcement of the nose ribs. The portion of CVAC Service Bulletin No. 240-219 pertaining to Station 111.6 and inboard, covers reinforcement of the carry-through structures.)

6. Replace 4 of the 10 rivets in each of the inboard elevator hinge brackets which attach CVAC P/N 240-2110702 to the bracket assembly with 3/16 inch close tolerance steel bolts or steel rivets.

(CVAC Service Information Letter No. 415 covers this same subject and shows location of the specific rivets to be replaced.)

7. Between horizontal stabilizer station B. L. 50.50 and B. L. 59.50, add 4 rivets (AN 462-4-14 blind rivets may be used) to both the upper and lower surfaces. The rivet line should be 0.44 inch aft of the aft face of the vertical leg of the front spar cap (approximately 1/2 inch aft of the leading edge of the skin, i.e., 1/2 inch aft of the butt joint between the stabilizer leading edge skin and interspar skins). The rivets should be evenly spaced between B. L. 50.50 and B. L. 59.50 and not closer than 5/8 inch to any existing rivet.

(CVAC Service Difficulties and Parts Failures Report No. 245 covers this same subject.)

Although evidence indicates that horizontal tail failures will be materially reduced after incorporation of the above, some additional cracking may yet occur. Therefore, special inspections required by AD 48-51-02 must be continued until sufficient evidence of trouble-free operation has been supplied to the FAA to warrant discontinuance of these inspections.

This supersedes AD 49-17-01.

FOOTER: