AD 79-16-04

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AD Number:
79-16-04
Document Type:
AD Final Rules
Docket Number:
79-ASW-4
Subject Heading:
Airworthiness Directives; SL Industries Models B-1 and B-1A Airplanes
Subject:
Wing Rear Spar
Status:
Current
Citation:
This information is not available.
Citation Publish Date:
Effective Date:
09/07/1979
Make:
Aerotek II, Inc.
Model:
B-1 | B-1A
Product Type:
Aircraft
Product Subtype:
Small 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Superseded AD: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Superseded By: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: 79-16-04
CITATION:   This information is not available.

PAGE NUMBER:  

DOCKET NUMBER:   79-ASW-4

AMENDMENT:   39-3523

AD NUMBER:   79-16-04

SUBJECT HEADING:   Airworthiness Directives; SL Industries Models B-1 and B-1A Airplanes

ACTION:  

SUMMARY:  

DATES:   Effective September 7, 1979.

ADDRESSES:  

FOR FURTHER INFORMATION CONTACT:  

SUPPLEMENTARY INFORMATION:  

REGULATORY TEXT:  
79-16-04 SL INDUSTRIES (CALLAIR): Amendment 39-3523. Applies to Models B-1 and B-1A Airplanes, all Serial Numbers, certificated in all categories with over 500 hours' time in service. Airworthiness Docket No. 79-ASW-4.

Compliance required within the next 50 hours after the effective date of this AD, unless already accomplished within the last 50 hours' time in service and thereafter at intervals not to exceed 100 hours' time in service from the last inspection.

To prevent failure of the wing rear spar at the wing-fuselage attachment fitting (P/N 160049) due to cracking, accomplish the following:

(a) Inspect both rear wing spars by the following procedures:

(1) Remove the wing-fuselage fairings covering the rear spar attach bolt.

(2) Hoist the wing and jack the landing gear to relieve the load on the rear spar attach bolt and remove the rear spar attach bolt.

(3) Remove the P/N 16049-1 and -2 spar fittings by removal of (6) AN 4 bolts attaching fittings to the spar web.

(4) Visually and with dye penetrant methods, inspect the spar web in the area of the P/N 16049-1 and -2 fittings for cracks. Give particular attention to the upper and lower fasteners in the pattern of (6) fasteners attaching the P/N 16049-1 and -2 fittings to the spar web. Inspect these holes for elongation beyond .254 inches.

(5) Visually inspect the inboard 24 inches of the spar web for corrosion.

(b) Repair any discrepancies found during the inspections of paragraph (a) as follows:

(1) For cracks or elongated fastener holes in the spar web, replace the damaged spar with a new spar.

(2) For corrosion on the spar web, repair as follows:

(i) Remove corrosion in accordance with AC 43.13-1A dated 1972.

(ii) If corrosion is less than 10 percent of spar web thickness locally and reduces the spar web cross-section area by less than 2 percent, treat the corroded spar web area with two coats of zinc chromate primer in accordance with MIL-P-6889 or MIL-P-8585A.

(iii) If corrosion exceeds 10 percent of local spar web thickness or 2 percent of spar web cross-section area, replace the spar or repair with a repair approved by the Chief, Engineering and Manufacturing Branch, FAA, Southwest Region.

(iv) Reinstall the 16049-1 and -2 spar fittings with the fasteners removed as specified in paragraph (a)(3).

(v) Reinstall the wing fairings removed during paragraph (a) inspections.

NOTE: (SL Industries Service Bulletin A-25 covers this same subject.)

(c) Modification of the rear spar by installation of the new wing-fuselage attach fittings of SL Industries Service Bulletin A-25A (or equivalent modifications approved by the Chief, Engineering and Manufacturing Branch, FAA, Southwest Region) will remove the requirement for the 100-hour repetitive inspections.

(d) Aircraft may be flown in accordance with FAR 21.197 to a base where the requirements of this AD can be accomplished.

This amendment becomes effective September 7, 1979.

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