59-18-04: Wing Spar Web Reinforcement
FAA order 59-18-04 is an airworthiness directive. The FAA's subject line: Wing Spar Web Reinforcement. System: airframe structure.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Lockheed Aircraft Corporation
- Models
- 1049C-55, 1049D-55, 1049E-55, 1049G-82, 1049H-82
Dates and paperwork
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (1,000 characters)
59-18-04 LOCKHEED: Applies to All Models 1049C, 1049D, 1049E, 1049G and 1049H Aircraft.
Compliance required as indicated.
The following inspections have been established as a result of recently found cracking in the inner wing rear spar web at Wing Station 458.
At the next block overhaul or 4,000 flight-hours, whichever occurs first, on all aircraft (regardless of accumulated flight time) inspect the inner wing rear spar web at Station 458 for cracks in the upper and lower notched web area shown in Lockheed Drawing 555353. Inspection is applicable to both left and right wings.
If cracks are discovered incorporate the reinforcements shown in Lockheed Drawing 555353, or equivalent.
If no cracks are discovered, the reinforcements shown in Lockheed Drawing 555353 may be incorporated. Otherwise, reinspection at 4,000 flight-hour periods or block overhaul, whichever is less, is required to insure detection of cracks.
(Lockheed Service Letter FS/231094 covers thissame subject.)
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/59-18-04.json · aircraft systems.