Japan's Transport Ministry strongly criticized maintenance practices at Japan Air Lines today and urged the carrier to correct them quickly and put "more work" into inspecting its planes' bodies.

The recommendation followed an emergency survey of maintenance facilities after the crash of a JAL jumbo jet last month, killing 520 persons.

JAL President Yasumoto Takagi said his company would comply in full. "All Japan Air Lines employes accept this recommendation solemnly and seriously," he said.

The ministry's statement did not blame poor maintenance for the accident, but it noted "suspicions" that it was the cause.

The Boeing 747 crashed on Aug. 12 after much of its tail section disintegrated during a domestic flight. Investigators are focusing attention on theories that the rear bulkhead suddenly collapsed, releasing pressurized cabin air with explosive force that damaged the tail.

Transport Minister Tokuo Yamashita recommended today that JAL take five specific steps and submit a new maintenance program within two months.

The five steps are: better inspection of the pressurized cabins of 747s; better inspection of the jets' body structures, with special attention to parts that have been repaired; thorough inspection of all components in important structural sections rather than inspecting a sample; full and prompt adoption of past recommendations, and tightened enforcement of safety rules.