China Airlines (CAL) said yesterday it had completed examinations on the slat track downstop assemblies on all of its 13 Boeing 737-800 planes on Friday.
The examination was one of the requirements listed in the emergency directive issued by the US' Federal Aviation Administration on Aug. 28 asking airlines worldwide to carry out the examination within 10 days upon receipt of the notice. Friday was the last day.
Steve Yuen (
The standard torsion value, as indicated in the directive, should be between 50 inches-lb and 80 inches-lb, but the majority of those found below standard had only 40 inches-lb.
Yuen said this was simply an issue they found during the examination and was not necessarily the cause of the aircraft blast at Naha Airport in Japan last month.
The inspection team also found some of the components on the assemblies were not placed in accordance with the Boeing aircraft maintenance manual.
However, Yuen said that the company's maintenance crew rarely tamper with the assemblies.
He said the crew started paying attention to the nuts on the slat track downstop assemblies only after Boeing Co issued a service letter in March last year indicating that two fuel leak incidents were reported to have been caused by loose nuts on one of the assemblies. Boeing further "suggested" that the nuts be changed.
Yuen pointed to a fleet team digest published on Aug. 23 last year, saying the loose nuts could cause a "streaming fuel leak."
CAL has changed five nuts on the assemblies following the issuance of the notice, including one on the aircraft destroyed in the Naha incident.
Yuen said that CAL would submit the inspection results to the Civil Aeronautics Administration tomorrow.