EASA AD ISR-I-35-26-01-01
Potential of arcing, fire and/or loss of crew oxygen supply due to insufficient clearances between electrical wiring and flexible oxygen hose
Summary
Airworthiness Directive AD ISR I-35-26-01-01 issued by the Civil Aviation Authority of Israel addresses a safety issue on Boeing 747-400 freighter aircraft converted under CAAI STC SA-151 or SA-152 and their validated equivalents. The directive highlights the risk of arcing, fire, and loss of crew oxygen supply caused by insufficient clearance between electrical wiring and the flexible crew oxygen hose. It requires inspection and corrective action to prevent potential hazards related to chafing and damage to oxygen hoses and electrical wiring.
What Changed
This new Airworthiness Directive introduces mandatory inspections of the crew oxygen bottle flexible hose and adjacent electrical wiring on affected Boeing 747-400 freighter conversions. It requires operators to inspect the area per IAI Service Bulletin SB 366-35-157 and to contact IAI immediately if any damage is found. The directive also permits a single ferry flight for maintenance if no damage is detected.
Why It Matters
This directive is critical for aviation professionals because it addresses a potential fire hazard and oxygen supply failure that could compromise crew safety. Operators and maintenance teams must ensure compliance to prevent in-flight emergencies related to electrical arcing and oxygen hose rupture. Timely inspections and corrective actions help maintain airworthiness and operational safety of affected aircraft.
What To Do
Operators of Boeing 747-400 aircraft converted under CAAI STC SA-151 or SA-152 must inspect the affected areas before the next flight following the procedures in IAI Service Bulletin SB 366-35-157. If damage or wear is found, they must immediately contact IAI for further instructions. If no damage is found, one ferry flight for maintenance purposes is allowed.