Meteoro

Flight Operations Briefing Notes

Operating Environment Volcanic Ash Awareness

Flight Operations Briefing Notes Operating Environment Volcanic Ash Awareness

I

Introduction
Flying through an ash cloud should be avoided by all means due to the extreme hazard for the aircraft. Experience has shown that damage can occur to aircraft surfaces, windshields and powerplants. Aircraft ventilation, hydraulic, electronic and air data systems, can also be contaminated. Partial or total engine power loss events caused by volcanic ash ingestion, while not frequent, are major safety concerns. Simultaneous power loss in all engines has occurred, where the crew succeeded in restarting the engines, after application of operational procedures. As weather radar is not effective in detecting volcanic ash clouds, crews must be informed by other means of the potential or effective presence of ash clouds on air routes. The aim of this Flight Operational Briefing Note is to provide information about volcanic ash effects on aircraft, and operational guidelines, in order to help preventing a volcanic ash cloud encounter.

II

Background Information

II.1 Statistical Data
The Pacific region represents one of the biggest concentration of volcanoes in the world, with over 100 active volcanoes (See Figure 1). Active volcanoes are capable of sending volcanic ash up to altitudes greater than FL300 after explosive eruptions. Encounters affecting aircraft performance have occurred 2 400 NM from the ash source and up to 72 hours after an eruption.

Page 1 of 12

Flight Operations Briefing Notes

Operating Environment Volcanic Ash Awareness

Figure 1 Active volcanoes in Pacific area Over 80 aircraft have reported to have flown into volcanic ash cloud between 1980 and 2000, with consequences ranging from increased wear of engines to simultaneous power loss in all engines. Alert messages (volcanic ash SIGMET) are issued by a Meteorological Watch Office (MWO) for its area of