Before revision: With the advent of cellphones and the Internet a seperate or integrated SDU can be used to offer telephone and Internet services to URL , retrieved 01 July URL , retrieved 01 July 2014 A330 TECHNICAL TRAINING MANUAL MECHANICAL & AVIONICS COURSE, pages 58 - 69, copyright Airbus S.A.S, published prior to 2014 but copyright date not given Logs of satellite communication have been used to inform search and rescue agencies of locations of missing aircraft, notably that of Malaysia Airlines Flight 370 whose position was unknown due to loss of RADAR contact and other communications.
After revision: With the advent of cellphones and the Internet a seperate or integrated SDU can be used to offer telephone and Internet services to URL , retrieved 01 July URL , retrieved 01 July 2014A330 TECHNICAL TRAINING MANUAL MECHANICAL & AVIONICS COURSE, pages 58 - 69, copyright Airbus S.A.S, published prior to 2014 but copyright date not given Logs of satellite communication have been used to inform search and rescue agencies of locations of missing aircraft, notably that of Malaysia Airlines Flight 370 whose position was unknown due to loss of RADAR contact and other communications.