Take a look at the following images; one of AirAsia QZ8501, and two more images of a Virgin Australia and Airbus library photograph of an A320. Spot the difference?
|QZ8501 - No SATCOM Box|
|Virgin Australia with SATCOM Box|
|A320 with SATCOM Box|
What Soucie noted was the absence of SATCOM on QZ8501.
What is SATCOM?
You will find a pretty good explanation at this link.
It is just one more piece of equipment that makes the search for missing aircraft that much easier...