NEW YORK ( TheStreet) -- The world awaits word on the cause of an airplane crash Tuesday morning in the southern French Alps.

The aircraft, an Airbus A320, is one of the two most common aircraft in the world: More than 6,000 are in operation. Single-aisle A320s and Boeing (BA) - Get Report 737s are the workhorses of global aviation.

Flight 4U9525 was en route from Barcelona to Dusseldorf. It carried 150 people including two pilots and four flight attendants. French President Francois Hollande has said he expects there are no survivors.

The aircraft, in service for 24 years, was moved last year from Lufthansa's fleet to Germanwings' fleet.

At 11:20 a.m., the aircraft disappeared off radar, Le Figaro reported. According to press reports, the aircraft rapidly lost altitude, falling from 38,000 feet to 7,000 feet in nine minutes.

The Associated Press reported that the owner of a French Alpine camping ground said he heard a series of loud noises in the air before the crash.

 "The noise I heard was long -- like 8 seconds -- as if the plane was going more slowly than a military plane speed. There was another long noise about 30 seconds later," Pierre Polizzi told the AP. Polizzi said it would be difficult to get to the site of the crash. "The mountain is snowy and very hostile."

 The most recent previous crash involving an A320 flown occurred in December. AirAsia Flight 8501, in route from Indonesia to Singapore, crashed into the Java Sea, killing 162 people. The cause is under investigation.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.