Boeing said the fire aboard one of its test 787 Dreamliners Monday was caused by the failure of a power panel and the ignition of a nearby insulation blanket. Seen here, the first 787 is shown off for the first time at the plane&39's official unveiling on July 8, 2007.

Boeing said today that the fire Monday aboard a 787 Dreamliner test aircraft started when an electronics bay power panel failed, igniting a nearby insulation blanket.

The fire forced the 787 to make an emergency landing in Laredo, Texas, and the immediate indefinite suspension of the test program. Boeing also said yesterday that because of the incident, it did not know if its plan to make the first Dreamliner deliveries to customers in the first quarter of 2011 was still viable.

According to a statement it issued late today, Boeing said that the P100 panel--one of several power panels in the 787's aft electronics bay--had failed during the flight, causing the nearby insulation blanket to catch fire. The P100 panel "receives power from the left engine and distributes it to an array of systems," Boeing said. "In the event of a failure of the P100 panel, backup power sources--including power from the right engine, the Ram Air Turbine, the auxiliary power unit or the batter--are designed to automatically engage to ensure that those systems needed for continued safe operation of the airplane are powered."

The test plane was able to land safely, with no injuries on board or on the ground, when the backup systems engaged properly, Boeing said.

The company also explained that the insulation blanket "self-extinguished once the fault in the P100 panel cleared." Now, the panel aboard the test plane--the second of six such planes in the Dreamliner program--has been taken off the aircraft. A new unit is being shipped to Laredo, where it will be installed to replace the failed panel, which suffered "significant" damage.

But Boeing said that nearby systems or airplane structure were not heavily damaged, though the company has yet to finish a full inspection of the aircraft. "It is too early to determine if there is significant damage to any structure or adjacent systems," Boeing said.

The incident is just the latest in a long string of delays that have plagued the much-anticipated Dreamliner. In August, Boeing announced that it was re-assessing the availability of an engine required for the 787's final flight tests, and previously, slowdowns have come as a result of a machinists strike, supplier shortages, and an issue with the joint between the Dreamliner's wing and its fuselage. When the plane was first shown off on July 8, 2007--07/08/07--it was thought that its first flight would take place just a month or two later. Instead, the first flight didn't take place until December 15, 2009.

News of the Monday incident and its impact on the test program and the ultimate first customer delivery continue to rock Boeing's stock. Yesterday, shares were down $2.18, or 3.15 percent, and today, Wall Street slashed another $1.70, or 2.53 percent from the stock.

Still, there's little doubt that the airline industry is eagerly awaiting completion of the test program and the first deliveries of the plane, since its innovative composite design is expected to offer carriers significant fuel efficiencies, and passenger comfort.