Today in hot transit news, a second fire in as many weeks has prompted Metrobus to recall 94 Orion VI buses. NBCWashington reports:

An Orion VI bus caught fire just after 6 a.m. Tuesday on Route 50 between Interstate 95 and the MLK Highway in Prince George’s County.

No passengers were on the bus at the time of the fire and no injuries were reported. A mechanic was driving the bus at the time.

Last Thursday, an Orion VI bus caught fire on I-66 in Fairfax. There were no passengers aboard and no injuries.

Taking the 94 buses out of the fleet of 1500 isn’t the most noteworthy part, if you ask us. What’s noteworthy is that this isn’t the first time spontaneous bus fire has prompted a recall of this particular group of buses.

In September of 2010, WMATA removed 99 Orion VI buses from service after one caught fire on I-495. At the time, WMATA wrote: “Metro’s Orion VI buses have been out of service since Thursday, Sept. 9, when Metro officials took proactive steps to remove 99 of the buses from service to repair a hydraulic pump, which may have contributed to a fire that damaged a Metrobus on Interstate 495 near Springfield on Sept. 9.” The buses were put back into service after WMATA made temporary repairs and approved plans for permanent fixes.

Two years later, we’re interested to know whether WMATA ever instituted the permanent fix it planned for the buses—and whether the latest fires are related to the hydraulic pump problem the agency identified in 2010. We’ve reached out to WMATA for comment, will update as needed.

UPDATE: WMATA’s Dan Stessel writes over email that hydraulic problem on the Orion VI buses was fixed in 2010, and inspectors are trying to figure out what caused the two latest fires.

The 2010 fire/recall was the result of a hydraulic fitting that broke, requiring a redesign by the manufacturer.  The redesigned fitting was installed on all of the Orion VI buses before they were returned to service.  We can confirm that in both cases over the past week, there was no damage to the hydraulic fitting in question.  We have outside fire protection engineers on the property this afternoon performing inspections on the two incident buses.

Photo by JLaw45 via Flickr/Creative Commons Attribution 2.0 Generic License