The National Transportation Safety Board (NTSB) determines that the probable cause of this accident was the failure of the motorcoach driver to maintain control of the vehicle due to his falling asleep while driving because of fatigue resulting from acute sleep loss, poor sleep quality, and circadian disruption and the failure of Sky Express, Inc., management to follow adequate safety practices and to exercise safety oversight of the driver. Contributing to the accident was the Federal Motor Carrier Safety Administration’s lack of adequate oversight of Sky Express, Inc., which allowed the company to continue operations despite known safety issues. Contributing to the fatalities and the severity of the injuries was the lack of a comprehensive occupant protection system, including systems for providing passenger restraint and for ensuring sufficient roof strength.
The accident investigation focused on the following safety issues:
- Driver fatigue. The motorcoach drifted from the travel lanes because the driver fell asleep while driving. The motorcoach crossed the shoulder, passing over the rumble strip and onto an earthen area before striking the cable barrier. The driver awoke and steered to the left, back toward the travel lanes. Due to the driver’s steering overcorrection and the cable barrier deflection, the motorcoach overturned and rolled onto its roof.
- Motorcoach deficiencies in roof strength and occupant protection. The accident resulted in four fatalities, all of whom were initially seated on the passenger side of the bus in the region of maximum roof deformation. These four people died as a result of crushing injuries, as the motorcoach rolled over and the roof collapsed. Injuries occurred during the rollover when passengers were thrown from their seats and the survivable space decreased due to the substantial roof crush. Passenger restraints were not available on this motorcoach. The NTSB is concerned about the lack of Federal standards for occupant protection and roof strength on motorcoaches.
- Federal Motor Carrier Safety Administration (FMCSA) failure to exercise adequate safety oversight of the accident motor carrier. In 2005, the interstate motor carrier operating this bus service sought operating authority from the FMCSA.2 The FMCSA passed the carrier in a new entrant safety assurance audit in early 2007, despite having identified deficiencies in the carrier’s safety systems. During its 6 years in business as an interstate passenger carrier, the accident carrier was the subject of five FMCSA reviews of its compliance with safety regulations. According to the results of these reviews and additional information uncovered during the investigation, this carrier, Sky Express, Inc., repeatedly failed to fulfill the requirements of Federal safety regulations and did not ensure its drivers complied with safety requirements. Despite its recognizing Sky Express’s safety deficiencies, the FMCSA did not remove the carrier’s operating authority until the accident occurred.
Parties to the investigation were the FMCSA; the National Highway Traffic Safety Administration (NHTSA); the Virginia Department of Transportation; the Virginia State Police; and Setra North America, the motorcoach manufacturer.
As a result of the investigation, the NTSB makes three new recommendations to the FMCSA, reiterates previous recommendations to the FMCSA and NHTSA, reclassifies a previous recommendation to the FMCSA, and reiterates and reclassifies a previous recommendation to NHTSA.
1. The injury status of five passengers could not be determined due to insufficient information.
2. In 2005, the carrier’s name was Lei Shi. It was subsequently changed to Sky Express, Inc.