Synopsis
On 3 July 2014 at 1815 hours local time, a Boeing B777-300ER, registration 9V-SWH, operated by Singapore Airlines, departed from George Bush Intercontinental Airport in Houston, Texas, USA, on a scheduled passenger flight to Moscow. The flight crew comprised a Captain (C1, pilot flying), a Senior First Officer (SFO, pilot monitoring), and a second Captain (C2). The aircraft departed via the INDIE ONE RNAV Standard Instrument Departure (SID).
Factual Information
History of the Flight
The departure clearance included the INDIE ONE RNAV SID. During the departure briefing, the PF (C1) read the first line of the 'Routing' section on the Jeppesen chart and then scrolled to the pictorial portion without returning to the text box, which contained the altitude restriction "MAINTAIN 4000' or as assigned by ATC." The PF concluded there were no altitude restrictions and set FL310 (the filed cruise altitude) in the Mode Control Panel (MCP) altitude window. The PF did not communicate his expectation that ATC would assign an intermediate altitude.
After departure, the SFO reported to ATC at 2,500 ft but did not state the climb altitude. The aircraft climbed above 4,000 ft, conflicting with another aircraft descending to 6,000 ft. At about 5,600 ft, the Traffic Alert and Collision Avoidance System (TCAS) issued a Traffic Advisory. Shortly after, ATC instructed the aircraft to descend to 5,000 ft in an urgent tone. The PF disconnected the autopilot and initiated descent. A TCAS Resolution Advisory (RA) "Climb, Crossing Climb" then activated, but the PF did not comply. A second RA "Level off" occurred 19 seconds later, and the aircraft continued descending. TCAS announced "Clear of Conflict" 8 seconds after the second RA, and the aircraft leveled off at about 5,000 ft. The entire RA episode lasted 27 seconds. Standard vertical separation was restored in less than 10 seconds.
The aircraft then began climbing again because FL310 remained set in the MCP. ATC queried the climb, and C2 noticed the FL310 setting. The PM changed it to 5,000 ft, and the aircraft leveled off. After the event, C2 reviewed his chart and identified the missed altitude restriction.
'Climb Via SID' Clearance
The "climb via SID" clearance phraseology was introduced by the FAA on 3 April 2014. The operator had briefed its crews on this procedure. The clearance required compliance with the SID's lateral path, speed restrictions, and altitude restrictions.
Discussion
The TCAS alerts resulted from the flight crew not noticing the 4,000 ft altitude restriction on the Jeppesen chart. The pilots were not systematic in their departure briefing and chart reading.