B737 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 17000
Workload; Situational Awareness; Confusion
ATC Issue All Types; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Chart Or Publication; Human Factors; Procedure
I was the Pilot Flying enroute to DFW on the BRDJE3 RNAV Arrival landing north. We were level at FL240 when ATC issued us a clearance to 'descend via the BRDJE3 arrival except maintain 310 kts' The Captain answered the clearance and since we were in continuous light/bordering moderate chop I elected to vacate the assigned altitude to find a lower smoother altitude; however; I failed to realize that we were not at waypoint TUSLE yet on the arrival. Our position was closer to CHMLI when I started the slow descent. So after our descent by about 300 feet ATC asked to confirm our arrival into DFW which we responded the BRDJE3. He then stated that TUSLE restriction is a FL240 and above and then told us to proceed direct to SEEVR and descend via the BRDJE3 Arrival and comply with speeds at SEEVR. The reason was I left FL240 was the deteriorating ride at that altitude and we did have a clearance to descend via the BRDJE3 Arrival. My [safe altitude] on the STAR was also confused by the poor illustration on Jeppesen page 60-2C for the BRDJE3 RNAV Arrival. If you look at the page you will clearly see NO ALTITUDE next to TUSLE; but what you will see is a small number 1 which then you must search the entire page to find out the number 1 means 'at 290 kts FL300 - FL 240.' I suggest that the Company; Jeppesen; FAA come up with a less cluttered and less sub-texted format for these arrivals. It can [confuse] the crew when ATC changes headings; speeds; and altitudes and goes back and tells crew to descend via the STAR. Sometimes we are left wondering where we are on the STAR. Too many changes and poor depictions on charts can lead to confusion.
B737 First Officer reported departing from assigned altitude on the BRDJE3 RNAV Arrival into DFW; citing a confusing and cluttered chart as contributing.