EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Workload; Situational Awareness; Human-Machine Interface; Distraction; Communication Breakdown; Confusion
ATC Issue All Types
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Chart Or Publication; Procedure
The flight was filed for the JOVEM STAR but with winds out of the south; we were reassigned to the DEBBB STAR with the IBAKE transition about 250 miles from DFW. Nearing FAWNT intersection; we were given a clearance to switch to the SHAAM STAR with the FAWNT transition; and to descend via. I got it changed and it was activated but then I couldn't figure out what altitude to set for the bottom of the descent clearance. I asked the First Officer who also didn't see one; so we then asked ATC who at the same time asked if we were going to make the crossing at GREGS at 9000. We explained that we didn't have any altitude depicted on our charts but that we would make the crossing; which I did. There was not violation at any time and ATC said nothing more of the event other than to question if we were going to make the crossing.The chart for the STAR is obviously flawed and needs to be fixed; its use suspended in the interim. Also; it would be helpful if ATC created a guideline for their controllers about changing STARS; maybe a distance or time limit would be helpful. Pilots have the expectations to fly a particular STAR; we've looked at it; checked the crossings and speed changes; and looked at the weather that overlays the route. To get a change very close to the TOD doesn't allow for any of this to be done to the newly assigned STAR. Now we just plug it in and hope its right. If last minute changes need to be made; a descent should be issued with a heading and the instructions to set up for a new STAR issued.
The reporter believed but was not certain that the same Controller had recleared them on the SHAAM STAR yet later asked whether they were going to make the '9;000'' restriction at GREGS which is not on the chart. Nor was he able to recall for certain whether the initial clearance might have contained a separate clearance to cross at 9;000 FT. He noted that his carrier is in the final stages of transitioning to iPad EFBs; but they were still carrying paper charts aboard the aircraft. After landing they thought perhaps the electronic display of the chart may have been coded in error and cross checked the paper chart; which turned out to be exactly the same with no altitude restriction of any type on the FAWNT.SHAAM route.Reporter expressed concerns with last minute changes which require time and attention consuming and; often; don't allow for proper confirmation; execution and briefing of programmed changes and; in addition; might not be accomplished quickly enough for the FMC to properly digest and regurgitate accurate data on a timely basis.
An EMB-170 flight crew inbound to DFW filed for; set up and briefed to descend via the JOVEM RNAV STAR; IBAKE transition was given two STAR changes during their descent; first to descend via the DEBBB then; as they approached FAWNT Intersection; via the SHAAM STAR. Upon programming they noted there was no 'bottom' altitude to set; in fact no bottom altitude anywhere on the arrival or the six transitions thereof. ATC then asked if they were going to make their 9;000 restriction at GREGS for which the only charted restriction is 'At 250 KT.'