B737-800
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Distraction; Confusion; Communication Breakdown; Workload
Deviation - Altitude Crossing Restriction Not Met; 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; Procedure
Flight was the return to DFW after a divert for thunderstorms; where we experienced a four hour maintenance delay for a Proximity Slat Electronics Unit light illumination on landing rollout. Flight was a ferry flight due to all passengers having deplaned and carried to DFW on busses. Our clearance was direct DEBBB JOVEM2. We were cleared for takeoff 'runway heading; climb to 15000.' After takeoff we were cleared direct DEBBB and handed off to Center; who told us to maintain 310 knots or greater and left us at 15000 feet for the entire cruise portion of the flight; which was planned at 27 minutes. We were subsequently cleared to resume published speeds at DEBBB. I was the Captain and Pilot Flying; so programmed the FMS speeds and checked the altitude constraints for the JOVEM2 arrival with the FO.Fort Worth Center cleared us to descend VIA the DEBBB2 arrival at this time. I did not catch the fact that he said DEBBB2 versus JOVEM2; which was our cleared arrival. We were never given a clearance change to the DEBBB2; simply told to descend VIA the DEBBB2. I had the JOVEM2 STAR selected on my iPad and programmed into the FMS but the First Officer (FO) had the DEBBB2 STAR selected on his iPad. The arrival points on the two stars are the same; but the altitude constraints are very different as it appears the JOVEM2 is designed for a north DFW flow and the DEBBB2 for a south. DFW had recently switched directions for the second time that day so was landing south; and I believe our flight plan was filed before the change. I began a VNAV descent to comply with the crossing restrictions on the JOVEM2 and the FO communicated to me that I was not going to make the altitude restriction at DEBBB. I initially reacted by selecting flight level change and speed brakes; but after referencing my iPad and the FMS which both were showing the JOVEM2 arrival; I retracted the speed brakes and told the FO we were fine with the altitude restrictions. At this time Fort Worth Center inquired about [our] altitude and seeing we were not going to make the restriction on the DEBBB2 simply told us to fly present heading and descend to 5000 feet at best rate. We were subsequently given a 090 degree vector and descent to 4000 feet with vectors to a visual approach to 18R at DFW. After receiving the initial inquiry from ATC the FO did inform him that our clearance was on the JOVEM2 and not the DEBBB2; which led to the subsequent heading and altitude clearance received from ATC. I believe that the Fort Worth Center controller assumed we were filed and cleared on the DEBBB2 and thus cleared us to 'descend VIA' the DEBBB2 versus first changing our arrival clearance from JOVEM2 to DEBBB2.There is a great potential for this type of error to occur when STARs contain the exact same navigational points but different altitude constraints. In this particular case; I believe it is important for the controller to change the STAR clearance before simply initiating a 'descend VIA' clearance to a new STAR. I am not sure what the ATC requirement is in this case; but since my aircraft was cleared on the JOVEM2 I would expect a new clearance to the DEBBB2 prior to the 'descend VIA' clearance being given. Of course we should have queried the controller because the 'descend VIA' clearance was given to a different STAR than we were cleared on; but I did not catch the distinction at the time of the call; especially since we were proceeding directly to the DEBBB navigational fix at the time. It wasn't until the FO made the initial comment regarding altitudes that I went through the thought process required to come to the conclusion that the cleared descent and cleared STAR procedures were different.
I don't know why we were filed and cleared for the JOVEM2 but cleared to descend via the DEBBB2. Maybe we were filed the JOVEM2 arrival when DFW was in north flow; but by the time we arrived at DFW after all of our lengthy delays; DFW was now in south flow. It can be very confusing when flying to a fix that is part of two different arrivals; but has vastly different speed and altitude constraints depending on which arrival it is part of.
A B737 pre-departure clearance to DFW included direct DEBBB JOVEM2. In flight the route clearance changed to the DEBBB2 STAR but since both JOVEM2 and DEBBB2 include the DEBBB waypoint; the crew somehow missed the revision which resulted in vectors for a high; fast arrival.