Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 229; Flight Crew Total 6346; Flight Crew Type 3706
Confusion
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Aircraft
Flying from ZZZ to IAH we planned to descend via the Mascot 4 arrival to Runway 27. We were switched to the DRLLR 5 arrival. Later we were then given Runway 26R so we set up for the ILS 26R. Switched again to RNAV Y 26R; so we reloaded and confirmed the box was correct. Given direct SKLER 6;000 feet @ 210 kts. Once we got to 6;000 cleared RNAV 26R after SKLER. Passed over SKLER and proceeded to next point DRKAR. For some reason the aircraft didn't turn and the FMC said vectors then DRKAR. Captain immediately clicked off autopilot and then ATC gave us a right turn to fly visual 26R. Gave another turn to intercept the LOC and then cleared us visual Runway 26R. The rest of the approach and landing was uneventful. We don't know how the fix sequence changed during the approach. After debriefing; Captain called and they said some aircraft have been having problems with this approach and trying to figure out why. They did not have a problem with us just wanted more information to figure out this ongoing problem.
We were cleared the RNAV Y Runway 26R at IAH at the last minute. This was the third runway or approach change that we received. We quickly loaded it; briefed it; set it up and activated it. Passing DRKAR we were surprised when the aircraft did not make the required right turn onto the arc. We immediately started to manually make the turn however Houston approach control also immediately saw the problem and started giving us vectors for the visual approach to 26R. Upon landing we were given an ATC phone number to call.  At the gate we called the phone number and spoke with Mr. X. He made it clear from the beginning that they were not filing a report against us; but said that he did have some questions for us. He told us that they had been talking about why some aircraft are rarely able to successfully able to fly this approach and wanted our opinion.
Air carrier flight crew reported aircraft was not turning at DRKAR while on the RNAV Y 26R arrival to IAH airport.  ATC advised the flight crew of problems with some aircraft not turning correctly at that fix.