A320
Flight Crew Last 90 Days 99; Flight Crew Total 999; Flight Crew Type 9
Human-Machine Interface
Deviation - Altitude Crossing Restriction Not Met; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Human Factors; Procedure; Aircraft
The airplane was unable to slow from 280 to 270 and descend at the same time to cross WOOKY at FL260 and 270 KTS. It's not an airplane issue; it is a physics issue with the crappy TSHNR1 RNAV STAR.
Prior to descent we discussed and verified proper altitudes and speeds programmed in the FMGC.  In the descent; however; the green donut several times showed us high when in reality we were low on the profile. We tried to 'recruise' to fix the issue but were still not confident in the information calculated by FMGC. Due to the confusion we did get high and I mentioned to First Officer he needed to take action.
An A320 flight crew was unable to comply with the crossing restriction at WOOKY on the TSHNR RNAV STAR to DEN.