B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 9
Distraction; Workload; Human-Machine Interface
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Undershoot; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Chart Or Publication; Aircraft; Human Factors; Procedure
Descending via the FLATI 1 RNAV Arrival to Denver; ATC gave us a clearance to cross ELLDO between 17;000 and FL210 (chart restriction is between 16;000 and FL210.  We did not know the exact format for that clearance; so the I (PF) (Pilot Flying) programmed in FL180.  No wonder we could not remember the format to enter.  The B737 Flight Manual states; 'Pilots cannot manually enter or modify altitude restrictions between two altitudes.  These types of altitude restrictions are only stored in the navigation database.'  This is a problem and causes distraction during a critical and busy phase of flight.  This clearance appears to consistently be given; as twice in two days on the FLATI 1 RNAV STAR; the same clearance to cross was given (once landing north; and once south).  This time we were landing south.  With FL180 in the window; I realize I should have put the bottom available altitude 17;000 feet in.  The FMS message came up 'steep descent'.  I utilized full speed brake; but went above the path up to 1300 feet.  Came down as aggressively as possible and even went slightly faster than the chart speed of 250 knots (did not exceed speed by more than 10 knots).  Crossed BSAFE about 200 feet high at around 258 knots.
Air Carrier Flight Crew flying 737 aircraft reports Air Traffic Control issues clearance conflicting with aircraft capability.