B737-700
Flight Crew Last 90 Days 260; Flight Crew Type 4000
Human-Machine Interface; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
General None Reported / Taken
Chart Or Publication; Aircraft; Human Factors; Procedure
The RYTHM 3 STAR to MSY requires flights to cross RYTHM at 250 KTS and to expect clearance to cross it at 11;000 MSL. This altitude is too high when executing the LOC 19 or the RNAV 19 approach. The descent plan without the restriction is greater than 3;000 feet lower; we were given the restriction.  I had planned to be lower before the fix; leveled five miles outside of the fix and slowed to 250 knots; as required. Lower was not available until we were switched to Approach. I managed the speed and slowed to 210 knots. Once over the fix and handed to Approach; we were given 4;000 FT and a left turn to intercept the LOC 19. I descended with full boards and continued to slow. Initially we were 3;000 FT high. Once slowed; I stowed the speedbrakes; asked for Flaps 5 then landing gear down and Flaps 15; and continued configuring for landing. I was on profile by 1;000 feet but it took a lot of effort and planning to do so. If [an IMC] approach had been required and I had to be configured and slowed at the FAF; it would have been even more difficult.This approach worked out OK; but it would be better if ATC could adjust the altitude and speed at RYTHM. I am not aware of what restrictions Houston Center and New Orleans Approach have in this area but a review of this arrival is a good idea. It is setting us up to be in an unstable condition and behind the aircraft.
A B737-700 First Officer reported the restrictions at RYTHM '...at 250 KTS; expect clearance to cross at 11;000 FT...' on the RYTHM STAR to MSY are excessively demanding when landing to the south.