B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 220; Flight Crew Total 16600; Flight Crew Type 297
Troubleshooting; Human-Machine Interface; Distraction; Workload
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification
Chart Or Publication; Procedure
There is NO pilot deviation or safety issue this flight because we planned ahead and we're ready. This report is for information only and to prevent other possible pilot/ATC deviations. There is a point on the DSNEE1 RNAV that is not possible to achieve. We saw this in advance; we asked for relief; we were given latitude to deviate from SoCal Approach Control; we tried to make the restriction and were unable; we brought this up to ATC controller's attention and he was in agreement. Upon loading the FMC before departure the 'TOO STEEP' message repeatedly appears for the next three hours. The issue is this: on the DSNEE 1 RNAV into SNA the crossing restriction at ROADE between 19000 and 17000 is too high so as to cross the next point PHIYA at or below 13000 within 11.3 NM at 280 kts. This exceeds the capabilities of the B737. SoCal ATC is aware of this; there have been other reports on this specific route structure; this needs to be changed.
B737 Captain reported the SNA DSNEE 1 RNAV Optimized Profile Descent (OPD) altitude constraints between ROADE at 17;000-FL190 and PHIYA at or below 13;000 ft are beyond B737 descent capabilities.