When a corporate jet flight crew set an ATC amended hard crossing altitude into the FMS for epick on...

Attributes
ACN	1256658
Time
Date	201504
Local Time Of Day	1201-1800
Place
Locale Reference	SFO.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Medium Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	STAR SERFR 1
Person 1
Function	Pilot Not Flying Captain
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance

Narrative:

While established on the serfr 1 arrival runway 28 transition into sfo; we were instructed by ATC to descend via the serfr 1 arrival except to cross epick at and maintain 12;000 feet. When we reprogrammed the FMS to change the epick crossing restriction to a hard 12;000 feet vice the published between 15;000 feet and 10;000 feet; the VNAV disengaged/failed to capture and we did not meet the assigned crossing restriction at wwavs (between FL190 [and] 15;000 feet). The first officer (pilot flying) noticed the deviation; just prior to the wwavs intersection; and leveled the aircraft at 13;500 feet. After passing the wwavs intersection we complied with the remainder of the STAR and landed at sfo without further difficulties. ATC never mentioned the deviation or queried us as to why we missed the crossing restriction. A lot of thought and planning has gone into the designing of current day RNAV sids and stars. Changing these procedures for no apparent reason; is setting crews up for failure.

Original NASA ASRS Text

Title: When a Corporate Jet flight crew set an ATC amended hard crossing altitude into the FMS for EPICK on the SFO SERFR1 Arrival; VNAV disengaged and failed to capture the crossing restriction at WWAVS.

Narrative: While established on the SERFR 1 arrival Runway 28 transition into SFO; we were instructed by ATC to Descend via the SERFR 1 arrival except to cross EPICK at and maintain 12;000 feet. When we reprogrammed the FMS to change the EPICK crossing restriction to a hard 12;000 feet vice the published Between 15;000 feet and 10;000 feet; the VNAV disengaged/failed to capture and we did not meet the assigned crossing restriction at WWAVS (between FL190 [and] 15;000 feet). The FO (pilot flying) noticed the deviation; just prior to the WWAVS intersection; and leveled the aircraft at 13;500 feet. After passing the WWAVS intersection we complied with the remainder of the STAR and landed at SFO without further difficulties. ATC never mentioned the deviation or queried us as to why we missed the crossing restriction. A lot of thought and planning has gone into the designing of current day RNAV SIDs and STARs. Changing these procedures for no apparent reason; is setting crews up for failure.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

When a corporate jet flight crew set an ATC amended hard crossing altitude into the FMS for epick on the sfo SERFR1 arrival; VNAV disengaged and failed to capture the crossing restriction at wwavs.