B757 flight crew reports crossing kikkr high during the gibbz arrival to iad. The local altimeter se...

Narrative:

While on the gibbz two RNAV arrival for washington dc (va) after passing tabbe on the high side of its altitude window and VNAV path displayed and also had the lowest altitude for the STAR set in the altitude window. At about FL195; pilot monitoring (pm) recognizing that the ATC altimeter from ATC was 30.28 (high) that we would be proactive in getting that set with no delay. And did so. Pm went heads down and requested the latest ATIS so as to verify and have the latest altimeter. Also a call from the cabin came at about this time and the pm answered it and had a short conversation. Pm then accepted and printed the ATIS and announces the altimeter at airport would be 30.30 inches. The pm then returned to monitoring the pilot flying (PF); at this time the pm noticed that it appeared we were going to be high for the next crossing (kikkr) yet while still in vpath. The pm asked the PF to confirm this and then instructed the PF to take immediate corrective action. Pm was still not satisfied with the aggressiveness of the corrective action and asked the PF to disconnect the autopilot and use full speed brake and push the nose over to get back on vpath; which the PF did. It would be reasonable to conclude we were high at kikkr but back on vpath for the next fix which was igggy. Just past igggy ATC radioed us to turn to a heading for vectors for a visual approach. There was no conversation with ATC reference our arrival and went on to land uneventful. Pm and PF debriefed at the gate and discussed this STAR. We both felt the VNAV path was very subtle in its inability to not maintain the path and was a surprise to us considering that we were on path from the very first fix and on speed with no changes from ATC. We thought the issue involved the high altimeter setting combined with slow technology of the FMC in conjunction with crossing the initial STAR fixes on the high side. Obviously we are not happy with the result.

Original NASA ASRS Text

Title: B757 Flight Crew reports crossing KIKKR high during the GIBBZ arrival to IAD. The local altimeter setting of 30.30 was set passing FL190 and the FMC path shown on profile while crossing KIKKR 1;000 feet high.

Narrative: While on the GIBBZ TWO RNAV ARRIVAL for Washington DC (VA) after passing TABBE on the high side of its altitude window and VNAV PATH displayed and also had the lowest altitude for the STAR set in the altitude window. At about FL195; pilot monitoring (PM) recognizing that the ATC altimeter from ATC was 30.28 (High) that we would be proactive in getting that set with no delay. And did so. PM went heads down and requested the latest ATIS so as to verify and have the latest altimeter. Also a call from the cabin came at about this time and the PM answered it and had a short conversation. PM then accepted and printed the ATIS and announces the altimeter at airport would be 30.30 Inches. The PM then returned to monitoring the pilot flying (PF); at this time the PM noticed that it appeared we were going to be high for the next crossing (KIKKR) yet while still in VPATH. The PM asked the PF to confirm this and then instructed the PF to take immediate corrective action. PM was still not satisfied with the aggressiveness of the corrective action and asked the PF to disconnect the autopilot and use full speed brake and push the nose over to get back on VPATH; which the PF did. It would be reasonable to conclude we were high at KIKKR but back on VPATH for the next fix which was IGGGY. Just past IGGGY ATC radioed us to turn to a heading for vectors for a Visual Approach. There was no conversation with ATC reference our arrival and went on to land uneventful. PM and PF debriefed at the gate and discussed this STAR. We both felt the VNAV PATH was very subtle in its inability to not maintain the path and was a surprise to us considering that we were on path from the very first fix and on speed with no changes from ATC. We thought the issue involved the high altimeter setting combined with slow technology of the FMC in conjunction with crossing the initial STAR fixes on the high side. Obviously we are not happy with the result.

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.

Attributes
ACN	1207258
Time
Date	201409
Local Time Of Day	0001-0600
Place
Locale Reference	ZDC.ARTCC
State Reference	VA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR GIBBZ TWO
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Pilot Not Flying Captain
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 20000 Flight Crew Type 5000
Person 2
Function	First Officer Pilot Flying
Experience	Flight Crew Last 90 Days 175 Flight Crew Total 7800 Flight Crew Type 900
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Altitude Undershoot Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Published Material / Policy

B757 flight crew reports crossing kikkr high during the gibbz arrival to iad. The local altimeter setting of 30.30 was set passing FL190 and the FMC path shown on profile while crossing kikkr 1;000 feet high.