Altitude deviating altitude excursion during descent on SID into sfo.

Attributes
ACN	179807
Time
Date	199105
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : oak
State Reference	CA
Altitude	msl bound lower : 9000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival other arrival star : star enroute airway : oak
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : private pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 210 flight time total : 4000 flight time type : 250
ASRS Report	179807
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 180 flight time total : 14000 flight time type : 1500
ASRS Report	179922
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While shooting the profile descent, I was trying to make each altitude restriction with minimal pitch/power changes for passenger comfort. The captain was nervous about my technique and kept questioning if I thought I would make each restriction. Each was an at or above or at restriction. The last 2 are '10000'' and 'begin descent to 6000.' the captain saw I met the 10000', but he misread the next one to say 'cross at 6000',' rather than 'begin descent to 6000'.' he directed me to lower my nose and expedite. I questioned him because I felt I was right. He insisted he was right, so I clicked off the autoplt to expedite the descent. As soon as I was stabilized, I reviewed the approach procedure and confirmed that I was right and he was wrong. Meanwhile, we had descended about 1000' below the 10000' required altitude. I immediately climbed back to 10000'. Approach control did not say anything about the incident, nor did we. This was a good lesson in humility for the captain and one in assertiveness for me. There was actually too much communication going on. From now on I verbalize all crossing restrictions as we approach them, so discussion can take place before it's too late.

Original NASA ASRS Text

Title: ALT DEVIATING ALT EXCURSION DURING DESCENT ON SID INTO SFO.

Narrative: WHILE SHOOTING THE PROFILE DSNT, I WAS TRYING TO MAKE EACH ALT RESTRICTION WITH MINIMAL PITCH/PWR CHANGES FOR PAX COMFORT. THE CAPT WAS NERVOUS ABOUT MY TECHNIQUE AND KEPT QUESTIONING IF I THOUGHT I WOULD MAKE EACH RESTRICTION. EACH WAS AN AT OR ABOVE OR AT RESTRICTION. THE LAST 2 ARE '10000'' AND 'BEGIN DSNT TO 6000.' THE CAPT SAW I MET THE 10000', BUT HE MISREAD THE NEXT ONE TO SAY 'CROSS AT 6000',' RATHER THAN 'BEGIN DSNT TO 6000'.' HE DIRECTED ME TO LOWER MY NOSE AND EXPEDITE. I QUESTIONED HIM BECAUSE I FELT I WAS RIGHT. HE INSISTED HE WAS RIGHT, SO I CLICKED OFF THE AUTOPLT TO EXPEDITE THE DSNT. AS SOON AS I WAS STABILIZED, I REVIEWED THE APCH PROC AND CONFIRMED THAT I WAS RIGHT AND HE WAS WRONG. MEANWHILE, WE HAD DSNDED ABOUT 1000' BELOW THE 10000' REQUIRED ALT. I IMMEDIATELY CLBED BACK TO 10000'. APCH CTL DID NOT SAY ANYTHING ABOUT THE INCIDENT, NOR DID WE. THIS WAS A GOOD LESSON IN HUMILITY FOR THE CAPT AND ONE IN ASSERTIVENESS FOR ME. THERE WAS ACTUALLY TOO MUCH COM GOING ON. FROM NOW ON I VERBALIZE ALL XING RESTRICTIONS AS WE APCH THEM, SO DISCUSSION CAN TAKE PLACE BEFORE IT'S TOO LATE.

Data retrieved from NASA's ASRS site as of July 2007 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.