Crossing restr not met.

Attributes
ACN	299530
Time
Date	199503
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : sbj airport : lga
State Reference	NJ
Altitude	msl bound lower : 11000 msl bound upper : 11500
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute airway : zny
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 154 flight time total : 11292 flight time type : 1498
ASRS Report	299530
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : undershoot altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Aircraft programmed to cross lizzi at 11000 ft from 13000 ft. Aircraft did not respond to program and aircraft descended autoplt off. Autoplt engaged and VNAV selected. Aircraft began an immediate climb disregarding the 11000 ft set in the altitude window. This scenario resulted in a missed altitude crossing restr and an altitude excursion from the climb. I feel that heavy reliance on programmed VNAV in high density areas may not be reliable enough for acceptable use. Callback conversation with reporter revealed the following information: the reporter flies the md-88 for a major united states air carrier. This incident 'happened so quickly, it was a question of who got there first.' the aircraft climbed 500 ft before it was brought back to altitude. The reporter knows that he could have stopped the climb earlier, but might have hurt someone in the process. The primary problem with this aircraft is the 'very slow autoplt trim system' that allows the aircraft to get off of or miss an altitude. As the reporter was flying in the ZNY area, he was spending more time looking out the window which diverts attention from managing the autoplt. 'Nobody reads while flying this aircraft.'

Original NASA ASRS Text

Title: XING RESTR NOT MET.

Narrative: ACFT PROGRAMMED TO CROSS LIZZI AT 11000 FT FROM 13000 FT. ACFT DID NOT RESPOND TO PROGRAM AND ACFT DSNDED AUTOPLT OFF. AUTOPLT ENGAGED AND VNAV SELECTED. ACFT BEGAN AN IMMEDIATE CLB DISREGARDING THE 11000 FT SET IN THE ALT WINDOW. THIS SCENARIO RESULTED IN A MISSED ALT XING RESTR AND AN ALT EXCURSION FROM THE CLB. I FEEL THAT HVY RELIANCE ON PROGRAMMED VNAV IN HIGH DENSITY AREAS MAY NOT BE RELIABLE ENOUGH FOR ACCEPTABLE USE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES THE MD-88 FOR A MAJOR UNITED STATES ACR. THIS INCIDENT 'HAPPENED SO QUICKLY, IT WAS A QUESTION OF WHO GOT THERE FIRST.' THE ACFT CLBED 500 FT BEFORE IT WAS BROUGHT BACK TO ALT. THE RPTR KNOWS THAT HE COULD HAVE STOPPED THE CLB EARLIER, BUT MIGHT HAVE HURT SOMEONE IN THE PROCESS. THE PRIMARY PROB WITH THIS ACFT IS THE 'VERY SLOW AUTOPLT TRIM SYS' THAT ALLOWS THE ACFT TO GET OFF OF OR MISS AN ALT. AS THE RPTR WAS FLYING IN THE ZNY AREA, HE WAS SPENDING MORE TIME LOOKING OUT THE WINDOW WHICH DIVERTS ATTN FROM MANAGING THE AUTOPLT. 'NOBODY READS WHILE FLYING THIS ACFT.'

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.