Altitude deviation. Undershot crossing restriction on descent.

Attributes
ACN	148510
Time
Date	199006
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lal
State Reference	FL
Altitude	msl bound lower : 24000 msl bound upper : 26000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zma
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 130 flight time total : 12500 flight time type : 130
ASRS Report	148510
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course none taken : unable none taken : insufficient time
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flight was in an large transport, dfw to orl, and on J58 to covia, then direct pie, J103 to orl. Before pie we were placed on a heading to expect direct lal. Later we were told to descend to FL240 and to be at FL240 by 55 NM west of lal. This I put in the FMC and was in the descent mode and on schedule. After we received ATIS from orl I was getting out my approach plate to runway 17 at orl reviewing it when my FMC went from VNAV speed to VNAV path, and I did not catch this until my copilot told me I was getting close to 55 DME, and since being on a vector the FMC was saying I was on path since we still had over 10 NM and 3000' or so to go. However, since we were on a heading and in VNAV path the aft was not on schedule descent, so I took over and missed the 55 DME by about 5 NM. Nothing was said by ZMA and we were handed off to another controller.

Original NASA ASRS Text

Title: ALT DEVIATION. UNDERSHOT CROSSING RESTRICTION ON DESCENT.

Narrative: FLT WAS IN AN LGT, DFW TO ORL, AND ON J58 TO COVIA, THEN DIRECT PIE, J103 TO ORL. BEFORE PIE WE WERE PLACED ON A HDG TO EXPECT DIRECT LAL. LATER WE WERE TOLD TO DSND TO FL240 AND TO BE AT FL240 BY 55 NM W OF LAL. THIS I PUT IN THE FMC AND WAS IN THE DSNT MODE AND ON SCHEDULE. AFTER WE RECEIVED ATIS FROM ORL I WAS GETTING OUT MY APCH PLATE TO RWY 17 AT ORL REVIEWING IT WHEN MY FMC WENT FROM VNAV SPD TO VNAV PATH, AND I DID NOT CATCH THIS UNTIL MY COPLT TOLD ME I WAS GETTING CLOSE TO 55 DME, AND SINCE BEING ON A VECTOR THE FMC WAS SAYING I WAS ON PATH SINCE WE STILL HAD OVER 10 NM AND 3000' OR SO TO GO. HOWEVER, SINCE WE WERE ON A HDG AND IN VNAV PATH THE AFT WAS NOT ON SCHEDULE DSNT, SO I TOOK OVER AND MISSED THE 55 DME BY ABOUT 5 NM. NOTHING WAS SAID BY ZMA AND WE WERE HANDED OFF TO ANOTHER CTLR.

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.