Crossing restr not met due to misprogrammed FMS and incorrect descent point calculation.

Attributes
ACN	336740
Time
Date	199506
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : iah
State Reference	TX
Altitude	msl bound lower : 10000 msl bound upper : 11800
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : iah
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
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 : flight engineer pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 220 flight time total : 20000 flight time type : 8000
ASRS Report	336740
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

In cruise at 35000 ft was cleared for rockit arrival iah direct rockit. Entered STAR in FMC with 250 KTS 10000 ft restr. Entered runway 8 but left route discontinuity in computer since runway not yet assigned. A few mins later ATC said delete speed on STAR. Entered delete/for fix entered. I calculated the approximately descent point in my head and did not see VNAV disengage to speed mode. I had done my descent point calculation on second inbound fix instead of first fix. ATC asked if we could make restr. That was when I recognized 2 errors. Speed mode versus VNAV mode and my error to calculate descent point to wrong fix. Missed 10000 ft restr by crossing fix at 11800 ft. Suggestion: any automatic mode change in VNAV or LNAV should be accompanied by a flashing control button light and require execution by pushing said control button to activate next mode.

Original NASA ASRS Text

Title: XING RESTR NOT MET DUE TO MISPROGRAMMED FMS AND INCORRECT DSCNT POINT CALCULATION.

Narrative: IN CRUISE AT 35000 FT WAS CLRED FOR ROCKIT ARR IAH DIRECT ROCKIT. ENTERED STAR IN FMC WITH 250 KTS 10000 FT RESTR. ENTERED RWY 8 BUT LEFT RTE DISCONTINUITY IN COMPUTER SINCE RWY NOT YET ASSIGNED. A FEW MINS LATER ATC SAID DELETE SPD ON STAR. ENTERED DELETE/FOR FIX ENTERED. I CALCULATED THE APPROX DSCNT POINT IN MY HEAD AND DID NOT SEE VNAV DISENGAGE TO SPD MODE. I HAD DONE MY DSCNT POINT CALCULATION ON SECOND INBOUND FIX INSTEAD OF FIRST FIX. ATC ASKED IF WE COULD MAKE RESTR. THAT WAS WHEN I RECOGNIZED 2 ERRORS. SPD MODE VERSUS VNAV MODE AND MY ERROR TO CALCULATE DSCNT POINT TO WRONG FIX. MISSED 10000 FT RESTR BY XING FIX AT 11800 FT. SUGGESTION: ANY AUTOMATIC MODE CHANGE IN VNAV OR LNAV SHOULD BE ACCOMPANIED BY A FLASHING CTL BUTTON LIGHT AND REQUIRE EXECUTION BY PUSHING SAID CTL BUTTON TO ACTIVATE NEXT MODE.

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.