Medium large transport failed to make altitude crossing restriction.

Attributes
ACN	105173
Time
Date	198902
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : syr
State Reference	NY
Altitude	msl bound lower : 14000 msl bound upper : 14000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport
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 : 210 flight time total : 8000
ASRS Report	105173
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approximately 80 DME west of syr VORTAC, at 11000', given clearance to cross 30 DME west of syr VORTAC. We had been descending at 1000 FPM from 33000' and were approaching FL240 when crossing restriction received. We acknowledged and were complying. The DME began to unlock several times on both DME's and when we looked back on we were high on profile at about 40 DME. I applied speed brakes and idle thrust to increase rate of descent when controller asked us to slow to 250 KTS. We said we were unable to make restriction and requested a vector. She said airspeed your discretion, and by then we were past 30 DME about 1000' high. We suspect that the combined tailwind, unreliable DME information at last minute and controller's inability to react fast enough to either delete or vector us away from crossing fix caused us to miss our crossing restriction. Suggestions: if no traffic conflict exists as in this case, why not just remove the restriction. These last minute dives to make some arbitrary window in the sky could prove dangerous to cabin personnel and increases possibility of penetrating altitude floor.

Original NASA ASRS Text

Title: MLG FAILED TO MAKE ALT CROSSING RESTRICTION.

Narrative: APPROX 80 DME W OF SYR VORTAC, AT 11000', GIVEN CLRNC TO CROSS 30 DME W OF SYR VORTAC. WE HAD BEEN DSNDING AT 1000 FPM FROM 33000' AND WERE APCHING FL240 WHEN XING RESTRICTION RECEIVED. WE ACKNOWLEDGED AND WERE COMPLYING. THE DME BEGAN TO UNLOCK SEVERAL TIMES ON BOTH DME'S AND WHEN WE LOOKED BACK ON WE WERE HIGH ON PROFILE AT ABOUT 40 DME. I APPLIED SPD BRAKES AND IDLE THRUST TO INCREASE RATE OF DSCNT WHEN CTLR ASKED US TO SLOW TO 250 KTS. WE SAID WE WERE UNABLE TO MAKE RESTRICTION AND REQUESTED A VECTOR. SHE SAID AIRSPD YOUR DISCRETION, AND BY THEN WE WERE PAST 30 DME ABOUT 1000' HIGH. WE SUSPECT THAT THE COMBINED TAILWIND, UNRELIABLE DME INFO AT LAST MINUTE AND CTLR'S INABILITY TO REACT FAST ENOUGH TO EITHER DELETE OR VECTOR US AWAY FROM XING FIX CAUSED US TO MISS OUR XING RESTRICTION. SUGGESTIONS: IF NO TFC CONFLICT EXISTS AS IN THIS CASE, WHY NOT JUST REMOVE THE RESTRICTION. THESE LAST MINUTE DIVES TO MAKE SOME ARBITRARY WINDOW IN THE SKY COULD PROVE DANGEROUS TO CABIN PERSONNEL AND INCREASES POSSIBILITY OF PENETRATING ALT FLOOR.

Data retrieved from NASA's ASRS site as of August 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.