Given an altitude crossing restriction for 25000', reporter developed mindset that he was cleared to...

Attributes
ACN	151153
Time
Date	199007
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : ilm
State Reference	NC
Altitude	msl bound lower : 24500 msl bound upper : 25000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 210 flight time total : 3900 flight time type : 2500
ASRS Report	151153
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 170 flight time total : 6000 flight time type : 2100
ASRS Report	150510
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While en route to rdu from pbi I was given a descent clearance to cross 35 mi southwest of wilmington at FL250. This was accomplished; however for some reason unknown to me I remembered hearing 'cross 25 mi southwest of wilmington at 24000''. I initiated another descent only to stop it abruptly at 24500 and recovered back to 25000'. I do not know why exactly I did this but I feel that horrible sleep the night before contributed greatly to this apparent reaction. Getting a good night sleep is critical to performing well. Also the captain was speaking to me about an unrelated topic and this might have contributed to this error (division of attention). Callback conversation with reporter revealed the following: reporter said that captain was an old acquaintance going back to when he was 15 years old. The conversation had nothing to do with flying and he felt very relaxed because of the acquaintanceship. He thinks he would have been more alert if he had been flying with a different captain.

Original NASA ASRS Text

Title: GIVEN AN ALT CROSSING RESTRICTION FOR 25000', REPORTER DEVELOPED MINDSET THAT HE WAS CLEARED TO 24000'.

Narrative: WHILE ENRTE TO RDU FROM PBI I WAS GIVEN A DSNT CLRNC TO CROSS 35 MI SW OF WILMINGTON AT FL250. THIS WAS ACCOMPLISHED; HOWEVER FOR SOME REASON UNKNOWN TO ME I REMEMBERED HEARING 'CROSS 25 MI SW OF WILMINGTON AT 24000''. I INITIATED ANOTHER DSNT ONLY TO STOP IT ABRUPTLY AT 24500 AND RECOVERED BACK TO 25000'. I DO NOT KNOW WHY EXACTLY I DID THIS BUT I FEEL THAT HORRIBLE SLEEP THE NIGHT BEFORE CONTRIBUTED GREATLY TO THIS APPARENT REACTION. GETTING A GOOD NIGHT SLEEP IS CRITICAL TO PERFORMING WELL. ALSO THE CAPT WAS SPEAKING TO ME ABOUT AN UNRELATED TOPIC AND THIS MIGHT HAVE CONTRIBUTED TO THIS ERROR (DIVISION OF ATTN). CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR SAID THAT CAPT WAS AN OLD ACQUAINTANCE GOING BACK TO WHEN HE WAS 15 YEARS OLD. THE CONVERSATION HAD NOTHING TO DO WITH FLYING AND HE FELT VERY RELAXED BECAUSE OF THE ACQUAINTANCESHIP. HE THINKS HE WOULD HAVE BEEN MORE ALERT IF HE HAD BEEN FLYING WITH A DIFFERENT CAPT.

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.

Given an altitude crossing restriction for 25000', reporter developed mindset that he was cleared to 24000'.