Altitude deviation. Overshoot on descent.

Attributes
ACN	129123
Time
Date	198911
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : iiy
State Reference	KY
Altitude	msl bound lower : 10300 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 10800 flight time type : 210
ASRS Report	129123
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

ZID assigned a descent crossing restriction: 'cross 40 mi west of louisville (iiu VORTAC) at 11000', 250 KTS.' PF (first officer) set 10000' and altitude alert. PNF (captain) acknowledged 11000' and PF verbally acknowledged 11000'. Neither pilot noted error on altitude alert setting. As aircraft approached 11000' in descent. PNF was distracted by a missed approach control frequency. This aircraft, an older model medium large transport, does not have dual control heads on the VHF. Each frequency set must be recorded on a log, and when a frequency is missed, returning to the previous frequency involves consulting the log and resetting the frequency--a distraction, particularly at night. While the PNF was fussing over the radio, the PF descended to 10300', realized the error, and climbed back to 11000'. PF was in the climb when PNF recognized the error. While this excursion is basically just a screw-up, one element deserves particular attention: over 95% of our descent xings in the us (including profile dscnts) are at 10000', with or west/O a speed restriction. The PF's setting 10000' on the altitude alert and then descending to that altitude was an unfortunate and dangerous habit. Pushing all xings down to 10000' could reduce the likelihood of this kind of error.

Original NASA ASRS Text

Title: ALT DEVIATION. OVERSHOOT ON DESCENT.

Narrative: ZID ASSIGNED A DSCNT XING RESTRICTION: 'CROSS 40 MI W OF LOUISVILLE (IIU VORTAC) AT 11000', 250 KTS.' PF (F/O) SET 10000' AND ALT ALERT. PNF (CAPT) ACKNOWLEDGED 11000' AND PF VERBALLY ACKNOWLEDGED 11000'. NEITHER PLT NOTED ERROR ON ALT ALERT SETTING. AS ACFT APCHED 11000' IN DSCNT. PNF WAS DISTRACTED BY A MISSED APCH CTL FREQ. THIS ACFT, AN OLDER MODEL MLG, DOES NOT HAVE DUAL CTL HEADS ON THE VHF. EACH FREQ SET MUST BE RECORDED ON A LOG, AND WHEN A FREQ IS MISSED, RETURNING TO THE PREVIOUS FREQ INVOLVES CONSULTING THE LOG AND RESETTING THE FREQ--A DISTR, PARTICULARLY AT NIGHT. WHILE THE PNF WAS FUSSING OVER THE RADIO, THE PF DSNDED TO 10300', REALIZED THE ERROR, AND CLBED BACK TO 11000'. PF WAS IN THE CLB WHEN PNF RECOGNIZED THE ERROR. WHILE THIS EXCURSION IS BASICALLY JUST A SCREW-UP, ONE ELEMENT DESERVES PARTICULAR ATTN: OVER 95% OF OUR DSCNT XINGS IN THE U.S. (INCLUDING PROFILE DSCNTS) ARE AT 10000', WITH OR W/O A SPD RESTRICTION. THE PF'S SETTING 10000' ON THE ALT ALERT AND THEN DSNDING TO THAT ALT WAS AN UNFORTUNATE AND DANGEROUS HABIT. PUSHING ALL XINGS DOWN TO 10000' COULD REDUCE THE LIKELIHOOD OF THIS KIND OF ERROR.

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.