B737 crew had altitude overshoot in ZID class a airspace.

Attributes
ACN	473150
Time
Date	200005
Day	Sun
Local Time Of Day	0601 To 1200
Place
Altitude	msl bound lower : 26300 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc tower : lax.tower
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	descent : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 225 flight time total : 6800 flight time type : 900
ASRS Report	473150
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 1800
ASRS Report	473158
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned altitude none taken : detected after the fact
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance Company
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On descent from FL280 to FL270, the captain was flying and briefing the approach. This particular aircraft has an SP77 autoplt without altitude capture. The captain failed to select altitude hold at FL270, and the aircraft descended to FL263 before recovering to FL270. This autoplt is nonstandard in our fleet (only 2 aircraft) and this was only my second time using this particular autoplt. Our air carrier does not give IOE on these 2 aircraft, instead they issue us a reference card with the differences.

Original NASA ASRS Text

Title: B737 CREW HAD ALT OVERSHOOT IN ZID CLASS A AIRSPACE.

Narrative: ON DSCNT FROM FL280 TO FL270, THE CAPT WAS FLYING AND BRIEFING THE APCH. THIS PARTICULAR ACFT HAS AN SP77 AUTOPLT WITHOUT ALT CAPTURE. THE CAPT FAILED TO SELECT ALT HOLD AT FL270, AND THE ACFT DSNDED TO FL263 BEFORE RECOVERING TO FL270. THIS AUTOPLT IS NONSTANDARD IN OUR FLEET (ONLY 2 ACFT) AND THIS WAS ONLY MY SECOND TIME USING THIS PARTICULAR AUTOPLT. OUR ACR DOES NOT GIVE IOE ON THESE 2 ACFT, INSTEAD THEY ISSUE US A REF CARD WITH THE DIFFERENCES.

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.