Flight crew deviated below assigned altitude during ILS approach at roc.

Attributes
ACN	438102
Time
Date	199905
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : roc.airport
State Reference	NY
Altitude	msl single value : 1500
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : roc.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 22 other
Flight Phase	descent : approach
Route In Use	approach : instrument precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 270 flight time total : 18000 flight time type : 6000
ASRS Report	438102
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 2100 flight time type : 150
ASRS Report	437934
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : far non adherence : clearance
Independent Detector	atc equipment : msaw other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : returned to intended course
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

First officer flying, vectored for ILS runway 22. Vectored across localizer to intercept from north. Altitude 2500 ft. I was retuning my navigation radio to lock in roc DME, then tuning back to roc ILS. I had taken the 2500 ft from the autoplt altitude set, so didn't get an altitude deviation aural signal. Saw the first officer had descended to about 1500 ft, and either tower or approach called to advise us of a low altitude alert in the tower. I was about to call a missed approach when I saw the airport. I told the controller we were 'visual.' he replied 'the control zone is IFR.' I said we're in visual contact with the airport. We were cleared to land, and asked to call the tower on the phone.

Original NASA ASRS Text

Title: FLC DEVIATED BELOW ASSIGNED ALT DURING ILS APCH AT ROC.

Narrative: FO FLYING, VECTORED FOR ILS RWY 22. VECTORED ACROSS LOC TO INTERCEPT FROM N. ALT 2500 FT. I WAS RETUNING MY NAV RADIO TO LOCK IN ROC DME, THEN TUNING BACK TO ROC ILS. I HAD TAKEN THE 2500 FT FROM THE AUTOPLT ALT SET, SO DIDN'T GET AN ALTDEV AURAL SIGNAL. SAW THE FO HAD DSNDED TO ABOUT 1500 FT, AND EITHER TWR OR APCH CALLED TO ADVISE US OF A LOW ALT ALERT IN THE TWR. I WAS ABOUT TO CALL A MISSED APCH WHEN I SAW THE ARPT. I TOLD THE CTLR WE WERE 'VISUAL.' HE REPLIED 'THE CTL ZONE IS IFR.' I SAID WE'RE IN VISUAL CONTACT WITH THE ARPT. WE WERE CLRED TO LAND, AND ASKED TO CALL THE TWR ON THE PHONE.

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.