Ags not authorized as alternate when the tower closed.

Attributes
ACN	167728
Time
Date	199012
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ags
State Reference	GA
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : ztl tower : dab
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 3000 flight time type : 1200
ASRS Report	167728
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far
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:

Captain selected ags as a landing alternate to ahn for clt ahn and advise myself, the first officer,. We had to divert to ags due to a line of strong thunderstorms which xed the ahn airport at our time of arrival. During the briefing for approach into ags, I realized that ags was not a legal alternate due to the tower being closed. However due to the fact that the problem arose through a lack of complete preflight planning. I as first officer now make it a point to check behind the captain's selection of alternate airports for legality.

Original NASA ASRS Text

Title: AGS NOT AUTHORIZED AS ALTERNATE WHEN THE TWR CLOSED.

Narrative: CAPT SELECTED AGS AS A LNDG ALTERNATE TO AHN FOR CLT AHN AND ADVISE MYSELF, THE F/O,. WE HAD TO DIVERT TO AGS DUE TO A LINE OF STRONG TSTMS WHICH XED THE AHN ARPT AT OUR TIME OF ARR. DURING THE BRIEFING FOR APCH INTO AGS, I REALIZED THAT AGS WAS NOT A LEGAL ALTERNATE DUE TO THE TWR BEING CLOSED. HOWEVER DUE TO THE FACT THAT THE PROB AROSE THROUGH A LACK OF COMPLETE PREFLT PLANNING. I AS F/O NOW MAKE IT A POINT TO CHK BEHIND THE CAPT'S SELECTION OF ALTERNATE ARPTS FOR LEGALITY.

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.