CRJ100 crew triggers low altitude warning during localizer approach to runway 22 at lex.

Attributes
ACN	708041
Time
Date	200608
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lex.airport
State Reference	KY
Altitude	msl bound lower : 1600 msl bound upper : 3200
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lex.tracon
Operator	common carrier : air carrier
Make Model Name	Canadair/Bombardier Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer only : 22
Flight Phase	descent : approach
Route In Use	approach : instrument non precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 23 flight time total : 7000 flight time type : 3500
ASRS Report	708041
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : far non adherence : published procedure
Independent Detector	atc equipment : msaw other controllera
Resolutory Action	controller : issued alert
Supplementary
Problem Areas	Airspace Structure Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

On approach to runway 22 at lexington; ky. First officer was pilot at controls. Aircraft was light at approximately 40000 pounds with a slow reference speed. ATC cleared to join the localizer; GS out of service at 3200 ft. We crossed bridl when NDB 090 degrees to 270 degree needle swings on both sides on the altitude. MDA was 1520 ft. As aircraft leveled at 1600 ft fully configured with autoplt on; ATC advised us with a low altitude alert. We advised level. With a landing reference of 134; we only needed 153 FPM rate of descent. Since approach had a long final fully configured; there were probably not enough parameters to trigger a GPWS alert. However; in review of flight manual; final approach segment should have a 1000 FPM descent rate. Language does not state 'shall.' also stabilized approach criteria states not exceeding 1000 FPM rate of descent 'before' descending below MDA. Therefore; this becomes a technical 'no man's land.' technically; this was a legal; standard approach; but it would have been safer with a shallower descent profile in my opinion. That also would not have caused ATC to become concerned about our closure rate to terra firma.

Original NASA ASRS Text

Title: CRJ100 CREW TRIGGERS LOW ALT WARNING DURING LOC APCH TO RWY 22 AT LEX.

Narrative: ON APCH TO RWY 22 AT LEXINGTON; KY. FO WAS PLT AT CTLS. ACFT WAS LIGHT AT APPROX 40000 LBS WITH A SLOW REF SPD. ATC CLRED TO JOIN THE LOC; GS OUT OF SVC AT 3200 FT. WE CROSSED BRIDL WHEN NDB 090 DEGS TO 270 DEG NEEDLE SWINGS ON BOTH SIDES ON THE ALT. MDA WAS 1520 FT. AS ACFT LEVELED AT 1600 FT FULLY CONFIGURED WITH AUTOPLT ON; ATC ADVISED US WITH A LOW ALT ALERT. WE ADVISED LEVEL. WITH A LNDG REF OF 134; WE ONLY NEEDED 153 FPM RATE OF DSCNT. SINCE APCH HAD A LONG FINAL FULLY CONFIGURED; THERE WERE PROBABLY NOT ENOUGH PARAMETERS TO TRIGGER A GPWS ALERT. HOWEVER; IN REVIEW OF FLT MANUAL; FINAL APCH SEGMENT SHOULD HAVE A 1000 FPM DSCNT RATE. LANGUAGE DOES NOT STATE 'SHALL.' ALSO STABILIZED APCH CRITERIA STATES NOT EXCEEDING 1000 FPM RATE OF DSCNT 'BEFORE' DSNDING BELOW MDA. THEREFORE; THIS BECOMES A TECHNICAL 'NO MAN'S LAND.' TECHNICALLY; THIS WAS A LEGAL; STANDARD APCH; BUT IT WOULD HAVE BEEN SAFER WITH A SHALLOWER DSCNT PROFILE IN MY OPINION. THAT ALSO WOULD NOT HAVE CAUSED ATC TO BECOME CONCERNED ABOUT OUR CLOSURE RATE TO TERRA FIRMA.

Data retrieved from NASA's ASRS site as of January 2009 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.