Cpr small transport descended below MDA while still IMC on approach to apa.

Attributes
ACN	94337
Time
Date	198809
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : apa
State Reference	CO
Altitude	msl bound lower : 6600 msl bound upper : 6660
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : apa tower : lga
Operator	general aviation : corporate
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	descent : approach landing : missed approach landing : go around
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 67 flight time total : 1655 flight time type : 1305
ASRS Report	94337
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
Events
Anomaly	non adherence : published procedure non adherence : far other spatial deviation other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : provided flight assist other other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While on approach to apa on the NDB 35R approach, I was advised by tower that approach had called and advised of a 'low altitude' alert. A xchk of instruments confirmed that we were, indeed, approximately 60' below the MDA. We had broken out and had visually transitioned ot the outside. Outside visual reference confirmed that we were to the left of course. However, we were 'in and out'. Accordingly, we immediately executed a missed approach. We then proceeded to den stapleton and shot the ILS to 26L, and landed there. I presume that the 'low altitude' alert sounded because we were so far to the left of course. This, I later concluded was attributable to 'rusty' NDB approach procedures. On my part I've resolved to practice them with some regularity. It is easy to become accustomed to ILS approachs and forget the others. Apa's ILS to 35R was out of service on the day in question.

Original NASA ASRS Text

Title: CPR SMT DESCENDED BELOW MDA WHILE STILL IMC ON APCH TO APA.

Narrative: WHILE ON APCH TO APA ON THE NDB 35R APCH, I WAS ADVISED BY TWR THAT APCH HAD CALLED AND ADVISED OF A 'LOW ALT' ALERT. A XCHK OF INSTRUMENTS CONFIRMED THAT WE WERE, INDEED, APPROX 60' BELOW THE MDA. WE HAD BROKEN OUT AND HAD VISUALLY TRANSITIONED OT THE OUTSIDE. OUTSIDE VISUAL REFERENCE CONFIRMED THAT WE WERE TO THE LEFT OF COURSE. HOWEVER, WE WERE 'IN AND OUT'. ACCORDINGLY, WE IMMEDIATELY EXECUTED A MISSED APCH. WE THEN PROCEEDED TO DEN STAPLETON AND SHOT THE ILS TO 26L, AND LANDED THERE. I PRESUME THAT THE 'LOW ALT' ALERT SOUNDED BECAUSE WE WERE SO FAR TO THE L OF COURSE. THIS, I LATER CONCLUDED WAS ATTRIBUTABLE TO 'RUSTY' NDB APCH PROCS. ON MY PART I'VE RESOLVED TO PRACTICE THEM WITH SOME REGULARITY. IT IS EASY TO BECOME ACCUSTOMED TO ILS APCHS AND FORGET THE OTHERS. APA'S ILS TO 35R WAS OUT OF SVC ON THE DAY IN QUESTION.

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.