MSAW activated by GA small aircraft on an IAP ILS approach to runway 20L at pdk.

Attributes
ACN	171798
Time
Date	199102
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : pdk
State Reference	GA
Altitude	agl bound lower : 300 agl bound upper : 500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : pdk
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach landing other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 20 flight time total : 1000 flight time type : 300
ASRS Report	171798
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	other spatial deviation
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Pilot was on an IFR flight to pdk and was cleared for a VOR 20L approach. Upon reaching the MDA the pilot visually sighted the approach lights and runway 20L with good visibility in all directions. As the bases were ragged the pilot started a slow descent to the runway to assure that the aircraft would not re-enter the clouds. During the descent (estimated between 1.5 mi and 2.5 mi from the threshold), the tower advised the pilot of an 'altitude alert.' the pilot advised the tower that he was visibility, had ground contact, and continued with normal landing. The pilot (with an INS ticket less then 1 yr old) upon reflecting back on this approach believes he may have descended below the MDA earlier than necessary, even though the runway was in sits and the descent normal. In part the pilot believes this is a result of training received, which always consisted of approachs to the MDA and the time limit, and then a missed approach. Little or no emphasis was placed on what to do if the runway appeared at all, much less when the aircraft is still a good distance from the threshold. Lesson learned.

Original NASA ASRS Text

Title: MSAW ACTIVATED BY GA SMA ON AN IAP ILS APCH TO RWY 20L AT PDK.

Narrative: PLT WAS ON AN IFR FLT TO PDK AND WAS CLRED FOR A VOR 20L APCH. UPON REACHING THE MDA THE PLT VISUALLY SIGHTED THE APCH LIGHTS AND RWY 20L WITH GOOD VISIBILITY IN ALL DIRECTIONS. AS THE BASES WERE RAGGED THE PLT STARTED A SLOW DSNT TO THE RWY TO ASSURE THAT THE ACFT WOULD NOT RE-ENTER THE CLOUDS. DURING THE DSNT (ESTIMATED BTWN 1.5 MI AND 2.5 MI FROM THE THRESHOLD), THE TWR ADVISED THE PLT OF AN 'ALT ALERT.' THE PLT ADVISED THE TWR THAT HE WAS VIS, HAD GND CONTACT, AND CONTINUED WITH NORMAL LNDG. THE PLT (WITH AN INS TICKET LESS THEN 1 YR OLD) UPON REFLECTING BACK ON THIS APCH BELIEVES HE MAY HAVE DSNDED BELOW THE MDA EARLIER THAN NECESSARY, EVEN THOUGH THE RWY WAS IN SITS AND THE DSNT NORMAL. IN PART THE PLT BELIEVES THIS IS A RESULT OF TRNING RECEIVED, WHICH ALWAYS CONSISTED OF APCHS TO THE MDA AND THE TIME LIMIT, AND THEN A MISSED APCH. LITTLE OR NO EMPHASIS WAS PLACED ON WHAT TO DO IF THE RWY APPEARED AT ALL, MUCH LESS WHEN THE ACFT IS STILL A GOOD DISTANCE FROM THE THRESHOLD. LESSON LEARNED.

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.