Air carrier large transport altitude excursion causes minimum safe altitude warning.

Attributes
ACN	103556
Time
Date	198902
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sat
State Reference	TX
Altitude	msl bound lower : 2600 msl bound upper : 3000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sat
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 240 flight time total : 5400 flight time type : 2850
ASRS Report	103556
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	aircraft : equipment problem dissipated flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

At 3000' altitude on final approach, landing gear lowered with subsequent illumination of red 'doors' light after 3 green 'land gear' lights. While checking hydraulic quantities/pressures and discussing situation, aircraft altitude deviation to 2600' MSL while manually flown. Tower advised 'altitude alert' and aircraft was climbed back to 3000' AGL. Landing gear recycled with subsequent light indications all normal. G/south intercept and normal landing followed.

Original NASA ASRS Text

Title: ACR LGT ALT EXCURSION CAUSES MINIMUM SAFE ALT WARNING.

Narrative: AT 3000' ALT ON FINAL APCH, LNDG GEAR LOWERED WITH SUBSEQUENT ILLUMINATION OF RED 'DOORS' LIGHT AFTER 3 GREEN 'LAND GEAR' LIGHTS. WHILE CHKING HYD QUANTITIES/PRESSURES AND DISCUSSING SITUATION, ACFT ALT DEVIATION TO 2600' MSL WHILE MANUALLY FLOWN. TWR ADVISED 'ALT ALERT' AND ACFT WAS CLBED BACK TO 3000' AGL. LNDG GEAR RECYCLED WITH SUBSEQUENT LIGHT INDICATIONS ALL NORMAL. G/S INTERCEPT AND NORMAL LNDG FOLLOWED.

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.