Wing slat failure causing uncommanded slat extension on one wing. Civilian owned ex military fgt.

Attributes
ACN	114798
Time
Date	198906
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ads
State Reference	TX
Altitude	msl bound lower : 4500 msl bound upper : 4500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : ads
Operator	general aviation : personal
Make Model Name	Light Transport
Flight Phase	cruise other
Flight Plan	None
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Transport
Flight Phase	cruise other
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 10 flight time total : 6000 flight time type : 30
ASRS Report	114798
Person 2
Affiliation	Other
Function	flight crew : single pilot
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Light transport was flying wing on an small transport aircraft during a photography flight. On the return to addison, the light transport was approximately 3000' higher than the small transport and the light transport started a descending left turn. During the descent a strong buffet was felt and the right slat had deployed and a partial failure of the right slat occurred. The pilot of the small transport (lead aircraft) advised addison tower of the problem. Addison tower asked if the light transport was declaring a mayday and the light transport confirmed mayday and requested the equipment. En route to addison the light transport confirmed the ctlability of the aircraft then flew a wide left arc for pattern entry to addison airport. The light transport then landed and taxied in without incident. Callback conversation with reporter revealed the following: reporter confirms that this aircraft is civilian owned ex military fighter. The slat failure presented fairly serious stability problems. The problem has been remedied by the permanent deactivation of the slat system on advice of the military operator of this type aircraft.

Original NASA ASRS Text

Title: WING SLAT FAILURE CAUSING UNCOMMANDED SLAT EXTENSION ON ONE WING. CIVILIAN OWNED EX MILITARY FGT.

Narrative: LTT WAS FLYING WING ON AN SMT ACFT DURING A PHOTOGRAPHY FLT. ON THE RETURN TO ADDISON, THE LTT WAS APPROX 3000' HIGHER THAN THE SMT AND THE LTT STARTED A DESCENDING LEFT TURN. DURING THE DSCNT A STRONG BUFFET WAS FELT AND THE RIGHT SLAT HAD DEPLOYED AND A PARTIAL FAILURE OF THE RIGHT SLAT OCCURRED. THE PLT OF THE SMT (LEAD ACFT) ADVISED ADDISON TWR OF THE PROBLEM. ADDISON TWR ASKED IF THE LTT WAS DECLARING A MAYDAY AND THE LTT CONFIRMED MAYDAY AND REQUESTED THE EQUIPMENT. ENRTE TO ADDISON THE LTT CONFIRMED THE CTLABILITY OF THE ACFT THEN FLEW A WIDE LEFT ARC FOR PATTERN ENTRY TO ADDISON ARPT. THE LTT THEN LANDED AND TAXIED IN WITHOUT INCIDENT. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: REPORTER CONFIRMS THAT THIS ACFT IS CIVILIAN OWNED EX MIL FIGHTER. THE SLAT FAILURE PRESENTED FAIRLY SERIOUS STABILITY PROBLEMS. THE PROBLEM HAS BEEN REMEDIED BY THE PERMANENT DEACTIVATION OF THE SLAT SYSTEM ON ADVICE OF THE MIL OPERATOR OF THIS TYPE ACFT.

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.