An SJ30 prototype jet aircraft experiences loss of aircraft control during test flight activity.

Attributes
ACN	352340
Time
Date	199611
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sat
State Reference	TX
Altitude	msl bound lower : 6000 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sat tower : sat tower : cle
Operator	other
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Navigation In Use	Other
Flight Phase	cruise other other
Route In Use	approach : straight in
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 180 flight time total : 19000 flight time type : 250
ASRS Report	352340
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : critical other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Prototype jet aircraft on test flight to evaluate air flow on and around slats/wing. Level flight, 125-130 KIAS. Flaps were selected to approach setting. Shortly thereafter uncommanded left roll commenced. The 30 degrees/second roll rate was countered with full lateral control (ailerons), full rudder, and full asymmetric thrust. Rolling through 120 degree of bank angle flaps were reselected to a takeoff setting (less flap) followed shortly by a loud snapping sound and accompanying roll rate decrease. Aircraft was recovered in level and straight flight at approximately 6000 ft MSL (a 3000 ft loss), heading roughly northeast. Power was reestablished symmetrically and emergency was declared. A low/no flap landing was planned at a relatively high vref (approach speed) (160 KIAS). The decision to return to sat was based on several factors: 1) the aircraft was controllable at the selected vref. 2) 'sat' airport was the closest airport with sufficient runway to allow a safe landing and in fact almost the closest airport of any sort. 3) crash and rescue personnel were immediately available for hot brakes/brake fire which I assumed were almost definite possibilities. 4) a nearly straight in approach (albeit to a downwind runway) was available with minimum maneuvering. Subsequent landing was uneventful with the exception of hot brakes. Crash crew cooled brakes with fans, and aircraft was towed to the hangar. I think it is important to point out the decision making process visibility a visibility the decision to return to sat versus some other less capable airport. The decision must be thought about prior to any emergency occurrence as 'in the heat of battle' decision process may be less than optimum because of a multitude of sensory distractions. The process must include the danger presented to the general public as well as the crew. All things considered the return to sat appeared safe as the aircraft exhibited controllability within the limits flown, and only the chance of hot brakes make the landing other than normal. Bottom line: in as much as possible, think through possible scenarios before they become reality.

Original NASA ASRS Text

Title: AN SJ30 PROTOTYPE JET ACFT EXPERIENCES LOSS OF ACFT CTL DURING TEST FLT ACTIVITY.

Narrative: PROTOTYPE JET ACFT ON TEST FLT TO EVALUATE AIR FLOW ON AND AROUND SLATS/WING. LEVEL FLT, 125-130 KIAS. FLAPS WERE SELECTED TO APCH SETTING. SHORTLY THEREAFTER UNCOMMANDED L ROLL COMMENCED. THE 30 DEGS/SECOND ROLL RATE WAS COUNTERED WITH FULL LATERAL CTL (AILERONS), FULL RUDDER, AND FULL ASYMMETRIC THRUST. ROLLING THROUGH 120 DEG OF BANK ANGLE FLAPS WERE RESELECTED TO A TKOF SETTING (LESS FLAP) FOLLOWED SHORTLY BY A LOUD SNAPPING SOUND AND ACCOMPANYING ROLL RATE DECREASE. ACFT WAS RECOVERED IN LEVEL AND STRAIGHT FLT AT APPROX 6000 FT MSL (A 3000 FT LOSS), HEADING ROUGHLY NE. PWR WAS REESTABLISHED SYMMETRICALLY AND EMER WAS DECLARED. A LOW/NO FLAP LNDG WAS PLANNED AT A RELATIVELY HIGH VREF (APCH SPD) (160 KIAS). THE DECISION TO RETURN TO SAT WAS BASED ON SEVERAL FACTORS: 1) THE ACFT WAS CONTROLLABLE AT THE SELECTED VREF. 2) 'SAT' ARPT WAS THE CLOSEST ARPT WITH SUFFICIENT RWY TO ALLOW A SAFE LNDG AND IN FACT ALMOST THE CLOSEST ARPT OF ANY SORT. 3) CRASH AND RESCUE PERSONNEL WERE IMMEDIATELY AVAILABLE FOR HOT BRAKES/BRAKE FIRE WHICH I ASSUMED WERE ALMOST DEFINITE POSSIBILITIES. 4) A NEARLY STRAIGHT IN APCH (ALBEIT TO A DOWNWIND RWY) WAS AVAILABLE WITH MINIMUM MANEUVERING. SUBSEQUENT LNDG WAS UNEVENTFUL WITH THE EXCEPTION OF HOT BRAKES. CRASH CREW COOLED BRAKES WITH FANS, AND ACFT WAS TOWED TO THE HANGAR. I THINK IT IS IMPORTANT TO POINT OUT THE DECISION MAKING PROCESS VIS A VIS THE DECISION TO RETURN TO SAT VERSUS SOME OTHER LESS CAPABLE ARPT. THE DECISION MUST BE THOUGHT ABOUT PRIOR TO ANY EMER OCCURRENCE AS 'IN THE HEAT OF BATTLE' DECISION PROCESS MAY BE LESS THAN OPTIMUM BECAUSE OF A MULTITUDE OF SENSORY DISTRACTIONS. THE PROCESS MUST INCLUDE THE DANGER PRESENTED TO THE GENERAL PUBLIC AS WELL AS THE CREW. ALL THINGS CONSIDERED THE RETURN TO SAT APPEARED SAFE AS THE ACFT EXHIBITED CONTROLLABILITY WITHIN THE LIMITS FLOWN, AND ONLY THE CHANCE OF HOT BRAKES MAKE THE LNDG OTHER THAN NORMAL. BOTTOM LINE: IN AS MUCH AS POSSIBLE, THINK THROUGH POSSIBLE SCENARIOS BEFORE THEY BECOME REALITY.

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.