A YAK52 pilot retracts his landing gear while shutting down his engine at the parking ramp.

Attributes
ACN	400537
Time
Date	199804
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Military Trainer
Operating Under FAR Part	Part 91
Flight Phase	ground : parked
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 20 flight time total : 900 flight time type : 30
ASRS Report	400537
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact none taken : insufficient time
Consequence	other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

After taxiing the aircraft (YAK52) to the parking area at the airport, the brakes were applied and the plane was brought to a stop. Prior to engine shutdown, it was noted that the flaps were still deployed. The flaps down light is directly adjacent to the gear lever on the panel. The flap control is on the side panel to the left of the pilot. Inadvertently, the gear lever was raised rather than the flap lever. Realizing the mistake, the engine was immediately shut down and the flaps retracted. Before the gear lever could be restored to the down position, the main gear, which pivots toward the leading edge of the wing, retracted. The nose gear, which pivots towards the rear of the aircraft did not retract (therefore, no damage to propeller or engine). When the mains retracted, the tail of the aircraft settled to the ground, broke the tie-down bracket and did minor (nonstructural) damage to the rudder. The problem with the landing gear system (pneumatic) on this aircraft is that there are no squat switches to prevent inadvertent gear retraction when the aircraft is not in flight. It does have a slider which prevents raising the gear lever, providing it is pushed in (it was not in this case). To prevent similar occurrences in the future, we are developing a spring loaded mechanism for the slider, so that it will have to be removed in order to raise the gear. It would also be useful to have, in addition, a squat switch arrangement of some sort to prevent retraction.

Original NASA ASRS Text

Title: A YAK52 PLT RETRACTS HIS LNDG GEAR WHILE SHUTTING DOWN HIS ENG AT THE PARKING RAMP.

Narrative: AFTER TAXIING THE ACFT (YAK52) TO THE PARKING AREA AT THE ARPT, THE BRAKES WERE APPLIED AND THE PLANE WAS BROUGHT TO A STOP. PRIOR TO ENG SHUTDOWN, IT WAS NOTED THAT THE FLAPS WERE STILL DEPLOYED. THE FLAPS DOWN LIGHT IS DIRECTLY ADJACENT TO THE GEAR LEVER ON THE PANEL. THE FLAP CTL IS ON THE SIDE PANEL TO THE L OF THE PLT. INADVERTENTLY, THE GEAR LEVER WAS RAISED RATHER THAN THE FLAP LEVER. REALIZING THE MISTAKE, THE ENG WAS IMMEDIATELY SHUT DOWN AND THE FLAPS RETRACTED. BEFORE THE GEAR LEVER COULD BE RESTORED TO THE DOWN POS, THE MAIN GEAR, WHICH PIVOTS TOWARD THE LEADING EDGE OF THE WING, RETRACTED. THE NOSE GEAR, WHICH PIVOTS TOWARDS THE REAR OF THE ACFT DID NOT RETRACT (THEREFORE, NO DAMAGE TO PROP OR ENG). WHEN THE MAINS RETRACTED, THE TAIL OF THE ACFT SETTLED TO THE GND, BROKE THE TIE-DOWN BRACKET AND DID MINOR (NONSTRUCTURAL) DAMAGE TO THE RUDDER. THE PROB WITH THE LNDG GEAR SYS (PNEUMATIC) ON THIS ACFT IS THAT THERE ARE NO SQUAT SWITCHES TO PREVENT INADVERTENT GEAR RETRACTION WHEN THE ACFT IS NOT IN FLT. IT DOES HAVE A SLIDER WHICH PREVENTS RAISING THE GEAR LEVER, PROVIDING IT IS PUSHED IN (IT WAS NOT IN THIS CASE). TO PREVENT SIMILAR OCCURRENCES IN THE FUTURE, WE ARE DEVELOPING A SPRING LOADED MECHANISM FOR THE SLIDER, SO THAT IT WILL HAVE TO BE REMOVED IN ORDER TO RAISE THE GEAR. IT WOULD ALSO BE USEFUL TO HAVE, IN ADDITION, A SQUAT SWITCH ARRANGEMENT OF SOME SORT TO PREVENT RETRACTION.

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.