Narrative:

Upon landing, initially thought we blew a tire, then it appeared the gear collapsed (right main). Propeller strike engine stopped. We exited the aircraft (2 souls on board) and found the right main gear to still be in the hole, it never extended. I had a green gear light during the entire approach and also on the ground, this was visually verified by the fire department personnel. Suspected cause of the problem was a gear box failure. The gear (green) light on this model baron works on the cam on the gear box, gear must have jammed in the well. As the motor turned the gears in the gearbox failed, but the cam turned and gave me a gear down and locked indication. There is only one green light to indicate a gear safe condition. No injuries, aircraft veered off the runway and turned 180 degrees onto the grass. Callback conversation with reporter revealed the following information: the reporter stated the failure of the right main landing gear to extend was caused by a frozen uplock roller. The reporter said the sequence of the landing gear extension is as follows: landing gear electric motor pwrs a gearbox driving rod arms to unlock left, right and nose gear uplock rollers. The reporter said the right rod arm was found bent due to the uplock roller failing to move. The reporter stated when the motor driven gearbox drove the rod arms to unlock the landing gear it rotated a cam which operated a microswitch turning on the green landing gear position light. The reporter said at this point the green position light was illuminated, but the landing gear was unsafe. The reporter said this is a design deficiency that must be corrected. The reporter stated the aircraft incurred damage to the right wing tip, flap, aileron, propeller and requires an engine tear down.

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Original NASA ASRS Text

Title: A BEECH 55 LANDED WITH THE R MAIN LNDG GEAR STILL RETRACTED WITH LNDG GEAR POS LIGHT GREEN INDICATING ALL GEAR DOWN AND LOCKED.

Narrative: UPON LNDG, INITIALLY THOUGHT WE BLEW A TIRE, THEN IT APPEARED THE GEAR COLLAPSED (RIGHT MAIN). PROP STRIKE ENGINE STOPPED. WE EXITED THE ACFT (2 SOULS ON BOARD) AND FOUND THE R MAIN GEAR TO STILL BE IN THE HOLE, IT NEVER EXTENDED. I HAD A GREEN GEAR LIGHT DURING THE ENTIRE APCH AND ALSO ON THE GND, THIS WAS VISUALLY VERIFIED BY THE FIRE DEPT PERSONNEL. SUSPECTED CAUSE OF THE PROB WAS A GEAR BOX FAILURE. THE GEAR (GREEN) LIGHT ON THIS MODEL BARON WORKS ON THE CAM ON THE GEAR BOX, GEAR MUST HAVE JAMMED IN THE WELL. AS THE MOTOR TURNED THE GEARS IN THE GEARBOX FAILED, BUT THE CAM TURNED AND GAVE ME A GEAR DOWN AND LOCKED INDICATION. THERE IS ONLY ONE GREEN LIGHT TO INDICATE A GEAR SAFE CONDITION. NO INJURIES, ACFT VEERED OFF THE RWY AND TURNED 180 DEGS ONTO THE GRASS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FAILURE OF THE R MAIN LNDG GEAR TO EXTEND WAS CAUSED BY A FROZEN UPLOCK ROLLER. THE RPTR SAID THE SEQUENCE OF THE LNDG GEAR EXTENSION IS AS FOLLOWS: LNDG GEAR ELECTRIC MOTOR PWRS A GEARBOX DRIVING ROD ARMS TO UNLOCK L, R AND NOSE GEAR UPLOCK ROLLERS. THE RPTR SAID THE R ROD ARM WAS FOUND BENT DUE TO THE UPLOCK ROLLER FAILING TO MOVE. THE RPTR STATED WHEN THE MOTOR DRIVEN GEARBOX DROVE THE ROD ARMS TO UNLOCK THE LNDG GEAR IT ROTATED A CAM WHICH OPERATED A MICROSWITCH TURNING ON THE GREEN LNDG GEAR POS LIGHT. THE RPTR SAID AT THIS POINT THE GREEN POS LIGHT WAS ILLUMINATED, BUT THE LNDG GEAR WAS UNSAFE. THE RPTR SAID THIS IS A DESIGN DEFICIENCY THAT MUST BE CORRECTED. THE RPTR STATED THE ACFT INCURRED DAMAGE TO THE R WING TIP, FLAP, AILERON, PROPELLER AND REQUIRES AN ENGINE TEAR DOWN.

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.