Narrative:

The event occurred at ZZZ on initial climb out on runway 32. After rotation and positive rate; I retracted the gear and noticed that the gear in transit light was still illuminated after a short period. After noticing this I slowed the airplane down to about 100 knots in hopes that a slower airspeed would allow the gear to retract. Once the slower airspeed did not work I leveled off and continued to troubleshoot the problem by rocking the wings and pitching up and down. I checked to see if hydraulic pressure was the problem and I could not get a hydraulic pressure warning while pressing the test switch; I then tested the annunciator to assess whether the hydraulic warning light was working; which it was. After several troubleshooting methods; I decided I would try and recycle then gear; upon doing so; the gear circuit breaker popped and the gear down green lights only indicated the nose and left main were fully down and locked. I pressed the gear down indicator to assure that the light had not simply burned out. I then reset the circuit breaker and attempted to put the gear up again. Again I received the gear in transition light for an extended period with a slight yawing moment. I then tried to put the gear down and received the same indications as previously stated and at that point proceeded with the emergency gear extension checklist. After possibly 30 to 45 min of cumulative pumping of the alternate gear extension lever; I could not get a gear down and locked green light indication for the right main. During that time I had reached ZZZ1 airport and had executed a low pass to confirm if the gear was down; and received a positive confirmation from the airport manager on the ground. I decided that I should query operations on what they wanted me to do before I made any decisions on my own since I had sufficient fuel for options. To do so I climbed to 4;000 and requested a phone patch through arinc; where I was advised to divert to ZZZ2. Once reaching ZZZ2 I was in contact with the acp via company frequency. I first attempted a low approach to confirm the gear was down and received a verbal confirmation from two people that it was. I then gave the emergency gear extension lever 3 more pumps and attempted the landing. While landing I touched the left main first and tried to keep pressure off of the right. Once the right main touched; the right wing slowly started sagging down. Once I recognized that the gear was not going to hold; I cut power and feathered the props and brought the plane to a full stop on the runway.

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Original NASA ASRS Text

Title: C99 pilot reported a landing gear issue that resulted in a right gear collapse after touchdown.

Narrative: The event occurred at ZZZ on initial climb out on runway 32. After rotation and positive rate; I retracted the gear and noticed that the gear in transit light was still illuminated after a short period. After noticing this I slowed the airplane down to about 100 knots in hopes that a slower airspeed would allow the gear to retract. Once the slower airspeed did not work I leveled off and continued to troubleshoot the problem by rocking the wings and pitching up and down. I checked to see if hydraulic pressure was the problem and I could not get a hydraulic pressure warning while pressing the test switch; I then tested the annunciator to assess whether the hydraulic warning light was working; which it was. After several troubleshooting methods; I decided I would try and recycle then gear; upon doing so; the gear circuit breaker popped and the gear down green lights only indicated the nose and left main were fully down and locked. I pressed the gear down indicator to assure that the light had not simply burned out. I then reset the circuit breaker and attempted to put the gear up again. Again I received the gear in transition light for an extended period with a slight yawing moment. I then tried to put the gear down and received the same indications as previously stated and at that point proceeded with the emergency gear extension checklist. After possibly 30 to 45 min of cumulative pumping of the alternate gear extension lever; I could not get a gear down and locked green light indication for the right main. During that time I had reached ZZZ1 airport and had executed a low pass to confirm if the gear was down; and received a positive confirmation from the airport manager on the ground. I decided that I should query operations on what they wanted me to do before I made any decisions on my own since I had sufficient fuel for options. To do so I climbed to 4;000 and requested a phone patch through ARINC; where I was advised to divert to ZZZ2. Once reaching ZZZ2 I was in contact with the ACP via company frequency. I first attempted a low approach to confirm the gear was down and received a verbal confirmation from two people that it was. I then gave the emergency gear extension lever 3 more pumps and attempted the landing. While landing I touched the left main first and tried to keep pressure off of the right. Once the right main touched; the right wing slowly started sagging down. Once I recognized that the gear was not going to hold; I cut power and feathered the props and brought the plane to a full stop on the runway.

Data retrieved from NASA's ASRS site 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.