Date: 201410
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: Viking/Turbo-Viking 17-30/31
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Takeoff / Launch
ATC / advisory: Ground ZZZ; Tower ZZZ
Aircraft component: Hydraulic Syst Valve
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Private
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Overcame Equipment Problem; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: On October 2014; I was cleared by tower for take-off out of ZZZ airport. The field was reporting VFR and I had advised I wished to depart to the west. I was departing in a Bellanca Super Viking; B17-31. Immediately after take-off I moved the gear lever to retract the landing gear. The nose gear light went out; however; the mains lights remained on. I advised tower of my problem and requested a low pass to confirm my main gear were still down. On the low pass tower advised that my main gear were in fact down and my nose gear was only partially retracted; to which I responded; 'That isn't good'. I continued to fly runway heading and was in the process of a climb to pattern altitude when I received a call from tower; requesting souls on board; fuel and intentions. I advised I was solo; with full fuel and I wanted to depart to the northwest to attempt to lower my gear; and then return for landing. Tower cleared me for a NW departure; gave me a squawk code and requested I remain up tower frequency to which I complied. I flew approximately 5 to 10 miles to the northwest and ran the emergency checklist. As soon as I lowered the emergency gear lever; the nose gear dropped. I was fairly certain the gear had locked into place because I felt the same sensation I feel in the pedals during normal lowering of the gear. I advised tower I had my gear down and would like to return for a low pass to confirm the gear down and then land. A low pass confirmed the gear were down. I flew a normal pattern and made a normal touchdown to landing with no further incident. I advised tower I would like to taxi to the departure end of 35L and exit taxiway B to the hangar of the company I use for maintenance. They cleared me to the departure end of 35L and advised I monitor Ground after departing the runway. When I came up on the Ground frequency I heard Ground releasing emergency personnel. I assume the fire department.

Callback: Reporter stated that the Aircraft Maintenance Technicians (AMTs) at the repair shop were very thorough in their troubleshooting of the failed gear retractions. Initially; the hydraulic power pack was replaced; but the problem with the partial gear retraction of the nose landing gear and the main gears not even moving continued. Hydraulic pressure was occurring on both the return and pressure sides of the extend/retract system. Manual extension of the landing gear however worked very effectively; since hydraulic pressure is removed from the system and the gears would quickly free fall to a 'Down and Locked' condition.Reporter stated the AMTs decided to remove the 'Gerdes Control Valve' that sequences and controls direction of hydraulic fluid to the landing gear actuators. There were three or four O-rings in the valve with one O-ring that appeared to be oversized. AMTs noted that the company that made the Gerdes Valve was out of business and suspected that someone had retrofitted some; or all of the O-rings on the valve. After installing a smaller diameter O-ring and performing multiple gear swings and flight tests; he has not had any landing gear problems.



Synopsis: Pilot of a Bellanca Super Viking B17-31 aircraft describes his efforts to verify all three landing gears were extended using Manual Extension procedures and fly-bys of a local tower; after the gears failed to retract following takeoff. Maintenance identified one of several O-rings in a Gerdes Control Valve that allowed hydraulic pressure to occur simultaneously on both; the return and pressure side of the landing gear's hydraulic system.