Date: 201902
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Cessna Citation Sovereign (C680)
Operator: Corporate
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Aircraft component: Squat Switch
Component problem: Malfunctioning
Reporter organization: Corporate
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Instrument
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Departure Airport
Contributing factors: Aircraft; Company Policy
Primary problem: Ambiguous

Narrative: I was the PF (Pilot Flying) for a flight departing ZZZ operating under Part 135 ops. I was SIC and Captain was PIC. We departed on an IFR flight plan in VFR conditions. We departed XXR with a clear board; after positive rate I called for 'Gear Up' and watched Captain grab the gear handle and as he pulled his hand slipped off. At that point tower switched us to departure; and Captain attempted two more gear retractions. The knob on the gear handle was not coming out of the unlock detent. We momentarily receive a WOW (Weight on Wheels) miscompare CAS (Crew Alerting System.) It lasted perhaps two seconds and went away. No master warnings or cautions were received.I continued to fly the departure; Captain and I discussed the gear not wanting to unlock and Captain called departure for a return to ZZZ out of an abundance of caution. We were so close to the ZZZ that it seemed to be the correct decision. The Controller asked us if we needed any assistance and we said no as there was no emergency. We were vectored back on final and landed without incident. We taxied to Signature flight support ZZZ and deplaned the pax. Still no indications from CAS or panel of any issues; all of the WOW LOGIC systems seemed to be functioning correctly. The aircraft was in a normal state. Total flight time 12 minutes.I called maintenance and we had a bad connection; so I called our Chief Pilot while Captain was researching what may have caused the issue. Our Chief pilot said that he would call our Duty Officer to call maintenance and see if he knew what might have caused the handle to not unlock. Our Chief Pilot called back and informed us that there was no maintenance at ZZZ and the closest maintenance facility was ZZZ1 approximately 20 minutes away; and to reposition to the service facility to see if they noticed any issues. I post-flighted the plane and went into the FBO while Captain post-flighted the plane and filed a flight plan to ZZZ1 and ran performance on a gear down trip. In the flight plan Captain filed 9k and 200 knots as to keep well under the gear limitations.During preflight and discussion there was no abnormal indications; lights; CAS etc; and the airplane appeared to be in its normal state. We formulated our plan to repo to maintenance and decided to not attempt to retract the gear out of an abundance of caution. We had no reason to think that there would be an issue; at that time; we just thought that on the previous flight there was a momentary lack of engagement of the WOW micro switch. The reposition flight was a short flight and according to the Captain's gear down performance review we had plenty (7.5k LBS) of fuel onboard; I asked Captain if there was any issue departing and flying with the gear down and he said 'no.' We had no caws; three greens; no warnings or cautions and no visual indications that the issue was not just a one off glitch. We departed ZZZ for ZZZ1 @10;000 FT @ 200 knots. The flight was without issue or incident. The airplane behaved as to be expected. We left it at [the service facility] and I called the Duty Officer to ask how to write up the squawk; and the Captain post-flighted the plane. The Duty Officer instructed to write up the squawk as gear would not retract. At this point we have not heard that there was any problem found from [the service facility.]Summary of issue:I think that the issue was a momentary wow logic glitch that immediately resolved itself on the next flight. We had no indication of any remaining issues; and the aircraft was visually inspected and correct. The concern is if we departed to maintenance and should have requested base to get a ferry permit. I asked the captain if we had an issue departing after returning to ZZZ and I received a non-hesitation 'no issue.' I was in agreement because the airplane in seemed correct. I think that we would benefit from instituting a MX; squawk and ferry permit training class at our 135 op.


Second narrative: I was the PIC and PNF (Pilot Not Flying) for a flight departing ZZZ operating under FAA Part 135. We departed ZZZ on an IFR flight plan in VMC conditions. We departed the ramp and taxied to runway and departed under normal conditions. The aircraft was sound and airworthy and no CAS (Crew Alerting System) messages or other anomalies indicated the aircraft was not fit for departure. My SIC was PF (Pilot Flying.) I called 'positive rate;' my SIC called 'gear up.' I grabbed the gear handle and attempted to raise it. My hand slipped off the gear handle and I figured I did not have a firm grip on the handle. I again attempted to raise the gear; and again; my hand slipped off. Tower then switched us over to departure; I called departure; and attempted another gear retraction. It was then; I realized the gear handle was firmly locked in the down and locked position. I informed my SIC of the issue. It was then that we received a 'WOW (Weight on Wheels) MISCOMPARE' CAS message. This message flashed on for a matter of a few seconds at most; then extinguished itself.SIC and I discussed the gear not wanting to retract and we elected to return to ZZZ out of an abundance of caution. I informed ATC of our intentions and we were given vectors back to land. I looked up; and ran the; emergency/abnormal checklist associated with a 'WOW MISCOMPARE.' The checklist was only advisory in nature; and I knew the aircraft would operate normally; considering the CAS message only momentarily flashed on and then immediately extinguished. I also looked for a checklist associated with a gear that would not retract; but only found checklists associated with gear that will not retract accompanied by a red unlock light. On attempted gear retraction; we were simply unable to move the gear handle and never did receive any unlock lights. Due to our immediate proximity to the airport; and an abundance of services on the ground we elected to return to ZZZ. I checked the FMS and verified we would indeed be able to make an immediate return to ZZZ and still land below our maximum landing weight of 27;100 pounds.The Controller asked us if we would be needing services upon landing and I replied 'No;' as there was no emergency and the aircraft was still operating safely and normally. We received vectors for a visual approach and landed without incident. We taxied to the ramp; and deplaned our passengers. There were still no abnormal CAS messages to indicate that anything was amiss. The aircraft was shut down in an ops normal state. Total flight time was 12 minutes. After deplaning our passengers; I researched the issue further; while SIC called our maintenance department. The phone connection was poor and the call was dropped so SIC called our company chief pilot. Our chief pilot informed us he would call our company director of operations who would get in contact with our company director of maintenance. Our chief pilot then called back and said that ZZZ did not have the best services for us and that ZZZ1 had a Service Center which could best assist us. He informed us that the Service Center in ZZZ1 was a 20 minute's flight away and that we should reposition the aircraft to the ZZZ1 Service Center.Both SIC and I post-flighted the aircraft; paying especially close attention to the landing gear and associated landing gear wells. We checked for leaking hydraulic fluid; we checked the hydraulic lines; the squat switches; the tires and the landing gear uplocks and control arms. All systems checked out. I then checked the Performance Manual Gear Down Operations section of the performance manual and verified our climb rates and fuel burns would be nominal while flying the leg gear down; if need be. All performance charts associated with gear down operations showed operations would be safe and legal. I then filed our flight plan to ZZZ1 and adjusted our filed speed to 200 KIAS; ensuring we would stay below the Vlo speed on the aircraft of 210 knots. We went back to the aircraft and preflighted the interior and exterior. Upon preflight; APU start and during engine start there were no CAS indications or other indications that would lead us to believe the aircraft was not sound; or operationally safe or legal for flight. SIC and I formulated our plan to reposition to ZZZ1 and decided not to attempt a gear retraction out of an abundance of caution. During discussion we concurred that there would be no reason to think that there would be an issue. We decided that on the previous flight there was a momentary lack of engagement of the WOW micro switch; so we decided we would rather not exacerbate any future issues.Engine start; taxi and takeoff were completely and totally ops normal. No CAS messages indicated that the landing gear WOW switches were not agreeing; and no other CAS messages or abnormal indications of any kind were present. The gear down performance numbers showed we would burn approximately 1100 pounds of fuel for our planned 24 minute flight. At the time we had well over 5;000 pounds of fuel onboard. The flight was conducted in VMC conditions. The flight was normal and the aircraft operated as it should. The aircraft produced no CAS messages; all landing gear lights were operating normally and we had no reason to believe the issue on the previous leg would occur again. We departed ZZZ for ZZZ1. Time enroute was 24 minutes. We landed in ZZZ1 and ended up using 993 pounds of fuel. The routing was conducted at 200 KIAS at 10;000 feet MSL. We left the aircraft at the Service Center and SIC phoned the company director of maintenance for the wording on the maintenance write up while I post-flighted the aircraft. The company director of maintenance instructed SIC to write the squawk as 'Gear Would Not Retract.'


Synopsis: Citation flight crew reported a malfunctioning weight-on-wheels switch after takeoff that prevented gear retraction and returned to the departure airport.