Date: 201412
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Rain
Light: Daylight
Aircraft: Citation Excel (C560XL)
Operator: Fractional
Operating under: Part 135
Mission: Passenger
Flight phase: Parked
Aircraft component: Gear Up Lock
Component problem: Malfunctioning
Reporter organization: Fractional
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Communication Breakdown
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Detector: Person Flight Crew; Person Maintenance
When detected: In-flight
Result: Flight Crew Diverted; General Maintenance Action
Contributing factors: Incorrect / Not Installed / Unavailable Part; Aircraft; Equipment / Tooling; Human Factors; Procedure
Primary problem: Human Factors

Narrative: Myself (PIC-PNF) and my SIC-PF; while operating a CE-560XL; experienced a failure of the right main landing gear to retract after takeoff from ZZZ during a positioning flight to ZZZ1 for an upcoming passenger trip. We diverted to ZZZ2 where the aircraft was placed in maintenance at the Cessna Citation Service Center. Five hours later I received a phone call from my Chief Pilot notifying me that a screwdriver had been found wire-tied to the landing gear mechanism.  Surprised that we had not spotted this during the preflight inspection; my SIC and I went back to the Cessna Service Center to examine the aircraft and talk with the Cessna mechanics to determine what might have happened. I believe I have an explanation for why the screwdriver was overlooked. First; I paid particular attention to the landing gear area; as well as the main cabin door during the preflight; since both those items had been worked on recently; and each had four or five repeat write-ups in the logbook. As is customary after any maintenance action; I am very diligent in ensuring that the aircraft is in a safe condition for flight. I know that my SIC operates the same way; being a qualified Airframe and Powerplant (A/P) mechanic himself. We have flown together numerous times and between the two of us have made a good team in spotting potentially hazardous issues with our aircraft. I didn't feel there was a problem with the landing gear system before operating the aircraft; even though most of my preflight time was focused on the main cabin door. The door hinge was damaged and it took some time in discussion with Maintenance Control; who had to escalate the issue to their supervisor; before they determined that we could operate the aircraft with a damaged main door because they had a 'letter' from Cessna stating that it was okay to operate with a damaged Main Entry Door Hinge Assembly; and that we didn't need any MEL; CDL; Non-Essential Equipment/Furnishings (NEF); Maintenance Carry-Over (MCO); ACI; AIN documentation etc.; for this condition (separate report filed). Because of the time it took dealing with Maintenance regarding the door; we departed seven minutes late. As we were lined up on the runway for departure; we spotted a flock of birds hovering over the runway touchdown zone and received clearance from the Tower to delay our departure until the birds flew away. When it looked like the birds had left; we commenced our takeoff. Just after rotation; however; we noticed a couple of small birds pass beneath us and we made a note to check for signs of a bird strike after landing. During climbout; my SIC/PF became aware of a slight rumbling feeling and the need for a large amount of Left rudder trim. At first we considered the possibility that we had struck a bird; but shortly discovered that the Right-hand Main Landing Gear (MLG) light remained illuminated. All signs now pointed to the right main gear having not retracted. My SIC flew the aircraft; maintaining a speed of under 200kts after trimming the aircraft to compensate for the yaw due to the drag of the extended gear. (Note - Cessna does not have a checklist procedure for this eventuality). Once we had the aircraft safely under control; I telephoned the on-duty Assistant Chief Pilot (ACP) for assistance and had a conversation with the ACP regarding our options.At this point the 'LO BRAKE PRESS' and 'ANTISKID INOP' and flashing Master Caution lights illuminated. The ACP (in conjunction with the Maintenance Director and Dispatch) and I agreed that the safest course of action would be to head north and land at ZZZ2 to take advantage of the better weather available and longer runway options. We were then re-dispatched to ZZZ2 by our Dispatcher. The weather at our departure and original destination and alternate airports was marginal in terms of visibility and ceilings. ZZZ2 had calm winds and higher ceilings and visibility. We had plenty of fuel to reach ZZZ2; so diverting to ZZZ2 was an obvious decision to make. All things being equal; ZZZ2 made for an ideal diversion airport given the availability of a Cessna Maintenance facility that would likely be able to facilitate an expeditious return to service for our aircraft; which would minimize disruption to our owners. The approach and landing at ZZZ2 were uneventful. After we extended the landing gear; the 'LO BRAKE PRESS' and 'ANTISKID INOP' lights extinguished; and we were able to land the aircraft without resorting to use of the emergency braking system; with no need to declare an emergency. During the postflight inspection; my SIC and I spent an especially long time examining the right landing gear area in an effort to determine any likely cause of our problems. He spend some time examining the gear area from the front of the aircraft looking for any signs of a bird strike; of which none could be found. I was on my knees behind the right main landing gear looking up into the wheel-well particularly at the strut to see if I could find anything amiss such as leaks; etc. I did not notice anything amiss in the wheel well; however; I did notice a fresh trail of oily fluid behind the landing gear area on the trailing edge of the flap. I spent more time looking in the wheel-well to see if I could determine the source of the fluid; but I could not. Maintenance Control instructed me to make a separate write-up for the fluid leak. After I had made the necessary write-ups; a Cessna Citation Maintenance Supervisor came out to examine the aircraft. He was aware of the gear problem and the fluid leak. He also spent time examining the landing gear area looking for problems and trying to track down the source of the leak. Neither myself nor my SIC; who were actively looking for problems in the gear area; nor the highly-trained Cessna maintenance expert also looking for problems in the gear area; noticed anything amiss. After a phone call from our Chief Pilot and a picture showing a screwdriver wire-tied into the gear Uplock mechanism; we went back to Cessna to look over the aircraft and speak with the mechanics. The Cessna maintenance supervisor told us that the Cessna mechanics didn't discover the screwdriver until the aircraft was put up on jacks in a brightly-lit hangar. Furthermore; the head of the screwdriver is dark black. When viewed from the rear (the position where I was kneeling when looking into the wheel-well area); that black circle is not something that stands out amongst all the other black parts in the gear area; you'd have to have been looking at the screwdriver from the side in order to discern its yellow body. Even then; the gear Uplock where the screwdriver was wedged is actually above the opening of the wheel-well; which explains why the mechanics spotted it once the aircraft was raised up on jacks; it's a lot easier to see if you're physically inside the wheel-well with your head in the recessed area; looking at it from the right angle. The Cessna Maintenance Supervisor; seemed to be of the opinion that this is not something that would likely be detected in a normal preflight; even if one were focusing attention on the gear area.Maintenance should examine whether wedging a screwdriver into the main landing gear Uplock mechanism and securing it to the Uplock switch with a wire tie is a safe procedure. The maintenance procedure of jamming a screwdriver into a main landing gear uplock mechanism should be modified such that a long; bright red flag be attached to the screwdriver to draw attention to it in the event that the screwdriver is not removed at the completion of the maintenance procedure. Maintenance procedures should include methods to account for all tools used so that all tools present before maintenance commences are accounted for at the completion of the maintenance procedure.


Second narrative: Cessna CE-560XL took off from ZZZ and diverted into ZZZ2 with the following:After takeoff from ZZZ; right landing gear did not retract normally. Right-Hand (RH) gear indicator light remained illuminated; other gear lights extinguished. Noted aircraft vibration and excessive yaw to right. 'LO BRK PRESS' and 'ANTISKID INOP' lights illuminated with flashing Master Caution light.  This aircraft was also previously worked in ZZZ; three days earlier; by Cessna mechanics from ZZZ2 for the following squawk:  In cruise; at FL400 the Main Landing Gear (MLG) Green RH Downlock light came on. It continued to flicker for 45 minutes.  During the same time the 'Low Brake Press' and 'Anti Skid' annunciators flashed on and off.  It stopped for about 15 minutes; then the anomaly occurred again for 20 minutes.  It stopped before descent. Upon inspection by technicians in ZZZ2; they found an awl tie-wrapped to the RH MLG Uplock switch; depressing the switch.  Recommend ensuring proper tools are used for troubleshooting.


Synopsis: A pilot and Maintenance Controller report a Cessna CE-560XL aircraft had diverted after takeoff due to the right main landing gear (MLG) would not retract. Maintenance later found an awl tool tie-wrapped to the RH MLG Uplock switch; that was depressing the switch.