Date: 202111
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Dusk
Aircraft: Citation V/Ultra/Encore (C560)
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Takeoff / Launch
ATC / advisory: Center ZZZ
Aircraft component: Air/Ground Communication
Component problem: Malfunctioning
Reporter organization: Corporate
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Communication Breakdown; Confusion; Distraction
Second reporter function: Pilot Flying; Captain
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: Taxi
Result: Air Traffic Control Issued New Clearance; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: When Number 1 for takeoff we were given a 10 minute takeoff window. We delayed a bit to recalculate some takeoff data then proceeded to takeoff. The PIC (Pilot in Command) was handling the clearance and radios. We thought we were still in the 10 minute window but later found that ATC thought we were 2 minutes past our void time. After takeoff we experienced an unsafe gear indication with a red Gear Fault light; also we showed a Hydraulic Press annunciator and a Stab problem light. We kept trying to contact Departure on the radio then finally determined that we had COMM 1 radio failure. When we finally got ZZZ1 on COMM 2 and then we received priority and requested a return to ZZZ. We ran the emergency checklist and were able to get the gear down and locked which also apparently fixed the associated hydraulic problems with the stabilator. We then landed at ZZZ. I feel that the late contact with ATC from which they may have deduced a void time departure was due to the abnormally long time from takeoff until radio contact. Obviously the long time was due to multiple emergencies and NORDO on COMM 1.When given a controlled takeoff: Write it down in Zulu time and confirm this Zulu time with ATC to ensure we are all on the same page; looking at the same Valid time.


Second narrative: This report is for Aircraft X. This landing gear [situation] during initial climb-out from ZZZ at dusk was coupled with a COMM 1 radio failure and possible late takeoff (after clearance void time). I was the PF (Pilot Flying) for this event.Prior to takeoff; we were issued a clearance void 'if not off in 10 minutes' clearance from ZZZ1 Approach (via cellphone call). Both myself & my trainee (Captain in training) thought we were within the 10 minute time frame. We were informed post-flight that in fact we had departed 2 minutes late.After takeoff; and call of 'positive rate' by my PM (Pilot Monitoring); I called for 'Gear UP.' He subsequently raised the gear. The 3 green gear indicator lights extinguished normally. However; the red UNLOCK indicator light remained illuminated. At this time; I started the turn toward our assigned after-departure heading of 090 & continued the climb to our departure assigned altitude of 5;000 feet MSL. I requested the PM to contact Departure. I purposely kept the aircraft at 160 knots during this maneuver since we had not raised the flaps due to concentrating on the gear [situation]. The PM was unsuccessful on COMM 1 in contacting ATC (ZZZ1 Departure). We then realized we were NORDO on the COMM 1 radio. I then tried them on COMM 2 via [frequency] & their Approach frequency of [frequency1]. I was successful on the COMM 2 radio & [received priority] due to unsafe gear indication; hydraulic pressure & stab mis-compare annunciations/malfunctions. Then the PM took the radios back. By this time; we were heading 090 & level at 5;000 feet MSL. We remained at 160 knots since the gear was still indicating UNLOCKed & the flaps remained at our takeoff setting of 7 degrees.Subsequently; we completed the appropriate 'Landing Gear Will Not Retract' checklist; & requested vectors for landing via ILS XX ZZZ. Thereafter; we landed without incident with a normal approach & landing.Landing Gear would not retract normally after takeoff during initial climbout & COM 1 radio inoperative.To prevent late takeoffs at an uncontrolled field (such as ZZZ) after Clearance Void Time issuance; insert a step in the checklist / SOPs to WRITE DOWN the actual clearance void TIME & require SIC (Second in Command) (PM) verify that exact TIME BEFORE brakes released takeoff.


Synopsis: CE-560 flight crew reported loss of multiple systems after takeoff resulting in a return to the departure airport.