Citationjet (C525/C526) - CJ I / II / III / IV
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 60; Flight Crew Total 5010; Flight Crew Type 800
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Flight Crew Overcame Equipment Problem; Flight Crew Returned To Departure Airport
Aircraft
We were assigned a trip ZZZ-ZZZ1. We performed the preflight; received our clearance; and taxied out to depart Runway XX. Upon departure both crew members recognized that both comms were not working. We immediately squawked 7600 and decided a left traffic pattern to come back to land was [the] best course of action. In the downwind the pilot monitoring ran the performance numbers and determined we would land overweight and that flying one more pattern would burn off enough fuel to land. We landed [on] Runway XX and taxied to the ramp.
After receiving a trip; the crew readied the airplane for flight by obtaining the ATIS; receiving the clearance; taxiing and takeoff all while engaging in two way communication with ATC. Immediately after rotation; the crew lost intercom capabilities between the crew and then quickly realized that communications with ATC was most likely lost due to a red 'X' box appearing over the commutations controls on the GTN [Garmin] 750. Due to still being VFR at the departure airport; a quick decision was to enter left traffic and to return for landing. 7600 was entered into the transponder.
Citation crew reported loss of comms with ATC immediately after takeoff.