Date: 201701
Local time of day: 0601-1200
Location: ZZZ.TRACON, US
Flight conditions: VMC
Light: Daylight
Aircraft: Citation V/Ultra/Encore (C560)
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: VHF
Component problem: Malfunctioning
Reporter organization: Air Taxi
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Contributing factors: Aircraft; Company Policy
Primary problem: Aircraft

Narrative: We departed on the departure and immediately after switching [frequencies; we] began experiencing communication problems. The #1 radio began to get 'scratchy' and only intermittently readable. We were able to hear well enough to take an initial turn to a heading 180 degrees and climb to 15000 feet. We were given a frequency change and this frequency was also very scratchy and almost unreadable. The controllers were also having a extremely hard time understanding our transmissions. We were given a turn to proceed direct to the ZZZZZ intersection and at this point the radios became almost impossible to hear or transmit at all. The #2 radio was MELed because the Radio Management Unit (RMU) digits would intermittently go to dashes and stay dashes. The radio would transmit and receive on which ever the last frequency that was dialed in but it would not switch frequencies. This flight the #2 Radio was stuck on the [departure airport] ATIS frequency. What little we could hear from ATC was them asking us if we wanted to return to [departure airport]. We transmitted in the blind numerous times that we believed the ZZZ2 was a better option due to longer runways and further away from ZZZ3 and ZZZ4 traffic. We were able to send a message to the company was able to inform ZZZ2 of our plan. During our decent we established communications well enough to inform ZZZ2 of our plan to hold over ZZZ1 VOR for 20 minutes to burn off fuel the proceed to ZZZ1 and land. While holding we were able to establish text communications on my cell phone. [Dispatch] provided me with the phone number for ZZZ1 tower and from there we were able to communicate via telephone with the control tower. The landing was uneventful.The Encore has limited communication methods when compared to other aircraft in the fleet. The telephone has been deactivated. The Encore only has two VHF radios and a HF radio that is almost never used. Our crewmembers are not current with HF radio operations so it leaves us few options in the event of a dual VHF radio failure. Because of this I believe we should not continue to MEL the #2 radio when it malfunctions. Instead we should have the airplane immediately repaired. In the case of this aircraft this is the 7th time that the #2 radio was MEL'd in the preceding 2 months.




Synopsis: CE560 Captain reported being dispatched with the number two radio deferred. Shortly after takeoff the number one radio becomes unusable. The crew was able to convey through the use of cell phones and data link communications that they wished to hold to burn fuel then divert. This aircraft had a history communication radio failures.