Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Aircraft Equipment Problem Less Severe
General None Reported / Taken
Aircraft
During the initial climb of the flight we experience several events of strong radio interference due to ACARS transmissions/crosstalk. These events caused both discomfort due to the very loud volume of the interfering transmissions and difficulty in understanding ATC communication.  In the last month many crews have been experiencing frequent events of radio interference due to ACARS transmissions/crosstalk. These interference events should be a safety concern. They caused; on more than one occasion; missed/misunderstand critical ATC communications and instructions during the departure phase of the flight. Something changed since December 2013. The cause can be changes in the ACARS communication software; protocols; procedures; equipment.  Usually after Weight Off Wheel both the FMS and the EICAS show an 'ACARS NO COMM' message; shortly after that a very loud burst of digital communication is heard in the pilot headsets. In the worst cases the interfering signal is repeated multiple times during the first few minutes after takeoff. There should be an investigation of these events. Pilots should be provided temporary procedures (like disabling the ACARS system) to be used during the departure phase of the flight.
The reporter states that he has an engineering background and is familiar with the sound that an ACARS transmission makes and that this interference is caused by the ACARS; but he does not know why. The company either does not know how to correct the problem or does not want to deal with the cost or down time to make the necessary repairs. A logbook write up will result in the ACARS being MELed; greatly increasing the communication workload for the flight crew. He believes that a similar issue was common years ago when the aircraft were first delivered from the manufacturer and was subsequently corrected.
CRJ-700 First Officer reports strong interference from ACARS transmissions occurring after takeoff on most of his company's CRJ aircraft and making ATC communication difficult. The reporter believes that changes in the ACARS communication software; protocols; procedures or equipment are the cause of the problem. The company does not currently have a solution to the problem.