Date: 201711
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Aircraft component: Headset
Component problem: Malfunctioning; Design
Reporter organization: Air Carrier
Reporter function: Captain; Check Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight; Taxi
Result: General None Reported / Taken
Contributing factors: Aircraft; Equipment / Tooling
Primary problem: Ambiguous

Narrative: I have been receiving electrical shocks through my TSO approved Clarity Aloft headset when I touch my iPad when it is hooked up to the charger that is plugged into the cockpit electrical outlet. I believe it is a system design failure that involves how the phone jack and cockpit electrical outlets are grounded. My headset consists of a painted metal band that goes around the back of my head; and it has a small paint chip on the right side where it's pressed against my temple. I have been receiving the shock through that chip. The headset is not modified nor damaged besides the small paint chip. The charger I am using is not the official iPad charger; but the results are the same when I use the official charger. The electric shock seems to happen on all of the airplanes but some are stronger than others. The pain ranges from a tingle to feeling like I'm being bitten by fire ants.The reason why I think it is a grounded issue is because it occurs when the PHONE plug is either plugged in or simply touching the metal of the PHONE jack. It does not have to be inserted for me to receive the shock. The shock occurs when the plane is on the ground or in the air. It makes no difference to the phase of flight. It does not matter the orientation of the iPad charger plug prongs. It also occurs in both the left and right seats. If I unplug the PHONE plug and touch the iPad or charger then I hear a buzzing sound in the headset if the microphone plug is connected.One thing that is very common in this airplane is a humming noise over the intercom when a pilot touches their iPad when it is charging and the microphone is hot. I do not know what headsets this occurs with but it happens with many different types of TSO approved headsets; although I have not heard anyone else report an electrical shock. It is almost like the alternator whine that you get when using an auxiliary cord in a car and plugging your phone to a lighter charger. I am not an aircraft engineer but I am surprised that a system is designed in a way that allows (a relatively high) potential voltage to exist between the PHONE jack and something connected to the cockpit outlet. I do not know how to fix this issue but maybe the Embraer engineers might be able to figure it out. My solution to this electrical shock is to put heatshrink over the end of my headset. This seemed to solve the issue; but I am writing this report as I don't think the potential for electrical shock over the headset should even be there at all.




Synopsis: Embraer 175 Captain reported receiving electrical shocks through a headset while in contact with  a charging iPad.