Date: 201904
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 900 (CRJ900)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class E ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Situational Awareness; Physiological - Other
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Clearance; Flight Deck / Cabin / Aircraft Event Illness / Injury; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Diverted
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Flight departed ZZZ Airport XA55 local time. While taxiing out; heavy precipitation was passing over the field and we had a release time per air traffic control at XB26 local time. We parked in the Hold Pad in ZZZ. It's important to note while stationary there was no odor; fumes; or noises out of the ordinary heard at this time. We received our takeoff clearance at XB28 local time and proceeded on course. At approximately 8;000 feet; we heard a loud whining noise begin to sound from in front of the panel area. I did not think anything of this at the moment; however; began to monitor the noise. I noticed the FO (First Officer) have a look of concern on his face and questioned if I was hearing the same noise. We both agreed and had not heard this type of sound before. (It is noted that when we landed in ZZZ1; I confirmed all external service doors has been shut; and not left open). As the climb continued both pilots complained of being very warm; when referencing the ECS (Environmental Control Systems) Synoptic Page temps were normal with a Left Pack selected temp of 22 and an output temp of 11: the Right Pack had a selected temp of 25 with an output temperature of 12. Prior to 17;000 feet; an intense electrical burning smell was first noticed by the Captain. Going through FL180; I recall being very distracted by this smell conducting the Climb Checklist. As the climb continued; the smell persisted and it was very present to both the Captain and First Officer. At FL270; we leveled and the smell intensified more through the flight deck. I called for the Non-EICAS Abnormal QRH for SMOKE/FUMES/DISPERSAL PROCEDURE; immediate descent was made while the Pilot Monitoring (PM) was running the QRH.ATC was notified; and coordination to divert to the nearest suitable airport was made. Flight Attendants were notified immediately for the Yellow Emergency; and passengers were briefed. Nearest suitable airport was ZZZ1. Oxygen was utilized until entering the terminal area were we removed them for improved communication as well as identifying ZZZ1 since there were similar layout airports in the area. Both Captain and FO experienced nausea; lightheadedness; and headache during the Approach. During the descent the whining noise from the front of the flight deck persisted. After clearing runway; I brought the aircraft to a stop; notified the passengers to remain seated and that airport fire and rescue would be following the aircraft. A call to the flight attendants had also been made to check on their wellbeing as well as the passengers. Once parked firefighters came on with a device to detect heat. There was an area detected of heat coming from CBP-1 (Circuit Breaker Panel) around breaker T5 'ESS 2B' and T2 'ESS TRU (Transformer Rectifier Unit) 1'. I had the firefighter check the nose area of the airplane; and a single TRU was found producing more heat than the others. Passengers were deplaned into the terminal and kept updated on conditions. Captain and FO received medical attention at the emergency room due to symptoms felt. Treated and released that evening.


Second narrative: Flight from ZZZ began with a 20 minute ground delay due to extreme precipitation that was detected off of the departure end of the runway. After the heaviest precipitation passed; we departed with the radar and continuous ignition both 'on.' At approximately 8;000 feet; the CA and FO noticed a whining sound that seemed to be coming from the nose. We commented on the unusual nature of the noise; as it sounded similar to when the service panel is left open in flight; but was different enough so that we determined it must be some other abnormality. The noise persisted as we continued our climb through FL180. At this point the CA recognized a burning odor. He checked the synoptic pages and all indications were normal. We also checked the breakers and found nothing popped. At this time the FO also recognized the strong burning odor normally associated with electrical fire fumes. We continued to climb to FL270; hoping that the smell would dissipate. However; it intensified rapidly so we began running the SMOKE and FUMES DISPERSAL procedure in the 900 QRH. The procedure calls for 'landing immediately at the nearest suitable airport.' The CA called for an immediate descent and the FO (Pilot Flying) initiated the descent. The CA (Pilot Monitoring) [notified ATC]; queried ATC for the nearest airport (ZZZ1); and took control of the aircraft. The CA and FO both donned oxygen masks. The FO continued running the checklist to dump the cabin and provided ATC with emergency info (SOB; fuel; nature of the situation). The FO set up the ILS XX into ZZZ1 and the CA determined the landing speeds using the speed cards. The burning smell persisted in the descent through 10;000 feet. The CA successfully landed on RWY XX at ZZZ1 without incident and ARFF standing by. Firefighters boarded the aircraft and detected abnormal heat coming from CBP-1 (Circuit Breaker Panel) T5 (ESS TRU 2B) and T2 (ESS TRU 1). We deplaned passengers and assisted as they exited down the steps. An air carrier pilot; jumpseater; seated in row 6 commented that he smelled an intense electrical burning smell when we opened the flight deck door on the ground. After inspecting the nose cone; ARFF stated that abnormal heat was also detected from TRU 1. Cause: Suspected TRU issue; but Maintenance review required.


Synopsis: CRJ-900 flight crew reported a diversion due to intense electrical fumes during climb.