Date: 201910
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Dusk
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class D ZZZ
ATC / advisory: Center ZZZ; Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew; Person Flight Attendant
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During cruise at FL250 the FO (First Officer) and I were having a conversation and mid-sentence we simultaneously noticed a strange odor. There was no visible smoke in the cockpit and we both agreed that it was not an electrical smell but something we could not identify. At that moment the FA (Flight Attendant) used the cabin emergency button to notify us that there was smoke coming out of the passenger vents. I immediately turned off the recirculating fan and radioed ATC and needed to land as soon as possible. He asked what airport and I asked what was closest. He mentioned ZZZ was only 20 miles away and knowing the runway is long and the weather in the area is good chose that and asked to immediately start a descent and vectors for the airport. At that point I had the FO take the radios and start getting down. We were given a lower altitude and he started a 3000 fpm descent. I then turned my attention to the QRH and ran the appropriate checklist. After turning off the gasper fan as well I wanted to know if that got rid of the smoke. I called the FA back and she said that the smoke was no longer coming out just some residual smoke in the cabin. She also said that they were all OK and there was no need for passenger oxygen and then continued with the QRH. It seemed that the smoke was no longer as big a threat; so having coming to an END point in the QRH I then began to prepare for landing. Even though there didn't seem to be any new smoke; the possibility that there was still a fire we could not see was a huge concern. I used the speed cards to get landing numbers and since the QRH was out quickly looked at the landing distance. We were now approximately 3000 feet and I ran the descent checklist. Looking at our current weight I realized that were about 450 lbs. overweight but decided it didn't matter. We were now getting vectored for approach and I just focused on landing. After landing we stopped on the runway and I told the passengers to remain seated. I communicated with ATC that I would like the fire trucks to check the aircraft for any issues we may not be aware of. At this point I made an announcement to the passengers to not be alarmed by the trucks; that we were just being overly cautious; that at this time there was no danger and to remain seated. After I called the FA and asked if she and everyone else was OK. She said yes. After the fire trucks notified us that they could not see any damage or issues; we taxied to the gate; and deplaned normally.The smell was obvious to us and the cabin crew saw the smoke. It seemed to be an issue with either the recirculating fan; gasper fan or pack 2. I had MELed pack 1 before we left the gate 3 flights prior. I believe we did everything we needed to and we landed with no injuries or damage to the aircraft. This has been an issue that to my knowledge has happened several times in the past few weeks and needs to be resolved. Not sure if it is the same aircraft or multiple ones.


Second narrative: While in cruise flight; shortly after the completion of the cruise checklist; the CA (Captain) and I noticed a strong odor consistent with something burning. The smell was not exactly electrical but of a nature we could not readily identify. Within a few seconds; the FA (Flight Attendant) chimed us on the cabin emergency button and told us smoke was rolling into the cabin from the air vents and the cabin was becoming filled with smoke. The CA immediately requested priority handling with Center and asked for the nearest airport; which was ZZZ. Center then cleared us for a decent at which time I began approximately a 3;000 fpm descent from FL250 to 10;000 feet. The CA began running the QRH and I continued to fly the aircraft and speak with ATC. Upon reaching 4;000 feet; ZZZ Tower began vectoring us for the visual to the runway. The CA ran the landing number via the speed cards; I quickly briefed the approach and landing; and began the approach. After landing; I stopped the aircraft on the runway and the CA told the passengers to remain seated. Fire rescued then visually inspected the aircraft and followed us to the gate. Strong smell of something burning. The smell was obvious to all of us and the cabin crew saw the smoke. It seemed to be related to the recirculation fan; grasper fan; or pack 2. Pack 1 was MELed three flights prior and was not operational during the flight. The crew completed all required tasks and safely landed the aircraft at a suitable airport in accordance with piedmont procedures and FOM. This seems to be a recurring issue; not sure if this is the same aircraft but within the last few weeks I am aware of several aircraft that have had to return to the field because of smoke. This issue needs to be resolved.


Synopsis: EMR-145LR flight crew reported a strong unidentifiable odor at cruise; which resulted in a diversion.