Date: 201706
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Dusk
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Antiskid System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted
Contributing factors: Aircraft; Manuals
Primary problem: Aircraft

Narrative: Prior to this trip we had to defer one of the Anti-Skid channels; this deferral results in much longer landing distance and requires both Thrust Reversers be operational. This information will be important once the situation during the climb was encountered. While climbing through around FL240 we received a Yellow Master Caution and an associated R Reverse Unlock EICAS message. The Captain instructed me to run the QRH. I went to the Index and looked up the message to locate the appropriate section. The index directed me to the immediate action items. I referenced the QRC but I was looking for a Yellow Caution Message and found no appropriate checklist. After completing the Immediate Action Items in the QRH; I then tried to find the appropriate QRH procedure. It was then that the captain and I realized the Yellow Master Caution Reverse Unlock is actually in the Red Master Warning section. There is no note or direction in the QRH immediate action item section or in the Index that directs the pilots to EMERGENCY section. We had to find the correct section on our own. Although running the checklists and handing the situation was successful it is my belief that I should have gotten to the appropriate QRC and QRH procedures faster than I did. After the emergency checklist was complete the Captain transferred the controls and the radios to me. We decided to [advise ATC] and divert to ZZZ. The Captain then began to communicate with our Flight Attendant; the passengers; and dispatch. Meanwhile I had begun my descent and was flying directly to the ZZZ airport. The Captain picked up the current weather in ZZZ and then we briefed the landing. This is when we encountered our next issue; we could not receive any landing data. Because the aircraft had a deferred anti-skid channel which required two Thrust Reversers yet we now only had use of one; no landing data would come through ACARS. We elected to continue to land and advised ATC that we wanted Emergency Vehicles standing by and that we expected a long roll out. The landing and rollout were uneventful and we taxied to the gate and deplaned the passengers. The causes of this event was a mechanical issue; a deferred maintenance item; and a confusing QRC/QRC procedure.  The only suggestion that I have to help prevent an issue of this nature in the future relates to the QRH/QRC procedure; as the actual mechanical issue was not pilot induced. Although the training department does a good job emphasizing the fact that a Reverse Unlock Yellow Master Caution should in fact be considered a Red Master Warning; in the heat of the situation it is difficult to see a Yellow Caution and think Red Warning. I believe the best way to mitigate this problem in the future is to make a revision to the QRC and QRH. The QRC immediate action items for Reverse Unlock should be highlighted in Yellow and Red. This will help crews locate the immediate action items correctly and quickly prior to this trip we had to defer one of the Anti-Skid channels; this deferral results in much longer landing distance and requires both Thrust Reversers be operational. This will be important once the situation during the climb was encountered.




Synopsis: CRJ-200 First Officer reported a Yellow Master Caution and Reverse Unlock EICAS message which coupled with a deferred Anti-skid system that did not allow the ACARS to transmit landing data. An uneventful landing occurred.