Date: 202107
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Indicating and Warning - Landing Gear
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Troubleshooting; Time Pressure; Communication Breakdown
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: Taxiing out we got the EICAS message LG NO DISPATCH.  We returned to the gate because the GRG (Ground Reset Guide) requires the procedure to be ran at the gate with engines; APU and hydraulics off and we also needed ground power as well.  Captain wrote up the discrepancy as well as the corrective action. Dispatch was informed and they passed that info to mx at the captain's request including the AFML (Air Frame Maintenance Log) page number. The GRG was successful at resetting and we left the gate.  When cleared for T/O on the second attempt we received the EICAS message LG NO DISPATCH again while lining up on rwy XX.  We returned to another gate because we could only reset using the GRG once.  The captain wrote it up again and called our dispatcher and what sounded to me MX as well.  We deplaned; I did a walk around and we swapped airplanes and departed with no further issues.I should've double and triple checked with my captain that MX was called.  Don't assume anything. Write it down.  Make a list what needs to be done and triple check it.  Call Chief Pilot if need be; to double the crew that nothing was undone.


Second narrative: We received EICAS message 'LG NO DISPATCH'.  Followed procedure with QRH guiding us to GRG.The GRG states that it must be accomplished at the gate with GPU on; and the APU & engines off. Proceeded to gate and followed GRG successfully. Kept dispatch informed and for new numbers due to different FOB (Fuel On Board); and asked to forward message to MX control; including all information and logbook page; via ACARS.On second taxi out all was good at first; but upon reaching rwy XX we received the same EICAS message. Being allowed to do the GRG once only; we had to go back to the gate. After keeping again everyone informed (ATC; FAs; passengers; and dispatch); and after securing the airplane at the gate; I proceeded to write it up. The gate agent asked for more information and I informed him that I will coordinate with dispatch. After being informed of a plane swap and the deplaning in progress; dispatch tells me that he will call me back after talking to his supervisor to verify that plane swap.In that moment I initially decided to call MX control to inform directly of the new open write up; but then received the call back from dispatch again; verifying the plane swap; at the same time of informing him from the happenings and procedures we had to do and as why.In that moment I must have assumed that either dispatch forward the information again to MX control or even that I did it already while waiting for the call back; but have actually not done it.Upon landing in ZZZ I talked to the Chief Pilot about this; and agreed that MX control always needs to be informed asap; yes; and that with all the circumstances I must have assumed myself that I did it but had not. I immediately called MX control to inform about the new write up. The first they got from dispatch; yet the second one they saw it while on the plane; prior to my call.Usually; I am on top of these things; especially with priorities (like inform MX control first; as more important); yet with all the communication back-and-forths; in addition to prior information fwd via ACARS; and subsequently talking to dispatch while just prior wanting to call MX control; I assumed very wrongly that I informed MX control.While they got notified after we landed in ZZZ; I keep thinking of the consequences; like what if another crew would have a repo flight that night and arrives at that grounded airplane with open write up and not being able to do their flight? Etc...What I have learned from this is several things: if I have to call MX control; do it right away; another caller can call back again or I will call them back after informing MX; but first things first! And while fwd the message via ACARS to MX via dispatch; take the time to call myself; even if the passengers are delayed already; just do it. Also; I shall not assume that I have kept everyone informed. Take a moment to reflect and think back the steps. Did I inform dispatch? Check! Did I inform crew; ATC; pax; etc.? Check! Did I personally inform MX control? No; do it right away! And if they are informed already; now they are informed twice; ok; but I made sure it is done correctly.What I have learned from this is not to assume anything; but to double check that all steps have been done and procedures followed; even if this means that; like in this case; MX control would get notified several times with the same information; but I will make sure that I will do this right away; keeping the priorities in place.Also; despite a long delay and coordinating with crew; GA; dispatch; etc.; to keep focused on pending tasks without assuming these have been done; knowing that in all the confusion; there is always something that was missed out; and to go through all steps until everything is being confirmed as accomplished. Slowing down and taking the time to do the things right and prioritize them; and not getting myself distracted that could lead me to think that a current procedure I am on just got done.


Synopsis: EMB-175 flight crew reported two gate returns and an aircraft swap caused by a landing gear no dispatch EICAS message. The flight crew reported concerns over communications issues with Maintenance and Dispatch.