Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 93
Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem
Human Factors
After push back; ATC advised us that it would be about 20 minutes prior to clearance for take off. We began taxi on one engine; and Captain (CA) then commanded shutdown of APU with the comment that we would perform a cross bleed start of #2 engine at the appropriate time. While waiting for the appropriate time to start #2; I forgot that the APU was off. CA called for #2 start; which I then did by the 'normal' steps of selecting engine #2 start/stop to start. I then started the timer. Neither of us remembered the need for a cross bleed start. During #2 start I was dividing my attention between preparing for departure and monitoring the engine start. I recall hearing an engine sound that I don't usually hear during engine start; and I focused my attention more carefully on the EICAS. I noticed the #2 temp rising beyond what I normally expect; with the N2 temp approaching max (red tick). I verbally noted this to the captain. I reached for the #2 start/stop in preparation to shut down the engine and it was then that I realized the problem was a result of not properly executing the cross bleed start procedure. I verbalized this to the captain also. The captain promptly increased power on the #1 engine to assist the cross bleed start; which resulted in an immediate decrease in N2 temp on #2. At this point the #2 start proceeded normally. At no time did #2 temp reach or exceed limitations; and no EICAS messages were annunciated before; during or after the start. Rest of the flight proceeded normally.As a new First Officer (FO); I have done very few and infrequent cross bleed starts. This lack of recency and experience contributed to my forgetting that the APU was off and a cross bleed start was required. Further; allowing myself to be distracted/multi task during the start led to delayed identification of the problem.How I will prevent this from happening in the future:-when I turn off the APU (per CA command) with the expectation of a later cross bleed start; I will bring up the ECS page on my MFD display as a reminder.-I will also note 'cross bleed required' on a piece of paper and put it on the engine start/stop switch; as a reminder.-during any engine start I will not divert my attention away from the EICAS until the start sequence is complete.
Embraer ERJ-175 First Officer reported attempting to accomplish a crossbleed start with the operating engine at idle thrust.