Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter CFTT / CFIT
Flight Crew Landed As Precaution; Flight Crew Became Reoriented; Flight Crew Returned To Departure Airport
Aircraft; Human Factors
aircraft was configured for take off on runway 5L. Take off clearance was received with a Climb to 6000 feet on a 050 heading; normal take off continued after rotation Speed hold was called for at that point both Flight Directors as well as the speed selected disappeared from both PFDs. Captain (Pilot monitoring) informed tower that we would want to remain with them and would be returning to the airfield. We were instructed to make right traffic at or below 2500 feet. upon entering the downwind at 2500 feet for 5L the flight directors returned; and autopilot was engaged; we then received the GPWS terrain advisory and climbed to 3000 feet advising tower were doing so. The flight then continued for a normal visual approach to runway 5L. threats: task saturation; night time; degraded automation; mountainous terrain undesired aircraft state: GPWS for terrain resulting in the immediate necessity of climbing. I have learned to keep my Situational awareness level higher now especially when operating at airports that include mountains etc. Looking back we should have queried about left or right traffic knowing that there were terrain considerations on the right downwind.
EMB-145LR First Officer reported getting a terrain advisory from GPWS in the pattern at TYS.