As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED, ON TAKEOFF AT GEAR RETRACTION HEARD 2-3 LOUD BANGS WITH 5 - 70 SEC PAUSE FOLLOWED WITH 2-3 MORE BANGS EGT MAXED ON ENGINE # 1 COMPRESSOR STALL WITH TOGA POWER. ONCE REDUCED POWER TO IDLE NO FURTHER STALLING. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO CLT WHERE IT LANDED SAFELY WITHOUT FURTHER INCIDENT. REPLACED ENGINE PER TASK CARD 26L40071001.