Incident Description
During the initial climbout phase, a flight attendant observed that the tailcone of the aircraft's number four engine was glowing. Upon reducing engine power, the glow ceased. The flight crew subsequently returned the aircraft to the departure airport without further incident.
Inspection Findings
Following the aircraft's return, the engine was inspected. The inspection revealed that the fuel manifold was cracked at the scallop radius.
Manufacturer Modification
The manufacturer later introduced a modification to the fuel manifold, increasing the wall thickness at the scallop radius to prevent future cracking. The modified manifold was not installed on the incident aircraft.