B777 flight crew received a 'Bleed Loss Body' EICAS message on take-off roll. Flight crew performed a rejected takeoff and returned to the gate.

Narrative

At approximately 65 kts on takeoff we received a Bleed Loss Body" EICAS message. I elected to reject the takeoff. Reject was initiated at about 80 KIAS. Below 85 KIAS as the rejected takeoff (RTO) did NOT engage. Tower was advised of the reject. The First Officer (FO) made a PA to "remain seated". We exited the runway I checked the doors page and the gear page and accomplished the related checklists and elected to return to the gate. Upon inspection Maintenance discovered that a large ADP bleed line (~5" in diameter) had ruptured in the wheel well with a section approximately 14" long mostly gone. Further investigation revealed that the rupture had sent shrapnel all over within the wheel well and the aircraft was removed from service to survey any secondary damage that may have occurred from the shrapnel. Passengers seated in the area reported hearing the bang. We heard nothing in the cockpit. During our debriefing we reviewed the low speed abort criteria and noted that a bleed loss body was not on the list specifically; but more generally under "system failure." Given the Mechanics description of the shrapnel we were left wondering what secondary failures might have been caused by the shrapnel; if any; had we taken the flight airborne. We were not sure what wires and lines run through the area. We did check the air synoptic and noted that the system had performed the automatic isolation as would be expected; thus after the rupture; bleed air was likely not being injected into the area. Perhaps the risk of secondary damage has been assessed; but not being aware of that; at this point I think that perhaps it should be considered to add bleed loss body to the low speed abort item list. As an aside; For XX+ years of my piloting career I have been trained to call out "abort." Being aware of that; since we changed to "reject;" I have briefed that "in the heat of the moment; I am not sure if I will call out reject or abort." It was a valuable briefing; as I called out "Abort." It was hard to unlearn decades of training. I knew as soon as I said it that it was the wrong call out; but my FO know what my decision was and performed perfectly. Also; knowing that the Reject checklist primarily focuses on engine failure/fire; after clearing the runway I called for the bleed loss checklist that was displayed as I was concerned about having hot bleed air ducting into areas it should not and the potential for a fire or related damage. Though we accomplished all of the items on the reject checklist; we realized during our debrief that we had failed to actually run the reject checklist. All of our training for rejects is either to not reject; or for an engine failure/fire. This did not fit into those 2 training events; and yet there were other considerations; hot bleed air leak; secondary damage. As we focused on assessing the potential impact of hot bleed air we forgot to actually run the reject checklist. As this was a low speed reject; without RTO (not as violent as we train in the sim) and an anomaly I have never had; either in the sim or on the line; we were out of the normal sequence where we have been trained to run the reject checklist. When we debriefed this; we reviewed the reject checklist and had in fact accomplished everything on it. I would suggest that training incorporate something like this event for reject training.I had never considered the potential for an explosive bleed line rupture that could cause secondary damage. Though the Maintenance Team did not know the extent of any secondary damage resulting from the shrapnel the potential further reinforced the correctness of my decision to reject the takeoff."