MD-11
Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft; Human Factors; Manuals
On departure we received a level one alert (Ice Det Single) followed quickly by another level one alert (Air System 1 off). The First Officer flew the jet while I worked radios and checklists. After reading the level one info; I didn't feel we had a manifold failure - just an anti ice issue and attempted to repressurize the system by introducing air from system 2. I then received a level 3 (manifold fail) warning. We complied with the appropriate emergency checklists and returned to [our departure airport]. The warning only lasted a few seconds as I cut off the air when the warning came on. Maintenance believes the manifold came apart during takeoff. The First Officer believes he heard a noise on takeoff roll. The level one warnings were inhibited until 400 FT. My action of trying to get the number 1 system back didn't cause the manifold failure; it only brought it to our attention.I think the reading of the level one alert could be more directive. It states not to repressurize the system if the manifold has failed. I didn't believe we had a manifold fail. It should simply state 'don't repressurize'.
Following an analysis of ice control and pneumatic manifold anomalies the flight crew of an MD-11 returned to their departure airport for maintenance.