Narrative:

After takeoff; we had a bleed 1-2 leak master warning. An emergency was declared and we returned to the field. All checklists were performed. Later found out that it was a bleed #2 leak; but where the sensors are located; we had an erroneous bleed #1 leak. Although there was no way to know that it was only a bleed #2 leak; we had to turn both bleeds off; depressurizing the airplane. Although we were at a low altitude; if we had been at a higher altitude; turning both bleeds off would have made it a more precarious situation. My feeling is that there should be a way to determine in the EMB145 where the leak is coming from. On mar/sat/05 at XA02; we pushed out of gate X in ZZZ. All checklists were accomplished before takeoff. At XA15 the first officer initiated the takeoff on runway 36R. After passing through 1000 ft; I silently performed the box items in the after takeoff checklist. Passing through 7000 ft; we both heard a loud boom like something had exploded. Approximately 10 seconds later; a master warning bleed 1-2 leak appeared on the EICAS; accompanied by a lighted baggage smoke fire extinguisher button on the overhead panel but no baggage smoke message on the EICAS. I decided to declare an emergency with approach and returned to ZZZ. The flight attendant called me to let me know she heard a loud noise and passenger were anxious. I told her that I would get back to her in a min and everything was under control. I also asked her if she was seeing any smoke or fire in the cabin. She told me the cabin was clear and free of smoke. The next step we took was to run the bleed 1-2 leak checklist in the manual. After closing the bleed 1-2; we got the message of bleed 1-2 closed. This action isolated the problem and the checklist was completed. Also; the baggage fire extinguisher was still illuminated but no indication of baggage smoke on the EICAS. I decided that although we had no message of baggage smoke on the EICAS; I was going to still run the baggage smoke checklist because of the indication on the overhead panel. Afterwards; I called the flight attendant and asked her about the situation in the back and if there was any visible smoke. She told me everything was clear but the passenger were asking questions. While speaking to the flight attendant; I told her what had happened and that no evacuate/evacuation was required. I also talked to the passenger and briefly explained to them what had happened and that everything was under control. As we got vectors to final on the ILS runway 36R; the first officer noticed he had no course guidance on his ILS 2. At this time; I noted my ILS was working and proceeded to xfer the controls and land safely. After landing; there was no visible indication of smoke and I proceeded to the gate where a normal deployment was made.

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Original NASA ASRS Text

Title: AN EMB145 IN CLB AT 7000 FT DECLARED AN EMER AND DIVERTED DUE TO MASTER WARNING 'BLEED 1-2 LEAK' ON THE EICAS. CLOSING #1 AND #2 BLEED VALVES ISOLATED PROB.

Narrative: AFTER TKOF; WE HAD A BLEED 1-2 LEAK MASTER WARNING. AN EMER WAS DECLARED AND WE RETURNED TO THE FIELD. ALL CHKLISTS WERE PERFORMED. LATER FOUND OUT THAT IT WAS A BLEED #2 LEAK; BUT WHERE THE SENSORS ARE LOCATED; WE HAD AN ERRONEOUS BLEED #1 LEAK. ALTHOUGH THERE WAS NO WAY TO KNOW THAT IT WAS ONLY A BLEED #2 LEAK; WE HAD TO TURN BOTH BLEEDS OFF; DEPRESSURIZING THE AIRPLANE. ALTHOUGH WE WERE AT A LOW ALT; IF WE HAD BEEN AT A HIGHER ALT; TURNING BOTH BLEEDS OFF WOULD HAVE MADE IT A MORE PRECARIOUS SIT. MY FEELING IS THAT THERE SHOULD BE A WAY TO DETERMINE IN THE EMB145 WHERE THE LEAK IS COMING FROM. ON MAR/SAT/05 AT XA02; WE PUSHED OUT OF GATE X IN ZZZ. ALL CHKLISTS WERE ACCOMPLISHED BEFORE TKOF. AT XA15 THE FO INITIATED THE TKOF ON RWY 36R. AFTER PASSING THROUGH 1000 FT; I SILENTLY PERFORMED THE BOX ITEMS IN THE AFTER TKOF CHKLIST. PASSING THROUGH 7000 FT; WE BOTH HEARD A LOUD BOOM LIKE SOMETHING HAD EXPLODED. APPROX 10 SECONDS LATER; A MASTER WARNING BLEED 1-2 LEAK APPEARED ON THE EICAS; ACCOMPANIED BY A LIGHTED BAGGAGE SMOKE FIRE EXTINGUISHER BUTTON ON THE OVERHEAD PANEL BUT NO BAGGAGE SMOKE MESSAGE ON THE EICAS. I DECIDED TO DECLARE AN EMER WITH APCH AND RETURNED TO ZZZ. THE FLT ATTENDANT CALLED ME TO LET ME KNOW SHE HEARD A LOUD NOISE AND PAX WERE ANXIOUS. I TOLD HER THAT I WOULD GET BACK TO HER IN A MIN AND EVERYTHING WAS UNDER CTL. I ALSO ASKED HER IF SHE WAS SEEING ANY SMOKE OR FIRE IN THE CABIN. SHE TOLD ME THE CABIN WAS CLR AND FREE OF SMOKE. THE NEXT STEP WE TOOK WAS TO RUN THE BLEED 1-2 LEAK CHKLIST IN THE MANUAL. AFTER CLOSING THE BLEED 1-2; WE GOT THE MESSAGE OF BLEED 1-2 CLOSED. THIS ACTION ISOLATED THE PROB AND THE CHKLIST WAS COMPLETED. ALSO; THE BAGGAGE FIRE EXTINGUISHER WAS STILL ILLUMINATED BUT NO INDICATION OF BAGGAGE SMOKE ON THE EICAS. I DECIDED THAT ALTHOUGH WE HAD NO MESSAGE OF BAGGAGE SMOKE ON THE EICAS; I WAS GOING TO STILL RUN THE BAGGAGE SMOKE CHKLIST BECAUSE OF THE INDICATION ON THE OVERHEAD PANEL. AFTERWARDS; I CALLED THE FLT ATTENDANT AND ASKED HER ABOUT THE SIT IN THE BACK AND IF THERE WAS ANY VISIBLE SMOKE. SHE TOLD ME EVERYTHING WAS CLR BUT THE PAX WERE ASKING QUESTIONS. WHILE SPEAKING TO THE FLT ATTENDANT; I TOLD HER WHAT HAD HAPPENED AND THAT NO EVAC WAS REQUIRED. I ALSO TALKED TO THE PAX AND BRIEFLY EXPLAINED TO THEM WHAT HAD HAPPENED AND THAT EVERYTHING WAS UNDER CTL. AS WE GOT VECTORS TO FINAL ON THE ILS RWY 36R; THE FO NOTICED HE HAD NO COURSE GUIDANCE ON HIS ILS 2. AT THIS TIME; I NOTED MY ILS WAS WORKING AND PROCEEDED TO XFER THE CTLS AND LAND SAFELY. AFTER LNDG; THERE WAS NO VISIBLE INDICATION OF SMOKE AND I PROCEEDED TO THE GATE WHERE A NORMAL DEPLOYMENT WAS MADE.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.