Narrative:

At about 1;500 ft AGL on the initial climb; engine #1 gave a loud bang which was followed by a series of flapping noises; similar to tarpaulin slapping against the fuselage. We (the first officer and I) both looked at each other and said 'what was that?' the first officer told me that she had a lot of right rudder. I looked at the engine gauges and the np and ng for both engines was steady. Engine #1's itt and torque were rising. The red overtemp warning light for #1 illuminated. I saw the torque gauge for #1 read 112%. I said to the first officer memory items and set the power lever for E1 to about 20% and the temperature stayed extremely high. As a precautionary measure; due to the overtemp/torque situation and not knowing what was causing the secondary sounds; I said that we will shut the engine down. I went through the checklist with the first officer confirming what to do. Departure gave us a heading to turn to and an altitude to climb to. I asked the first officer to get vectors to come back and to declare an emergency. We leveled at 5;000 ft as we completed the nn--east checklist and the after takeoff checklist. I told the flight attendant that we had an emergency and that we would be returning to the airport. I also addressed the passengers and apprised them of our situation and the intention to return to the airport and land; taxi; and disembark as normal. I also tried contacting dispatch about 5 times and operations both inflight and afterwards on the ground to no avail. I ended up getting the departure controller to contact both operations and dispatch. A few notes: before constant torque on takeoff was dialed down and switched off; the engine #2's torque gauge indicated 112%; the first officer says that she noticed it slightly higher than this but I can't confirm or deny. On my postflight inspection; I found a 5-7 cm horizontal crack on one of the propeller blades of engine #1. I also noticed traces of oil or grease on all of the blades. I asked the first officer about the contaminated props and she said the blades were clean and that none of the contaminant was there. Apart from the crack and contamination; I didn't notice anything else out of the ordinary with the power plant or the nacelle. The engine shutdown was a precautionary move on my part because I didn't know what was causing the slapping sounds. With the illumination of the overtemp light; the noise and the first officer applying full right rudder I honestly thought that something had broken. The safest course of action in my opinion was to remove the unstable element and secure it. We shut the engine down and returned to the point of departure.

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Original NASA ASRS Text

Title: SF340 flight crew experienced; on departure; a loud 'flapping' noise accompanied by an overtemp warning on the number one engine. A precautionary engine shutdown was completed; emergency declared and a uneventful return to landing was accomplished.

Narrative: At about 1;500 FT AGL on the initial climb; engine #1 gave a loud bang which was followed by a series of flapping noises; similar to tarpaulin slapping against the fuselage. We (the First Officer and I) both looked at each other and said 'What was that?' The First Officer told me that she had a lot of right rudder. I looked at the engine gauges and the Np and Ng for both engines was steady. Engine #1's ITT and torque were rising. The red overtemp warning light for #1 illuminated. I saw the torque gauge for #1 read 112%. I said to the First Officer memory items and set the power lever for E1 to about 20% and the temperature stayed extremely high. As a precautionary measure; due to the overtemp/torque situation and not knowing what was causing the secondary sounds; I said that we will shut the engine down. I went through the checklist with the First Officer confirming what to do. Departure gave us a heading to turn to and an altitude to climb to. I asked the First Officer to get vectors to come back and to declare an emergency. We leveled at 5;000 FT as we completed the NN--E checklist and the After Takeoff checklist. I told the Flight Attendant that we had an emergency and that we would be returning to the airport. I also addressed the passengers and apprised them of our situation and the intention to return to the airport and land; taxi; and disembark as normal. I also tried contacting Dispatch about 5 times and Operations both inflight and afterwards on the ground to no avail. I ended up getting the Departure Controller to contact both operations and Dispatch. A few notes: Before Constant Torque on Takeoff was dialed down and switched off; the engine #2's torque gauge indicated 112%; the First Officer says that she noticed it slightly higher than this but I can't confirm or deny. On my postflight inspection; I found a 5-7 cm horizontal crack on one of the propeller blades of engine #1. I also noticed traces of oil or grease on all of the blades. I asked the First Officer about the contaminated props and she said the blades were clean and that none of the contaminant was there. Apart from the crack and contamination; I didn't notice anything else out of the ordinary with the power plant or the nacelle. The engine shutdown was a precautionary move on my part because I didn't know what was causing the slapping sounds. With the illumination of the overtemp light; the noise and the First Officer applying full right rudder I honestly thought that something had broken. The safest course of action in my opinion was to remove the unstable element and secure it. We shut the engine down and returned to the point of departure.

Data retrieved from NASA's ASRS site as of April 2012 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.