A SF340 lost power during approach descent because the ctot (constant torque on takeoff) switch was ...

Attributes
ACN	817982
Time
Date	200812
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 8000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	common carrier : air carrier
Make Model Name	SF 340B
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
ASRS Report	817982
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	817983
Events
Anomaly	non adherence : published procedure non adherence : company policies other anomaly
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : became reoriented flight crew : regained aircraft control flight crew : declared emergency
Factors
Maintenance	performance deficiency : fault isolation
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

On our way into ZZZ I was descending from 11000 ft to 8000 ft with approach. The captain began the descent checklist. Once leveling off at 8000 ft; I added power to both engines and the right engine yawed along with the white ignition light. I pulled the power back and waited for the ignition light to go out. We could not get the power levers above 40% without the aircraft yawing. We continued to try and figure out why we could not add power above 40% torque to the right engine. Approach gave us another descent to 5000 ft and we requested to stay at 8000 ft for the moment until we could figure out the problem. We were then sent to ZZZ approach; where we informed them we were having engine problems. Then we were unable to add power to the left engine above 50%. We were 28 miles from the airport; 8000 ft; 170 KIAS; and unable to add power to either engine. At that point the captain declared the emergency and gave approach the fuel and souls on board. He also asked about a closer airport in case we lost both engines and had to glide in. I continued to fly as he continued to figure out what was wrong. We were cleared for the visual runway xxl and pilot's discretion to 3000 ft. We requested to stay at 8000 ft until we had the runway in sight. At that point the captain realized it was the constant torque on takeoff switch. When he set the power to 100%; he also inadvertently turned the switch to 'on.' he turned the switch off and slowly added power. We told approach we figured out what the problem was and that both engines were working fine. They switched us to tower. Upon checking in; we told them we were ok and had resolved the problem. They said they were going to keep crash fire rescue out as a precaution. We landed safely and taxied in to the gate. On the taxi; tower asked what the problem was and how it was fixed for their paperwork. We told them it was a missed item in the checklist along with a switch in the wrong position. After parking at the gate the crash fire rescue personnel came on board to make sure everything was ok and get the captain's personal information. When I added power after leveling off; the airplane would yaw. Initially just the right engine; then both.

Original NASA ASRS Text

Title: A SF340 lost power during approach descent because the CTOT (Constant Torque on Takeoff) switch was left in the on position after takeoff. An emergency was undeclared after the crew discovered the reason for the power loss.

Narrative: On our way into ZZZ I was descending from 11000 FT to 8000 FT with Approach. The Captain began the descent checklist. Once leveling off at 8000 FT; I added power to both engines and the right engine yawed along with the white ignition light. I pulled the power back and waited for the ignition light to go out. We could not get the power levers above 40% without the aircraft yawing. We continued to try and figure out why we could not add power above 40% torque to the right engine. Approach gave us another descent to 5000 FT and we requested to stay at 8000 FT for the moment until we could figure out the problem. We were then sent to ZZZ approach; where we informed them we were having engine problems. Then we were unable to add power to the left engine above 50%. We were 28 miles from the airport; 8000 FT; 170 KIAS; and unable to add power to either engine. At that point the Captain declared the emergency and gave Approach the fuel and souls on board. He also asked about a closer airport in case we lost both engines and had to glide in. I continued to fly as he continued to figure out what was wrong. We were cleared for the visual Runway XXL and Pilot's Discretion to 3000 FT. We requested to stay at 8000 FT until we had the runway in sight. At that point the Captain realized it was the Constant Torque on Takeoff switch. When he set the power to 100%; he also inadvertently turned the switch to 'on.' He turned the switch off and slowly added power. We told approach we figured out what the problem was and that both engines were working fine. They switched us to Tower. Upon checking in; we told them we were OK and had resolved the problem. They said they were going to keep Crash Fire Rescue out as a precaution. We landed safely and taxied in to the gate. On the taxi; Tower asked what the problem was and how it was fixed for their paperwork. We told them it was a missed item in the checklist along with a switch in the wrong position. After parking at the gate the Crash Fire Rescue personnel came on board to make sure everything was OK and get the Captain's personal information. When I added power after leveling off; the airplane would yaw. Initially just the right engine; then both.

Data retrieved from NASA's ASRS site as of May 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.

A SF340 lost power during approach descent because the ctot (constant torque on takeoff) switch was left in the on position after takeoff. An emergency was undeclared after the crew discovered the reason for the power loss.