Date: 201707
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Light: Daylight
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Throttle/Power Lever
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Within minutes after Top of Climb; the First Officer (as the Pilot Flying) stated 'I think we have a problem. The number 1 throttle will not retard'. We began a process of carefully determining the situation. The number 1 throttle would not physically retard past the equivalent N1 of 91 percent. We determined that this was throttle linkage binding and did not attempt to force the throttle to any position. We used the next 10 minutes to discuss our situation; our options and our course of action. I notified ATC that we had an engine problem; that we would be shutting engine 1 down just prior to descent; the reason for the shutdown; fuel and souls on board and that we would want emergency vehicles to be present on landing and that all other indications on board were normal. I attempted to contact Dispatch via ACARS but 'NO COMM' was the situation. I called Operations for a COMM patch to Dispatch. The connection was not made so I had Ops pass on our situation and that [there was an emergency situation]. I talked to the Flight Attendants during cruise and had them clean up the cabin and be seated and also explained our situation and reassured them they were safe and that their perception of flight should be normal other than a higher speed on touchdown. I let the Flight Attendants know that I would talk to the Passengers. After talking with the Flight Attendants (one forward and one aft); I selected PA and gave an announcement to the Passengers of the situation and the course of action. I wanted the PAX to know that the perception from their position on the aircraft should be normal. I let them know that we have practiced this single engine procedure hundreds of times in the simulator over the years and we are well prepared. My First Officer and I then reviewed the QRH for the engine shutdown; completed performance calculations and brainstormed a bit to make sure we were completing all necessary tasks and thought processes. Just prior to Top of Descent; aircraft control was transferred to me (the Captain) and we then performed the engine shutdown for the number 1. Air Traffic Control gave us a clearance direct to [the airport] and we descended. We were vectored onto final approach. The Landing touchdown should have been normal for the Passengers with a fairly light roll on. Because the #1 engine thrust lever was advanced quite a bit the speed brakes did not auto deploy upon touchdown and had to be manually deployed. In addition the takeoff configuration warning horn initiated and remained on for the duration of taxi and shutdown and while power was being supplied to the aircraft. After blocking-in at the gate; I was concerned for the Flight Attendants and the Passengers; however; my concerns were eased with smiles and 'thank you's' from the FAs. I was concerned that the Passengers seemed very normal and none seemed to be connected to the experience which just happened. A few minutes later I learned that my original PA during cruise flight did not come over the speaker system. I am very sad that this happened; and hope that we can determine contact information for each. I desire to add a letter of explanation and thank you along with a letter from the Company. Two Firefighters entered the aircraft and advised me that all seemed normal with no fire and no smoke; however; one Firefighter stated that the main gear was 'red hot'. I immediately ordered all Personnel to depart from the aircraft. I left the aircraft and ensured on the ground that personnel departure was complete. I was met by Airport Operations personnel who wanted to know if the Firefighters were released and I expressed that the Firefighters and our Mechanics must determine when the gear is safe before they depart. I observed the gear and did not see evidence of 'red hot' metal or smoke or visible heat signs. I returned to the flight deck to complete calls to the Chief Pilot on Duty as well as Dispatch. The logbook was completed and we departed the aircraft.I have followed this maintenance process through the event day. The problem was isolated to the throttle quadrant. The foreign object has not been determined as of this writing and or to my knowledge.




Synopsis: B737 Captain reported after level-off at cruise altitude that the number 1 engine power lever would not physically retard past 91 percent N1. The crew shut down the engine at the beginning of descent and executed an uneventful single-engine landing.