B737 flight crew reported landing gear malfunction and a safe return to departure airport.
Synopsis
B737 flight crew reported landing gear malfunction and a safe return to departure airport.
Narrative
First flight of the day for the crew and the aircraft. Preflight duties were conducted normally; release was broken for a 'flap bypass valve activation report' and the mechanics cleared the message and we received the release before pushing back about 15 mins late at XA:15. Started both engines after pushback and taxied out to runway XXR for departure. CA was PF and FO was PM. After rotation and CA called 'positive rate; gear up' the FO moved the gear handle up however the handle stopped at the OFF position and would no got up. After a few attempts at trying to move the handle to the Up position without success the FO used the override trigger to lift the handle to the UP position which was success. The FO watched as the landing gear lights went from green to red and then extinguished ensuring that the gear was up and locked. At acceleration altitude the CA asked for Flaps 1; the FO moved the flaps from 5 to 1; CA then asked for flaps up and the after takeoff checklist. The FO moved the flaps from 1 to up and as soon as the handle moved to UP the TAKEOFF CONFIG red light illuminated and the TAKEOFF CONFIG horn aural warning started. The CA turned on the autopilot shortly after. The after takeoff checklist was completed by the FO which included moving the gear handle to the OFF position. The CA initiated a change of controls from CA to FO and then the CA began running the Takeoff Configuration checklist in the QRH; which was no benefit in the air. The aircraft was climbing to 7;000ft and the FO asked ZZZ Center to level off at 7;000ft to troubleshoot a problem. Once the aircraft levelled off at 7;000ft with a speed of 240kts the CA and FO agreed to cycle the landing gear to see if that would resolve the warning. The landing gear was lowered; with 3 green lights and then was raised again but same problem where it wouldn't go past of the OFF position; and after the override trigger was used if was able to go to the UP position and the lights extinguished however the aural warning continued. The CA then started the '(NG) Landing Gear Lever Will Not Move Up After Takeoff' QRH checklist. When stop 8 was performed which was the pull the circuit breaker for the LANDING GEAR TAKEOFF WARNING CUTOFF; this stopped the aural horn. After the completion of the checklist the CA requested priority handling with ZZZ Center and stated that we would be returning to ZZZ. The CA then informed the purser followed by the passengers; then informed dispatch and Maintenance Control . It was determined that an overweight landing would be a possibility as we were 10;000 lbs over landing weight. CA asked dispatch if they could ask Maintenance Control if that was acceptable. The FO was being given vectors from ATC to set up for an approach onto runway XX at ZZZ; whilst the CA was setting up the FMC for the ILS runway XX and running landing speed numbers. The CA thoroughly briefed the approach with the configuration differences per the QRH. As a crew the CA and FO determined that it was safe to land overweight and informed they were ready to commence the approach. The CA took over as PF for the approach and landing and the FO ran the deferred item descent checklist. The aircraft was fully configured for landing approx. 10 miles out from touchdown and landing checklist was completed from the QRH procedure. After landing as a crew we felt the aircraft was safe to taxi off the runway and once clear we were inspected by the airport fire team and they reported everything looked good on their end so we felt comfortable to taxi to the gate. After parking; shutting down the engines and running the parking checklist we debriefed the event; the CA then spoke to the passengers; the CSA (Customer Service Agent) and maintenance and it was decided that we would deplane the passengers. The CA then debriefed the flight attendants and all agreed they were fit to fly when the replacement aircraft was found.
Second reporter narrative
On departure from runway XXR at ZZZ; the gear handle would not retract when called for by the pilot flying (PF). The crew used the landing gear override trigger to bring the gear handle to the UP position. The gear then retracted normally and indicated up. Passing through the acceleration altitude of 800 feet above field elevation; the PF called for flap retraction on schedule. Once the flaps were fully retracted and the aircraft indicated clean; the TAKEOFF CONFIG light illuminated and the configuration warning horn began to sound and could not be silenced. Autopilot A was engaged to reduce task saturation and boost awareness. The aircrew continued to fly the departure; but limited the speed to 240 knots indicated. In accordance with FOM chapter 2; the CA designated the FO as PF and in charge of the ATC communication.The CA searched TAKEOFF CONFIG in the aircraft flight manual and the checklist indexed for this annunciation was FM 2.XXX.X; Takeoff Configuration (Pilot Awareness) and the checklist was initially executed. The crew acknowledged that this checklist was in the context of being on the ground; but no other guidance was immediately indicated by a cursory search. The Takeoff Configuration (Pilot Awareness) checklist directed the crew to confirm configuration. Aircraft configuration was confirmed to be clean by both the gear handle lights and gear indicator lights on the aft overhead panel; as well as the flap gage indicating zero and the PFD speed tape moving the upper speed limit band to VMO/MMO. This led the aircrew to suspect the light and warning horn were an effect of a sensor fault during gear retraction. The crew cycled the gear in an attempt to see if it would remedy the light; but the TAKEOFF CONFIG annunciation and configuration warning horn were not cancelled by doing so.Passing approximately 16;000 ft MSL; vectors were requested to troubleshoot the issue. Above 10;000 feet MSL the aircraft was briefly accelerated past 250 knots at the request of ZZZ Departure; but only after confirming the state of the aircraft to be clean. The assumption at the time was that the condition would be remedied and the aircraft would continue to its destination. After an open text search; the CA located FM 2.XXX.XY; Landing Gear Lever Will Not Move Up After Takeoff checklist. This checklist was executed and directed a landing at the nearest suitable airport. The crew requested priority handling with ZZZ departure and was given a descent and vectors back to the field. The CA resumed PF duties when the checklist was complete except for deferred items. Out of concern for passenger safety and comfort it was determined that an overweight landing was appropriate; and flaps 30 were selected in accordance with FM 7.XX.Z. The approach to runway XX was performed using the deferred landing items as indicated by FM 2.XXX.XY. On touchdown the PF manually deployed the speed brakes and manually applied the aircraft brakes in accordance with the checklist. The rollout was uneventful and the aircraft vacated at taxiway 1; where emergency vehicles were waiting. After inspection by the fire department; the aircraft was taxied to the gate uneventfully. Maintenance logbook entries were made for the overweight landing; possible brake wear; and the execution of FM 2.XXX.XY; Landing Gear Lever Will Not Move Up After Takeoff checklist.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.