B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 221; Flight Crew Total 7150; Flight Crew Type 4467
Situational Awareness
Aircraft Equipment Problem Less Severe
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport
Aircraft
On Flight XXX we [requested priority handling] airborne after a couple [of] stick shaker events and returned to land [at the departure airport] uneventfully. The flight started off with an AUTO SLAT FAIL light after push back when we moved the flaps to one during the after start checklist. We consulted with [Maintenance Control] and they deferred the item. The FTR on the flight placed a maintenance label on the item and completed the report. Once the maintenance item was completed we received a new [Maintenance Release] and took off without any further issues on the ground. During the VFR climb out the CA's (Captain) ADI (Attitude Display Indicator) displayed SPD LMT (Speed Limit) and he also lost vertical guidance intermittently. Later during climb out there was a momentary stick shaker. Controls were passed to me sometime during the climb due to the issues on the CA side of the aircraft. We consulted the QRH but none of the conditions firmly matched any specific checklist although we did consult Airspeed Unreliable QRC and QRH since that was the closest match. Also we consulted Display Source since it included Speed Limit Flag. We cross-referenced all three airspeed indicators; attitude displays; and altimeters. All our instruments matched and they made sense with where we were in the flight profile. The CA later SAT (Satellite Phone) conferenced in with Dispatch and [Maintenance Control] while I flew the aircraft. Shortly after ending the call we had our second stick shaker event on the CA side. At that point we decided to air return and [requested priority handling]. I continued to fly the aircraft while the CA coordinated with ATC; Dispatch; Ops; flight attendants and he also made a PA to the passengers. Later the CA requested the CA from [other] crew come up in order to provide additional support. The [other] CA was briefed on the situation and the game plan to return to [the departure airport]. He then read through the Airspeed Unreliable checklist as we descended. We experienced at least 5 more activation of the stick shaker on only the CA side during the remainder of the flight. We later landed uneventfully back [at the departure airport].
Upon push back and running the after start checklist; a 'recall' test was performed and an 'AUTOSLAT FAIL' light illuminated. The QRH was consulted and directed us to contact [Maintenance Control] for an ELB (Electronic Logbook) entry and new [Maintenance Release]. All were satisfactorily accomplished and a normal departure was made. During the climb out an amber 'speed limit' warning flag was annunciated on the Captain's ADI (Attitude Direction Indicator) as well as an intermittent loss of vertical guidance on the flight director on the Captain's ADI; control was subsequently transferred to the First Officer whose indications were normal. The intermittent amber SPD LMT (Speed Limit) warning and loss of vertical guidance on the Captain's ADI continued for the remainder of the flight. While we were attempting to determine if the amber SPD LMT annunciation was related to the deferred AUTOSLAT system; we received a momentary stick shaker on the Captain's control wheel. All indications suggested this stick shaker to be a false warning. The QRH was consulted; yet no procedure fit the conditions we were experiencing. Consultation with Dispatch and [Maintenance Control] yielded no resolution nor suggestion on a return or continuation. A second actuation of the stick shaker occurred at cruise flight and the decision was made to air return to [the departure airport]. During the recovery flight back; the stick shaker actuated approximately 5 additional times. During the recovery; one crew member of the second crew was called to the flight deck to assist with the emergency and to search for QRH checklists or other items we might have missed. The flight returned to [the departure airport] and landed uneventfully with ARFF (Airport Rescue and Firefighting) meeting the aircraft. Upon arrival; the [Chief Pilot] called the crew to assess the crew's human factor fitness level.
B737 flight crew reported multiple flight control and instrumentation anomalies inflight resulting in an air return.