Date: 201809
Local time of day: 1201-1800
Location: LAX.Airport, CA
Flight conditions: VMC
Aircraft: B737 Next Generation Undifferentiated
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B LAX
ATC / advisory: TRACON SCT
Second aircraft: B737 Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Fatigue; Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Deviation / Discrepancy - Procedural Landing Without Clearance; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Procedure; Environment - Non Weather Related
Primary problem: Human Factors

Narrative: LAX Approach Control cleared us to maintain 180 kias to LIMMA; cleared visual 25L. Tower frequency was preset on VHF #1 in standby mode and forgot to obtain landing clearance from LAX Tower. Attributing to our error was: not being told to contact Tower by Approach; encountering some wake turbulence from preceding 737 on final while Captain was hand flying/adjusting to a slightly higher glide path to avoid; possibly some fatigue from our 10hr duty day/7.5hr flight time/day 4 of the trip after a 12hr layover; following an [early] arrival the day before.


Second narrative: We landed 25L without clearance from LAX Tower. Approximately 10-12 miles from airport; SoCal Approach cleared us to 'maintain 180 knots until Limma; cleared Visual Approach 25L.' I didn't hear or read back the switch to Tower and was planning to query Approach if not switched by Limma (FAF). During the Arrival (HLYWD1) and Approach; we hit 4-5 pockets of pretty strong wake turbulence starting about 100nm from the airport. We hit 1-2 more pockets of wake turbulence between 10-20nm from airport and we briefed that the Pilot Flying (PF) (Captain (CA)) would fly 1/4-1/2 dot high on the glideslope to stay above the wake turbulence until touchdown. It was pretty bumpy below 1000' and I believe we were both focused on the wake turbulence and flying slightly high on glideslope and forgot to query Approach on the switch to Tower. The runway was clear and it was an uneventful landing. We had made the callouts on final and at 1000' the CA (PF) stated cleared to land and I (First Officer (FO)/PM) didn't catch the mistake. When exiting the runway; Approach called us on the radio and asked us to switch Tower. We then noted that Approach was still the primary frequency and Tower was in standby. We were both monitoring Guard frequency and heard no calls. Tower gave us normal taxi instructions. We asked Tower if we needed to call him on the land line and he said no. Regardless of the manual frequency push from Approach we made the mistake here and should have done better. I believe we were both tired. We were on day 4 of a 4 day trip; we had 7.5 hours of block time that day; a 10 hour duty day; and we were landing at our home base which made us more comfortable. That day; we had worked hard dodging thunderstorms. No excuses and want to own the mistake and learn from it.


Synopsis: B737NG flight crew reported landing without clearance following a wake turbulence encounter. Fatigue was cited as a contributing factor.