Date: 202012
Local time of day: 1801-2400
Location: LAX.Airport, CA
Flight conditions: VMC
Aircraft: B737-900
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B LAX
ATC / advisory: Tower LAX
Second aircraft: B777 Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure; Environment - Non Weather Related
Primary problem: Ambiguous

Narrative: We were cleared for a visual approach following a Boeing 777 to Runway 25L at LAX. On short final we encountered what was most likely wake turbulence from the proceeding aircraft on short final ~300 feet AGL. This presented as a roll and shear to a headwind. This apparent shear to a headwind along with an addition of some thrust put me high on the profile and ~15 knots above target speed. The severity of the event was below what I would describe as an 'upset'. When the turbulence subsided we appeared to be in a good position to land; so I continued the approach and landed. Being high on profile and bleeding off the excess speed in the flare resulted in a touchdown that was most likely beyond the touchdown zone. Despite this we were in position; with normal braking; to exit at taxiway H8. Tower instructed us to exit at H9.


Second narrative: Upon landing on Runway 25L at LAX we landed outside of the normal 3000 feet of the touchdown zone after being preceded by a 777 to landing during light tail wind conditions. The briefing and approach were completely routine. We had originally planned to land on 24R but we were prepared for a possible change to Runway 25L. We were told on downwind that we would be following a heavy 777 and could expect 25L. Conditions were clear and we had the aircraft in sight. As I reconfigured the aircraft for landing on the south runway; the Captain made the comment that he would be prepared to fly a dot high. The Captain flew as he briefed and we experienced mostly calm winds all the way down the glideslope. By 200 feet AGL; we were back on glide slope.  The aircraft sank somewhat and by 100 feet we were almost a half dot low when we started to feel some of the wake of the 777.  The winds were still light; about 300/7.  The plane was very controllable and the Captain pitched up and added power slightly to stay on top of the wake. In doing so; the speed increased almost 15 knots and I considered calling for a go around.  It still appeared that we were going to be touching down in the first 3000 feet so I allowed the approach to continue.  The Captain flared the aircraft so that it looked like we would touch down right at about 3000 feet.  Without trying to hold the aircraft off; the plane continued down the runway at what seemed like 1 foot. The aircraft finally settled a couple hundred feet later and we turned off the runway and proceeded to the gate without any further issues.This was a case where one limit almost being crossed led to another limit being crossed. It looked like it was all going to work out.  We have all encountered 'disturbed' air from a wake before on landing especially at busy airports like LAX.  The question is how much of an adjustment do you have to make and at what point do you go around.  This looked very doable.  We had plenty of runway and performance.  This looked familiar with a landing in the touchdown zone.  I only thought later and realized that the Captain had elected to do a flaps 40 landing in a 737-900ER.  I know I have not done many flaps 40 landings in a 900ER in the last couple years; so I think my sight picture was off a bit for the flare and the touchdown.  We may have also gotten a bit more of ground effect than what I would have imagined.  The speed did not bleed off as fast as I had anticipated.


Synopsis: B737 flight crew reported encountering wake turbulence from preceding B777 on approach to LAX that resulted in a long landing.