Date: 201503
Local time of day: 0001-0600
Location: LAX.Airport, CA
Flight conditions: VMC
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B LAX
ATC / advisory: Tower LAX
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Flying
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Airport; Procedure
Primary problem: Procedure

Narrative: Instructed by approach to maintain 170 knots to FOGLA and contact tower. Called tower at FOLGA and received clearance to land and advised one aircraft in position. First Officer (FO) flying aircraft. Normal approach and stabilized and on speed at 1000 feet. At approximately 500 feet we observed one aircraft on takeoff roll and another aircraft lining up in position. The aircraft lining up was cleared to takeoff just as aircraft on the roll was lifting off. At this time we realized that it was going to be very close between our landing and aircraft taking off. We considered a go around but decided that with one aircraft lifting off and one aircraft rolling our safest action would be to land. Had we executed a go around we thought we would have a direct conflict with the aircraft on the roll. We ended up landing just as the proceeding aircraft lifted off. In my opinion; this is an unsafe practice. We are concerned that our option to maneuver safely was limited by the reduced interval.Because of the closure of 25L at LAX we are landing and departing 25R. It is imperative that safe separation is maintained.


Second narrative: On visual approach to RW 25R; we were cleared to land as we were well past the FAF (FOGLA waypoint). ATC advised that there would be one departure prior to our arrival. This is a normal procedure at LAX; especially now that 25L is closed for construction. However; this time; the departing aircraft was slow to take the runway and then ATC was slow to clear them for takeoff. The departing aircraft was slow to initiate takeoff roll and we ended up landing extremely close to their departure from the runway - although they were airborne before we touched down. The problem was that by the time tower cleared them to take off and the time they actually did take off; the Captain (CA) and I felt we had insufficient room to execute a go around. We would have been in conflict with the departing aircraft and would have had to take evasive action while in a go around configuration. In other words: We felt that ATC left us with no good options. Neither the CA nor I liked the event or our proximity to the departing aircraft. Upon clearing the runway; CA called LAX ground and asked them to advise LAX Tower that we were not comfortable with the separation on our landing. He advised us he'd relay our message. Nothing further was said by either party. No action was taken by ATC or requested of us by ATC after the flight concluded.  ATC needs to give arriving aircraft more spacing. I realize they're doing their best to keep up a decent traffic flow during r/w construction; but we felt unsafe with our situation; since we felt we didn't have a legitimate go around option. Perhaps ATC should have had the departing aircraft clear the runway once they realized how close we were. Or held them short until we landed. Again - we felt we had no good options on go around once we realized how slow the aircraft in front of us was departing.


Synopsis: A B737-800 flight crew reported they were uncomfortable with ATC spacing on approach to LAX and felt they had no viable go-around option.