Date: 201510
Local time of day: 1801-2400
Location: SAN.Airport, CA
Flight conditions: VMC
Light: Night
Aircraft: Small Aircraft; High Wing; 1 Eng; Fixed Gear
Operator: Air Taxi
Flight plan: IFR
Flight phase: Final Approach
Airspace: Class B SAN
ATC / advisory: TRACON SCT; Tower SAN
Second aircraft: Medium Large Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Situational Awareness; Communication Breakdown
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
Result: Air Traffic Control Provided Assistance
Contributing factors: Procedure; Airport
Primary problem: Procedure

Narrative: Aircraft X was number 1 to the runway on Visual approach. Aircraft Y was number 2. I cleared Aircraft X; for a Visual Approach at about a 10 NM final; Aircraft Y was still 22 miles from the runway and following Aircraft X; but not on a visual approach. I slowed Aircraft Y to 190 Knots while he was still around 10 miles in trail of Aircraft X; in order to prevent a compression situation. I transferred Aircraft X to SAN tower at about a 6 NM final. I almost immediately noticed that Aircraft X has slowed to about slowest possible speed and was indicating 120 knots. I then slowed Aircraft Y to '160 knots or less'. At this time I looked to view the SWIM resource tool; this display allows me to see what the SAN Tower has on the runway/ movement area. My instinct was correct in that the Tower had decided to put an aircraft on the runway in front of Aircraft X; and thereby requiring Aircraft X; to go as slow as possible to prevent himself from going around. This in turn led to the aircraft behind Aircraft X; Aircraft Y; to compress rapidly. I issued traffic to Aircraft Y in hopes that I would be able to clear him for a Visual Approach to follow Aircraft X; he was unable to see the small aircraft down low in the buildings. Again I issued traffic to Aircraft Y and advised that due to compression I would only be able to allow him to continue the approach if he was able to visually obtain preceding traffic. The pilot read back roger were going to the tower. Separation decreased to about 2.76 miles. Aircraft Y landed without incident. At no time did the tower call to tell me that they could provide visual separation. At no time did the tower advise me that they were going to be slowing the first aircraft on my final to slowest speed 5 NM from the runway. Although I had time to break Aircraft Y off of the approach I allowed him to proceed for a number of reasons. First; it was safe to do so. Secondly; SAN tower has now made this move a common occurrence; it is ridiculous; and there is no reason for me as a controller to have to punish the pilot and passengers on-board Aircraft Y for the poor decision making ability of the SAN tower.1. If the tower is going to require a hole for a departure they should use the land-line to advise as such.2. If the tower is going to slow the first aircraft in a sequence to make a non-existent hole for a departure; they should advise approach to plan for compression.3. If the tower is going to cause a situation that will result in less than the standard IFR separation of 3 NM; they should have the professional courtesy to advise approach control that another form of separation is/will be used. ie; tower approved visual separation.4. Tower controllers should not be slowing aircraft inside the final approach fix as this is not approved. Usage of the phrase 'there will be traffic departing before you' or' traffic taking the runway now for departure is a B737' Is all but telling the pilot 'you better go as slow as you can because if you don't you're going around'. It amounts to a speed assignment inside the final approach fix.5. The tower should look at the RADAR display and pick and use good judgement as to when a 'squeeze play' is necessary. In this situation there were ZERO aircraft in trail of Aircraft perhaps a good indication that a 'squeeze play' was unnecessary. If the departure has a TMU release window they should again advise approach that they require a hole for a departure.




Synopsis: An Approach Controller had a jet following a slower single engine prop airplane on final approach to the same runway. The controller felt there was sufficient space between arrivals to account for the jets' faster speed. After shipping the first slower aircraft to the Tower he observed the speed of that aircraft reduce drastically; more than normal for that type of aircraft. The controller issued the preceding traffic to the jet in an attempt to achieve Visual Separation. The jet acknowledged the traffic call without stating they saw it and switched frequency to the Tower on their own. The Approach Controller saw the spacing reduce to less than minimum required while both aircraft were on the tower frequency. Both aircraft landed.