Date: 201212
Local time of day: 1201-1800
Location: ZMA.ARTCC, FL
Aircraft: Citation V/Ultra/Encore (C560)
Operator: Fractional
Operating under: Part 91
Flight plan: IFR
Flight phase: Cruise
Airspace: Class A ZMA
ATC / advisory: Center ZMA
Second aircraft: Challenger Jet Undifferentiated or Other Model
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Situational Awareness; Confusion
Second reporter function: Captain; Pilot Not Flying
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
Result: Air Traffic Control Issued New Clearance
Contributing factors: Weather; Procedure; Human Factors
Primary problem: Procedure

Narrative: While working a extremely busy sector; 2 airplanes converged. I was assigned D25 while the sector was yellow and was going to stay yellow or red for at least the next hour. There was a solid line of moderate to extreme precipitation from west of SRQ northeast. After working approximately 15 minutes we were assigned a tracker. The tracker and the R-Side worked the traffic as I constantly busy with coordination from other sectors and dealing with the URET issues. URET always has redundant blue routes or blue routes because of a qualifier problem. I did my best to take care of those as time allowed. We were supposed to have 15 miles in trail for aircraft going to Palm Beach. We received several airplanes near MOLLE Intersection who wanted to deviate or stay high for the weather. Aircraft were asking to stay high to stay above the weather and to then descend on the other side. We had a C560 and a CL60. They were both at FL350 deviating [or] wanting to stay high. As I was busy doing coordination; I missed most of what happened. What I saw was that the CL60 caught the C560 who was slower. When it was recognized that we had an overtake situation; we tried to descend the C560 but it was too late. The sector had way too many airplanes. We never got the 15 MIT we should have gotten from ZCJ. We were solid red for almost the entire time I was plugged in about 45 minutes. Not only was there volume to PBI but also volume to MIA and FLL. These other aircraft also were deviating and wanting to stay high for the weather. The weather was affecting all 3 arrival streams. Also add in westbound traffic from MIA/FLL and adjacent sector traffic wanting to deviate into our airspace. When 15 MIT is applied it should be applied to all aircraft on the arrival not just the ones going to a specific airport. The CL60 was a BCT lander but should be considered for in trail as he was flying the same arrival and the C560. Flow control needs to factor that in. Also; flow did a horrible job as the number for the sector is 17 and we had at least 30 aircraft the entire time. We need better procedures when things are bad and not just make up poor procedures when it goes to hell. Flow needs to do a better job of spacing things out. FLM's needed to make decisions and stand by them. No one wants to make the call to be the bad guy and we suffer at the sector. Unfortunately this time safety was compromised as a result of FLM and TMC in-actions!


Second narrative: I was the pilot not flying on our flight to PBI. On our descent into PBI; we were on the WLACE 2 arrival. The Miami Center frequency was very busy with many people stepping on others' transmissions. The Center Controller also sounded a bit stressed with all the traffic. While we were level at 35;000 the Controller in one transmission very quickly gave us a squawk code change and a right turn of 250 which was about 90 degrees turn. I read back the new squawk and the right turn to 250. I changed the squawk code and we made the turn. Several minutes later the Controller told me to squawk another code. I confirmed this and made the change. I don't know if I read it back wrong or if he initially gave it to me wrong. He was talking very fast and did not correct me when I initially read it back. Shortly after I put the correct squawk in the radio the Controller gave us a descent from 350 to 340 and asked us to expedite. We did our best to quickly begin the descent. Just as we began the descent the pilot flying and I then noticed a blue diamond TCAS target at our 3-4 o'clock position at our same altitude. As we were descending the target got within four miles and about 500 FT at our 4 o'clock position. When were about 34;400 FT the Controller asked us again to 'expedite' in a stressed and hurried voice and gave us a new altitude of 28;000. We complied with the instructions and experienced no further issues during the flight.


Synopsis: ZMA Controller experienced a loss of separation event during a very busy and complex traffic period citing Traffic Management shortfalls as contributory.