Date: 201604
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: King Air C90 E90
Operator: FBO
Operating under: Part 91
Flight plan: None
Mission: Skydiving
Flight phase: Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Second aircraft: Commercial Fixed Wing
Reporter organization: FBO
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Situational Awareness
Anomaly: ATC Issue All Types; Conflict Airborne Conflict
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Separated Traffic; Flight Crew Took Evasive Action
Contributing factors: Procedure; Human Factors
Primary problem: Ambiguous

Narrative: Was flying a load of skydivers jumping over the drop zone. Was in positive radar contact (squawk assigned and ID'd) with Approach; who previously cleared us into and out of Class B airspace during our VFR climb to 13500 MSL as was normal for the skydiving operation. Approach also had advised to call them 1 minute prior to jumpers exiting; which is also a normal and accepted practice with the jump ops. Normally; after making the 1 minute call; Approach immediately broadcast an advisory call that jumping operations are in progress. Although no clearance is given or required for permission to deploy jumpers; standard procedure at the skydiving operation is to exit the jumpers from the airplane unless Approach explicitly advises to halt the jumping operations prior to or after the 1 minute call. Due to frequency saturation and subsequent late contact with Approach with respect to the required jump run ground track (at the end of the planned exit points;) I terminated the first pass without exiting jumpers. The second pass was also terminated due to delayed exit by the first jumper in the aircraft. I made the third pass and called 1 minute prior to jumping call as requested by ATC. The jumpers exited and I started a turn to the west along with a descent of approximately 2500 feet per minute and advised ATC of the descent and requested clearance back through the Class B airspace; the normal descent profile for the skydiving operation; unless otherwise advised by ATC. Approach immediately advised to 'Hold jumpers.' I advised the controller they were already gone and that I had made the requested 1 minute prior to jump call with no subsequent restriction from approach. At the same time as this call; I visually acquired an airliner headed northeast bound below my altitude; but on a course that would have caused a conflict had I had maintained the descent on the westerly heading. I started a turn towards the south and slowed the descent. At the same time; a different controller (supervisor?) advised to stop the descent and turn south. I advised him that I had (visually acquired) the airliner and was turning south to avoid. The rest of the descent to landing was uneventful.The skydiving operation and [local] approach have a long and rich history of working together that spans over 10 years; without any major threats to air safety in and around the Class B airspace. Yesterday's incident was an unfortunate anomaly in this record. I understand Approach is currently working on a Memorandum of Understanding (MOU) with the skydiving operation which will codify the procedures used daily over the past 10 years. This is a good thing and will provide a reference to standardize the operations to help eliminate the threat to safe operations brought on by necessary pilot and controller turnover. The MOU will also help to codify common situational expectations of both Approach controllers and the jump pilots so that threats to air safety can be eliminated immediately during the actual jump operations.




Synopsis: The pilot of a skydiving aircraft reported ATC gave late notice of a commercial aircraft transitioning the area.