Date: 201305
Local time of day: 0601-1200
Location: PDK.Airport, GA
Flight conditions: VMC
Light: Daylight
Aircraft: Small Transport; Low Wing; 2 Turbojet Eng
Operator: Corporate
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class D PDK
ATC / advisory: Tower PDK
Reporter organization: Corporate
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Situational Awareness
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight; Taxi
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Airport; Procedure; Human Factors; Airspace Structure
Primary problem: Ambiguous

Narrative: While in the terminal area approaching PDK; I called PDK in sight 5 miles to the west at 3;000 FT MSL. Atlanta Approach advised 'to slow to 160 KTS; cleared for the visual approach; contact Tower.' I began my descent and began to slow as I was cleared late and still high for the approach and switched to Tower. I had descended below approximately 2;700 FT when Tower advised that due to traffic on approach south of me (which meant I was closer to the airport) I needed to turn south for a downwind and that the Tower would call my base. I was given no specific heading so turned south to 180 degrees and ceased descending at approximately 2;500 FT MSL; as I was aware that the MSA in the area was 3;700 FT and I was being vectored in a visual pattern regardless of being an IFR aircraft. I was given no altitude clearance or advisory even though my previous clearance for a 'visual' instrument approach was effectively cancelled by the Tower vector. I noticed the large antenna array approximately 2 miles in front of me. The Tower was busy with small aircraft training; and took [some] time to get back to me. I cleared the antennas without evasive action however IFR vertical terrain clearance was questionable. The approach and landing was completed without incident to Runway 3L. During taxi; another potential loss of separation occurred once with PDK ground. An aircraft in the pattern was using a non-preferred crosswind runway (Runway 34; while landings on 3L and 3R where in progress). I was cleared to taxi on A; crossing Runway 34 to the FBO. I began my taxi and was told less than 20 FT from the intersection to 'Stop Immediately' and Hold Short of [Runway] 34 for landing traffic. The Ground Controller was a different voice than before and sounded agitated. I was able to stop before crossing the runway threshold; however higher then usual braking force was required; causing passenger questions. I was eventually cleared to the FBO and I requested a phone number. I called the PDK Tower and inquired as to the chain of events; possible loss of terrain clearance in the air; and traffic clearance on the ground. I was advised that they had a conflict with the other inbound traffic and that Atlanta Approach had miss sequenced my arrival speed and vector. The Tower Controller said that I was safely clear of the antennas and that they were watching me. I reminded them that I was an IFR aircraft; and that they had given me a radar vector towards terrain without any altitude restrictions or advisories in an area where I was previously assigned and below the MSA. They said they would make note of that. I was advised that on the ground I was taxing to fast (my taxi speed was approximately 10 KTS; uphill; and as I was able to bring the aircraft to a stop in less than 20 FT; I dismissed this excuse/explanation). They advised that they were monitoring the situation and if I had not been able to stop or did not respond to the radio (the ground frequency was also busy as they were reading IFR clearances on the same channel) the Tower could have had the aircraft on approach 'go around' and that separation was never an issue. When I asked why the 'plan B' was to have the aircraft go around; knowing the pilot of the aircraft was training; and possibly a student pilot; why was I cleared only seconds prior to taxi across the runway; they said that they had several controllers monitoring the situation. At this time I became aware that the initial Ground Controller was also in training. I feel that ATC workload was exceeded or at the ragged edge of the human factors margin during these events and that given another variable in the chain; an accident could have occurred. Thankfully the weather was good; and visual avoidance was adequate.




Synopsis: Small Transport pilot reports being cleared for the visual approach to PDK by Atlanta Approach then issued a heading by the Tower for traffic. The reporter stops descent at 2;500 FT and on a southerly heading passes over antennas depicted as 2;049 FT on the RNAV 3R approach chart. After landing during taxi; a late hold short clearance requires a sudden stop.