Date: 201309
Location: SZP.Airport, CA
Flight conditions: VMC
Light: Daylight
Aircraft: Pitts S-2 All Series
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Descent
Airspace: Class E SZP
ATC / advisory: CTAF SZP
Second aircraft: PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Second reporter function: Single Pilot; Pilot Flying
Anomaly: Conflict NMAC
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Aircraft; Airport; Environment - Non Weather Related; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: I departed OXR with a right hand departure on a heading of 360 degrees climbing to approximately 2;500 FT. I remained on this heading approximately 4.5 NM. I was in communication with the OXR Tower. I received a frequency change approval from OXR Tower and changed frequency to SZP CTAF. I changed heading to approximately 075 degrees and remained of this heading for approximately 2 NM at 2;500 FT. I heard no incident relevant communication on this frequency. I then changed heading to approximately 098 degrees while beginning a descent to 1;800 FT intercepting the SATICOY reporting point approximately .5 NM north. About 20 seconds prior to reaching this position I gave a position report. The report consisted of the following information. 'Santa Paula Traffic; [aircraft colors] Pitts; One thousand eight hundred approaching Saticoy bridge; Santa Paula'. Upon reaching my intended intercept point I began a ~30 degree bank to align with the downwind entry for Santa Paula Runway 22. This is the recommended entry point for traffic arriving from the SATICOY reporting point. It should be noted that due to the limited visibility of the Pitts (biplane); as a standard procedure I make shallow S-Turns at frequent intervals to enhance visibility. Prior to and during this turn I did not see the Cherokee. Immediately after completing this turn I heard a garbled radio message for the Cherokee that I had passed him within 50 FT.  Subsequent to the near-miss the Cherokee pilot and I (who I had not met previously) spent a great deal of time discussing what had occurred. He never saw my aircraft; only heard it. During our discussion; an area of concern for me was the Cherokee's interpretation of posted arrival procedures. I [have flown out of ZSP many times] and have never heard of the procedure he described. We discussed this and I believe the posted arrival procedure posted at the fuel dock and the hangar door is in need of revision. The standard approach used by most all aircraft arriving from CMA reporting 'SATICOY' is to join the downwind at SATICOY and proceed to RWY 22 reporting at 'JUNKYARD' then 'GOLF COURSE.' A recently installed video camera in the Cherokee captured the events minutes before and during the encounter as seen from the Cherokee. I had a discussion of the encounter with my brother (pilot; based nearby) suggesting I always monitor CMA (airport which handed off Cherokee) and listen for departing aircraft; a procedure which he uses. If I had done so I might have heard the Cherokee frequency change alerting me to possible aircraft in the vicinity of Saticoy. I will use this procedure going forward.


Second narrative: Timeline regarding a near collision near CMA; this timeline constructed from a video clip of the subject incident. Events from Cherokee perspective:XA:00 Cherokee departed CMA earlier after a last touch & go on Runway 26; and is climbing out to the north towards Saticoy Bridge (a reporting point for SZP; CMA and OXR airports).Cherokee is enroute to SZP. Conditions present are that of a CAVU SoCal day.Cherokee plans to enter the traffic pattern at SZP by joining the left upwind leg over Santa Paula city at 1;500 FT. This approach to SZP is non-standard (and is not published in the AFD). However; this approach is advertised by and is recommended for use by aircraft approaching/departing SZP airport.XA:04 Throttle down Cherokee (camera stops image oscillation).XA:11 Camarillo Tower approves a frequency shift for the Cherokee approximately 1.5-2 miles south of Saticoy Bridge.XA:21 Cherokee shifts to frequency for SZP CTAF.XA:4-XB:22 Cherokee executing S-turns looking for traffic while continuing towards Saticoy.XB:31 Pitts makes a position report. Cherokee hears the aircraft description and the word 'Saticoy' clearly but the rest of the position report is not readable.XB:40 Cherokee starts to make a position report for Saticoy Bridge.XB:43 Cherokee's position report is interrupted as the Pitts crossed ahead (west to east) about 10-20 FT higher and within about 40-50 FT ahead of the Cherokee. Cherokee pilot exclaims the word 'Jesus' with the microphone keyed about a second after the near-miss.XB:51 The Pitts pilot reports the Cherokee transmission as unreadable.XB:55 Cherokee transmits; 'You just crossed over me at 50 FT.'Both aircraft continue to SZP on different approach paths for Runway 22 (Cherokee as noted above; and the Pitts more directly via another approach published by SZP airport).Contributing factors from the Cherokee's point of view:1) The relative position of both aircraft contributed to poor visibility of the Pitts by the Cherokee on an otherwise CAVU day. The Pitts was on a west to east course and closing the Cherokee. The Cherokee was on a south to north course and closing the Pitts. The angle of crossing was roughly 90 degrees. Looking to the west (from the Cherokee) into the late afternoon sun made spotting aircraft in that direction difficult.2) The angle of view of the Pitts from the Cherokee (primarily a nose on view) reduced the visual cross-section of the Pitts. This exacerbated the difficulty to see the Pitts at an azimuth close to that of the low angle to the horizon late afternoon sun.3) The relative closing speed of the two aircraft (relatively high) reduced the time to see and then avoid the other aircraft.4) The Cherokee received a relatively early frequency shift from CMA Tower while departing the CMA Class D. The frequency shift for the Cherokee occurred about 1.5-2 miles south of the Saticoy Bridge reporting point (while still in CMA's Class D airspace). The Cherokee was doing S-turns looking for traffic; but did not make an immediate position report upon receiving the frequency shift. This may have mitigated the situation but only if the Pitts was on the SZP CTAF at the same time as the Cherokee.5) The CMA Tower sometimes gives aircraft traffic reports regarding inbound and outbound aircraft in the vicinity of Saticoy Bridge out to the north boundary of the CMA Class D. However; for this departure the frequency shift was relatively early. The work load of the CMA Tower Controller was probably relatively high due to multiple aircraft in the pattern at CMA at the time of departure of the Cherokee.6) There are multiple approach paths into SZP. However; the number of possible approaches to SZP is reduced and traffic is concentrated into high density flow paths due to the surrounding terrain.7) SZP recommends several approach and departure procedures. There are the standard generic FAA recommended approach procedures to consider also (for aircraft not aware of local procedures). SZP is next to an approximately 1;000 FT AGL line of hills (or a ridge) to the south making standard approaches essentially impossible from that direction. To the east is an aerobatic box that affects traffic from the east. While the SZP recommended approach procedures help bring order to the flow of high density traffic approaching and departing SZP; they are not published in the AFD.8) Saticoy Bridge is a busy approach and departure reporting point for three airports in relatively close proximity. Point Magu NAS (a fourth Class D airport adjoining nearby OXR and CMA airports) is also a contributing factor to the concentration of local traffic flow patterns.Suggested factors for consideration:1) Aircraft transitioning between the three airports in the area (OXR; CMA; SZP) do not have time to request traffic advisories (radar advisory services) from Magu Approach. There simply is not enough distance and therefore not enough time to establish the use of these services. Therefore; the transition from and to various frequencies leaves little opportunity to establish good situational awareness. This is particularly true when departing one of the three GA airports that are in such close proximity to go to one of the other nearby airports.2) Both the terrain and adjoining Class D airspace (three airports with shared Class D boundaries) tends to reduce the possibilities for approaches/departures to/from certain directions for all four airports. This concentrates traffic in this busy area into high density traffic flow approach and departure paths. Frequency shifts are often required that result in gaps in situational awareness for transitioning aircraft.3) Saticoy Bridge may be overused; considering aircraft density peak traffic periods; as it receives approaching and departing traffic from three airports (two towered and one non-towered airport).4) Emphasis on traffic advisories being provided in the four airport area to some distance outside the Class D boundaries should be considered. And; even though SZP is non-towered it should be part of any potential overall advisory scheme.5) The control towers at both CMA and OXR have been targeted for closure at various times this year for what appears to be simple political manipulation (to cause pain to the flying public at the cost of safety). Closing any of these facilities would be a serious degradation to safety of flight in this area. The consequences will be no doubt written in blood if one or both of these towers cease operations.


Synopsis: The anatomy of an NMAC near SZP as reported by the two pilots involved.