040405 Jt PH Cond Use, Develpo Agmt, Zoning, etc.-Geneva Commons Proj 200 E. First American Way

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The "Y" obstacle surface begins at the height of the "X" surface and rises at a slope of 1:7 perpendicular to the final approach course. Diagram A shows the protected area overlying an aerial image of John Wayne Airport. So as not to impact the ILS approach, buildings and /or other objects would be restricted to the following height at a position abeam the Geneva Commons Site at the nearest point on the extremity of the "Y" surface to an elevation of 454.9' AMSL2. This is well above the proposed building height and and is located 1300' away from the edge of the ILS area. This discussion is only relevant to the ILS procedure which offers the lowest landing minimums at SNA. Other instrument procedures at SNA have different required obstacle clearances such as the localizer only, RNAV and LDA. These were discussed in the original report. III. LOCALIZER BACK COURSE RUNWAY OIL The back course localizer approach to R01 L offers the lowest instrument approach minimums to Runway 01 L at SNA. The missed approach procedure is "Climb to 800, then climbing left turn to 2300 via SLI R -120 to SLI VORTAC. The missed approach point for the SNA Runway OIL BC localizer procedure is located 0.7 nm to the south of R01 L. The distance from the missed approach point to the building is 3.44 statute miles (18,163'). The missed approach altitude for the procedure is 480' AMSL. FAA designs procedures for the missed that take into account the worst possible aircraft performers. However, a minimum climb rate of 200' in the missed approach is required. This figure is not realistic with modern aircraft that can safely exceed 1,000 feet per nautical mile in the missed approach procedure. However, even at a minimum climb rate of 2007NM the aircraft will begin a left turn at 800' MSL to the northwest and at this altitude is already well above the proposed building sites, and the commencement of the turn will occur approximately 1.82 statute miles prior to the proposed buildings. At a 10007NM climb rate the left turn to the northwest would commence at least 2.77 statute miles prior to the proposed building sites. IV. Conclusion The proposed Geneva Commons building site at the FAA approved elevation of 287' AMSL will not affect any of the instrument procedures at John Wayne Airport. 2 The height (Dy) = Height of Rise of Rise of "W" Sfc "X" Sfc "Y" Sfc Dy= D_t2001 Dx —Dw Do —Dx =454.9 S 4 7 Where D =the distance in feet from the LTP; Dx = the perpendicular distance in feet between course centerline and "x" surface outer boundary, Do = perpendicular distance in feet between course centerline and an obstruction in the °Y" surface.