Cessna Single Piston Undifferentiated or Other Model
Flight Crew Sport / Recreational
Flight Crew Last 90 Days 18.8; Flight Crew Total 145; Flight Crew Type 125
Communication Breakdown; Other / Unknown
No Specific Anomaly Occurred All Types
General None Reported / Taken
Environment - Non Weather Related
I was planning a visual approach to the runway to descend to pattern altitude. I circled at an area 10 miles northwest of the field and then commenced a 10 mile 45 degree approach to left downwind of the runway. I noticed at the time that after descending to pattern altitude; the hills northwest of the field blocked my line of sight to the area corresponding to left crosswind and the first half of the downwind leg for the pattern of the runway. I announced my intentions on the CTAF at 10; 5; and 3 miles from the field. I heard radio transmissions from an aircraft approximately 5 miles behind me also approaching the field; but was unsure as to whether there were any other aircraft in the pattern at the time. As it turned out; there was another aircraft in the pattern that had just turned from crosswind to downwind at the time I entered the pattern. I had not heard or seen the aircraft already in the pattern; and transmissions from this aircraft suggested that the pilot had not heard any of my transmissions and was not aware of my presence until I joined the pattern. There was no risk of collision in this particular incident. I believe that the pilot already in the pattern slowed his aircraft and then extended his downwind to ensure separation was maintained. The hills to the northwest of the airport appear to interfere with the ability of aircraft on a 45 degree approach to left downwind for the runway and aircraft on left crosswind for the runway to see each other and hear each others' radio transmissions. I think that it would be much better for safety if this runway had a right-hand pattern to avoid interference to vision and radio propagation from the hills to the northwest of the airport.
This light aircraft pilot reported that because of terrain on the downwind side of the left hand traffic pattern it is difficult to acquire and maintain visual contact with other aircraft in the traffic pattern. It is additionally stated that the hills possibly block or hinder radio transmissions.