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Controller complaint concerning visibility restriction due to tree growth.
| Attributes | |
| ACN | 127805 |
| Time | |
| Date | 198911 |
| Day | Mon |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : tvl |
| State Reference | CA |
| Altitude | agl bound lower : 0 agl bound upper : 6500 |
| Aircraft 1 | |
| Controlling Facilities | tower : tvl |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Flight Phase | ground other : taxi |
| Route In Use | arrival other departure other |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : local |
| Qualification | controller : non radar |
| ASRS Report | 127805 |
| Events | |
| Anomaly | other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | none taken : unable |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Airport |
| Air Traffic Incident | other |
| Situations | |
| Airport | other physical facility |
Narrative:
Problem: limited visibility at tvl. A major visibility problem at tvl is at the north end when aircraft are landing runway 18. There is a tree line, west side of runway, which blocks the controller's view when aircraft are on right base or straight- in runway 18, altitude approximately at or below 6500' MSL. Since aircraft are very difficult to see, the controller relies on pilot position reports, which are sometimes incorrect. When the traffic scenario has arrs and departures, there are times the controller must hold a departure because the aircraft on final cannot be observed at a position at which they normally should be seen. At the south end of the airport, there is a visibility problem when aircraft are entering the left base leg or straight in runway 36, altitude approximately at or below 6500' MSL. Again, the restriction is a large tree line west of the runway extending to the southwest abeam the airport boundary. Over the last 11 yrs, this tree line has been trimmed only twice in certain areas. Another visibility problem is at the south portion of alpha taxiway--the parallel which extends north and south abeam runway 18/36. A small tree line is located on the west side of the taxiway starting abeam the landing displaced threshold and hides a small portion of the taxiway. On numerous occasions, there is veh traffic parked in the vicinity of the tree line where tower personnel cannot see them. When aircraft are taxiing out to runway 36, the controller must be extremely alert to where vehicles are located. Sometimes the veh operators' radio xmissions are unreadable from that area, or they can't hear the controller's transmission. Cautionary advisories are helpful, but there is risk of veh traffic entering the taxiway west/O the controller's knowledge, opp direction of traffic flow. In addition, aircraft such as twins and single-engine propellers cannot be seen when they taxi by the tree line, or when they hold abeam the tree line. Recently, the tower manager addressed the visibility problem to the airport manager. When the airport manager investigated financing for tree removal, he discovered funds were not available.
Original NASA ASRS Text
Title: CTLR COMPLAINT CONCERNING VISIBILITY RESTRICTION DUE TO TREE GROWTH.
Narrative: PROB: LIMITED VISIBILITY AT TVL. A MAJOR VISIBILITY PROB AT TVL IS AT THE N END WHEN ACFT ARE LNDG RWY 18. THERE IS A TREE LINE, W SIDE OF RWY, WHICH BLOCKS THE CTLR'S VIEW WHEN ACFT ARE ON RIGHT BASE OR STRAIGHT- IN RWY 18, ALT APPROX AT OR BELOW 6500' MSL. SINCE ACFT ARE VERY DIFFICULT TO SEE, THE CTLR RELIES ON PLT POS RPTS, WHICH ARE SOMETIMES INCORRECT. WHEN THE TFC SCENARIO HAS ARRS AND DEPS, THERE ARE TIMES THE CTLR MUST HOLD A DEP BECAUSE THE ACFT ON FINAL CANNOT BE OBSERVED AT A POS AT WHICH THEY NORMALLY SHOULD BE SEEN. AT THE S END OF THE ARPT, THERE IS A VISIBILITY PROB WHEN ACFT ARE ENTERING THE LEFT BASE LEG OR STRAIGHT IN RWY 36, ALT APPROX AT OR BELOW 6500' MSL. AGAIN, THE RESTRICTION IS A LARGE TREE LINE W OF THE RWY EXTENDING TO THE SW ABEAM THE ARPT BOUNDARY. OVER THE LAST 11 YRS, THIS TREE LINE HAS BEEN TRIMMED ONLY TWICE IN CERTAIN AREAS. ANOTHER VISIBILITY PROB IS AT THE S PORTION OF ALPHA TXWY--THE PARALLEL WHICH EXTENDS N AND S ABEAM RWY 18/36. A SMALL TREE LINE IS LOCATED ON THE W SIDE OF THE TXWY STARTING ABEAM THE LNDG DISPLACED THRESHOLD AND HIDES A SMALL PORTION OF THE TXWY. ON NUMEROUS OCCASIONS, THERE IS VEH TFC PARKED IN THE VICINITY OF THE TREE LINE WHERE TWR PERSONNEL CANNOT SEE THEM. WHEN ACFT ARE TAXIING OUT TO RWY 36, THE CTLR MUST BE EXTREMELY ALERT TO WHERE VEHICLES ARE LOCATED. SOMETIMES THE VEH OPERATORS' RADIO XMISSIONS ARE UNREADABLE FROM THAT AREA, OR THEY CAN'T HEAR THE CTLR'S XMISSION. CAUTIONARY ADVISORIES ARE HELPFUL, BUT THERE IS RISK OF VEH TFC ENTERING THE TXWY W/O THE CTLR'S KNOWLEDGE, OPP DIRECTION OF TFC FLOW. IN ADDITION, ACFT SUCH AS TWINS AND SINGLE-ENG PROPS CANNOT BE SEEN WHEN THEY TAXI BY THE TREE LINE, OR WHEN THEY HOLD ABEAM THE TREE LINE. RECENTLY, THE TWR MGR ADDRESSED THE VISIBILITY PROB TO THE ARPT MGR. WHEN THE ARPT MGR INVESTIGATED FINANCING FOR TREE REMOVAL, HE DISCOVERED FUNDS WERE NOT AVAILABLE.
Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.