ARW
120-Day Re-Assessment Plan
Site Visits
2.3.10 Paso Robles Municipal Airport, Paso Robles, CA
Background
A team visited the Paso Robles Municipal Airport (PRB) located in Paso Robles, CA, on May 21, 1997. PRB is a non-towered, Service Level D airport and weather observations are provided by an FAA contract. The Flight Service Station was closed on September, 1987. The ASOS at Paso Robles has been installed for over a year in a non-commissioned, test mode, and as of this date, has no projected commissioning date. The contract for weather observations will be canceled concurrent with the ASOS commissioning. Traffic activity in PRB is predominantly general aviation. At the time of the site visit, the ASOS was still reporting in the old SAO format without METAR software version 2.4. It was subsequently upgraded shortly after the site visit.
Five contract weather observers staff the facility seven days a week, 24 hours a day. The observers use lighted towers and mountains for visibility markers and a ceiling light for determining ceilings at night. The observers also turn the airport beacon on and off when the weather goes from instrument flight rules to visual flight rules and vice versa.
Data from the FAA Airport Master Record as of January 10, 1996 indicates that a total of 168 aircraft are based at the Paso Robles airport. Operations for the 12 months ending January 10, 1996 totaled 31,600 including 2,400 air taxi, 18,000 general aviation local, 10,000 general aviation transit, and 1,200 military.
PRB is located in the coastal range of mountains along the Central/North Central California coast. It is just south of the San Francisco Bay area and north of Santa Barbara; near San Louis Obispo and Monterey. Due to its proximity to the ocean, PRB is subject to frequent fog conditions. PRB is in a unique position in that it is not located adjacent to water, but in a shallow coastal mountain valley where fog may form and remain trapped for longer periods than in other areas. Major weather concerns for PRB would be reduced visibility in fog, occasional summer rain/thunderstorms, and occasional high winds blowing in from the ocean during the day and out at night. In extremely dry conditions, PRB is subject to the summer fires that plague much of the central to southern coastal mountain communities.
Participants
Airport manager, Citizen Advisory Committee representative, two contract weather observers from Central Coast Weather, two California Highway Patrol pilots (Paso Robles), certified flight instructor, and FAA/NWS team.
Synopsis of User Comments
This section of the report is a record of the comments received during the meetings, interviews and discussions that took place during the site visits. It is intended to present a summary of the input from the users on a particular subject. These comments may include technical inaccuracies and user perceptions that do not reflect actual conditions.
The closure of the Flight Service Station in 1987 has created some level of animosity about service changes. There was strong negative sentiment over the closure of the Flight Service Station according to the airport manager.
He stated that -
"After having been promised ‘equal or better service’ by the FAA after the closure of the Flight Service Station, the loss of contract weather observers is viewed as yet another loss of services and jobs."
The ASOS is located mid field between runways in order to represent the airport. Some pilots stated that -
"We think the site may be a problem."
The airport manager stated -
"He does not want the ASOS moved to another location."
Further discussion revealed that the ASOS is actually located about one mile from the touchdown area of the primary runway. The touchdown area was not determined to be in an acceptable location due to local obstructions and terrain. Because there are no precision approaches to the airport, it was determined that this site location would better represent the airport weather.
The airport manager stated that –
"Paso Robles has approximately 35,000 operations annually including fixed wing and rotary. Users include the California Highway Patrol, forestry service, military (C130), medivac services, and recreational vendors, such as sky diving and balloons."
Paso Robles has visual flight rules weather conditions about 87% of the year.
The California State Patrol pilots stated they-
"Worry about VFR (visual flight rules) arrivals when they are departing IFR (instrument flight rules) without a human observer on the field. IFR arrivals can create major fuel reserve concerns for them. The weather observer can confirm VFR when the ASOS states IFR."
A flight instructor stated -
"The ASOS is very helpful for his students’ training and he likes it."
The airport manager stated -
"The area did not get rapidly changing weather and very seldom had thunderstorms. The area has unique climate conditions due to the mountains, including morning fog."
"The repair technician does not understand weather."
"The ASOS was great when it was working, but when problems came up, it would take 2-3 days to get it repaired. In fact, the system was down for 6-8 weeks at one point."
The NWS representative said that -
"The technician in this area has about 23 ASOS sites to maintain and he cannot keep up with all the sites, especially a site that is not commissioned."
The airport manager stated -
"When the technician does maintenance, no warning or notification is given to airport manager or the contract weather observer."
"He does not believe the ASOS is ready for commissioning due to unreliable system performance and maintenance problems."
"The contract weather observers do not communicate with the pilots."
The pilots and the contract weather observers stated –
"A very strong positive point for the ASOS is the communications dissemination via the ground-to-air transmitter and the long line. The UNICOM may or may not have anyone to answer when aircraft call in."
Both the airport manager and the contract weather observers stated that -
"The lack of communications training on the ASOS was a frustration, and the users are unclear about what ‘test’ means in the observations."
Other statements captured were -
"The ASOS has a positive capability, specifically for winds and pressure, and the pilots depend heavily on the ASOS wind and pressure data."
"The ASOS will not pick up smoke layers; (forest) fires in the surrounding areas sometimes send smoke layers over the airport."
"ASOS fails when the temperature is about 87 degrees."
The contract weather observers stated -
"The ASOS is slow to clear fog and sometimes carries an incorrect ceiling height for a long period of time."
"The dew points were often wrong, for example, 50 degrees on ASOS when they were recording 10-20 degrees.."
"We want the ability to input sector and prevailing visibility and partial obscurations. ASOS does not provide this data."
Information Provided
The team provided information on ASOS performance capabilities and the commissioning process. The thunderstorm/lightning detection information through the lightning data network was discussed.
Issues Identified
Maintenance issues appear to be the most prevalent problems at Paso Robles. Response times, extended system outages and poor communications between the airport manager and maintenance personnel were reported by system users. The loss of the contract weather observer positions and services was viewed as more evidence of the FAA’s lack of commitment to the "equal to or better service" promise issued when the Flight Service Station was closed in September, 1987. The temperature/dew point sensor was identified as being frequently inaccurate.