ARW
120-Day Re-Assessment Plan
Site Visits
2.3.14 Edward F. Knapp State Airport, Montpelier VT
Background
A team visited the Edward F. Knapp State Airport (MPV), located in Montpelier, VT on July 9, 1997. MPV is a non-towered, Service Level D airport with a stand alone ASOS. The ASOS was commissioned June 18, 1996. The FAA contract for weather observations was canceled on September 30, 1996.
Data from the FAA Airport Master Record as of June 12, 1996 indicates that a total of 61 aircraft are based at the Montpelier airport. Operations for the 12 months ending June 12, 1996 totaled 32,500 including 1,000 air taxi, 17,000 general aviation local, 13,500 general aviation transit, and 1,000 military.
Instrument flight rules arrival and departure traffic for the airport is controlled by the Boston Air Route Traffic Control Center, located in Nashua, New Hampshire, on frequency 135.7. Pilot pre-flight weather briefings and Notices to Airman issuance services are provided by the Automated Flight Service Station located in Burlington VT. Duplex communications are provided by Burlington Automated Flight Service Station through the MPV RCO on frequencies 122.6 and 122.2.
Edward F. Knapp State Airport lies below the 45th parallel in the Green Mountain range and has fairly rapid moving weather systems from the west with changing weather patterns. The area experiences extremes in climate from frigid winters to warm summers. Low stratus and fog events are frequent in the spring, with radiation fog common in the summer
The FAA Regional Office received congressional correspondence concerning the Edward F. Knapp State Airport ASOS.
Participants
Airport manager, former contract weather observer, transient commercial pilot, captain for Wiggens Airways, air carrier contractor to United Parcel Service, 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 airport manager stated -
"The airport has two daily scheduled FAR 135 arrivals and departures. Both are Wiggens Airways, a contract carrier for United Parcel Service. One arrives late afternoon, and another early mornings, Monday through Friday."
"The ILS approach is from the north and is 13 miles long. There is usually a greater chance of aircraft picking up ice in this area due primarily to the Green Mountain range. Wind is primarily north, north-west causing more cloud accumulation on the approach area of ILS 17."
"ASOS is not what was promised, without at least one more sensor no one will be happy. From my understanding it is not capable of reporting accurate ceiling or visibility. The unit assumes clouds will move along through the air and they don’t. Sugar Bush ski area located nearby has the best skiing in the east due to standing lenticular clouds that stay in the area for long periods of time. Clouds sit over the airport all day; the ASOS can’t tell cloud coverage at all."
A former contract weather observer told the team -
"Fog generally comes from the north side of the airport. Ceiling and visibility are areas of most non-representative weather. This may be due to the site location, but it has very bad representation at this area."
"ASOS can’t keep up with the changing weather. ASOS reports no snow depth measurements; we used to have this data with the contract weather observer, being a forecaster. This is now inadequate. Temperature sensors are OK, maybe a little cool as all ASOS are. Altimeter is great, dew point is a little slow."
"Snow squall’s last 15 minutes; three to four have gone by and ASOS is still reacting to beginning squall. Someone will get killed here if ceiling and visibility are not corrected. Transient pilots will fly through area when ASOS is calling ceiling 200 overcast, when it is actually 900 feet overcast. Someone will fly into mountain."
"Morrisvile site seems to be fairly accurate, but Montpelier is not accurate. ASOS Underreports wind gusts by 5 to 10 knots or so, most winds are out of Northwest. ASOS does not report sea level pressure, dew point temperature is not accurate, and altimeter reports 100 % accurate, winds we can live with. ASOS will not report blowing snow, also reports snow when it may be haze. Blowing snow during winter months is a problem due to not being reported. Twelve hour data seems to be missing quite frequently."
"Finally I don’t like ASOS because it took away my job as a CWO (contract weather observer)."
A transient commercial pilot stated -
"I flew into Montpelier airport after attempting to land at Burlington airport. Had to execute the missed approach at Burlington, VT. Weather was low enough that I was unable to get in. After executing the missed approach I tuned in the ASOS for Montpelier. ASOS at Montpelier reported 600 broken, 900 overcast few clouds at 1000 feet. I honestly can not remember exactly what the reported visibility was, but I remember it was more than needed to complete the approach. I asked for vectors for the ILS 17 to Montpelier, received them shot the approach broke out just above minimums and landed. I think ASOS was representative of the weather here this morning, and worked really well for me."
"The ASOS at Fitchburg, Massachusetts my home airport is in the test mode. When winds are out of the west trees affect the reported winds. I think this will be corrected before they take it out of the test mode."
A captain for Wiggens Airways, an FAR 135 scheduled air carrier contracted to United Parcel Service, stated -
"We fly into here twice a day carrying United Parcel Freight. Once in the evening and once in the early morning. The only problem I have had with the ASOS is when the CWO (contract weather observer) complained it was not representative of the actual weather. As a result of this the airport manager called the FSS (Flight Service Station) and issued a NOTAM (Notices to Airmen) stating the ASOS was out of service due to not being representative of the actual weather. The FAA principal operations inspector for Wiggens Airways came out every morning for a week to observe the weather and stated the ASOS was representative of the weather. I have never started an approach when ASOS reported weather was at or above landing minimums and had to go missed approach. I did have trouble at Montpelier before ASOS was commissioned trying to reach the CWO to obtain current weather."
The ASOS maintenance technician for the Montpelier airport stated -
"I feel this ASOS is maintained to perform exactly as designed. Currently, we do not have a database for preventative maintenance due, or a database showing the last time preventative maintenance was completed and to what extent. I monitor ground to air radio, and work to correct any problems as they come up. Initially, we had to change the antenna location to correct a RF (radio frequency) problem, but the system is working fine now with no problems."
At the meeting, the team discussed the capabilities of the ASOS, explained the limitations of the ASOS sensors, and provided information on ranking criteria.
Issues Identified