Automated Weather Observation Station (AWOS) Task Force Recommendations

Introduction

The Michigan Aeronautics Commission (Commission) and the Office of Aeronautics (Aeronautics) is charged with preserving and promoting a safe and efficient statewide aviation system. To support that mission, the Commission has prioritized all weather accessibility across the Michigan Aviation System. With a robust and resilient network of weather stations and weather dissemination equipment, airports across the State are able to attract and retain airport users during times of inclement weather. With this increased accessibility, local municipalities are able to maintain and grow the over $20 billion economic impact general aviation provides to Michigan annually through XXXX jobs. As of 2021, the Office of Aeronautics maintains 41 non-federal AWOS Stations supporting the additional federally-operated weather stations at 30 commercial service airports.

The Commission convened the AWOS Task Groups in 2020 to examine the long-term viability of the Michigan AWOS System as component availability decreases, experienced technicians are increasingly sought after, and available resources decline as the aviation community’s reliance on Non-Federal AWOS systems continue to grow. During the Task Group’s initial meetings, the following goals were established:

1. Reassess the practical impact and level of service provided by the state-supported AWOS network in Michigan.

2. Examine future AWOS needs in order to continue providing pilots with real time aviation weather observations at the airport for pre-flight planning, and while airborne, to enhance the safety of flight operations.

3. Make recommendations to ensure ongoing maintenance and upgrades of the existing Michigan AWOS network.

4. If required, advocate for financial support needed to upgrades the existing Michigan AWOS network.

AWOS Component and System Overview

The FAA has many different designations for AWOS, depending on what all sensors are installed and certified. Early on in MDOT Aero’s original All Weather Access Plan, we identified that the AWOS IIIP type was the most cost-efficient system for our aviating public. Included in this installation, are the certified sensors for the following measurements: wind speed and direction, barometric pressure, temperature, relative humidity (reported as dewpoint), visibility, present weather, and cloud height (ceiling). An updated requirement for AWOS III commissioning is the addition of a precipitation accumulation sensor. While this is not a reportable METAR element, it is included in the remarks section, and helpful to the communities and NWS for hydration tracking. All 41 sites we support are AWOS IIIP. In addition, a handful of stations have the precipitation accumulation sensor and one also includes a thunderstorm sensor (making it an AWOS IIIP/T). Ancillary equipment installed on all station include:

1. VHF radios for local aerial voice broadcast output

2. Onsite battery powered Uninterruptable Power Supply (UPS) for commercial power interruptions

3. UG wiring/UHF radios/terminal building computers for local AWOS weather display, long line dissemination via internet, and remote maintenance access. , Our current state supported AWOS model includes an MDOT internal unit of technicians to oversee all facets of AWOS, including scheduled maintenance, unscheduled maintenance, scheduling of and conducting required inspections, and maintaining all required specialized calibrated tooling and spare parts repository.

All of the previously mentioned equipment and processes help to generate weather data, but this speaks nothing to what we do once its generated. The FAA allows us, as non-fed AWOS sponsors, to input our AWOS generated data from all 41 sites into the FAA’s Weather Message Switching Center Replacement (WMSCR) system. This can be utilized by pilots who are looking for suitable destinations based on weather, as well as airborne aircraft receiving such data (through SirusXM, ADS-B In, etc.) for situational awareness. We utilize and have under contract Mackinac Software Inc. to perform many functions on the data end of our AWOS network. Mackinac Software performs and supplies the necessary equipment and processes to:

1. Collect our AWOS data within the airport’s terminal building and visually display this data to pilots within the building and via internet web-screen

2. Port our collected AWOS data for long line dissemination through FAA’s National Airspace Data Interchange Network (NADIN) to the Weather Message Switching Center Replacement (WMSCR)

3. Analyze output (for missing/bad/stuck/outage data), alert via email, and display via web-screen a system wide map of the current and historical status of all AWOS statewide

4. Provide for remote maintenance connectivity via internet for technicians to analyze and troubleshoot system problems (before site arrival) for possible repair and parts needs

5. Host a secure website to securely access/lockout these functions All of the above is done at each of the 41 AWOS stations we support.

Buy-n-large, most airports with federally supported AWOS/ASOS systems, have those for one of three reasons:

1. Significant airline service is at that particular airport

2. It has a military (federal) AWOS version already installed

3. The National Weather Service (NWS) has identified that airport as a needed location based on needs for observations for local area weather phenomenon, and potential impacts to forecasting data requirements.

Challenges Facing Current Network

For the past thirty years, the Michigan AWOS network has performed exceedingly well as a result of the dedication of local airport sponsors, MDOT Aeronautics staff, and the Commission for providing support to the network. However, recent changes in the AWOS manufacturing and support community has called into question the long term sustainability of the existing Michigan network as a result of less market competition for component manufacturing and the elimination of support for older legacy systems that exist in Michigan.

Including one site which is not supported by the state at this time (Hart/Shelby has an AWOS A/V installed), ALL of Michigan’s non-fed AWOS sites are based on 1990’s technology, and components for such legacy systems are hard to find, hard to repair, and are mostly no longer supported. Within our existing network, all sites have a combination of certified current and legacy components. An upgrade to any particular site could necessitate a small sensor replacement for longer life. Conversely, a complete system replacement might be required to maximize investment funds for other sites. Because of this current situation, a thorough review of available funds, short and long term strategies for statewide AWOS needs, and availability of replacement parts/costs is required to plan for efficiently operating and improving the current network within our state.

Federal Support for Non-Federal AWOS Systems

Non-federal AWOS systems have been installed in many locations across the nation by forward thinking states and municipalities seeking to provide the highest levels of aviation safety within their communities when federal resources were not available or could not be utilized in certain circumstances.

Today, Federal Aviation Administration Airport Improvement Program (AIP) Funding is available to support AWOS installation under certain circumstances however upgrades of existing systems that have become obsolete generally are not eligible for federal AIP support.

The FAA issued a Memorandum on October 29, 2009, which established policy that required all non-Federal AWOS equipment connections to the Weather Message Switching Center Replacement (WMSCR) be from a certified and commissioned AWOS-III or better, and the equipment must be certified in accordance with Advisory Circular 150/5220-16. The data from an AWOS-II (or lower), could not be disseminated to WMSCR, and that policy still exists today.

On June 18, 2014, the FAA issued Program Guidance Letter (PGL) 14-04, to clarify guidance on the eligibility of airports to qualify for an AIP funded AWOS-III. The basic premise of this PGL, was that an airport must meet a Benefit Cost Analysis ratio of 1.0 or greater to qualify for an AWOS-III or greater. For those airports who could not achieve 1.0 or greater, they could purchase and install up to and including an AIP funded AWOS-II, but there were restrictions. The FAA issued a new Airport Improvement Program (AIP) Handbook, (Order 5100.38D), dated September 30, 2014, which cancelled PGL 14-04. This handbook still requires a BCA ratio of 1.0 or better to qualify for an AWOS-III or greater, but with FAA approval, an airport can install an AWOS-II, add a ceilometer, present weather sensor, and tipping bucket to make it an AWOS-IIIP. However, the sponsor must pay for all costs to purchase and install these three sensors when they are added.

A recent email to MDOT Aero’s State Block Grant Coordinator for the FAA Detroit Airport District Office (ADO) indicated that the BCA requirement has been rescinded within the handbook.

Michigan Aeronautics Commission AWOS Task Group Determinations and Recommendations

1. The state-maintained AWOS network, in conjunction with the federally supported AWOS/ASOS network, continue to provide unparalleled safety benefits to the aviation community in Michigan. With a >99% reliability rate, the 41 non-fed AWOS stations in Michigan allow safe and efficient access to all areas of Michigan – many of which would experience tangible declines in services offered to the general public and reduced economic impact without the benefit of the Michigan AWOS network.

2. The Task Group recommends the Commission to support ongoing efforts of the Office of Aeronautics to train, retain, and preserve the dedicated staff needed to maintain the Michigan AWOS network.

3. In light of aging AWOS infrastructure and limited replacement components for the majority of existing AWOS systems, the Task Group recommends the Commission request the Michigan Legislature consider a one-time appropriation of $X million to support a phased upgrade of existing AWOS systems over the next 5 years.

Chronology

· 1990 - Aeronautics began a state-local program for the purchase and installation of Automated Weather Observation Systems (AWOS-IIIP) to enhance safety and efficiency of the Michigan Aviation System.

· 1991 - The first non-federal AWOS in Michigan was installed in 1991 at Mackinac Island. This system was a Model V-B manufactured by Artais Weather Check, Inc.

· 1993 - Aeronautics entered into a contract with Pan Am Weather Systems for the purchase and installation of three AWOS. Pan Am subcontracted those systems to Handar, Inc., resulting in Handar systems being installed at Cadillac, Howell, and Port Huron. Maintenance of the systems at all four locations was conducted by Aeronautics technicians, under a cost sharing arrangement with the airport sponsor.

· 1995 - Aeronautics established the Artais AWOS as the standard system for non-federal systems in Michigan, which resulted in the purchase and installation of ten Artais systems.

· 1996 - Artais merged with Vaisala, Inc., which is headquartered in Helsinki, Finland. All subsequent purchases since that year, including the replacements of the three Handar systems, have been systems manufactured by Vaisala. An additional 5 systems purchased and installed

· 1999 – Vaisala unveils new V-C and V-D models. Utilizing state funding only, 13 AWOS systems were installed

· 2004 – As state resources for AWOS installations declined, 10 AWOS Systems were installed using Federal Aviation Administration Airport Improvement Program resources.

· 2007 – With 38 Vaisala AWOS systems active in the State, Vaisala indicated all existing Model V-B, which included 15 AWOS systems in Michigan, have reached the end of their useful life and any component support would cease by 2008. This end-of-life (EOL) announcement ended support for 16 of the 38 AWOS systems in the State.

· 2010 – 2016 Utilizing a variety of funding sources, 16 unsupported AWOS stations were upgraded. Additional purchase and install of 4 AWOS stations.

· 2014 – Vaisala issued end of life notice for CT25K ceilometer and Park Air Model 4004 VHF Transmitter

· 2016 – Vaisala’s United States AWOS Program is purchased by DBT Transportation. Along with this change, Vaisala ended production of the V-C and V-D model AWOS. DBT ramped up production of their newly certified AW20 model (an IP based system). Numerous EOL’s were issued for older sensors including legacy barometers, temperature and relative humidity, ultrasonic wind, visibility, present weather, thunderstorm, ceilometer sensors, and UHF datalink radios.

· 2020 – MDOT’s recent review of current spare stockpiles revealed a need for a longer term strategy in maintaining current AWOS levels cost efficiently.