Why do only large airports have AWOS?

Only 1,609 automated weather systems across entire USA*

In a report to FPAW*, FAA reported the following:

*Estimated value from public sources

**  2012 FAA report to Home | Friends and Partners in Aviation Weather | FPAW

AWOS Projects Too Costly and Complicated for Smaller Airports

Initial AWOS cost $300-500K USD or more
• Project take 3-7 years or more
• High up-front engineering costs
• Many pre-approvals required
• High initial infrastructure costs
• Complex installation & commissioning

Yearly AWOS cost $5-10-15k USD per year or more
• Labor-intensive inspections
• Require constant maintenance
• Costly specialized technical support
• Expensive replacement parts
• Systems require periodic complete replacement

At major airports human observers are still required!
• Human observers interpret / backup AWOS data
• AWOS failures block flight ops
• Large airports still rely on observers as backup

AWOS Require Separate VHF Frequency

• AWOS transmit continually
• Requires set-aside frequency for AWOS exclusive use
• Frequency approval often takes years
• VHF frequencies may not be available

Approval takes years 

Pilots off traffic frequency

Increases mid-air risk

AWOS Projects Take Years

AWOS Require Too Much Airport Land

• Requires up to 1,000 ft (300 m) radius clear area
• Condemns 18 acres (7 hectares)
• Prevents other airport land use
• 10m sensor mast introduces a runway hazard
• AWOS hazard forces sensors far from runway

Smaller Airports Cannot Meet Setback Requirements