Avian Hazard Advisory System

How to use AHAS

AHAS Questions

1. What is the Avian Hazard Advisory System?

AHAS is an online, near real-time, geographic information system (GIS) used for bird strike risk flight planning across the continental United States. Using NEXRAD (WSR-88D) weather radars and models developed to predict bird movement, AHAS monitors bird activity and forecasts bird strike risk as well.

2. Why was AHAS created?

AHAS was created to provide Air Force pilots and flight scheduler/planners with a near real-time tool for making informed decisions when selecting flight routes. It was created in an effort to protect human lives and equipment during air operations throughout the conterminous United States.

3. Who uses AHAS?

AHAS is used by the Department of Defense and is available to the general public through this Internet application.

4. How can you determine if an AHAS query in the next 24 hours contains forecast or historical data?

The "BASED ON" column shows where the risk is coming from.

Anytime you request data BEFORE the current day and time, you will always receive the NEXBAM risk. You only receive NEXRAD risk for the CURRENT hour. From 12 - 24 hours in advance, you can get the soaring model risk. See the power point tutorial in the downloads section.

5. Why is AHAS telling me my data is based on the NEXBAM during the current hour?

If the current NEXRAD data and the soaring model are not available the default is the NEXBAM data. This happens when the NEXRAD or weather data are not available.

NEXBAM Questions

1. What is the NEXBAM?

The NEXBAM is a bird avoidance model based on NEXRAD data. It is a tool used to show the hourly trend for areas in AHAS based on five years of NEXRAD data. This data is used in the background to help determine the AHAS risk when current NEXRAD data and the soaring model data are not available. It can also be viewed as a chart that shows the hourly risk for the selected day.

2. Why was the model created?

The model was created to provide Air Force pilots and flight scheduler/planners with a tool for making informed decisions when selecting flight routes.

3. How was the model created?

AHAS extracts the NEXRAD risk for all areas in the system every 6 minutes. This SQL data is archived. The NEXBAM uses the last five years of data to create an hourly average for every day of the year.

5. What is the chart showing?

The chart shows the threshold for severe risk in a straight red line and the threshold for moderate risk in green. The orange shaded area shows the maximum risk over the past five years. The green shaded area (sometimes not visible at all) shows the minimum risk over the past five years. The average risk from the past five years is shown as a yellow line. When looking at a day in the current month, you can also see a blue line showing the current risk and a gray line for the previous day.

AHAS and BAM Questions

1. How do the Low/Moderate/Severe risk levels in the AHAS table compare with the levels of risk presented in the NEXBAM chart display?

They are both primarily based on NEXRAD data. The table uses the most current data for the selected day. The NEXBAM uses data from the last five years. The NEXBAM only uses the data from the last five years, but the table uses the current data, the soaring model and the NEXBAM.

2. Are there any graphical depictions of risk levels available in AHAS?

Yes, a graphical representation of AHAS can be seen by using the Google Earth button, the Google Map button or the AHAS plus button. Charts for some areas are automatically displayed. For some areas you must click the name highlighted in blue to see the chart.

3. Is the NEXBAM updated in real-time to reflect the current and forecast risk data generated by AHAS?

No. The NEXBAM is based on the last 5 years of NEXRAD data and is updated every month.

4. Is it safe to fly if the chart or table shows a severe risk?

The model uses NEXRAD data from the previous five years to provide the user with an effective decision making tool. Because birds are dynamic creatures whose migratory behavior is initiated by weather events in any given year, the model can not be said to predict the exact movement of bird species through space and time. Chart patterns that show a severe risk according to the model should be not be ignored and should be avoided. It is not suggested that pilots fly within the "Severe Zone" unless it is mission essential.

5. Where can I find more information about bird strikes?

The committee provides bird hazard and bird hazard prevention information.

The team's goal is the preservation of war fighting capabilities through the reduction of wildlife hazards to aircraft operations.

Military Pilot Questions

1. Are there step-by-step instructions for using AHAS?

Yes. The Instructions tab contains detailed information on how to use AHAS and what the results mean.

2. How can a pilot or planner use AHAS?

When planning more than 24 hours in advance of a flight, the table will be based on the NEXBAM. The chart will show the risk for a 24 hour period and can be used to look at any day.

When planning a flight less than 24 hours in advance, the table option will evaluate the risk from soaring birds and the risk from the NEXBAM data and show the user the highest risk.

When using the table option in the same hour of the flight, AHAS adds in the most recent NEXRAD data. The risk for the current hour is determined by comparing the NEXBAM risk, the soaring bird risk and the current NEXRAD data. Whichever result is the highest is the risk for that hour. Also, when checking the risk for the current hour, a NEXBAM chart is displayed. This shows what the bird activity is expected to be for the selected day.

The 12HR RISK option can be used to look at the risk for 12 hours past the selected time.

The AHAS plus button can be used to see the risk for the selected time plus the next 3 hours. This option also displays a map showing the current risk.

Updating AHAS Questions

1. The coordinates for my flight area have changed. What should I do?

Depending on what type of area you are flying, please send the following information to ahas@DeTect-inc.com:

  • Routes: start coordinate, end coordinate and the distance to the left and right
  • Ranges and MOAs: all bounding coordinates
  • Military Airfields: the one central coordinate
2. My flight area is not in AHAS. Why not and what should I do to get it included?

If your area is not included in the DAFIF, it would not automatically be included in AHAS. If you are a civilian airport, the FAA would have to become involved in AHAS for your area to be included.

If you feel that your area should be included in AHAS, please email us at: ahas@DeTect-inc.com

Printing Questions

1. How do I print the background colors in the table?

If you are using Internet Explorer, go to Tools --> Internet Options --> "Advanced" tab --> scroll down and place a check next to "Print background colors and images"

warning !

The Avian Hazard Advisory System (AHAS) was constructed with the best available geospatial bird data to reduce the risk of bird collisions with aircraft. Its use for flight planning can reduce the likelihood of a bird collision but will not eliminate the risk. The AHAS organizations are not liable for losses incurred as a result of bird strikes.