I recently came across an interesting website that uses data to help pilots mitigate the risk of experiencing a deadly bird strike.
It reminded me of a bird strike I unknowingly experienced shortly after I earned my private pilot certificate.
I took a mountain flying course out of Deer Valley Airport in Arizona. The one-day course included 2.5 hours of ground instruction and 3.0 hours of mountain flying and high density altitude training, and included landings and takeoffs at three of northern Arizona's most popular high-elevation airports.
We launched from Deer Valley Airport (elevation 1,478' MSL), flew direct to Flagstaff Pulliam (elevation 7,011' MSL), then Sedona Airport (elevation 4,827' MSL), then Payson Airport (elevation 5,157' MSL), and back to Deer Valley Airport.
Read this Ahead of the Power Curve blog column for the story behind that mountain flying course experience.
While taking off out of Payson (KPAN), we had just become airborne in our Cessna 172S when I caught a glimpse of a bird at about my 10 o'clock position flying low toward the runway ahead of us.
I assumed the bird flew below or behind us as our Skyhawk gained altitude on our initial climb out just after liftoff, and I quickly forgot about the bird.
An hour later after arriving back home at Deer Valley Airport and shutting down, I exited the Cessna and immediately noticed a red streak along the left side of the airplane.
We did indeed have a bird strike.
The small bird must have hit the tip of the propeller, as there were a few marks remaining on the prop. The rest of the bird hit the lower left side of the Cessna's engine cowling.
While we were never in any danger in our small bird strike incident (the strike caused no damage to the airplane), other pilots have not been so lucky.
Arguably the most famous bird strike airplane accident happened in January 2009 to US Airways Flight 1549.
After taking off from New York City's LaGuardia Airport, an Airbus A320 struck a flock of Canada geese and lost engine power. Unable to reach any nearby airports, pilots Chesley Sullenberger and Jeffrey Skiles successfully and safely ditched the passenger plane in the Hudson River. All 155 people onboard were rescued by nearby boats.
The NTSB determined the probable cause of this accident was "the ingestion of large birds into each engine, which resulted in an almost total loss of thrust in both engines and the subsequent ditching on the Hudson River."
A few months earlier in March 2008 a Cessna 500 crashed about two minutes after takeoff from Wiley Post Airport (KPWA) in Oklahoma City, Oklahoma.
After taking off and climbing to 3,100 ft, the airplane crashed four miles south of the airport. A wildlife refuge area was located within a 5-mile radius of the airport.
The airplane impacted one or more large birds, which likely damaged the airplane's wing structure. The pilot, the second pilot, and the three passengers were fatally injured in the crash.
The NTSB determined the probable cause of this accident was "airplane wing-structure damage sustained during impact with one or more large birds (American white pelicans), which resulted in a loss of control of the airplane."
Because a bird strike can happen suddenly and without warning, it must be impossible for pilots to plan for, and mitigate the risk of, bird strikes.
Or is it?
The Avian Hazard Advisory System (AHAS) is an interesting website all pilots can use to help reduce the likelihood of bird collisions with aircraft resulting in potentially deadly accidents.
According to the AHAS website, "The United States Avian Hazard Advisory System (USAHAS) program objective was to develop a predictive Avian Hazard Advisory System using Geographic Information System (GIS) technology as a key tool for analysis and correlation of bird habitat, migration, and breeding characteristics, combined with key environmental, and man-made geospatial data."
The Avian Hazard Advisory System was built using geospatial bird data and the United States Air Force's Bird Avoidance Model, making it possible for pilots to know about the potential risks of bird strikes at certain airports, at certain times of the year, and at certain altitudes.
The USAF Bird Avoidance Model is "...a key tool for analysis, predictability, and correlation of bird habitat, migration, and breeding characteristics, combined with key environmental, and man-made geographic data. The model was created to provide United States Air Force pilots and flight scheduler/planners with a tool for making informed decisions when selecting flight routes. The model was created in an effort to protect human lives, wildlife, and equipment during air operations throughout the United States and Alaska. The model is used by the Department of Defense and is now available to the general public through this Internet application."
How does it work?
Go to www.usahas.com, then:
1) select an area (such as an airport identifier, an instrument route, or other locations);
2) select a month, day and time;
3) select the type of risk format to display.
Risks can be displayed for the current hour, for the next 12 hours, and as a visual representation via colored polygons on a Google Map. Green equates to a low risk, yellow is a moderate risk, and red is a severe risk.
In the Oklahoma City accident mentioned previously where the airplane crashed four miles south of the airport, a wildlife refuge area was located within a 5-mile radius of the airport.
It's impossible to say if the Cessna 500 pilots were aware of or used the AHAS tool in their pre-flight planning, or if they knew of the risk of bird strikes at Wiley Post Airport (KPWA).
But for pilots in similar situations, having this knowledge at flight planning time could help lead to a safer outcome by giving pilots enough information so they can change the flight plan if necessary to avoid known risk areas.
The FAA reported that in 2015 there were 13,795 bird strikes.
Among commercial aviation and general aviation bird strikes combined, the FAA reported that about 61% of bird strikes with civil aircraft occur during landing phases of flight (descent, approach and landing roll), while 36% occur during take-off run and climb. The remainder, about 3%, occur during the en-route phase.
Mitigating the risk of bird strikes is possible when you know the trends, the geographical locations where bird strikes are more likely to occur, and the times of the year when they may occur.
The AHAS website is one more tool in your flight-planning toolbox that can help you be more aware of the risk of an accident due to bird strikes.
Just remember this warning from the AHAS website: "Its use for flight planning can reduce the likelihood of a bird collision but will not eliminate the risk."
The Flight Chain App team
Flight Chain App and its companion blog www.AheadOfThePowerCurve.com are committed to reducing general aviation accidents, helping improve aviation safety, and growing the pilot population.
An easier way to read NTSB aviation accident reports.