A BASH Success Story

  • Published
  • By Maj Brad Gillette
  • 80 FTW
Bird and wildlife strikes are a hazard for every type of aircraft in all environments. This is one threat that cannot be totally eliminated, but with proper planning and implementation, a good BASH plan can greatly reduce this threat and make a safer flying environment. 

Sheppard AFB, TX averaged 73 birdstrikes per year from FY 1999 to 2004, with FY 2003 through FY 2004 averaging 85 birdstrikes per year. These alarming statistics led Sheppard to make some big changes in its BASH program in attempts to reverse this costly and potentially life-threatening trend. 

In August 2004, Sheppard hired a US Department of Agriculture (USDA) wildlife biologist to assist with its BASH program on and off base, and ultimately reduce the number of bird and wildlife strikes that were occurring on the airfield. The plan developed by the Flight Safety office with the help of the wildlife biologist, was straight forward. If the number of birds on or around the airfield can be reduced, the number of birdstrikes (at least on the airfield) should decrease as well. In order to reduce the number of birds on and around the airfield, the first step was to identify which types of birds had the largest presence on base and which type was involved in the majority of aircraft birdstrikes. Once this was determined, methods to mitigate the birdstrike risk from these identified species could be developed.

The 80 FTW Flight Safety office and Mr Ted Pepps, Sheppard's USDA wildlife biologist, took a look at which birds attributed to the majority of birdstrikes on the airfield. In FY 2005, 23% of all the birdstrikes on the airfield were identified as Eastern Meadowlarks. In FY 2006, this number increased to 28% of identified bird species. Eastern Meadowlarks accounted for $588,000 in aircraft damage from FY 2004 through FY 2006. Armed with this data, the safety office looked into ways to reduce the Eastern Meadowlark population on Sheppard AFB. With the help of the USDA wildlife biologist, it was discovered that the ideal grass heights for the meadowlarks to build their nests was 10 to 20 inches with the tops of their covered nests being 6 to 7 inches off the ground in the grass. AFI 91-202 directs grass heights on airfields to be 7 to 14 inches. The 80 FTW Safety office requested a waiver to maintain grass heights at 5 to 12 inches during the meadowlark nesting and breeding season of March through June. Cutting the grass to 5 inches cuts off the tops of the meadowlark's nests leaving them exposed and causing the birds to abandon their nests and seek shelter elsewhere. This shorter grass height is also a less attractive nesting habitat for the meadowlarks, causing them to nest elsewhere. The Air Force Safety Center approved the grass height waiver to maintain the airfield grass heights between 5 and 12 inches. Sheppard started maintaining this new grass height in March 2007 and as of the end of May 2007, there has been only one identified meadowlark birdstrike out of 27 total birdstrikes, with no damage to the aircraft.

Another major concern on base was the Great-tail grackles and European starlings. In FY 2005, there were approximately 55,000 grackles and starlings congregating on and around Sheppard. These numbers were highest around sunrise and sunset. Sheppard's USDA wildlife biologist developed an aggressive plan to disperse and depredate these blackbirds in order to reduce their numbers. Depredation and dispersal activities were carried out in FY 2005 through FY 2006. During this time period, over 34,000 blackbirds and starlings were depredated and over 8,500 were harassed in attempts to have them leave the airfield area. Because of these efforts, the blackbird and starling numbers have decreased dramatically to 15,000 in January 2007. A few weeks later, the grackle and starling numbers were reduced to almost nothing on Sheppard AFB.

Airfield topography was evaluated by the wildlife biologist in an effort to reduce areas on the airfield that were conducive to increased bird activity.  Besides monitoring grass heights throughout the airfield, the USDA wildlife biologist identified areas of bare ground and areas of standing water, which also attract birds and other wildlife. Work orders were submitted to civil engineering to rectify these problem areas. A major drainage project is still ongoing at Sheppard AFB, in an attempt to reduce standing throughout the airfield and reduce potentially attractive bird and wildlife congregation areas. 

As well as recommending topography changes to the airfield, Mr Pepps maintains a daily presence on the airfield, controlling or capturing wildlife before they become a hazard to flight operations. The fence lines around the airfield were found to have gaps in the bottom, with enough room for coyotes and jack rabbits to enter the airfield. Until these gaps in the fences were corrected, Mr Pepps remained busy removing wildlife on the airfield. Fifty-five coyotes, seventy-one jack rabbits, eleven deer and eleven cows were removed from the airfield over FY 2005 and FY 2006. 

In order to maintain the required grass heights, the grass mowing on the airfield cause smaller birds, mammals, and insects to disperse into the open. These smaller birds, mammals, and insects attract larger soaring birds which feed on these displaced animals and insects. In the spring and summer months, soaring bird activity increases as Turkey vultures, Red-tailed hawks and Swainson's hawks migrate into the area in search of food. In terms of damage costs per 100,000 flying hours, these birds rank 4th, 6th, and 25th respectively among USAF birdstrikes. Mr Pepps has been able to remove or harass over 32 vultures and 103 Red-tailed and Swainson's hawks. Some of these birds have been marked, relocated to areas away from the airfield, and released back into the wild. 

BASH awareness among the 80 FTW has increased in part due to recommendations made by the USDA wildlife biologist. As he identifies increases to migration over and around the airfield, this information is rapidly disseminated to the flying squadrons. Updates are posted on video displays in the hallways, where people can see this information as they walk by. The information is also e-mailed to the squadron flight safety officers for dissemination. While this may not directly prevent a birdstrike, it does make the pilots more aware that the threat has increased, and they are more prepared to handle a birdstrike if it happens. Three or four times from April to October, the migration routes, altitudes, and times of bird migration updates are sent to the flying squadrons. 

Since the USDA wildlife biologist has been working at Sheppard AFB, birdstrike and wildlife strikes have decreased every year. Birdstrike rates at Sheppard per 100,000 flying hours from FY 2004 to FY 2006 have decreased from 1.06 to 0.77, respectively. Damage costs have also decreased from $350,090 in FY 2004 to $232,231 in FY 2006. A more telling statistic for the improvements that have occurred since FY 2004 is the birdstrikes that occur on the airfield. The percentages of birdstrikes that have occurred on the airfield have dropped from 80% in FY 2004 to 43% in FY 2006. As of May 2007, airfield birdstrikes have accounted for only 30% of all birdstrikes on Sheppard AFB aircraft. Many factors can be associated with the vast improvement of bird and wildlife strikes at Sheppard since FY 2004. Most of the BASH improvements can be associated to the direct involvement of Mr Pepps, the USDA wildlife biologist at Sheppard. The cost of having a USDA biologist at Sheppard AFB has been more than justified with the decreased wildlife strikes and decreased damage costs to USAF assets, not to mention the potential lives saved. It only takes one birdstrike to cause a loss of an aircraft or even worse, a loss of life. In FY 2006, one birdstrike event caused a T-38 to abort a takeoff and engage a BAK-15 barrier, causing $187,000 in damage to the aircraft. This one mishap accounted for 80% of the damage costs for FY 2006. If we can prevent one less birdstrike every year, we may be able to avoid that "golden BB" that brings an aircraft down or causes a loss of life.