|AT-802 Air Tractor makes second dispersal application over Deepwater Horizon oil spill in Louisiana
by Bill Lavender
|Search Articles // View updated photos (June 29, 2010)|
HOUMA, LA — May 18, 2010 was the day an Air Tractor dual cockpit AT-802 made history by applying an oil dispersant over the Deepwater Horizon oil spill that originated from a damaged BP offshore oil rig. Never before in the North American oil recovery industry has a single engine aircraft conducted this procedure. After more than 16 years of demonstrating and working with oil recovery companies, a consortium of AT-802 operators have finally been able to implement a “proof of concept” where a single engine agricultural aircraft can be a critical tool in the armament needed during an oil spill crisis.
(R) Queen Bee Air Specialties of Rigby, Idaho provided the dual cockpit AT-802 Air Tractor for the initial applications. QBAS provided the four pilots needed, Steve Willey, Aldo Leonardi, Bruce Spaulding and Chip Kemper. It also provided the A&P licensed mechanic, Jay Jackson and ground support personnel, Jeff Haack
Until now, with safety as a priority, oil recovery and oil companies have required multi-engine and dual pilots for its aerial oil dispersal operations. The Deepwater Horizon incident is different from other spills. Its sheer size and unknowns have required BP to take every step possible to stop the source, remove the oil from the water with skimmers,, burn fresh oil off the water near the spill site, contain it with booms and spray it with dispersants; enter the AT-802.
With Deepwater Horizon, BP has a tiered approach for attacking the oil, starting at the well head. Conditions that are ideal for skimming and burning are not the same as conditions that are ideal for dispersing the oil and vice versa. No single method is 100% effective.
The oil dispersal product is a surfactant that has been used successfully for over 40 years. It is manufactured by Nalco Chemical Company. When applied over surface oil, it penetrates the oil and breaks the surface tension that separates the oil from a floating mass into microscopic particles that are suspended vertically in the water column, effectively diluting it to an acceptable ppm that will be less likely to affect the environment, providing a net environmental benefit. Because of the Deepwater Horizon incident, Nalco has increased the manufacturing rate of its dispersal product, Corexit. As much as 56,000 gallons have been applied in a day on the spill.
The AT-802 can play a critical role by dispersing the oil before it breaches land and the inshore environment. Because of its speed and maneuverability, it can respond effectively to its spotter plane commands as it treats ribbon lengths or small sections of surface oil. The aircraft can work as close as three miles offshore and as far out as ten miles in a minimum of 10-meter deep water during this proof of concept.
The Deepwater Horizon spill is an unfortunate event, but has presented a unique opportunity to provide the consortium of AT-802 operators a chance to demonstrate the effectiveness of the AT-802. The primary reason ag-aircraft have not been able to work oil spill dispersal applications in the past has been its single engine configuration. If this opportunity for the AT-802 proves to be positive, new doors for industry expansion could be opening in the future. Single engine ops are the norm in ag-flying. Aircraft owners, pilots and mechanics understand it is critical to keep the widest possible safety margin. The reality for ag-pilots is spraying at 75 feet over water with both a life vest and a life raft is considerably safer than 10 feet over a crop with power lines and trees to circumnavigate.
Spraying over water presents hazards of its own. The AT-802 is equipped with an artificial horizon, two-way communications, transponder and laser radar altimeter. The pilots must be IFR rated, as well as meet pilot minimums requirements stated in the contract and operations manual. The pilots must be able to deal with loss of horizon, which is not uncommon over water. Other weather phenomenon, like fog and offshore thunderstorms, can challenge the pilots. Operations for aerial oil dispersal are usually conducted from controlled airfields that require extensive radio communication.
Incident command systems are in place to facilitate the organized response and application of the dispersal product. Movements by the AT-802 and the spotter plane are coordinated through the Command Center, which currently has approximately 1,000 people working in it. Paperwork takes nearly as long as the application. Air Boss meetings are required daily with pre and post-flight pilot briefings. Speed is not as significant of a factor as with ag-ops. Safety is paramount, to the degree it slows down the system, but gets the job done safely. Although the oil may be drifting toward shore, the rate doesn’t compare to armyworms devouring a crop. Time is critical, but following protocol and being safe are more so.
A typical scenario for an oil spill dispersal application starts with a request from the Command Center for a spotter aircraft to locate and identify threatening oil. After the proper paperwork is filed and the weather meets a minimum of 1,500-foot ceiling and five miles visibility, the King Air spotter aircraft with its two pilots depart for a predetermined grid area. The King Air pilot and copilot must not only be good pilots, but also be able to distinguish algae and other deceivers in the water from surface oil. With the AT-802 operation, by the time the oil arrives in the aircraft’s area of responsibility, there is a risk of it being “weathered”, or exposed to the elements too long. As it becomes weathered, the oil’s response to the dispersal product is reduced and will become ineffective.
After locating the oil, the spotter aircraft returns to base and a strategy is developed to aerially disperse the oil with the AT-802. The first application on May 18 was only 200 gallons, about 40 acres worth.
(R) Taken from the cockpit of the King Air spotter aircraft, the AT-802 heads out into the Gulf of Mexico for the first single engine dispersal operation in North America. The 10-nm limit has been extended to 15 miles. A second applications with 650 gallons of dispersant was applied May 21
The spotter aircraft and the AT-802 will depart using the coordinates for the application with the spotter aircraft flying above and behind the AT-802 calling out directional commands as the aircraft enter the application area. The application may be straight progressions of an A-B line on the GPS, or patches of applications, turning the spray on and off as necessary. Any aquatic life, turtles, dolphins, etc., cannot be sprayed or drifted on. Marine mammals have a 3 nm no spray zone. Boats and oil rig platforms have a two-mile buffer zone. A P3 aircraft is overhead, monitoring the process live to the Command Center. Often, there may be at one time several dozen aircraft in the air, spraying and transporting personnel and supplies.
Time will reveal if the AT-802 will become a permanent fixture for aerial oil spill recovery operations. Many eyes are focused on how well this aircraft will perform. There is no room for error. What happens over the Gulf of Mexico waters in the next few days or weeks, or however long it takes to disperse the oil, will determine the future of ag-aircraft working oil spills. The industry is fortunate the AT-802 operators, the King Air spotter pilots, the support personnel and equipment are topnotch.
|Search articles // View updated photos (June 29, 2010)|