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BASH: Not getting much better

The acronym was created in the sixties when Bird Aircraft Strike Hazard had become a true menace. Even though the battle had been going on for years the cost of repairing turbofans hit by birds was only part of it. Planes were capable of crashing after such mid-air collisions and there are several such incidents on record with major loss of life.
The fight continues to this day and the rulers of the sky still demand and get their tax.
The impact point of a small bird on a Jumbo jet is like being hit by a bullet. The impact with a big bird like a goose or an eagle is tantamount to a midair collision.
Both military and civilian aircraft are vulnerable.
The fight goes on. When it comes to freedom of the skies, birds still have the edge. The world’s air traffic control system locks aircraft into an airway system which only makes use of around five percent of the available space in the sky.
So what is implied in the concept of flying free as a bird if one is talking in the context of a commercial aircraft? To understand the difference, it is necessary to understand how an aircraft’s flight path is determined.
Basically, the flight path is a ‘contract’ between the pilot of the aircraft and the air traffic controller (ATC) at the airport or ground station.
This contract requires the aircraft to fly along a predetermined specific route.
A pilot cannot deviate from this path without the consent of the ATC.
For example, if (s)he encounters a thunderstorm, the pilot must inform the ATC who will then redesignate the flight path to avoid the storm.
Given the fact that a traditional ATC system relies on a rigid and inflexible ground-based infrastructure — comprising thousands of navigation beacons, radar installations and landing aids — following the instructions of the ATC may often take an aircraft out of its way, place it at altitudes that reduce its efficiency, or send it into head winds that slow it down.
As a result, an air carrier takes more time, and burns more fuel, than is necessary to reach its destination, raising airline costs and, thus, the cost of air transportation for travelers and shippers.
Breaking this total dependency on ground infrastructure is central to the Free Flight concept.
It gives an air carrier greater discretion in choosing the routes, altitudes and speeds it flies, particularly during the cruise phase of flight, permitting it to follow the most advantageous route between takeoff and landing, as well as seek out the most favorable wind conditions.
Enabling an aircraft to navigate independently of ground systems, and be tracked accurately without the need for radar, will allow the air carrier to operate more efficiently, saving customers time and money.
It will also increase airspace capacity and reduce congestion. This is crucial. Given the fact that the air traffic system is growing at an annual rate of about 3-5 percent annually it is predicted that the current ATC system and airspace architecture will not be able to handle this increase over the next 15 years.
In fact, the ATC system is not designed to handle even current traffic levels.
Congestion, flight delays and safety concerns are the order of the day and the prospect of airspace gridlock could loom within a few short years.
And birds aren’t the best of friends, because they tend to vie for the same airspace, very often with tragic results. Ask Tom Agee of Condor Express. He was among the luckier ones that early September morning when he brought his King Air in to land at Danbury Municipal in Connecticut. The weather was picture postcard perfect. A flock of Canada geese waddled around utterly unperturbed by the sound of his approaching airplane. But moments before Agee could touch down, a Cheyenne taxied out for departure, spooking these permanent denizens of the area. The big brown, white and black birds rose as one into the air, straight into the King Air’s line of descent.
“I had no room to maneuver,” Agee recalled.
“Before I could tell which way they were going, they hit me. One was coming right for the co-pilot window, it was a hard jolt – knocked the oxygen mask down and tossed around some cups in the back.”
The pilot experienced a yaw and loss of lift on one side, but managed to land safely. A post-collision inspection turned up five goose carcasses. One bird had hit the right nacelle just after the prop, one struck the fuel siphon spout under the wing, and one hit the leading edge between the nacelle and deice boot with such force that it left a concave depression. Two birds hit the nose, one bouncing off and striking the co-pilot window, while the other put large dents in the avionics bay.
Agee’s frightening experience is repeated often. Collisions between wildlife and aircraft occur regularly at airports across the US and around the world.
According to a recent FAA study, nearly 700 mammal strikes and over 25,000 bird strikes are reported annually. Worldwide, more than 420 aircraft have been destroyed and over 400 persons killed as a result of wildlife strikes, making these accidents the second leading cause of aviation fatalities. Damages to aircraft cost the industry around $400 million annually.
The first reported bird strike occurred in 1912, and cost Cal Rogers (the first man to fly across the US) his life.
Among others, on October 4, 1960, a Lockheed Electra 4 engine turboprop taking off from Boston’s Logan International Airport ingested a flock of starlings. The aircraft lost power in three of its four engines and crashed into Boston Harbor, killing 62 of the 72 passengers on board.
Equally unlucky was the crew of a US Air Force AWACS plane, a few years back. The Boeing 707 lost two of its four engines after striking a flock of geese during take-off. The crash killed all 24 people on board.
Bird strikes are also particularly serious for helicopters, whose aerodynamics can be completely compromised by the resulting damage.
In one dramatic example, the pilot of a Bell 47G-2 attempting to maneuver around birds induced rotor flapping that exceeded the stop-to-stop clearance.
The rotor contacted the synchronized elevator, causing the pilot to lose control.
The aircraft crashed inverted in the backyard of a residence in Tulsa, killing the pilot and destroying the helicopter.
Just random examples to show how serious an impact with birds can be. Think about the physics — an average duck weighs 1 to 4 pounds and geese can go up to 25 pounds. A 200 knot collision with a two-pound gull can have an impact force of the order of 8,000 pounds, while a 12-pound bird struck at 130 knots has the same force as a 1,000 pound weight dropped from 10 feet.
At 125 knots, an impact with one of the larger birds approaches 100,000 ft lbs of energy. Aircraft are not designed to withstand or survive such strikes.

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