Hazard of Aircraft and Bird Strike

 What is a bird strike


Bird strike is a collision of bird or bat with an airborne vehicle such as an aircraft. Usually, a bird strike is fatal to bird and it causes damages to aircraft structures. The area of high possibility to get a bird strike is radome, windscreen, fuselage section, wing leading edge and, engine inlet area.
Ingestion of a bird into an aircraft engine will cause the engine to shut down abruptly. This will cause the aircraft to suffer some power loss and loss of lift. Hence, the effect of a bird strike should not be underestimated. A bird strike will cause the operator to have an issue of increasing aircraft maintenance costs due to the damage of the aircraft. Sometimes a bird strike will cause a fatal accident. I have listed down some of the accident that was caused by a bird strike.

HAZARD SPECIES


The following are the species identified as possible threat to aircraft. This list is in decreasing the level of threat.

 Crested Honey-buzzard -Pernis ptilorhynchus


This species is both migratory and an uncommon resident in Malaysia. A medium-sized hawk, this species feeds on rodents, lizards, snakes and the larvae of honeybees (hence its name). The average weight is 750 to 800 gms. During the northern winter, this species congregates in large numbers and heads south from continental Asia to the Malay Archipelago (Medway & Wells 1976).
Largest numbers occur as they move into Peninsular Malaysia from the north. Observations on this migration over the past thirty years have shown that these birds cross the Straits of Malacca at Cape Rachado (Tanjung Than) in Melaka. This is the narrowest point between Peninsular Malaysia and Sumatra. This southward migration begins in mid-October, lasting until December. Peak numbers on the passage, however, have always been recorded within the first six weeks from October.
In the spring, the birds return to their breeding grounds in Asia, starting the second leg of their annual migration cycle. Honey-Buzzards on northward migration arrive at Cape Rachado from late-February to early March. This spectacular sight of these birds coming in low and then spiralling upwards has been attracting locals and foreign birdwatchers to Cape Rachado for many years.\n2.3.2 Brahminy Kite -Haliastur Indus
This medium-sized bird (weight; 700 -750 gms) is the most common resident bird of prey in Malaysia. In 1991, this species accounted for 16 strikes involving aircraft at Malaysian airports. On account of the weight of this bird, it makes this species the bird most likely to cause severe damage to aircraft in the country. Though found in most habitats, it is more common along the coast and feeds on fish and carrion. It, therefore, poses a hazard mainly at airports along the coast. This species was not recorded at Subang in 1991 (Sebastian 1992a). Previous studies have also determined the Brahminy Kite to be attracted to airports that have shorebirds wintering at the airfield. Apart from hunting these shorebirds, these kites also feed on the carcasses of birds struck by aircraft, thus posing a direct threat to aircraft landing and taking off.
This species was recorded in all habitats within the study area. With the new KLIA development and the imminent advent of large areas of short grass, there is a distinct possibility that this species would be attracted to the airfield.

Brahminy Kite -Haliastur Indus


This medium-sized bird (weight; 700 -750 gms) is the most common resident bird of prey in Malaysia. In 1991, this species accounted for 16 strikes involving aircraft at Malaysian airports. On account of the weight of this bird, it makes this species the bird most likely to cause severe damage to aircraft in the country. Though found in most habitats, it is more common along the coast and feeds on fish and carrion. It, therefore, poses a hazard mainly at airports along the coast. This species was not recorded at Subang in 1991 (Sebastian 1992a). Previous studies have also determined the Brahminy Kite to be attracted to airports that have shorebirds wintering at the airfield. Apart from hunting these shorebirds, these kites also feed on the carcasses of birds struck by aircraft, thus posing a direct threat to aircraft landing and taking off.
This species was recorded in all habitats within the study area. With the new KLIA development and the imminent advent of large areas of short grass, there is a distinct possibility that this species would be attracted to the airfield.

Other migrant raptors


The migratory route taken by the Honey-Buzzards is also used by other species. Although individually they do not pose a regular and serious hazard, collectively over a short period, they could be cause for concern. The more common ones are described below.

Black Baza -Aviceda leuphotes


This is a small raptor (weighing 250 -300 gms) migrating in large flocks. This species winters in small numbers in the Peninsular, using forested areas such as rubber plantations and swamp forest. This species was involved in one strike at Subang International in 1991 (Sebastian 1992a).

Accidents caused by bird strike


The investigator will be having an investigation if an aircraft accident or incident occurred. The purpose of the investigation is to prevent similar issues from happening again and to raise safety issues and recommendations. All investigation is conducted by ICAO Annex 13 which was Aircraft Accident and Incident Investigation. The investigators will produce a final report that includes detail of the accident, cause of the accident, analysis of the cause of accident, conclusion and safety recommendations after the investigation has been completed. Bird strike normally happened at low flight altitude, during aircraft take-off and landing. This is because this was the ideal height range normally where birds fly. Normally, bird strikes cause damages to aircraft structures and usually fatal for birds. Bird strike also poses a threat toward flight safety.

Eastern Airlines flight 375 accident


Eastern Airlines flight 375 was a Lockheed Electra L-188 operated by Eastern Airlines. The aircraft registration number was N 5533. On October 4, 1960, the aircraft crashed after take-off from runway 09 at Logan International Airport in Boston, Massachusetts due to crash with a large flock of Starlings at 120 feet. The accident caused 62 fatalities of 72 onboard: ten people survived, nine-passenger serious injury.
At a height of 120 feet, the bird has been ingested into engines 1, 2 and 4. Engine 1 has been shut down by the flight crew while engines 2 and 4 facing abrupt power loss before recovering. This led to thrust asymmetry and a decrease in airspeed which causes the aircraft to crash. Thrust asymmetry caused the aircraft yawing to the left. At certain low speed, aircraft controllability has been reduced. This led to the left-wing of the aircraft dropped, its nose pitching up, and rolled to the left. Eastern Airlines flight 375 almost fell vertically into Winthrop Bay.\nUS Airways flight 1549
On January 15, 2009, US Airways Airbus A 320 has been hit by a flock of Canada geese after take-off from runway 4 at LaGuardia's, New York City. The registration number was N 106US. The aircraft is flying a route from LaGuardia Airport, New York City to Seattle-Tacoma International Airport Seattle, Washington via Charlotte Douglas International Airport, Charlotte, North Carolina. This incident has no fatalities but 100 passenger injuries (95 minor, 5 serious).
At 2818 feet, the aircraft has been hit by a flock of Canada geese. This hit cause both engines flamed out. The pilot attempt to take control of the aircraft and restart the engines. The aircraft continued to climb to 3060 feet for a further 19 seconds at 185 knots and began a glide descent which accelerating to 210 knots. Finally, the pilot makes an emergency landing in the middle section of the North Hudson River. This incident has been described by worldwide as Miracle on the Hudson. Due to their heroic and unique achievement in aviation, the flight crews have been awarded the Master's Medal of the Guild of Air Pilots and Air Navigators.

Some methods of bird deterrent system


In this section, we will describe some methods of bird deterrent system and how these systems work. It is important to have an effective bird deterrent system to reduce the risk of getting a bird strike and provide a safe environment for air operation and its aviation industry.
Audio system
The aviation industry normally uses an audio deterrent for bird control. These devices use bird calls or ultrasonic sound to encourage birds to find another safer area. Hence, the audio system for bird control is much more environmentally friendly.
Ultrasonic sound
Ultrasonic sound bird deterrent system is often being used as a method of bird deterrent. Ultrasonic sound produces a very high-frequency sound that is normally not audible to the human for the purpose of bird deterrent. The birds will feel discomfort to the signal and try to find another safer place. There is a conflict of using ultrasonic sound as an effective bird deterrent system. This is because birds could not hear a very high-frequency sound as birds almost have the same hearing frequency as humans.
Advantages
It was environmentally friendly
It does not damage to infrastructure and building
Limitations
It will cause noise pollution
The effect is temporary as the birds will return after the audio signal is off
Birds cannot hear the frequencies which were too high