One of the biggest problems that pilots encounter are bird strikes. Bird strikes are sometimes called bird ingestion (for engines) or bird aircraft strike hazard (BASH). It is a collision between the moving vehicle and an airborne-type animal (such as bats or birds). Usually, it occurs when aircrafts are in low altitude, especially during take-off and landing.
How dangerous are they?
The first accident was recorded in 1905 when Wilbur Orville flew over the cornfield in Ohio.
Based on FAA data, in the US, Mourning Doves are the usual bird species involved in bird strikes. These accidents may be caused by nature but they are dangerous and sometimes deadly. In 1960, Eastern Airlines flight 375 had suffered a deadly crash after they were struck by a flock of European starlings during takeoff; damaging all four engines that led to a crash in the Boston harbor which has led to 62 deaths. Out of 72, 10 have 10 survived and 9 people suffered from injuries.
In the Philippines the last-known bird strike accident happened in 2019, where Cebu Pacific flight 5J 381 took off at NAIA and suffered bird strike. Thankfully,all of the passengers and crews were safe.
Most of today’s bird strikes are manageable, again this wasn’t meant to happen. This is just one of the accidents that naturally occurs.
How do they affect the aircraft?
Global reports from 1988-2019, 217 civil aircraft are either destroyed, or damaged beyond repair due to a wildlife strike. Small numbers, but it matters.
Also, the data showed that most of the parts that are destroyed are engines, accounting for 27% for all damaged components last 2019. It is also the most precious part of the aircraft.
For most general aviation aircrafts, they suffer from structural damages such as shattered flight deck windscreens and control surfaces. Airliner jets mostly suffer from bird ingestion that can also lead to permanent deformations, sudden loss of thrust and engine failure. Although airliners can withstand and operate with one engine, it may compromise the safety of the passengers and crew on board. The common part of the jetliners that suffers from bird strike is windshields, nose cones and leading-edge slats.
How do they address bird strikes?
First, let’s talk about engines. Engineers and manufacturers make sure that every engine of the aircraft can withstand the strike with at least hitting one (1.8kg) bird on the engine. This will ensure that after the strike, the engine will suffer minimal damages and can still operate. It is also checked by the regulators such as FAA and EASA. Manufacturers should pass the standard specifications set by the regulators to ensure safety.
Pilots flying small aircraft up to jetliners are professionally trained on how to handle bird strikes. Even in such situations, pilots can ensure that they can fly the aircraft safely when they encounter bird strikes.
The further counter-measures:
- Wildlife management (lethal and non-lethal)
- Non-lethal
- Habitat Manipulation – depriving of food source
- Exclusion – Putting 3-meter fences with barbed-wire (to avoid also other wildlife strikes)
- Visual Repellants – Using prey birds, landing lights, effigies, and even dogs!
- Auditory Repellants
- Tactile Repellants
- Chemical Repellants
- Relocation of wildlife
- Lethal
- Reinforcement
- Population Control
- Non-lethal
Prior to popular belief, engine markings (such as spirals) were considered as a misconception. According to an article by Boeing’s Aero Magazine, “spirals do not prevent birds from flying into the engine, as the rotation would be too fast for the birds to see the spiral”.
Sources:
https://interestingengineering.com/heres-why-airplane-engines-have-white-spiral-marks-on-them
https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1127&context=icwdm_usdanwrc
https://news.abs-cbn.com/news/07/16/19/bird-strike-forces-plane-to-return-to-naia
