Bird Strike & Aircraft Icing Technology
Aviation safety, as a business and academic focus, evolves; as efforts eliminate/reduce some risks, more is learned about specific problems and new challenges are posed. One of the two recent technological developments has great promise to minimize the potential for bird strikes and the second invention may improve the detection of aircraft icing. That’s great news.
Professor John Swaddle of the College of William and Mary’s Institute for Integrative Bird Behavior Studies conducted a study on how to deter birds from flying near planes. It found that the subject species have a strong need to communicate (hearing alarm sounds from others in the flock AND from predators [the feathered type]). If a noise is broadcast at the same pitch, it acts as a virtual “sonic net” that keeps them from the danger zone defined by the airports’ take-off and landing tracks.
The W&M researchers surveyed the number of birds that landed at or flew over a military airfield near Newport News, Virginia, over a month to define a baseline. Then they used a large outdoor speaker and amplifier, which played acoustic noise for 24 hours a day. The noise played at about the same volume as a noisy restaurant, according to the release. During the experiment period, the data showed a decrease by 82 percent of birds over the airport area.
The study contrasted its white noise which interferes with birds’ ability to hear critical signals with the previous deterrents (loud noises, predator sounds, fake hawks, alarm calls). Bird brain is a misnomer, for ornithologists have shown that their subjects are quite good at learning. Over time, in true Pavlovian fashion, the fact that the “predator sounds” do not correlate with threats results in the birds’ ignoring that sound. Since the W&M system continuously negates hearing, its strength as a “net” does not appear to diminish over time.
Non-lethal, effective reduction of birds in the area of an airport may be a major permanent reduction of this threat.
The National Research Council of Canada (NRC) is working on technology which may mitigate the risk of icing encounters with two minimally intrusive and cost-effective detection systems. RAIR (reducing aviation icing risk) research program is a collaborative effort of which NRC is one of 34 partners from 15 countries. It is funded by the European Commission.
The first invention, the particle ice probe (PIP), detects ice crystals by measuring changes in the electrical characteristics of the surrounding air. The small, lightweight device–about the size of a clenched fist–is designed to be flush-mounted to any aircraft or engine inlet surface, with no measurable effect on fuel consumption or aerodynamics. The PIP has been subjected to 750 hours of ice-crystal altitude tunnel testing, and 140 hours of flight time with four research flight campaigns.
NRC’s second instrument, the ultrasound ice accretion sensor (UIAS), sends out acoustic signals to measure potential icing conditions inside an aircraft’s engine. The credit card-sized sensor detects the buildup of ice particles from airflow passing near the intake area of the powerplant. The UIAS can also be installed on engine surfaces to assess the “classical” icing formed by super-cooled liquid water.
Use of acoustic waves allows the sensor to be mounted anywhere near the engine, positioned close to airflow of the intake. “The methodology behind both technologies is fundamentally similar, to be unobtrusive and easy to install, with the primary difference involving sensor design,” Dan Fuleki, NRC icing group project manager noted. “In both cases, we needed to maximize the signal available while minimizing sensor ‘noise.’”
Both of the NRC projects involve collaborative processes; so industry is familiar with the retrofit techniques, the costs of the equipment and their benefits. Acceptance of a final product is thus likely.
Ain’t technology great!
PS The Huffington Post adorned its article on birds and airports with this copy of a New York Daily News front page story about birds:
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