Ingestion tests: birds and water

If an airplane encounters a flock of geese on its way to warmer climes, it’s not only a bloody encounter for the birds, it is also a major risk for those inside the plane. Even small birds can cause an engine to stall or explode.

According to a recent study conducted by the International Bird Strike Committee, there is only about one accident that results in human death in one billion flying hours. Most bird strikes cause little damage to the plane – but the collision is very often fatal to the bird. And such accidents cause damage to commercial aircraft costing some $1.2bn to repair every year.

One of the aviation pioneers, Cal Rodgers, was the first person to die from a bird strike. In 1912, his aircraft collided with a gull over Long Beach, California that became tangled in his plane’s control cables. Rodgers’ plane crashed and he drowned.

To ensure that engines continue to operate even after a bird strike, engine manufacturers do just that: throw dead birds into test engines on the ground with a so-called “chicken gun”– a large-diameter, compressed-air cannon. The chicken gun was invented in the 1950s by de Havilland in the UK; freshly killed chickens were packed into a compressed air gun and fired at the windscreen and engines. Aircraft manufacturers also simulate bird strikes at cockpits, also using the gun to propel birds onto a windshield, to ensure that it won’t break the plane’s windows or change the way it flies.

 

How space tourism and rockets to Mars became 'critical' business during the pandemic

Vacant office buildings, factories and restaurants across the country serve as ghostly reminders of an economy shuttered by the Covid-19 pandemic. But the US space industry has remained open for business.

SpaceX, for example, continues to build and test early prototypes of its Starship spacecraft, which CEO Elon Musk has long billed as the vehicle that will one day carry the first humans to Mars. And the company continues to launch batches of satellites into orbit as part of its plan to debut a multibillion-dollar telecom business later this year. Factories belonging to Blue Origin and Virgin Galactic (SPCE) — both of which are developing rocket-powered vehicles designed to send wealthy tourists to the edge of space — also remain open for workers. And some startups, such as Firefly and Relativity, are still working to design rockets that might not be ready to fly for months or years into the future.

In Covid-19 guidelines it issued in March, the US government deemed the space industry part of the country's "critical infrastructure." The Department of Defense and NASA have asked their private-sector partners to continue working on key programs, such as SpaceX's upcoming mission to shuttle two NASA astronauts to the International Space Station.

Lightning tests

On average, every commercial plane is hit by lightning about once a year, according to the Cardiff University’s “lightning lab” in the UK – a recently established laboratory where Airbus, for example, conducts lightning tests. The university’s lab is formally called the Morgan Botti Laboratory at the School of Engineering.

Despite lightning strikes, traditional aluminium planes are usually able to continue their journey safely – the high electrical conductivity of aluminium can dissipate the electricity through the aircraft structure quickly without causing any damage. But not all planes are made from metal anymore: to reduce weight and therefore fuel consumption, next-generation aircraft are built from new and much lighter materials such as carbon fibre, which tend to have much lower electrical conductivity than aluminium, says Airbus’s Matthew Cole.

This can lead to up to 25% improvement in fuel efficiency. These materials, however, need to be protected against lightning strike. It is usually done by adding a thin layer of metal mesh or foil. “This layer is safe and effective and successfully dissipates the charge, mitigating damage,” says Cole. The problem, though, is that it adds weight.