Drone collisions with airliners may not be fatal, US study suggests

And UK Department for Transport faces questions over scary rival study


Updated A ground-breaking US study has shown that while drone collisions do pose a threat to airliners, the odds of a collision causing a crash are much lower than a rival British government study claimed.

The American Federal Aviation Administration (FAA)’s drone research divison, Assure, conducted a study into the effects of drones colliding with commercial aircraft. Public concern over potential collisions is high, even though only two have ever been recorded across the world.*

Computer simulations carried out by Assure found that a 1.2kg quadcopter striking the windscreen of a commercial jet airliner travelling at 250 knots simply bounced off, leaving a few marks or chips on the windscreen.

“Due to the low angle impact in the transparency (~45°), the UAS impacts were deflected without inducing considerable damage to the windshield,” wrote the study’s authors. The worst damage likely to be caused was permanent damage to the windscreen but no failure of the whole structure.

A simulated DJI Phantom 3 hits a Boeing 737 windscreen. Pic: FAA/Assure

A simulated DJI Phantom 3 hits a Boeing 737 windscreen. Pic: FAA/Assure

“The FAA study chose to test at 250kts - the reason being that this is the maximum speed below 10,000ft according to ICAO,” drone researcher Ian Povey of Clear Vision Security told The Register. “Clearly the FAA study was attempting in part to recreate the most likely collision environment in real-world terms.”

The Assure simulations assessed what would happen if either type of drone smashed into the wing leading edges, windscreens, tail fin leading edge or tailplane (horizontal stabiliser) leading edges of the aircraft. Researchers used computer models of a Boeing 737 and a Learjet 31A, representing narrow-body airliners and small business jets respectively, based on each aircraft’s approximate size.

Models of the two drone types used in the simulations – a DJI Phantom 3 Standard quadcopter and a fixed-wing Precision Hawk Lancaster Hawkeye III – were obtained by 3D-scanning real-world items and turning the resulting files into finite element analysis (FEA) models.

The computer simulations of the collisions themselves were validated by dropping the real-world drones from various heights, with the resulting smashes filmed on high-speed cameras and compared to simulator predictions. Researchers found a high match between simulated damage and actual damage.

Fires caused by batteries were also considered by the researchers. While a collision at full speed with the windscreen, wing leading edges or tail fin was most likely to completely destroy the battery, scattering its components, a collision with either aircraft’s horizontal stabiliser (tailplane) was considered most likely to partially damage a drone’s battery and start a fire.

The British government ain’t going to like this

In contrast to the American study being released in full for public discussion, a similar British government-funded study – seemingly carried out with the intention of giving the government a public reason for introducing sweeping new restrictions on drones – was only revealed in summary form, making it impossible to draw meaningful conclusions from the research.

Further criticism was levelled at the fact that military research firm Qinetiq, the British study’s author, couldn’t find a way to launch its test drone at the Airbus A320-series windscreen being used as a target for real-world validation of its simulations. A red-faced Department for Transport (DfT) public relations flunkey refused to give El Reg a statement detailing why mandarins didn’t want to release the full study... which is being used as a basis for legislation.

Licensed drone operator Ian Hudson was scathing about the British study, telling El Reg: “Drone industry experts the world over were bemused at the UK DfT study choosing to not use a testing methodology that assessed drone risk using a modern drone airframe; they chose a prehistoric Flame Wheel body with a Nikon bridge camera (an unrealistic imaging device) and also an unrealistically large LiPo battery, then arranged it into a javelin configuration.”

A DfT spokesperson told us today: “Drones have great potential and we want to do everything possible to harness the benefits of this technology as it develops. This is a new and technically complex field and research is essential to ensure any safety risks are properly addressed. The Department is considering the US research and will look to engage further with the FAA on this issue.”

Clear Vision Security’s Povey added that he had been told the DfT’s modelling was carried out at a simulated speed of 340kts, which is the sort of speed airliners reach when well above 10,000ft. However, the Assure study gave the service ceiling of the DJI Phantom 3 as 19,685ft (6,000m), though its firmware sets a height-above-ground limit of 394ft/120m.

Drone operators are also unhappy with UK.gov

The British drone industry is disgruntled with the government’s proposal to require licensing for all drone operators from late next year. While nobody disputes that some kind of registration and mandatory safety training scheme is necessary, the arguments on either side centre on where to draw the lines and on what basis. A Parliamentary bill setting out the licensing scheme is in the works and due for publication in spring 2018, we understand.

Underpinning that bill is the “science” of the DfT drone study. The lower weight limit for drone operators requiring a licence is just 250 grams, based on the findings of the DfT study – though an EU plan to impose mandatory licensing, publicly announced last week, also picked 250g as its lower limit, suggesting some behind-the-scenes string-pulling by Brussels.

“It's a disservice to image of the UK as a country where businesses can conduct testing on new technology when the government can't conduct impartial, credible and transparent risk analysis that is open to peer review,” thundered Hudson.

Povey of Clear Vision Security added: “Either the FAA have endangered the safety of commercial airliners by releasing so much information, or the DfT have lied to the public. If it's the case that the DfT have lied about the reasons for covering up the report methodologies and data this has stark implications for the proposed legislation and regulation of drone users scheduled for next year.”

American flight safety experts are treating the drone problem seriously, undertaking peer-reviewed research and opening up their methodologies and results for public inspection and critique. By contrast, the DafT approach, in concert with Qinetiq, has become impossible to sustain, particularly in the face of international criticism over its deliberately unscientific approach. ®

Bootnote

One drone collision occurred in Canada; the other was in the US, involving a military helicopter.

Update

The Assure study also looked at what happens when a medium-sized business jet engine ingests a drone, using the same drone models as for the airframe analysis and a generic model of the first stage of a turbofan engine.

Although the researchers found that in no simulated scenario did drone ingestion result in an uncontained engine failure, they only modelled the first stage of the compressor fan, and not any of the multiple stages of turbines found behind the fan in most turbofan engines. The researchers acknowledged this, writing: “As was discussed in an FAA UAV ingestion safety report, a very small hard body fragment as little as 0.66 pounds poses the potential for severe engine damage. So even for the case where there is only minor damage to the fan, the engine might not survive the UAV ingestion.”

They also recommended further research be done into the effects of drone ingestion on a commercial airliner-sized turbofan engine.

Similar topics

Narrower topics


Other stories you might like

  • Microsoft Azure to spin up AMD MI200 GPU clusters for 'large scale' AI training
    Windows giant carries a PyTorch for chip designer and its rival Nvidia

    Microsoft Build Microsoft Azure on Thursday revealed it will use AMD's top-tier MI200 Instinct GPUs to perform “large-scale” AI training in the cloud.

    “Azure will be the first public cloud to deploy clusters of AMD's flagship MI200 GPUs for large-scale AI training,” Microsoft CTO Kevin Scott said during the company’s Build conference this week. “We've already started testing these clusters using some of our own AI workloads with great performance.”

    AMD launched its MI200-series GPUs at its Accelerated Datacenter event last fall. The GPUs are based on AMD’s CDNA2 architecture and pack 58 billion transistors and up to 128GB of high-bandwidth memory into a dual-die package.

    Continue reading
  • New York City rips out last city-owned public payphones
    Y'know, those large cellphones fixed in place that you share with everyone and have to put coins in. Y'know, those metal disks representing...

    New York City this week ripped out its last municipally-owned payphones from Times Square to make room for Wi-Fi kiosks from city infrastructure project LinkNYC.

    "NYC's last free-standing payphones were removed today; they'll be replaced with a Link, boosting accessibility and connectivity across the city," LinkNYC said via Twitter.

    Manhattan Borough President Mark Levine said, "Truly the end of an era but also, hopefully, the start of a new one with more equity in technology access!"

    Continue reading
  • Cheers ransomware hits VMware ESXi systems
    Now we can say extortionware has jumped the shark

    Another ransomware strain is targeting VMware ESXi servers, which have been the focus of extortionists and other miscreants in recent months.

    ESXi, a bare-metal hypervisor used by a broad range of organizations throughout the world, has become the target of such ransomware families as LockBit, Hive, and RansomEXX. The ubiquitous use of the technology, and the size of some companies that use it has made it an efficient way for crooks to infect large numbers of virtualized systems and connected devices and equipment, according to researchers with Trend Micro.

    "ESXi is widely used in enterprise settings for server virtualization," Trend Micro noted in a write-up this week. "It is therefore a popular target for ransomware attacks … Compromising ESXi servers has been a scheme used by some notorious cybercriminal groups because it is a means to swiftly spread the ransomware to many devices."

    Continue reading
  • Twitter founder Dorsey beats hasty retweet from the board
    As shareholders sue the social network amid Elon Musk's takeover scramble

    Twitter has officially entered the post-Dorsey age: its founder and two-time CEO's board term expired Wednesday, marking the first time the social media company hasn't had him around in some capacity.

    Jack Dorsey announced his resignation as Twitter chief exec in November 2021, and passed the baton to Parag Agrawal while remaining on the board. Now that board term has ended, and Dorsey has stepped down as expected. Agrawal has taken Dorsey's board seat; Salesforce co-CEO Bret Taylor has assumed the role of Twitter's board chair. 

    In his resignation announcement, Dorsey – who co-founded and is CEO of Block (formerly Square) – said having founders leading the companies they created can be severely limiting for an organization and can serve as a single point of failure. "I believe it's critical a company can stand on its own, free of its founder's influence or direction," Dorsey said. He didn't respond to a request for further comment today. 

    Continue reading
  • Snowflake stock drops as some top customers cut usage
    You might say its valuation is melting away

    IPO darling Snowflake's share price took a beating in an already bearish market for tech stocks after filing weaker than expected financial guidance amid a slowdown in orders from some of its largest customers.

    For its first quarter of fiscal 2023, ended April 30, Snowflake's revenue grew 85 percent year-on-year to $422.4 million. The company made an operating loss of $188.8 million, albeit down from $205.6 million a year ago.

    Although surpassing revenue expectations, the cloud-based data warehousing business saw its valuation tumble 16 percent in extended trading on Wednesday. Its stock price dived from $133 apiece to $117 in after-hours trading, and today is cruising back at $127. That stumble arrived amid a general tech stock sell-off some observers said was overdue.

    Continue reading

Biting the hand that feeds IT © 1998–2022