Ooops, Did We Just Close An Airport Over A UFO Sighting?

Picture this: it’s late in the evening on a freezing cold, dark, and windy December night in southern England, and an airport worker at Gatwick — London’s second international airport — sees something fly past in the gloom above the floodlights. The weather and darkness makes it difficult to see what the object was, but the report is phoned in to security. What was it? A flock of birds? A piece of plastic litter caught by the wind and blown through the night? In this case, the call is recorded as a drone. Because the magic D-word has been uttered, a security plan swings into action, the airport is put on a high state of readiness, and flights are suspended.

Gatwick by night, on an evening far less inclement than last week. News Oresund [CC BY 2.0].
Gatwick by night, on an evening far less inclement than last week. News Oresund [CC BY 2.0].
Thousands of people across the site are put on alert, watching for the drone. And of course, the drone reports roll in, and the story takes on a life of its own. People who have no idea what a drone looks like in the air are now expecting to see one, so of course when a flock of birds or a plastic bag caught by the wind crosses their peripheral vision they too are convinced that it is the drone. Night turns into day, there is a lull in the reports so the airport re-opens, only to be closed again following a fresh spate of sightings. Flights are diverted all across the country, and tens of thousands of passengers are stranded in the terminals.

No, it's not a speck of dirt on your screen, it's a drone! BBC (Fair use)
No, it’s not a speck of dirt on your screen, it’s a drone! BBC (Fair use)

There follows three days of airport closure drama. No photos emerge despite almost every one of the many thousands of people on the site having a camera phone from which they are Tweeting about the queues in the terminal. There is a grainy video, but it is indistinct, and crucially it doesn’t have anything in it that is identifiable as Gatwick. Meanwhile the police are frustrated in their search for the drone operators, who like their drone, prove difficult to pinpoint

During the third night a pair of arrests are announced, a local couple. The police have saved the day, the culprits are under lock and key. Everyone breathes a sigh of relief, the airport re-opens, and that’s the end of that. Except of course it isn’t, because inconveniently the pair are found to be blameless and released. When pressed during an interview, a police spokesman then makes the embarrassing admission that there is a possibility that there may never have been a drone at all.

You Couldn’t Make It Up

If these are the drone parts they've found, they're doing it wrong. Francis Wood [CC BY-SA 3.0]
If these are the drone parts they’ve found, they’re doing it wrong. Francis Wood [CC BY-SA 3.0]
You might imagine that this was the fictional plot of a thriller novel, but sadly not. All of the above is a tale of the last few days of events in the British news, save for most of the first paragraph which is our guess at how the first drone sightings may have happened. At the time of writing there remains the possibility that there could have been a drone over Gatwick, but given the current dearth of evidence it is one that seems tenuous. There are reports of drone wreckage, but since readers with long memories will recall UK police once identified RepRap parts as a 3D printed gun we’ll wait until we see it before we call it that.

If there was indeed a drone then of course we would like to see its operators brought to justice forthwith. But what concerns us at Hackaday are the implications the episode could still have for those of our community with an interest in multirotors. The usual clamour was made for Government to do something about it, and we know that would have meant a fresh set of onerous regulations for responsible multirotor owners while doing nothing about the criminals, because of course criminals have little regard for laws.

So if we are to glean anything from this sorry mess, we must examine it from several angles. Why is there a lack of drone detection technology in place? How should drone reports initially be treated and investigated on the ground? How should they be dealt with in official inquiries, and how then should lawmakers see them? This will inevitably have a British flavour to it because of the incident in question, but the points are just as valid worldwide.

When a Drone Report Comes In, We Need a Reliable Way to Evaluate It

An oft-shared drone identification guide for airline pilots, of uncertain provenance (phantompilots.com).

When we are told something new, it passes a process of evaluation in our minds. We look at the source, and weigh up the story itself. If a guy with crazy hair in the street tells us that the aliens have landed and are controlling the Prime Minister with a ray gun, it will probably be discounted. But if Hackaday tells us that someone has hacked a VGA chipset to work as a software-defined radio we’re guessing most of you would be very interested indeed.

When a fresh drone incident is reported it appears that this evaluation process has historically been defective. We have previously discussed official incident reports that come with no physical evidence of a drone, but contain descriptions of drones with capabilities unmatched even by jet fighter aircraft. It seems like any eyewitness report in which the culprit is named as a drone is automatically taken at face value no matter how unlikely it may be. The fact that a report may have come from a pilot is sometimes mentioned as a boost to its credibility, but that is a false assumption. A pilot who is not familiar with either how drones appear from a distance or what the capabilities of a drone are in the air can only be considered an unreliable witness, because while they may know a lot about aircraft they lack the required expertise for this judgement. So what can be done to help boost the quality of reporting and to immediately highlight credible reports while requiring more for dubious ones?

In the case of a near miss in open airspace there may be little effect on ground-based facilities, but at an airport such as Gatwick there can be no chances taken by the authorities. A drone collision on an aircraft on final approach could cause hundreds of fatalities, so upon receipt of a report they must have had little choice but to close the runways. There appears to have been a lack of drone detection technologies in place at Gatwick which means that the only source available to the airport would have been the eyewitnesses themselves, and since we have amply demonstrated the potential for eyewitness reports being unreliable then the current confusion becomes an inevitability. It is imperative that more reliable detection technologies be fitted or developed if necessary. This is especially true when precautionary shut-downs stretch past minutes or hours into world-news-making delays as happened in this instance.

Competent Police Investigations and Responsible Journalism on Drone Reports

The mass media tech story cycle. Our apologies to Gartner. Curve image: Jeremykemp [ CC BY-SA 3.0 ]
The mass media tech story cycle. Our apologies to Gartner. Curve image: Jeremykemp [ CC BY-SA 3.0 ]
Once an incident has started and news of it emerges there is a consequent effect upon members of our community. Legitimate drone fliers away from the airport will find themselves under more scrutiny, and since it is already a common tale to hear of police being called when flying is under way that means they could face harassment and wrongful arrest. Indeed though we do not know all the details of the pair arrested near Gatwick it smacks of their being arrested in a round-up of convenient local drone enthusiasts rather than as a result of meaningful investigation. That the names of the pair were leaked and they became the subject of a media frenzy further shows the danger in which they were placed, as well as the irresponsibility of the reporters who covered their plight.

Perhaps Most Importantly: We Need Accurate Official Incident Reports

Whatever happens in a drone report, whether it be an arrest or an embarrassing debacle, there will inevitably be an official incident report from the Civil Aviation Authority, the regulator of British civilian airspace. This will form the official record of the event, and thus should strive to be as accurate as possible, but here the process falls short for the final time. There appears to be no evaluation step performed on the available evidence and no requirement for physical proof. So if an eyewitness reports behaviors about the drone that no drone ever built could possibly be capable of, it is solemnly recorded as fact. Our previous article on this subject highlights multiple such accounts, and this is an important point because as the official record these reports are what informs legislators. When they make laws pertaining to drones it is imperative that their decisions are based upon accurate evidence, and it is clear that this is not the case. Given that they will no doubt be reviewing drone legislation in the wake of this fiasco it is particularly important that the investigators consult people with specialist knowledge in the field, demand physical proof rather than heresay, and most importantly question accounts that stretch credibility.

It seems obvious that the multirotor hobbyist is caught in a perfect storm of incompetent authorities, deeply flawed investigations, shoddy journalism, and clueless legislators. This incident has laid bare some of the shortcomings, and it is to be hoped that a few lessons might be learned to produce less of a debacle surrounding future drone incidents. It is still a developing story so there may be a breakthrough and the whole narrative will change, and if that turns out to be the case then we hope they find the correct perpetrator this time and send them away at Her Majesty’s pleasure for a very long time. We’re guessing though that every effort will be made to push it as far under the carpet as possible to save red faces among officialdom. As multirotor enthusiasts we must keep the issue of poor investigation alive though, for if we let it be buried once more it will come back to trouble us again.

London Gatwick Airport Shuts Its Doors Due To Drone Sighting

If you could pick a news story you would prefer not to be woken with, it’s likely that a major airport being closed due to a drone sighting would be high on the list. But that’s the news this morning: London’s Gatwick airport has spent most of the night and into the morning closed due to repeated sightings. Police are saying that the flights appear to have been deliberate, but not terror-related.

We’ve written on reports of drone near-misses with aircraft here back in 2016, and indeed we’ve even brought news of a previous runway closure at Gatwick. But it seems that this incident is of greater severity, over a much longer period, and even potentially involving more than one machine. The effect that it could have on those in our community who are multirotor fliers could be significant, and thus it is a huge concern aside from the potential for mishap in the skies above London’s second largest airport.

It is safe to say that if there was indeed a multirotor above Gatwick last night then its operator should be brought to justice and face the appropriate penalty without delay. Responsible fliers are painfully aware of the rules involving multirotor flight, and that airports of any description are strictly off-limits. It matters not whether this was a drunken prank or a premeditated crime, we hope you’ll all join us in saying that anybody flying outside the law should be reported to the authorities.

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The Guts Of Switched Mode Power Supplies, Brought To You By Oscilloscope Repair

The Tektronix 2000 series of oscilloscopes are a mainstay for any electronics lab. They work, they’re relatively cheap, they’re good, and they’re available in just about any surplus electronics store. [Mr.RC-Cam] has been hoarding one of these for twenty years, and like any classic piece of equipment, it needs a little refurbishment every now and again. Now, it’s time. Here’s how you repair one of the best values in analog oscilloscopes.

This repair adventure began when the scope died. There were no lights, no screen trace, and a brief hiss sound when it was powered on. (Ten points if you can guess what that hiss sound was!) Armed with a schematic, [Mr.RC-Cam] dove in and pulled the power supply, being careful to discharge the CRT beforehand.

There were no bulging capacitors, no obviously overheated components, and just a little bit of dust. The only solution was to look at the parts with a meter one at a time. Removing the big caps provided access to a row of diodes, which revealed the culprit: a single shorted diode. This part was ordered, and a few other housekeeping tasks were taken care of. The lithium battery on the processor board responsible for storing the calibration constants was replaced, and the new, smaller, caps got lovely 3D printed mounting flange adapters. Now, this old ‘scope works, and we’ve got a lovely story to tell around the electronic campfire.

New Transistor Uses Metal And Air Instead Of Semiconductors

The more things change, the more things stay the same. Early electronic devices used a spark gap. These have been almost completely replaced with tubes and then semiconductor devices such as transistors. However, transistors will soon reach a theoretical limit on how small they can be which is causing researchers to find the next thing. If the  Royal Melbourne Institute of Technology has its way, we’ll go back to something that has more in common with a spark gap than a conventional transistor. You can find the source paper on the Nano Papers website although the text is behind a paywall.

The transistor uses metal, but instead of a semiconductor channel — which is packed with atoms that cause collisions as electrons flow through the channel — the new device uses an air gap. You might well think that if fewer atoms in the channel are better, why not use a vacuum?

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Putting That Airplane On The Map – Live And With Python

Mankind’s fascination with airplanes is unbroken. Whether you’re outside with your camera, getting an actual glimpse of the aircraft, or sitting at home with your RTL-SDR dongle and have a look at them from a distance, tracking them is a fun pastime activity. Provided, of course, that you are living close by an airport or in an area with high enough air traffic. If not, well there’s always real-time tracking online to fall back to, and as [geomatics] will show you, you can build your own live flight tracking system with a few lines of Python.

As it’s usually the case with Python, a lot of functionality is implemented and readily available from external modules, which lets you focus on the actual application without having to worry too much about the details. Similarly, plenty of data can be requested from all sorts of publicly accessible APIs nowadays. If you are looking for a simple-enough example to get into both subjects with a real-world application, [geomatics]’ flight tracker uses cartopy to create a map using Open Street Map data, and retrieves the flight information from ADS-B Exchange‘s public API.

We have seen ADS-B Exchange mentioned a few times before, for example with this ESP8266 based plane spotter and its successor. And if you’re more curious about the air traffic in your direct surroundings, it’s probably time for a DVB USB dongle.

1,000 Watt Power Supply Tear Down And Repair

[TheSignalPath] wanted to repair a broken Instek PSW80-40.5 because it has a lot of output for a programmable power supply — 1,080 watts, to be exact. This isn’t a cheap supply — it looks like it costs about $2,200 new. The unit wasn’t working and when he took it apart, he found a nasty surprise. There is a base PCB and three identical power supply modules, and virtually no access without disconnecting the boards. He continued the teardown, and you can see the results in the video below.

Each of the power supply modules are two separate PCBs and the design has to account for the high currents required. The power supply is a switching design with some filtering on the motherboard. One of the boards of the power supply module rectifies the incoming line voltage to a high DC voltage (about 400 volts). The second board then does DC to DC conversion to the desired output.

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Professional Results From Cheap Air Compressors

The portable air compressors sold at big box hardware stores like Lowe’s and Home Depot are perfectly suited for the jobs they’re advertised for: namely throwing some nails into the wall or filling tires. But if you try to respray your car with that $50 Black Friday pancake air compressor, you’re going to have a bad day. The relatively small amount of air they hold is almost guaranteed to be contaminated with oil and moisture, making it unsuitable for painting or even just blowing the dust out of electronics.

But all is not lost. [Stephen Saville] has done an excellent job documenting his work to turn these low cost homeowner-grade air compressors into something suitable for spraying auto body panels. But even if you aren’t looking to put a sick pearlescent finish on the family minivan, these tips are worth checking out. From increasing the usable volume of air in the system to separating out contaminants, these modifications can unlock a whole new world of pneumatic projects.

The big one (literally and figuratively) is the swirl tube [Stephen] builds out of an old CO2 cylinder. The idea is that this will centrifugally clean the air, not unlike a cyclonic dust separator. As the air enters the top of the cylinder and spins around, contact with the cold metal will cause any moisture to condense out and collect down at the bottom. Oil and other particles in the air should also get spun out, leaving a central column of cleaner air. The collected water and contaminants at the bottom can be occasionally purged out by way of the cylinder’s original valve.

With a source of clean and dry air sorted, [Stephen] next wanted a way to get it around his shop. Using scrap metal pipes he puts together a system that not only gives him air where he needs it, but also increases the volume of compressed air he has available. By using large smooth metal pipes rather than something like flexible rubber hose, the plumbing puts very little resistance on air flow. The pipes therefore can be considered something of an extension of the compressor’s primary tank.

In the video after the break, [Stephen] shows off his new air system by laying down a very nice looking coat of paint on a car hood, but he also goes through the whole build process if you want to see the nuts and bolts of his system. He gives some great tips on welding and working with dissimilar metals which are worth the price of admission alone.

Outfitting the workshop with an integrated compressed air system sounds like the perfect second project to tackle once you’ve got the built-in dust collection system up and running.

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