The Drone Files

Since the first models featuring it appeared last year, altitude hold has become all the rage in the toy drone segment. The feature that was once available only in more expensive drones such as the DJI Phantom 3 is now slowly becoming a standard key feature in all toy drones.

Altitude hold 101: a feature that allows a drone to autonomously maintain its altitude without throttle input from the pilot. An air pressure sensor or barometer is used by the drone to determine its altitude and the flight controller uses this reading to determine the right amount of throttle needed to maintain a fixed altitude. This is a great feature to have for beginner pilots who lack the skills needed to fly a drone in manual mode. Altitude hold frees a pilot’s attention on the throttle stick so more focus can be given to the aileron and elevator controls.

The Syma X5HW belongs to a new wave of toy drones that feature altitude hold.

Altitude hold works best in calm flying conditions where there is little to no wind currents. However, things can get a bit tricky when the wind picks up. Which is the point of this article.

When flying against strong winds, a drone’s flight controller can be tricked into thinking that it is flying at a lower altitude. For example, a drone that is flying at a height of 50 meters against a strong wind current might think it is flying at 10 or 5 meters above its launch altitude. This is because a wind current can cause a drone’s barometer to register higher than normal air pressure readings.

In some cases, if the wind is strong enough, the drone might even think it is flying 10 meters below its launch altitude. Such inaccurate readings can cause a lot of complications such as:

1. ‘Malfunctioning’ Throttle Stick — Imagine flying a drone that refuses to obey your throttle inputs. Push the throttle stick all the way down and the drone simply maintains its altitude or maybe does something even more bizarre — it starts to gain altitude slowly! A drone that has flown up to 50m before getting hit by strong winds will think it is losing altitude so pushing the throttle down to zero might not cause it to descend. Instead, it might maintain its altitude or could even gain altitude.
2. Disabled Auto-Land Feature — If your drone has the ‘auto-land’ feature, strong winds can render this feature useless or even plain risky. On a few occasions when I was flying in strong winds, pressing the auto-land button did nothing. In some cases, I have witnessed my drone actually gaining altitude after pressing the auto-land button — a classic example of a drone thinking it’s flying below its launch altitude.
3. Choppy Flight Performance — In the days when toy drones didn’t have altitude hold, flying in windy conditions was not so complicated. With altitude hold, things have become a little bit choppy. When being hit by gusts of wind, a drone’s barometer constantly gets fed with varying degrees of air pressure, causing the drone to adjust its throttle constantly which results in a very bumpy flight.
4. Plunging Flips — Toy drones generally flipped quite well, until altitude hold came along. Drones with altitude hold tend to plunge dramatically after performing flips, almost as if someone shut the throttle down to zero. This is due to a confused flight controller which sees a sudden spike in altitude readings via its pressure sensor at the start of a flip and tries to over correct the spike by dramatically reducing propulsion which causes the drone to plunge. It then takes a split second before the flight controller realizes that the drone is plunging to bring its propulsion back up again which explains the dramatic plunge.

If you’re faced with situations 1 and 2 above and think you’ve lost control of your drone, the best solution would be to perform an emergency shutdown of the motors. Shutting down the motors and just letting the drone drop down where you can easily retrieve it is a much better option than losing it in a fly away or having it crash onto someone or into a pool, etc.

With that said, I believe toy drone manufacturers really should include a button on their transmitters that allow users to turn off the altitude hold feature when needed. Until that happens, the best thing you can do is simply avoid flying when it’s very windy. If you have to fly in windy conditions, make sure you are aware of the risks and how to act when things go wrong.

Last Friday, a pilot who was landing at Wheeler Airport near Kansas City spotted a drone and reported it to air traffic control which then notified local police.

KSHB Kansas City reported that a police helicopter was sent to investigate and eventually spotted the drone. However, the drone managed to escape.

The pilot, who was flying a small Beechcraft, managed to land safely.

Under FAA regulations, drones are not permitted to fly within 5 miles of an airport. They are also required to fly no higher than 400 feet and cannot weigh more than 55 pounds.

Last Friday, a pilot who was landing at Wheeler Airport near Kansas City spotted a drone and reported it to air traffic control which then notified local police.

KSHB Kansas City reported that a police helicopter was sent to investigate and eventually spotted the drone. However, the drone managed to escape.

The pilot, who was flying a small Beechcraft, managed to land safely.

Under FAA regulations, drones are not permitted to fly within 5 miles of an airport. They are also required to fly no higher than 400 feet and cannot weigh more than 55 pounds.

Monday evening, as Chopper 7 covered a fire in a Spanaway salvage yard, KIRO-TV Chief Photographer Scott Crueger turned the camera toward another helicopter taking video for KOMO-TV and KING-TV.

A drone was flying above it.

“We got a drone out here somewhere,” Crueger alerted colleagues in the newsroom.

He guessed the drone was flying at about 1,500 feet.

It isn’t easy following something so small with a helicopter camera, but Crueger kept on it.

He followed the drone as it descended, and spotted a man on the ground operating it.

“I was thinking, ‘How could you be that stupid?’” Crueger said later.

If helicopters strike anything, like birds, they can easily fall out of the sky

Chris Wright is a problem solver. Her clients come to her with an issue, a question, a mystery, and she figures out the best way to find the answer – using whatever tools she can. “I use a combination of new technology and old technology, because I have to solve a problem. So I’ve used everything from geese and dogs to Roombas to drones to GPS.”

Wright is a private investigator – and owner of the Wright Group – based in Anaheim, California. She’s worked in the business for more than 40 years, and has seen the tools available to investigators change dramatically. Early on, stakeouts in vans were important. More recently new technology in the form of tiny cameras and social media have begun to play a role. And she’s embraced those changes. Today, when the problem calls for it, she uses drones to do her work.

Consumer drones such as the Yuneec Q500 come with high quality cameras and gimbals that are excellent for surveillance use (Photo by Yuneec).

She gives me a few examples. If two people are meeting in a public place, a drone can be a helpful way to discreetly watch them. “We stay at about 50-75 feet [15-23 metres] above so nothing can be heard.” Drones are also helpful for aerial surveillance of locations that are hard to access on foot. And if a school or church is worried someone might be stealing or vandalising property, drones or small off-road vehicles (“Roombas on steroids” as she calls them) can film the property.

The man who was responsible for the recent drone crash at the White House will not be charged, according to a statement by the US Justice Department yesterday. Shawn Usman, who is a federal employee, caused international headlines in January when a DJI Phantom quadcopter he was piloting crashed at the South Lawn of the White House. The incident caused deep concern among security experts, who said the crash had exposed weaknesses in the security detail around the White House. Law enforcement officials have speculated that drones could carry explosives, weapons, cameras and other potentially dangerous equipment near or into the White House and other sensitive areas.

Apparently, Usman had borrowed the drone from a friend and started flying it indoors in the living room of his apartment at around 3am on the day of the incident. He then guided the drone out of his apartment window to fly outside for a while before guiding it back in again. In his second attempt at flying outside, Usman lost control of the drone and it flew away, quickly rising a few hundred feet into the air before heading east. Usman frantically called his friend to report the incident. Both men decided that there was nothing they could do at that time of the day and went to sleep. It was only at 8am the next morning did both realize the gravity of the situation when TV stations began reporting on a quadcopter that had crashed into the White House compound.

Consumer drones have a history of flying away mostly due to pilot error.

Consumer drones such as the DJI Phantom are known to fly away due to technical issues. Most cases of drones flying away are the result of pilot error but can sometimes be caused by equipment failure or poor GPS reception.

Federal prosecutors decided that Usman had not deliberately attempted to fly his drone into the White House compound despite having enough evidence to indict him. Although it is illegal to fly a drone outside in the District of Columbia, laws that were designed to protect the airspace around the White House do not specifically detail unmanned flying vehicles such as drones.

The Federal Aviation Administration (FAA) has approved Amazon’s request to begin testing its drones in rural areas of Washington state — a move many see as the first step towards making commercial delivery of packages by drones a reality in the US. Amazon was issued an experimental airworthiness certificate which allows the company to fly its drones for testing, research and training purposes only.

The FAA’s experimental certificate stipulates that Amazon flies its drones below 400 feet and in “visual meteorological conditions”. Drone pilots are required to have a private pilot’s certificate and medical certificate. On top of that, Amazon is also required to provide the FAA with detailed monthly reports on its test flights.

In late 2013, Amazon CEO Jeff Bezos had expressed his interest in launching a service involving the use of drones to deliver packages directly to customers. The service, called “Prime Air”, will make it possible for the e-commerce giant to deliver packages directly to customers living within 16km of an Amazon distribution center. The entire process –from the moment a customer pays for an order right to delivery — is expected to be less than 30 minutes.

Amazon has already been conducting drone tests outside the United States, in countries that have less stringent aviation regulations and has already been developing drones that can fly autonomously and avoid collision with objects during flight.

While Amazon.com Inc. and Google Inc. aim to use drones to ship packages to customers—an exceedingly complex task—one Silicon Valley startup says there is an easier way to deliver with drones.

Matternet Inc. is working on creating networks of delivery drones that fly on largely fixed routes between base stations. The system can serve as a cheap and efficient infrastructure to transport crucial goods in the developing world, the company says, or a shipping pipeline for companies to move inventory between stores or to frequent large-scale customers.

Matternet aims to sell its delivery-drone system to companies, governments and aid groups. “We want to be the people that enable FedEx and UPS and many other smaller and bigger players to take [drone delivery] to the marketplace and make it widespread,” said Andreas Raptopoulos, Matternet’s 41-year-old chief executive.

Drone delivery direct to consumers, as Amazon and Google envision, faces technical hurdles including short battery life which limits range, and the need for sensors and software to avoid obstacles. Companies are also grappling with how to safely and accurately drop off packages.

Matternet claims its self-contained delivery network clears many of those hurdles. Its base stations can swap in new batteries when drones arrive, enabling Matternet’s devices to carry 2.2 pounds within a 12.5 miles radius—farther than many competitors. And flying fixed routes means drones can operate autonomously without collision-avoidance technology because their routes can be mapped to account for known obstacles like trees or power lines, Mr Raptopoulos said.

When shopping for a drone, you will inevitably reach a stage where you have to decide on what type of camera gimbal to choose from. Drones with camera gimbal systems typically come with 2-axis or 3-axis brushless gimbals and which type of gimbal you choose depends on what you plan to use it for.

A 3-axis gimbal is not necessarily better than a 2-axis gimbal. Saying a 3-axis gimbal is better is like saying a car is better than a motorcycle simply because it has more wheels. Both 3-axis and 2-axis gimbals have their own pros and cons.

Walkera G-3D gimbal and iLook+ camera.

3-axis gimbals generally provide better video stability than 2-axis gimbals. This is because 3-axis gimbals stabilizes your video on all 3 axis (yaw, pitch and roll) while 2-axis gimbals stabilizes only on the pitch and roll axis. Jello, or jittery horizontal movement, is more obvious in videos taken using a 2-axis gimbal due to the lack of stabilization in the yaw axis. 3-axis gimbals are able to greatly reduce and sometimes completely eliminate jello due to a third motor that helps absorb unwanted movement in the yaw axis.

However, 3-axis gimbals are heavier and more expensive than their 2-axis counterparts. They also draw more battery power due to having more motors. To illustrate this point, Walkera’s G-3D gimbal (3-axis) is about 48g heavier and costs roughly $50 more than its 2-axis sibling.

Helipal.com has an excellent video that demonstrates the differences between the DJI H3-2D (2-axis) and H3-3D (3-axis) gimbals. Both gimbals had GoPros installed and were attached to two different Phantom quadcopters which were attached to a larger hexacopter. The hexacopter was then flown in different flying conditions to show the differences in video quality from the two gimbals.

For Filmmakers and Aerial Photographers

If you plan to do professional aerial photography, you will definitely want to go for a 3-axis gimbal. Despite its weight and cost penalty, a 3-axis gimbal produces far better video than a 2-axis gimbal. Video stability is crucial when producing documentaries or Hollywood-grade films which is why 3-axis gimbals are the favorite choice of professional aerial photographers. Using 3-axis gimbals will result in shorter flight times so to solve this problem, simply bring along extra batteries when you go out flying.

For even more impressive video stabilization, pair a camera that has built-in stabilization with a 3-axis gimbal. Any video shake that has not been eliminated by the camera gimbal is taken care of by the camera’s own video stabilizer.

Besides providing better video stability, 3-axis gimbals are excellent if you have a separate operator for your camera. When flying with two operators, two radio transmitters are used — one for piloting the drone and the other strictly for controlling the camera. With a 3-axis gimbal, the camera operator can freely pan the camera without having the pilot to pan the drone. This cannot be done when a 2-axis gimbal is used which requires the pilot to pan the drone in order to move the camera angle along the yaw axis.

It is also important to note that 2-axis gimbals can perform as well as their 3-axis counterparts when it comes to taking still images. The only thing that really sets these two gimbals apart are videos. So if you focus strictly on taking still images from the air and hardly do any videos, a 2-axis gimbal will do just fine especially when you have a tight budget.

For the FPV Enthusiast

If you want to fly your drone in first-person-view (FPV) for the sheer fun of flying, you will want to choose a 2-axis gimbal which provides 2 advantages due to its lighter weight — longer flight times and a more agile drone. The heavier your drone, the less agile it becomes so every gram you put on your drone counts. There is no doubt a 2-axis gimbal makes for a lighter drone than a heavier 3-axis gimbal.

Although 2-axis gimbals tend to produce more horizontal shake in your video feed, it is not significant enough to affect your flying. Generally speaking, FPV enthusiasts prefer to fly without any gimbal, mounting the camera directly onto the frame. This setup allows for a far more agile drone but if you must have a gimbal when flying FPV then go for a 2-axis gimbal.
The Yuneec Q500 Typhoon has one of the best 3-axis camera gimbal system for a quadcopter kit below $2,000 (photo by Yuneec).

For All Those in Between

A 3-axis gimbal is the ideal choice if you’re planning to do a little bit of both. It provides excellent video stabilization when you’re out shooting videos for professional use and is not too bad if you’re flying your drone just for thrills. Just remember to bring extra batteries along as a 3-axis gimbal can drain your battery slightly faster than a 2-axis gimbal.

A drone has been used in a daring night-time attempt to smuggle drugs and weapons into a high security jail.

The plan was only thwarted when the machine became entangled in razor wire on a security wall and was then spotted by staff at Bedford Prison.

It is the first known case of a remote-controlled aircraft being used to infiltrate a British jail.

The Chinese-made machine was carrying a package containing drugs, mobile phones, screwdrivers and a knife.

Prison staff spotted it on the razor wire and managed to retrieve it.

One theory is that the ‘pilot’ planned to direct the drone to a spot where it could hover outside a cell window.

A prisoner might then have been able to reach out and grab the illicit cargo.

The miniature aircrafts are already a major concern to police, who want to be given powers to seize them if they suspect they are being misused.

The one flown into Bedford Prison two weeks ago was a DJI Phantom 2 Vision, which weighs just 2.5lbs but has a range of nearly half a mile.

The device is fitted with a wide-angle camera and can be bought online or at an electrical retailer for around £900.

A Bedfordshire Police spokesman said: ‘We were called to reports that a small drone had been discovered alongside a package at HMP Bedford at 11.30pm on March 6.

‘Both the device and the contents of the package are currently being examined and investigations are on-going.’

The jail can contain around 500 inmates.

A recent report by HM Inspectorate of Prisons said the main challenge facing staff was the prevention of ‘the inward trafficking of unauthorised items, including mobile telephones and illegal drugs’.

Adam Bailey, of the Association of Remotely Piloted Aircraft Systems, said: ‘It’s a pretty stupid way of trying to get stuff into a prison.

‘A drone sounds like a swarm of bees and has flashing lights so you’re likely to attract attention. You’d have to be very skilled to pull this off and these guys clearly weren’t.’

A possible rehearsal for the drone’s flight may have taken place a month ago.

Farhat Erdogan, who works in a Londis store close to the site, said he thought two men had been involved.

Mr Erdogan, 29, said: ‘I saw these guys in their 30s with a drone and wondered what they were doing.

‘They were standing near traffic lights a couple of hundred yards from the prison. I watched as they sent the drone up into the air.’

Shop worker Paddy Pain, 22, said a friend serving a sentence at the jail had been offered money by fellow inmates to accept a delivery of banned substances.

And Sonya Minney, 55, chief officer of the Bedford Guild House charity, which backs on to the prison, said: ‘Staff have recently covered up the cell windows that face outwards to prevent stuff being thrown in.

‘We often hear the police helicopter and sometimes they patrol the perimeter with sniffer dogs but we’ve never seen a drone.’ Drones have been widely used in the United States and Canada to fly drugs into penal institutions and in October a miniature helicopter packed with pills crashed into a net guarding the exercise yard of a jail in Ireland.

Phantom Vision devices are small enough to fit into the corner of a suitcase and manufacturer DJI claims they can fly for up to 50 minutes if fitted with an extra battery.

There have been no arrests in connection with the Bedford incident yet. Police have appealed for information.

A Prison Service spokesman said that the package had been ‘quickly intercepted by vigilant staff’.