[Peetwo]

Spot the trend??

Reference Accidents Domestic thread:

Drone taxi crash report - "Where's the kill switch?"  

Via Popinjay central: 

RPA taxiing loss of control incident highlights the importance of fatigue management and controller design



An Australian Transport Safety Bureau investigation into a 19 June 2020 loss of control incident involving a remotely piloted aircraft (RPA) while it was taxiing following a maintenance flight highlights to RPA operators the importance of fatigue management and controller design.

After landing at Bruhl Airfield, Queensland after completing a successful autonomous test flight, the pilot of the RF Designs Mephisto RPA - a high-performance autonomous testbed which has a 2.6 m wing span and a 35 kg max take-off weight - toggled the controller’s automatic mode switch to disengage the aircraft’s automatic mode for taxi back to the hangar, the investigation report details.

The pilot then increased the throttle to provide the RPA with sufficient momentum to taxi. As the RPA turned towards the pilot, the pilot determined that it was not responding to commands to reduce the engine thrust. The pilot considered attempting to arrest the RPA by hand but determined it was moving too quickly and instead toggled the automatic mode switch to regain control and turn it away from bystanders.

The pilot then directed the RPA across the airfield and it came to rest against the perimeter fence, resulting in minor damage to the aircraft’s skin.

“The ATSB’s investigation into the incident determined that the pilot did not correctly disengage the RPA’s automatic mode,” said ATSB Director Transport Safety Stuart Macleod.

“Subsequently, when they increased the throttle to provide the aircraft with momentum to taxi back to the hangar the ‘abort landing’ function activated, increasing the throttle to maximum and overriding the pilot’s commands to decrease throttle.”

Mr Macleod noted this incident has 3 key learnings for RPA operators.

“RPA operators should be mindful of the risk of fatigue, particularly in high tempo commercial operations,” he said.
“Even when fatigue management is not mandated, operators should ensure that their fatigue management processes are robust and effective.”

The incident also highlights the importance of controllers being as simple and reliable as possible.

“If a control leaves room for human error, then it will increase the risk of this error occurring even if procedural controls are in place. Consideration should also be given to a system that allows the remote pilot to shut down the aircraft immediately in the event of an unexpected state or failure.

“Lastly, operators should be prepared for the RPA to do something unexpected and know and frequently practice emergency procedures.”

Read the report AO-2020-035 Loss of control during taxi, involving RF Designs Mephisto, remotely piloted aircraft Bruhl Airfield, 2 km south-west of Tara, Queensland on 19 June 2020

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Plus:

OK: and - then what????

Popinjay - ""Consideration should also be given to a system that allows the remote pilot to shut down the aircraft immediately in the event of an unexpected state or failure."

What a bloody good idea - a 'Kill-switch" - pearls of wisdom drop from the ATSB boss; although from which end of the boss they dibble we ain't sure.

1.852 converts Knots to KpS. 1 nm/sec = 1.852 KpS. 30 knots = 0.5 nm/ minute: so do the maths -  35 Kg @ 30 Knots = 0.926 Kilometres distance travelled - after the 'kill switch is toggled. F= MA provides the impact force of a 35 Kg thing with a 2.6 meter wingspan hitting something. All very esoteric - but if you ever want to experience F=MA in the real world, try this. Place your thumb on the workbench and allow a 0.5 Kg hammer to drop from eye height onto it. Quite a wallop ain't it; sore for a week at least, for a month's worth of pain - swing that hammer with some force (malice aforethought) - you'll get the message fast enough.  Sure, it is not a regular occurrence, but it happens and there are no 'fail safe' measures to prevent it (bar common sense). My hammer weighs in at 24 ounces (0.68 Kg) the fail safe is me. The 'drone' under consideration has no built in 'fail safe' - loose control of it, at speed and altitude and the operator who hits the 'kill' switch has no further control (non whatsoever) from that moment over 35 Kg @ 10 knots = 18.5 kilometres per hour/ 60 = 0.3 K per minute. Allow what; say a 1.5 minute descent after the 'kill' that's 2/3 kilometre (ish) travelled before it reaches the deck - out of positive control. Kill switch - yeah, OK but what about 'control' after the event - the 'impact' maths get complicated from here - but it is quite a whack. Every aircraft has an alternate means of control after say an engine failure- Aye; 'tis limited but it at least it has a fighting chance of not hitting Bunning's out of all control on a Sunday morning.. Bring on the Drones if you must - but lets have some 'fail safe' control built in with a little more imagination than just a stellar example of ATSB safety thinking like - "hit the kill switch" (and then what?)..........A well trimmed man-hole cover on descent....

And now this, from Popinjay central..

RPA fly-away results in minor injuries after shattering hotel room window



Key points:

• DJI Inspire 2 became unresponsive to control inputs before colliding with hotel window, injuring an occupant;
  
• As a result of accident, DJI has updated user manuals for a number of products to provide additional guidance;
  
• Drone fly-away events are not rare, and there may only be a few seconds to properly respond when such an event is about to occur.
  

A fly-away incident where a DJI Inspire 2 remotely piloted aircraft (RPA) collided with a hotel window, injuring an occupant, serves to remind operators to be familiar and well drilled in emergency procedures, an ATSB investigation notes.

On 15 January 2021, the DJI Inspire 2 was being used for aerial photography and videography above Cockle Bay in Darling Harbour, Sydney.

Shortly after take-off, the RPA unexpectedly accelerated away from the pilot, and became unresponsive to control inputs. It accelerated to its maximum speed and, a short time later, collided with the window of a hotel adjacent to Darling Harbour.

The RPA shattered the window but did not penetrate it. A person inside the hotel received minor injuries from flying glass, and the RPA was destroyed.

The ATSB investigation into the incident found the compass of the RPA failed due to electromagnetic interference during flight, leading to the fly-away.

“Occurrence data reported to the ATSB indicates RPA fly-away occurrences are not rare,” ATSB Director Transport Safety Stuart Macleod said.

In the four years from 2017 to 2020, 94 occurrences of partial or complete loss of transmission and/or reception of digital information from an RPA were reported to the ATSB.

The majority of these occurrences resulted in damage to either the aircraft, property, or both.

“It’s important RPA pilots ensure they are familiar and well drilled in emergency procedures, as well as being proficient in flying in all flight modes,” Mr Macleod said.

Mr Macleod noted that during an RPA fly-away, there may only be a few seconds in which a pilot can take avoiding action.
“In the event of a compass failure, switching to the fully manual attitude flight mode may assist regaining control of the RPA,” he noted.

Following a review of the occurrence, the RPA’s manufacturer, DJI, updated the user manuals for a number of its products, including the Inspire 2.

The changes provide additional guidance to users regarding the use of the fully manual attitude flight mode in the event of compass interference.

Although not contributory to this occurrence, the ATSB investigation also found the pilot did not follow the operator’s emergency procedures, or comply with the regulator’s operational permissions to fly in restricted airspace.

“Adhering to operational guidelines and limitations remains important for ensuring the safe operation of RPAs,” Mr Macleod said.

“This is particularly true in populated areas, where risks are potentially elevated.”

Adhering to the limitations and guidance provided by the regulator will ensure these risks remain as low as reasonably practicable, Mr Macleod concluded.

Read the report: AO-2021-001 Loss of control and collision with terrain involving DJI Inspire 2 remotely piloted aircraft Darling Harbour Sydney, New South Wales on 15 January 2021

MTF...P2