Battery failure report on Goverment website

[Mrgs1]

AAIB investigation to Yuneec Typhoon H480, (UAS, registration n/a)

Loss of electrical power on approach to land, RAF St Athan, Wales 26 September 2018.

www.gov.uk

If we didn't know already the battery can fall and Yuneec admitted it. Seems like disproval in wording that such an accident can occur.

 

[PatR]

The report uses typical accident investigation terminology, and follows a similar path with conclusions, or more accurately, possible causal conclusions. It’s unfortunate but incident investigations performed by government agencies generally don’t make “absolute” conclusions, instead they deliver one or more possible causal factors that could, through one or more in combination, cause an incident. The reader is left to “read between the lines” as they are often provided a list of causal factors that can range from “most probable” to “possible”.

In this case the manufacturer did not establish a definitive cause but made it clear that the aircraft could be operated with an improperly secured battery, which is suggestive of performing more thorough pre flight inspections. That’s a good thing as it becomes a semi official “alert” to double check the battery installation while providing a new line item for addition to SOP pre flight inspection documentation. Part of “process improvement”.

Although on the surface the report might appear to fault Yuneec what it actually did was cause Yuneec to make a public statement relative to battery security. In truth it was not listed as a “battery” failure, but could also have been an operator set up and pre flight inspection error as no system failure points were found by the manufacturer during their aircraft inspection.

 

[AH-1G]

Battery not inserted properly, my positive and absolute correct opinion!?

 

[PatR]

Mine too but as one that used to perform incident investigations and write causal reports I can tell ya that if you write a report that makes a hard definitive call you better have had multiple smoking guns, 20 eye witnesses that were focused on the flight from start to finish, all in agreement, and an absolute admission of fault before publishing or you’ll have your back side handed to you by a department head or someone high up the management food chain.

 

[Fred Garvin]

Unless there is a mechanical or design fault that allows a properly seated battery to come loose, disengage, and/or fall out....it’s pilot error.

By properly seated, I mean that it is inserted, clicked in place and secured....in actuality or has indicated to a Reasonably Prudent Person that this has occurred.

 

[AH-1G]

Where was the 2nd LT to double check the check list?

 

[Fred Garvin]

He was making sure nobody left a coffee cup on the table.

 

[DoomMeister]

In this case the manufacturer did not establish a definitive cause but made it clear that the aircraft could be operated with an improperly secured battery, which is suggestive of performing more thorough pre flight inspections. That’s a good thing as it becomes a semi official “alert” to double check the battery installation while providing a new line item for addition to SOP pre flight inspection documentation. Part of “process improvement”.

Although on the surface the report might appear to fault Yuneec what it actually did was cause Yuneec to make a public statement relative to battery security. In truth it was not listed as a “battery” failure, but could also have been an operator set up and pre flight inspection error as no system failure points were found by the manufacturer during their aircraft inspection.

From this incident report I come away with Yuneec admitting that the aircraft can be powered with an improperly mounted battery thereby allowing power loss at anytime during the flight. We all know this one and have the check in our preflight routine.

This also becomes the most likely cause as there were no other faults found from the telemetry or onboard flight logs by the manufacturer.

In other words someone failed to ensure the battery latch was fully engaged. Sure can make for an unexpected ground piercing touch down.

Side note: looking at telemetry from several dozen Yuneec craft (Breeze, Q500, H480, H520, and TH Plus) I have only seen three or maybe four total power loss cases that were attributable to something other than the battery not being latched. Those few were diagnosed by Yuneec as a failure in the FC (PX4) in H520 and very early TH Plus. Yuneec made full restitution in all of those cases I am aware of.

 

[Phaedrus]

Sort of like a manned airplane can take off with nearly empty gas tanks.

 

[DoomMeister]

It doesn’t pay to skip steps in the preflight checklist. Especially if you are sitting in the aircraft.

 

[AH-1G]

It doesn’t pay to skip steps in the preflight checklist. Especially if you are sitting in the aircraft.

Amen!

 

[Mrgs1]

It doesn’t pay to skip steps in the preflight checklist. Especially if you are sitting in the aircraft.

It adds a scenario that one latching system isn't sufficient, it doesnt help pilot error, vast majority on here know the drill flight check. Governments and policy makers see it differently, a possible way to restrict or ban a said piece of equipment, especially if there are more incidents, personally I think most authorities are in bed with Dji, I think the authorities like the log on before you fly and want to take it further with all your details and flight being checked before you take off. Something a lot of other manufacturers wouldn't provide.

 

[Mrgs1]

From this incident report I come away with Yuneec admitting that the aircraft can be powered with an improperly mounted battery thereby allowing power loss at anytime during the flight. We all know this one and have the check in our preflight routine.

This also becomes the most likely cause as there were no other faults found from the telemetry or onboard flight logs by the manufacturer.

In other words someone failed to ensure the battery latch was fully engaged. Sure can make for an unexpected ground piercing touch down.

Side note: looking at telemetry from several dozen Yuneec craft (Breeze, Q500, H480, H520, and TH Plus) I have only seen three or maybe four total power loss cases that were attributable to something other than the battery not being latched. Those few were diagnosed by Yuneec as a failure in the FC (PX4) in H520 and very early TH Plus. Yuneec made full restitution in all of those cases I am aware of.

If you admit there's a problem, then it is a problem.

 

[AH-1G]

I would think most want a plug and play (fly) feature, without the hassle of using brain power.?

 

[Phaedrus]

If you admit there's a problem, then it is a problem.

I do not see them "admitting" there is a "problem" as much as recognizing that user error may prevent the pack from being fully seated. This is no more a fault with the design than not ensuring the props are attached correctly and the batteries charged. These are not toys, people need to stop thinking of them as such.

 

[Mrgs1]

I do not see them "admitting" there is a "problem" as much as recognizing that user error may prevent the pack from being fully seated. This is no more a fault with the design than not ensuring the props are attached correctly and the batteries charged. These are not toys, people need to stop thinking of them as such.

The damage is already done, the bad feeling from the public and press have caused severe damage to the hobby, I'm putting it from a view of the authorities, no there not toys, and so shouldn't be in the hands of hobbyists,

 

[Mrgs1]

I would think most want a plug and play (fly) feature, without the hassle of using brain power.?

What the authorities here want is your name, address, serial number etc uploaded before you fly, where you want to fly, prior notification to other users in the area, personally I like manual flight, plug and play takes the fun out of the hobby.

 

[DoomMeister]

@Mrgs1

I am a little confused with your last two posts. Are you saying UAV’s like the TH should not be in the hands of hobbyists or that the lawmakers are saying hobbyists should not be flying?

What is really needed is a major clamp down on the alarmist media blowing everything out of proportion both in the UK and here in the US.

Should there be registration and knowledge testing? I would respond with a resounding YES. These are tools to accomplish a task and those using them need to treat them with the respect due any other tool that can cause harm.

 

[DoomMeister]

There is a simple solution to the problem by incorporating a limit switch that has to be made by the battery latch. The limit would have to control a relay to allow full power to the ESC circuitry. Yet that just puts more pieces of equipment into the equation that have to be set properly and can fail electrically and physically.

The battery has to make contact with the internal connector before the latch catches in order to fully mesh the contacts.

I liken most government safety oversight to the chicken little story. OSHA has gotten so ridiculous in many areas that it takes longer to set up safety equipment than to do the job itself. Mostly with manlift and ladder operations. It got to the point that if you used a ladder for anything over 6 feet you had to wear a harness and be tethered to an approved attachment/anchor point ( that required a manlift to reach ).

 

[PatR]

Indeed. Many mandated PPE and safety oversight requirements severely limit one’s ability to perform the task. They can add hours and a great many $$ to a job that would normally require but a few minutes to execute.