Loss of thrust, electric aircraft.

[Thruster88]

This could be the first loss of trust in an electric aircraft in oz. The electric version of fuel starvation. 

 

 

11/3/2023	Lilydale	VIC	Pipistrel	Alpha	Pipistrel/Emrax	EEM60MVLC (Electric)	STATUS: Under review OCCURRENCE DETAILS SUBMITTED TO RAAUS: the aircraft was conducting circuit o...
STATUS: Under review OCCURRENCE DETAILS SUBMITTED TO RAAUS: the aircraft was conducting circuit operations on when, on the climb of the 4th circuit at 600ft AGL, an instrument display warning appeared 'Power control lever failure' which resulted in complete loss of power. The pilot pitched for a glide and a turn back, attempted a reboot cycle of all switches off, pulled the power control breaker, powered on all systems in sequence but the same warning appeared. They repeated this one more time, but power control was not restored. The pilot didn't feel they had enough height and speed to reach the aerodrome/runway, so made an uneventful emergency landing in a field to the immediate North of the runway.

[onetrack]

Yep, I reckon a loss of thrust in one of them new-fangled electric aircraft, would soon lead to a loss of trust! 

[kasper]

18 minutes ago, onetrack said:

Yep, I reckon a loss of thrust in one of them new-fangled electric aircraft, would soon lead to a loss of trust! 

Like all things in aviation its a balance …

the level of pucker you can accept for power loss vs pucker risk of batteries overheating … 

 

my electric home built has a power control system that’s, like me, basic.  
 

there are no real override cutouts in my controller for computer says if you keep going you’ll damage your batteries and/or overheat them.  
 

I have a system that will allow me to cook my batteries so I have to monitor them manually via the displays of draw/charge state and pack temperature.  
 

horses for courses - I’d rather cook the batteries and have power to control my emergency arrival then save the batteries and have to do it dead stick.  

Edited March 16, 2023 by kasper

[spacesailor]

Kasper silly question .

IF your batteries , start to overheat , will a '' shutdown '' , & glide , manage to cool them sufficiently , to make a controlled descent .  ( hopefully ).

My garden 18 volt batteries take forever to cool, but have no cooling applied to them.

spacesailor

[kasper]

1 hour ago, spacesailor said:

Kasper silly question .

IF your batteries , start to overheat , will a '' shutdown '' , & glide , manage to cool them sufficiently , to make a controlled descent .  ( hopefully ).

My garden 18 volt batteries take forever to cool, but have no cooling applied to them.

spacesailor

Not silly. If they start to overheat I can in most areas of flight plan to shut down as the sapphire I have has a nice thick fabric wing and floats easily.

But the airframe was selected for lower power to maintain cruise and the motor draw on the batteries is very low for them so I really never will need max draw on the batteries per their design so I'm hopeful the system will never run into overheat. 

[RFguy]

Most likely, the motor controller, a highly complex , specialized bit of electronics may have failed.

 

Batteries DO NOT disconnect themselves from the load if they overheat- Well maybe some consumer POS you buy .

 

There is temperature and balance awareness for the charging system, that's all.

 

Best option is a 2nd motor controller, or a very well derated single controller that never gets hot. Or a 2nd motor and controller on single shaft.

[jackc]

Fly an electric aircraft designed where battery pack is mounted at C of G into a compartment at bottom of the fuselage.

IF you get a battery fire situation, you simply jettison the pack and you then become PIC of a…….Glider! 

Rather take my chances that way, than  burning to death…….

[turboplanner]

20 hours ago, Thruster88 said:

This could be the first loss of trust in an electric aircraft in oz. The electric version of fuel starvation. 

 

 

11/3/2023	Lilydale	VIC	Pipistrel	Alpha	Pipistrel/Emrax	EEM60MVLC (Electric)	STATUS: Under review OCCURRENCE DETAILS SUBMITTED TO RAAUS: the aircraft was conducting circuit o...
STATUS: Under review OCCURRENCE DETAILS SUBMITTED TO RAAUS: the aircraft was conducting circuit operations on when, on the climb of the 4th circuit at 600ft AGL, an instrument display warning appeared 'Power control lever failure' which resulted in complete loss of power. The pilot pitched for a glide and a turn back, attempted a reboot cycle of all switches off, pulled the power control breaker, powered on all systems in sequence but the same warning appeared. They repeated this one more time, but power control was not restored. The pilot didn't feel they had enough height and speed to reach the aerodrome/runway, so made an uneventful emergency landing in a field to the immediate North of the runway.

Good to see the minute by minute management.

Same thing happens a lot with electric power tools when they're working hard. 

[FlyBoy1960]

Probably flew too far from the airport and the extension cord disconnected ?

[RFguy]

 batteries are to electric as fuel is to ICE

motor controller for electric  is a carb/thottle body  is to an ICE

a brushless motor is to electric as the pistons and cylinders are to an ICE

not sure where fuel vapourization, fuel contamination, fouled plugs, worn rings, burned valves, worn bearings and lobes, leaking gaskets, broken thru bolts, CO2 poisoning , selecting wrong tank, mixture controls, detonation, bad leads, faulty magnetos , intermittant starter solenoids    

not sure where they all fit in to electric, in analogy.

 

 

[facthunter]

ICE means INFERNAL Combustion Engine. Ready to self destruct at the drop of a hat.    Nev

[spacesailor]

E V stands for ' Extra Volatile ' .

Next 

spacesailor

[Bosi72]

16 hours ago, RFguy said:

 

not sure where fuel vapourization, fuel contamination, fouled plugs, worn rings, burned valves, worn bearings and lobes, leaking gaskets, broken thru bolts, CO2 poisoning , selecting wrong tank, mixture controls, detonation, bad leads, faulty magnetos , intermittant starter solenoids    

not sure where they all fit in to electric, in analogy.

 

 

it's a whole new world of problems:

bad soldering, corrupted disk, memory leak, overheated cpu, software bugs, viruses... similar to cars where you need a mechanic with a computer to tell you what the problem is..

 

[onetrack]

So ... I presume all of the above contributors, fearful of electric motive power, are never going to fly commercial, ever again?

 

Just look at all that wiring and electronic crap that those Boeings and Airbusses rely on, to stay airborne!  

 

I think the main thing we need to avoid, is the desire of manufacturers to impose excessive levels of electric and electronic components on our equipment.

 

There are many components that function quite admirably with mechanical or mechanical/electric operation. Adding in electronics where it's not really necessary, simply adds to potential problems.

 

I have no problem with the installation of properly engineered electric and electronic components, of durable construction, and with extensive thought having gone into whether they're an improvement over a basic mechanical function.

[facthunter]

Things like self test and limp home mode and overides have a place in aviation where a lot of redundancy has always been the practice in all bar the most basic machines.  Nev

[turboplanner]

On 17/03/2023 at 3:18 PM, RFguy said:

 batteries are to electric as fuel is to ICE

motor controller for electric  is a carb/thottle body  is to an ICE

a brushless motor is to electric as the pistons and cylinders are to an ICE

not sure where fuel vapourization, fuel contamination, fouled plugs, worn rings, burned valves, worn bearings and lobes, leaking gaskets, broken thru bolts, CO2 poisoning , selecting wrong tank, mixture controls, detonation, bad leads, faulty magnetos , intermittant starter solenoids    

not sure where they all fit in to electric, in analogy.

 

 

To work that out would start with a comparison analysis based on real facts in the application.

Your trail of ICE issues are a bit like what was being used by promoters on the auto industry about three years, but the average car engine goes usually goes to the crushing plant with plenty of hours left, the killer issues being accidents, electrical, suspension, rust, cost of DPF replacement exceeding the car value.

 

A good example is what's driven me nuts for a few months. A lot of alternators on cars now have sprag clutches. If you hear a "tinkle" when you start the car, welcome to the beginning of the end of the sprag clutch. Once upon a time if a sprag clutch had been fitted, we could have unplugged the alternator terminals, slackened the belt pulleys and slipped the V Belt off, undone three nuts, and put it on the bench.

 

If it needed a new V Belt (i.e. 30 - 40 years old) you just threw the old one in the bin and flicked on a new one.

 

Today we have the serpentine belt which the Millenial engineers use for just about anything on the car with usually about five pulleys, all different buried under the engine around the fan shroud with half a spanner space. Not only that, but to be fail, the engineers have the power steering and some other pump their own belt with four pulleys, which prevents the big one from being taken out................... Today I'm in the spanner invention business.

 

 

 

All of these except the DPF lso occur on electric, and despite the same promoters touting service-free cars, a lot are towed to dealerships for extended stays with electric issues. The electrics issues in both ICE and BEV are not usually the foundation system, but electronics and equipment which stops doing what it's supposed to do from windscreen wipers, windows, ABS to cooling fans to air conditioning.

 

The replacement sprag clutches come from ..............................China. Just heard the first tinkle from the new one yesterday.

 

 

[turboplanner]

On 17/03/2023 at 12:04 PM, jackc said:

Fly an electric aircraft designed where battery pack is mounted at C of G into a compartment at bottom of the fuselage.

IF you get a battery fire situation, you simply jettison the pack and you then become PIC of a…….Glider! 

Rather take my chances that way, than  burning to death…….

That's a very good idea; removes the inherent risk.

All we really need for BEA is a breakthough in battery design to get the range required and either something like you're suggesting, or a breakthrough with thermal runaway.

[facthunter]

I think you'll find dropping things from a plane is not permitted. That's fairly understandable as much as you'd see your own situation as dire, and needing something to be done, someone has to write the rules and I'd say there'd be some opposition to dropping fiery  batteries from the sky and the fix might not be what you wanted.  Nev

[RFguy]

Battery fire risk is extremely low if  properly designed, derated, sourced and qualified. 

especially you are you willing to sacrifice 20% in capacity to have a battery that will never catch fire from a maximal capacitor/weight type.  (LIFEPO4 versus Lithium Polymer). 
But Lithium batteries with new elecrodes, etc are much much better
They get a bad rap from the bad old days, and all the sh1tbox batteries used in scooters etc which are often the factory seconds......

 

[turboplanner]

2 hours ago, RFguy said:

Battery fire risk is extremely low if  properly designed, derated, sourced and qualified. 

especially you are you willing to sacrifice 20% in capacity to have a battery that will never catch fire from a maximal capacitor/weight type.  (LIFEPO4 versus Lithium Polymer). 
But Lithium batteries with new elecrodes, etc are much much better
They get a bad rap from the bad old days, and all the sh1tbox batteries used in scooters etc which are often the factory seconds......

 

I'd suggest no one can afford to sacrifice 20% of range at present, given that the primary users seem to be operating on a per circuit basis that's giving them a little less than the air time they need for a 1 hour lesson.

[Old Koreelah]

5 hours ago, turboplanner said:

All we really need for BEA is a breakthough in battery design to get the range required…

Those breakthroughs are coming thick and fast:

 

On 17/3/2023 at 7:10 AM, RFguy said:

Batteries DO NOT disconnect themselves from the load if they overheat- Well maybe some consumer POS you buy .

Car builders like Toyota have been developing their EVs for years, so electric aircraft could learn from them.

Given the speed of our little planes, natural air flow should be enough. 

Toyota uses forced air cooling in it’s hybids and liquid cooling in larger battery packs.

[Old Koreelah]

5 hours ago, turboplanner said:

If it needed a new V Belt (i.e. 30 - 40 years old) you just threw the old one in the bin and flicked on a new one.

Not many drive belts under the bonnet of Hybrids and EVs. Water pumps, AC, power steering etc. tend to each have their own super-reliable electric motor. Cabbies are getting years of trouble-free motoring in these cars. Mechanics rarely see them.

[facthunter]

 You had to check and adjust Vee belts pretty frequently. Multi V's have a tensioner that operates automatically.  Nev

[Old Koreelah]

21 minutes ago, facthunter said:

 You had to check and adjust Vee belts pretty frequently. Multi V's have a tensioner that operates automatically.  Nev

I see V-belts (several at a time) driving tail rotors on helicopters. Must be reliable.

[facthunter]

i think they are driving everything The engines installed with the crank vertical. Nev