Complete Failure of INSPIRE 1 during flight - Dropped from 400 feet

[SanCap]

I did not see if anyone asked this yet, was your battery at 100% when you took off and was it a recent charge?

 

[Jimmykjimmy]

I do not believe that the self locking props would cause an esc to fail unless they were somehow overloading the motor and esc.

So, is their any relationship between any type of prop attachment and esc failure?
This is the first time I've heard of an esc failure..but there always is a first.

 

[ringolong]

There are many conditions that can cause an esc to fail. This particular craft could have been exposed to moister, abnormal stress, or something unknown that caused something to fail. I do not think that a dji prop adapter would have been something that would cause an esc to fail.

 

[afx]

According to your flight time before (21 hours) there might be a battery problem.

 

[SanCap]

According to your flight time before (21 hours) there might be a battery problem.

Can you elaborate in this?

According to your flight time before (21 hours) there might be a battery problem.

Can you elaborate on this? I want to make sure that this does not happen to me.

 

[James Waugh]

I did not see if anyone asked this yet, was your battery at 100% when you took off and was it a recent charge?

The battery was at 94% when I took off. The charge was a few days old. Why I replay the data on the flight there is no sudden drop in battery. The entire flight was 5 minutes. The battery was at 61% when this happened.

 

[James Waugh]

According to your flight time before (21 hours) there might be a battery problem.

I have 4 batteries that I use so it's not 21 hours on one battery. This particular flight had a 5700mAh battery that is approximately 5 months old.

 

[James Waugh]

So, is their any relationship between any type of prop attachment and esc failure?
This is the first time I've heard of an esc failure..but there always is a first.

I really don't think there was any prop problems on this flight. All 4 props were tight on the crashed inspire. I had locking clips that were still on all 4 props. One prop has partially damaged on impact. A second prop was broken near the center but I found the missing piece less that 2 feet from the impact area which indicates to me that it didn't break during the flight.

 

[Scotflieger]

Is there a relationship between the esc failure and a bad prop? Not sure if your saying that, or just that people are using the self locking props.So does having self locking props minimize the risk of esc failure, guess that's what I'm asking.

You are conflating two issues that have been suggested as the cause of this incident. Either could be the case and not related to each. A failure of the ESC electronics can happen at any time although very unlikely. A prop failure is more likely as they are made of plastic and mechanical failures are more likely. They can crack and split through normal use or even a minor impact leading sudden catastrophic failure. Some believe that the original screw-on type are more secure and less likely to detach if properly locked. I understand that early crashes were caused by unlocked blades detaching under heavy braking manoeuvres. DJI responded by introducing the quick release props. These rely of 2 thin plastic tabs to stop the props releasing. Damage to the tabs can weaken the prop security. This is why before and after inspections of blades is essential for safe flight regardless of the prop design you using.

 

[Steven Powter]

I have both systems the screw on with locks..and..the quick release, both have given no trouble with 200 hours FT between the two.. i have 2 Inspires ... i doubt very much it was prop failure, unless they had been damaged...

 

[Aviator]

One of the good things about the QR props is that it forces the pilot to hold the prop by the center hub when attaching the props to the motors.
On the original spin on props, I have seen pilots tighten them down by holding the blade of the prop and give them a good "tug" for good measure which could theoretically introduce stress fractures.

 

[crashburn]

Should have seen a "not enough force" error message if there was a prop failure of any kind. Otherwise, probably not prop related crash

 

[afx]

Can you elaborate on this? I want to make sure that this does not happen to me.

The problem was met in Phantoms first time and also I had notices from my friends who own Inspires. After some time the battery comes low voltage for a short period of time and then come back to normal. Maybe because of motor overload or whatever else. But this may cause the controller to restart.
It's only one of the issues it could be. I don't hear the sound in video, it may tell you what happened with props in the flight, did they have force or just rotated by the wind..

 

[Steve Domigan]

Horible crash, but the above discussions raise a good point. We can check and change our props regularly, motors don't give much issue as long as you keep an eye on the bearings, but how long can we expect out of an esc? It's not something we can check and a failure would be terminal.

 

[Kevin Hancox]

Hmmm... That's not dropping like a stone - You still have power to your rotors and obviously power to the gimbal as it is correcting itself on the way down.
The aircraft is in an uncontrollable yaw which implies to me prop failure or possibly esc failure.

Were all your props attached when you recovered it?

I actually don't think there was power to the motors, and the reason i give for this, is that ANY drone that falls from the sky, that still has 4 props on it, will generally spin up the props on all 4 corners, they normally spin the wrong way, giving the appearance of some kind of balance, the difference is how quickly any failure happens, i had a solo shut down, flip over and fall flat, i have seen other solos fall after shutdown the right way up, the common theme in any falling craft though, is that they are always slowed by opposite spinning props...! This gives the appearance of motors still running and corrections happening..

 

[James Waugh]

Should have seen a "not enough force" error message if there was a prop failure of any kind. Otherwise, probably not prop related crash

I had no warning message appear before it started to drop. As it was falling I did get a RED NO SIGNAL warning.

 

[Aviator]

Analyzing the footage it should noted that the aircraft took approx 34 secs to reach its position of failure but only approx 8 seconds to fall to earth and the one prop we can see spinning is turning clockwise when under power it would be turning anti-clockwise.

 

[Kilrah]

but how long can we expect out of an esc? It's not something we can check and a failure would be terminal.

No idea. Same with the flight controller, as well as any internal or external electrical connection...

 

[Tj_]

Analyzing the footage it should noted that the aircraft took approx 34 secs to reach its position of failure but only approx 8 seconds to fall to earth and the one prop we can see spinning is turning clockwise when under power it would be turning anti-clockwise.

Can we be sure the prop was spinning properly, or improperly? I ask because when I film a prop to an airplane from the cockpit it appears to be spinning improperly. Just as if I film a wheel on a car driving down the road, it appears to be rolling backwards.

Just a point to ponder!

 

[The Editor]

I actually don't think there was power to the motors, and the reason i give for this, is that ANY drone that falls from the sky, that still has 4 props on it, will generally spin up the props on all 4 corners, they normally spin the wrong way, giving the appearance of some kind of balance, the difference is how quickly any failure happens, i had a solo shut down, flip over and fall flat, i have seen other solos fall after shutdown the right way up, the common theme in any falling craft though, is that they are always slowed by opposite spinning props...! This gives the appearance of motors still running and corrections happening..

But the aircraft still had power as the gimbal was functioning