Drone vs. aircraft wing testing

[LuvMyTJ]

In a test designed to mimic a midair collision at 238 miles per hour, researchers in UDRI’s Impact Physics group launched a 2.1-pound DJI Phantom 2 quadcopter at the wing of a Mooney M20 aircraft. The drone did not shatter on impact, but tore open the leading edge of the wing as it bore into the structure, damaging its main spar. “While the quadcopter broke apart, its energy and mass hung together to create significant damage to the wing,” said Kevin Poormon, group leader for impact physics at UDRI.

The Source of the story is here - University of Dayton Research Institute - Risk in the Sky? - sUAS News - The Business of Drones

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[ac0j]

WOW! It said that was simulated to 238 MPH, but it sure seemed a LOT faster that that!
Also thought it was interesting that a similar sized "gel bird" did MORE damage to the wing surface than the drone, but didn't penetrate as far. Seems like that would happen 1000x more often than drone strikes.
I wonder what is worse, more damaged leading edge material from the bird, or a smaller hole with a dent in a spar from the drone???
Neither is wanted, of course.
Also, I would think there would be massive air pressure values around that wing in flight that would have a shielding effect or at least a little deflection. Glad someone is actually testing.

 

[sar104]

WOW! It said that was simulated to 238 MPH, but it sure seemed a LOT faster that that!
Also thought it was interesting that a similar sized "gel bird" did MORE damage to the wing surface than the drone, but didn't penetrate as far. Seems like that would happen 1000x more often than drone strikes.
I wonder what is worse, more damaged leading edge material from the bird, or a smaller hole with a dent in a spar from the drone???
Neither is wanted, of course.
Also, I would think there would be massive air pressure values around that wing in flight that would have a shielding effect or at least a little deflection. Glad someone is actually testing.

The similar-weight gel bird will have been less dense and therefor larger, hence the more extensive but less deep damage zone. The streamlines around the leading edge of a wing will have a negligible effect on an incoming projectile.

 

[gnirtS]

Wing spar damage is one thing but id worry about about fragile areas like static/pitot tubes, intakes and control surfaces.

 

[lmel2005]

I doubt if an IMU calibration could fix the drone after this.

 

[gnirtS]

I doubt if an IMU calibration could fix the drone after this.

Im sure DJI support on forum would first ask was he using an approved device then suggest he reinstall Go4 to fix it.

 

[Trees138]

Feeling a little homesick all of a sudden.

 

[LuvMyTJ]

In case anyone was wondering, this is the type of aircraft they used. It's a Mooney M20...

 

[dirkclod]

Breaking News: DJI Demands Withdrawal of Drone Crash Video

 

[ac0j]

It’s about time. That was so unreal. A moonie is is super light weight and old tech.

 

[sar104]

Breaking News: DJI Demands Withdrawal of Drone Crash Video

That's a poor response from DJI - factually incorrect as well as unreasonable. The test involved current DJI design hitting a production light aircraft, at a speed that is lower than the top speed of the Mooney M20 range. It's a simple impact test, and there is little room to claim there was anything wrong with it.

 

[WithTheBirds]

Breaking News: DJI Demands Withdrawal of Drone Crash Video

Perhaps DJI might have been best to say nothing than to draw further attention to the findings. Maybe the test needs to be repeated with a phantom 4P and Inspire 2 and a correction (if required) to impact speed at 500m altitude.

 

[ac0j]

That's a poor response from DJI - factually incorrect as well as unreasonable. The test involved current DJI design hitting a production light aircraft, at a speed that is lower than the top speed of the Mooney M20 range. It's a simple impact test, and there is little room to claim there was anything wrong with it.

If you believe that the speed was accurate. I believe that appeared to be in the 1000fps or more range. I find it hard to believe it was the around 300fps they claimed. It was video was slowed down so slow much that a Phantom motor was suspended in the frame throughout the rest of the video almost. and gravity didnt start pulling it down. Yet the Phantom covered the field of view in the same slow motion in a few frames.
SECOND, I'll need a Physicist to confirm, but I dont think you get the correct result hitting the stationary wing with a drone at an impossible velocity. It seems to me hitting a flying baseball with a bat, and hitting a flying bat with a baseball at the exact same speed would yield completely different results. or like throwing a bird at a suspended BB

 

[WithTheBirds]

If you believe that the speed was accurate. I believe that appeared to be in the 1000fps or more range. I find it hard to believe it was the around 300fps they claimed. It was video was slowed down so slow much that a Phantom motor was suspended in the frame throughout the rest of the video almost. and gravity didnt start pulling it down. Yet the Phantom covered the field of view in the same slow motion in a few frames.
SECOND, I'll need a Physicist to confirm, but I dont think you get the correct result hitting the stationary wing with a drone at an impossible velocity. It seems to me hitting a flying baseball with a bat, and hitting a flying bat with a baseball at the exact same speed would yield completely different results. or like throwing a bird at a suspended BB

Why would they lie about the speed? It won’t be a mistake either, there are more than enough frames from the high speed camera for them to have confirmed it with good accuracy as an assurance. It’s easier to get the phantom to the desired impact speed than the wing.

 

[ac0j]

Why would they lie about the speed? It won’t be a mistake either, there are more than enough frames from the high speed camera for them to have confirmed it with good accuracy as an assurance. It’s easier to get the phantom to the desired impact speed than the wing.

I question the speed because of what is seen in the video. I watch a lot of high speed video related to guns. Often in the 2000fps range. The debris from the targets hangs for a long time before it starts to drop, and when it drops it is REALLY slow. My opinion is the video is of a drone at a similar ballistic speed. If you watch a high speed video of an Indy car wreck at 200+ MPH (293fps as the video claims) The debris reacts much faster frame by frame.
Again, a Physics question, would the 1.5 lb drone have as much energy if hovering and hit by the plane at speed? It seems logical that the drone would be moved physically away in the same direction as the wing is moving as soon as it touches dramatically reducing the destructive effect implied by the video. Its the object in motion effect.

ETA: I dont know why they would lie. BUT just because they say its true proves nothing. You cant even make out the drone at real speed.

 

[WithTheBirds]

I question the speed because of what is seen in the video. I watch a lot of high speed video related to guns. Often in the 2000fps range. The debris from the targets hangs for a long time before it starts to drop, and when it drops it is REALLY slow. My opinion is the video is of a drone at a similar ballistic speed. If you watch a high speed video of an Indy car wreck at 200+ MPH (293fps as the video claims) The debris reacts much faster frame by frame.
Again, a Physics question, would the 1.5 lb drone have as much energy if hovering and hit by the plane at speed? It seems logical that the drone would be moved physically away in the same direction as the wing is moving as soon as it touches dramatically reducing the destructive effect implied by the video. Its the object in motion effect.

ETA: I dont know why they would lie. BUT just because they say its true proves nothing. You cant even make out the drone at real speed.

Fair enough- given the testing was supervised by the university group leader in impact testing who is a renowned expert in bird strikes and other aircraft impacts I strongly suspect he might have a great interest in maintaining his academic reputation.

 

[Goof]

Again, a Physics question, would the 1.5 lb drone have as much energy if hovering and hit by the plane at speed? It seems logical that the drone would be moved physically away in the same direction as the wing is moving as soon as it touches dramatically reducing the destructive effect implied by the video. Its the object in motion effect

It makes zero difference whether or not the drone or the wing is moving, all that matters is their relative speeds.

 

[ac0j]

It makes zero difference whether or not the drone or the wing is moving, all that matters is their relative speeds.

This is where I cant grip it. There is a certain amount of energy gained with speed, that energy has to be expended. I feel a stationary drone hit by a plane at 200mph would not have the same energy as the drone fired from a cannon. In an actual in air collision, the hovering drone would have a certain amount of "give" that is does not have at speed. The stationary wing wont "move"as a result of being hit by a 1.5lb drone, BUT a hovering 1.5lb drone WILL react to being hit by a 1000lb plane. because there is little resistance to overcome.
at 200mph (so the video says) there is some kinetic energy adding destructive power to the moving drone that is not present hovering in free air.

I am thinking If I drop a balloon on a knife, and if I drop a knife on a balloon.

 

[Goof]

In an actual in air collision, the hovering drone would have a certain amount of "give" that is does not have at speed.

The "give" is still present in this collision, present in the fact that the drone slows down when it hits the wing.

I am thinking If I drop a balloon on a knife, and if I drop a knife on a balloon.

Completely irrelevant, those involve external acceleration.

 

[ac0j]

The "give" is still present in this collision, present in the fact that the drone slows down when it hits the wing.



Completely irrelevant, those involve external acceleration.

External acceleration is what I thought they did with the drone.
A drone going 200 mph has more "weight" to stop than a stationary drone. A wing hitting a hovering drone, doesnt have to slow the drone down so the drone will be a less heavy target when the plane is the one moving, Right?