Prop Strike... Now What?

[N9344H]

Ok, so I was practicing ATTI flying today to make sure I was prepared in the event of lost GPS. I was only flying about 18-24" inches off the ground (in ground effect) at low low speeds when I bumped into a tree, striking two of the props. I cleaned the props with a damp cloth to get the sap off, and checked the leading edges with my eyes and fingertips, and found no detectable aberrations.

If this was a Cessna, it would be off to the prop shop, but the is not a Cessna. Are they safe to fly?

 

[GoodnNuff]

Yes, a Cessna is safe to fly.

As is your Phantom.

 

[FotoGeek]

Probably OK...but I'd replace them to be on the safe side. You can get a set of 4 for about $15. Is it worth saving a few bucks and potentially losing $700-1200?

 

[jason]

Ok, so I was practicing ATTI flying today to make sure I was prepared in the event of lost GPS. I was only flying about 18-24" inches off the ground (in ground effect) at low low speeds when I bumped into a tree, striking two of the props. I cleaned the props with a damp cloth to get the sap off, and checked the leading edges with my eyes and fingertips, and found no detectable aberrations.

If this was a Cessna, it would be off to the prop shop, but the is not a Cessna. Are they safe to fly?

Since you didn't hit the tree hard enough to damage the props and see no reason to worry but try to find an area without trees around and fly a bit higher than 24" off the ground.

Probably OK...but I'd replace them to be on the safe side. You can get a set of 4 for about $15. Is it worth saving a few bucks and potentially losing $700-1200?

I would n't be so quick to buy those props for $15 or you be replacing more then props the next time.

 

[FotoGeek]

I would n't be so quick to buy those props for $15 or you be replacing more then props the next time.

Which props? I'm talking about the official OEM DJI props. You can get them on Amazon

Amazon.com : 2 Pairs Genuine DJI Phantom 3 9450 Props Part #09 Self-Tightening Propeller 9" All Composite For Professional and Advanced : Camera & Photo

 

[jason]

Which props? I'm talking about the official OEM DJI props. You can get them on Amazon

Amazon.com : 2 Pairs Genuine DJI Phantom 3 9450 Props Part #09 Self-Tightening Propeller 9" All Composite For Professional and Advanced : Camera & Photo

That's a good price for OEM replacements. Haven't bought any in a while and they use to be $15.00 a pair.at the time.

 

[N9344H]

Since you didn't hit the tree hard enough to damage the props and see no reason to worry but try to find an area without trees around and fly a bit higher than 24" off the ground.

I was not always 24" off the ground. I was just doing some very low altitude drills in my yard. I wanted to get the feel for ground effect. And it wasn't really a tree, but more of a ornament tree.

Also, I have another set of props that I will swap out.

 

[jason]

I was not always 24" off the ground. I was just doing some very low altitude drills in my yard. I wanted to get the feel for ground effect. And it wasn't really a tree, but more of a ornament tree.

Also, I have another set of props that I will swap out.

It makes no difference if it was ornament tree or not it's still a tree. Is it not?? There's no need to change props but it would be better to fly where you have more room like an open field. Today it's the tree next it's the house be care careful my friend.

 

[N9344H]

It makes no difference if it was ornament tree or not it's still a tree. Is it not?? There's no need to change props but it would be better to fly where you have more room like an open field. Today it's the tree next it's the house be care careful my friend.

Oh, I get that. I agree. It was a bonehead move on my part, but my intentions were good. I wanted practice before an emergency. There was a break in the weather, so I stepped out to fly.

 

[jason]

Oh, I get that. I agree. It was a bonehead move on my part, but my intentions were good. I wanted practice before an emergency. There was a break in the weather, so I stepped out to fly.

Until you have the experience it's best to find an open field. It's nearly impossible to have a good level flight in a backyard due wind currents around structures. I do testing in my yard but I also 21 months of practice behind me. And yes I've hit the house, the deck and the telephone cables but have managed not to fly into the high voltage wires.

 

[N9344H]

Until you have the experience it's best to find an open field. It's nearly impossible to have a good level flight in a backyard due wind currents around structures. I do testing in my yard but I also 21 months of practice behind me. And yes I've hit the house, the deck and the telephone cables but have managed not to fly into the high voltage wires.

My confidence was buoyed by a couple of months of flying a UDI 818A, leading me to believe I was ok. I was (wrongly) in a 30x30 open space flying backwards, mostly just hovering. You see what confidence gets you.

 

[jason]

My confidence was buoyed by a couple of months of flying a UDI 818A, leading me to believe I was ok. I was (wrongly) in a 30x30 open space flying backwards, mostly just hovering. You see what confidence gets you.

But I do know what panic gets you into.

 

[Mbundy]

Yes, a Cessna is safe to fly.

As is your Phantom.

No, if the Cessna has a Lycoming engine a complete tear down is required. Your phantom doesn't have a Lycoming so is just fine to fly. Check the base of the blades at the hub for any signs of stress.

 

[GoodnNuff]

No, if the Cessna has a Lycoming engine a complete tear down is required. Your phantom doesn't have a Lycoming so is just fine to fly. Check the base of the blades at the hub for any signs of stress.

Welcome to the list Mbundy!
I was being humorous, it fell flat.

I doubt a low speed collision with a large bush/ornamental tree is going to leave any stress marks in the props. From the OP's description of the flight, I think wiping the leaf stains off the props is all that is required.

 

[DAP-UAV]

If the props have no visible or tactile damage and they are not bent, the only other thing I would do is check the balance. If they are balanced or the balance can be corrected, I would have no problem using them again. Can ground effect can occur on a Phantom 2 that high in the air? I am not sure about helicopters but for fixed wing it's about half the length of the wing. It would be nice to know about how high ground effect occurs for 9" wings x 4. Of course all would have to be adjusted for environmental factors like temp. etc. I think it is somewhere between 5 - 10 inches above the ground, but's that's off the top of my head. I haven't done any calculations. Someone out there someone might know. Watch out for those trees, that's exactly what I did my first day flying my first quad. All was repairable thankfully.

Yeah just check the balance and go flying. The more you fly, the better you get.

 

[pb7424]

Which props? I'm talking about the official OEM DJI props. You can get them on Amazon

Amazon.com : 2 Pairs Genuine DJI Phantom 3 9450 Props Part #09 Self-Tightening Propeller 9" All Composite For Professional and Advanced : Camera & Photo

If you review the comments on Amazon for these props, you'll see that these are not OEM DJI props. I wouldn't buy them.

 

[FotoGeek]

If you review the comments on Amazon for these props, you'll see that these are not OEM DJI props. I wouldn't buy them.

Sometimes Amazon mixes comments with like products. The seller is DJI.

 

[msinger]

Sometimes Amazon mixes comments with like products. The seller is DJI.

The seller is not DJI in the above link. The "by DJI" just mean the props are manufactured by DJI. The link is currently linking to a seller named "TOY DJ Factory".

If anyone wants to buy these props on Amazon, get them here instead. Rotorlogic is an authorized DJI dealer, so you can be sure you'll be getting legit OEM props. They are also a bit cheaper.