How To Check For "Hidden" Damage After A Minor Crash?

[Just Mark]

What sort of damage should I check for after a very minor crash? And how would I check for it?

I was on a job site and started my P3A AC up in F mode instead of P mode. There was a it of wind and the props hit some bushes.

Luckily for me, it was only about three feet off the ground and the battery ejected immediately on impact. So despite landing propeller side down, it seems like the motors stopped immediately. And it landed on grass.

I gave it a cursory inspection, then started it up (this time in P mode), gave it a couple quick launches and landings, and it seemed fine. So I finished the job.

So now that i have a few days before my next job, is there a good way to inspect the P3A?

I think in particular I am worried most about possible damage to the motors. I didn't see any errors when I was flying later that day, but since I am cautious, should I go out to some field and try some specific flight maneuvers and see if there are any errors?

Thanks in advance for any things I should check.

 

[BigAl07]

P mode and F mode should behave exactly the same (GPS and VPS enabled). F-mode simply allows 3rd party apps access to the Flight Controller (Litchi etc).

Maybe it was in A or Atti-mode?

First off you need to spend some time practicing and getting intimately familiar with Atti Mode for many reasons but this one is at the top of the list. You never know when "conditions" may mandate switching into Atti mode or the AC could drop into ATTI mode automatically and you need to be competent and confident when that happens.

Since you went ahead and completed the "job" everything must be in pretty good shape. Thank goodness since you went ahead and flew and THEN asked how to inspect it. For the most part these birds are tougher than we think... usually.

Really after a minor mishap we do a visual and sound inspection to see if anything looks or sounds off. In addition to the above I touch/move every square millimeter of the aircraft feeling for anything loose, rough, missing, or damaged. This is an excellent time to take a damp cloth (or alcohol pad) and wipe the whole aircraft down giving it an inspection and cleaning at the same time. Then we take it for a hover flight watching and listening. Then if that goes well and nothing is getting hot (sign something is rubbing/dragging) we go up and test all flight modes and go from there.

If it's more than a minor incident we go ahead and dig inside the shell looking for loose connections or pinched wired etc as well as the above mentioned inspections.

I've crashed mine from dozens of feet in the air, replaced the props and never missed a lick of flying.

 

[With The Birds]

Hopefully the only thing damaged was your pride. It’s likely what happened here was the AC hadn’t acquired a GPS lock before launch, if that was the case your homepoint recorded would have been some distance from the launch point (would have set when GPS lock was completed). I hope the client wasn’t watching.

Correcting for the drift should have been almost instinctive if your going to be launching/flying in tight locations. As BigAl has said, some hours on the sticks in ATTI mode will serve you well.

As for damage I would be paying particular attention to the motor mount bosses in the lower shell, they are prone to cracking. I would probably replace the props also.

 

[Just Mark]

P mode and F mode should behave exactly the same (GPS and VPS enabled). F-mode simply allows 3rd party apps access to the Flight Controller (Litchi etc).

Maybe it was in A or Atti-mode?

First off you need to spend some time practicing and getting intimately familiar with Atti Mode for many reasons but this one is at the top of the list. You never know when "conditions" may mandate switching into Atti mode or the AC could drop into ATTI mode automatically and you need to be competent and confident when that happens.

Since you went ahead and completed the "job" everything must be in pretty good shape. Thank goodness since you went ahead and flew and THEN asked how to inspect it. For the most part these birds are tougher than we think... usually.

Really after a minor mishap we do a visual and sound inspection to see if anything looks or sounds off. In addition to the above I touch/move every square millimeter of the aircraft feeling for anything loose, rough, missing, or damaged. This is an excellent time to take a damp cloth (or alcohol pad) and wipe the whole aircraft down giving it an inspection and cleaning at the same time. Then we take it for a hover flight watching and listening. Then if that goes well and nothing is getting hot (sign something is rubbing/dragging) we go up and test all flight modes and go from there.

If it's more than a minor incident we go ahead and dig inside the shell looking for loose connections or pinched wired etc as well as the above mentioned inspections.

I've crashed mine from dozens of feet in the air, replaced the props and never missed a lick of flying.

Thank you for the response and suggestions.

Well... I am 100% certain it WASN'T in P mode, that is for sure. I would say I am 90% certain it was in F mode, but could have been in A mode.

Ironically enough, I actually have been practicing with a simulator lately because I actually am concerned about being able to operate the AC when it loses satellite connection. I guess my reflexes weren't quick enough though. I think I got distracted because I was using a new phone and I pressed the standby button on the phone by accident. (I know, that is a big mistake to use a new phone on a job without trying it out first...)

And while I am a card-carrying member of the "Ready... Fire... Aim" squadron, I did certainly give the AC more than a passing glance and did listen for strange noises. As well as a couple of test take offs and landings, before putting her back up. So I wasn't being COMPLETELY irresponsible... And besides, that is what Verifly is for, right???

Tomorrow I will do a more thorough inspection and cleaning as you suggest, and Wednesday I will (hopefully) have time to head out to the flying field and give it a thorough hover test and listen for any strange noises.

Thanks again.

 

[Just Mark]

Hopefully the only thing damaged was your pride. It’s likely what happened here was the AC hadn’t acquired a GPS lock before launch, if that was the case your homepoint recorded would have been some distance from the launch point (would have set when GPS lock was completed). I hope the client wasn’t watching.

Correcting for the drift should have been almost instinctive if your going to be launching/flying in tight locations. As BigAl has said, some hours on the sticks in ATTI mode will serve you well.

As for damage I would be paying particular attention to the motor mount bosses in the lower shell, they are prone to cracking. I would probably replace the props also.

Thanks for the reply.

I don't know if this matters, but I do have it set up to "hover" if it loses connection. I don't know for sure if that is what you mean. When I checked the homepoint, it seemed to be accurate. However, my new phone was acting laggy (and eventually the app crashed, but I was luckily only about 40 feet AGL and about 20' away horizontally so I just flew her in and landed).

 

[BigAl07]

It sounds like you've got a solid plan. Practice in ATTI mode each and every time you fly (even if only the last couple of minutes on a flight) and at some point you'll realize ATTI mode is just another day in the office.

Good luck and safe flights

 

[Just Mark]

It sounds like you've got a solid plan. Practice in ATTI mode each and every time you fly (even if only the last couple of minutes on a flight) and at some point you'll realize ATTI mode is just another day in the office.

Good luck and safe flights

Thank you for the advice and thank you for the good wishes. I always appreciate your input.

 

[BigAl07]

Thank you for the advice and thank you for the good wishes. I always appreciate your input.

My pleasure. We all started at the same place and had to learn along the way. I was fortunate that I had some amazing people helping me get to where I am today.

 

[Traveler]

What sort of damage should I check for after a very minor crash? And how would I check for it?

I was on a job site and started my P3A AC up in F mode instead of P mode. There was a it of wind and the props hit some bushes.

Luckily for me, it was only about three feet off the ground and the battery ejected immediately on impact. So despite landing propeller side down, it seems like the motors stopped immediately. And it landed on grass.

I gave it a cursory inspection, then started it up (this time in P mode), gave it a couple quick launches and landings, and it seemed fine. So I finished the job.

So now that i have a few days before my next job, is there a good way to inspect the P3A?

I think in particular I am worried most about possible damage to the motors. I didn't see any errors when I was flying later that day, but since I am cautious, should I go out to some field and try some specific flight maneuvers and see if there are any errors?

Thanks in advance for any things I should check.

You can consult the manual, but to the best of my knowledge, the P3 series will default to P mode on startup. ATTI has to be intentionally selected by way of moving the switch from current mode to ATTI after starting the AC. As an example, if you land in ATTI and turn off the AC for a battery swap or other reasons, the transmitter may still be in ATTI on the switch, but it will default to P mode. Move switch from ATTI to P, then back to ATTI if that’s actually your intention.

I know the P3P and P4P work that way, so I would expect the same in the “A”.

Best guess is you had some wind and or not many GPS sats locked in on takeoff.

When I fly my 3 vs 4, I have noticed that the 4 is much better at position hold on takeoff than the 3. Add some tight space to the mix and you have a disaster waiting to happen.

Just my .02 cents.

Traveler...

 

[Just Mark]

You can consult the manual, but to the best of my knowledge, the P3 series will default to P mode on startup. ATTI has to be intentionally selected by way of moving the switch from current mode to ATTI after starting the AC. As an example, if you land in ATTI and turn off the AC for a battery swap or other reasons, the transmitter may still be in ATTI on the switch, but it will default to P mode. Move switch from ATTI to P, then back to ATTI if that’s actually your intention.

I know the P3P and P4P work that way, so I would expect the same in the “A”.

Best guess is you had some wind and or not many GPS sats locked in on takeoff.

When I fly my 3 vs 4, I have noticed that the 4 is much better at position hold on takeoff than the 3. Add some tight space to the mix and you have a disaster waiting to happen.

Just my .02 cents.

Traveler...

Thanks so much for the info. I will check that out on my P3A just to see if it works that way, too.

 

[Just Mark]

If you have a moment, maybe you all wouldn't mind taking a look at my take off spot (and whether the conditions I was in might have been a factor).

I was launching from that middle area that looks like grass (it was really astro turf on top of concrete). At the narrowest point, it was probably about 15 feet wide.

I did a compass calibration trying to stay away from metal as best as I could, but those are metal roofs on the building and I don't know if there was a lot of metal in the concrete below the takeoff spot or not.

I thought my compass point was correct, but as mentioned above, the app was laggy (and the app did crash later on).

Out of the frame (at the bottom) was some power lines (the drone was about 15 feet above them when I snapped this shot.

I am assuming that - in general - this is kind of a bad environment to fly in. (Yes, I have my 107 and had purchased insurance from Verifly, in case anyone was wondering). The wind was mild, but I have been fooled by the wind before...

 

[Traveler]

Mark, the entire area looks very bad for a compass calibration. You have probably read this before, but here it is again. Go to a clear area (free from metal), calibrate and forget it. Doing so will allow for the AC to monitor takeoff locations for any compass interference before takeoff. I honestly can’t tell you the last time I calibrated my compasses. The Go app will alert you to calibrate or move to a new location if a problem is detected. If you do happen to get that message, stop, look around, consider that it’s location vs a need to calibrate. Most likely it’s just a need to move. I have rebar under my driveway, common of course, so after moving my AC to various spots on my driveway, I was able to find a good takeoff point that works so well that I placed an X on the site for all takeoffs from same.

I have personally traveled 3000 miles and still didn’t need to recalibrate.

If you maintain as much distance as you can from the metal surrounding your takeoff point you would probably be okay, but if in doubt, find a better location. You could even open a compass app on your device and move it around in the area to check for influences.

I made a mistake the other day at our RC field. Taking off from a wooden table I failed to account for the steel bolts holding down parts of the table and as soon as I got airborne it went squirrelly. I had lots of room, little wind, and all the confidence I needed to fly it around until the compass normalized, but point being, sometimes it doesn’t take much. Take a deep breath, climb a little higher, and make subtle changes on the sticks to regain control.

 

[Just Mark]

Mark, the entire area looks very bad for a compass calibration. You have probably read this before, but here it is again. Go to a clear area (free from metal), calibrate and forget it. Doing so will allow for the AC to monitor takeoff locations for any compass interference before takeoff. I honestly can’t tell you the last time I calibrated my compasses. The Go app will alert you to calibrate or move to a new location if a problem is detected. If you do happen to get that message, stop, look around, consider that it’s location vs a need to calibrate. Most likely it’s just a need to move. I have rebar under my driveway, common of course, so after moving my AC to various spots on my driveway, I was able to find a good takeoff point that works so well that I placed an X on the site for all takeoffs from same.

I have personally traveled 3000 miles and still didn’t need to recalibrate.

If you maintain as much distance as you can from the metal surrounding your takeoff point you would probably be okay, but if in doubt, find a better location. You could even open a compass app on your device and move it around in the area to check for influences.

I made a mistake the other day at our RC field. Taking off from a wooden table I failed to account for the steel bolts holding down parts of the table and as soon as I got airborne it went squirrelly. I had lots of room, little wind, and all the confidence I needed to fly it around until the compass normalized, but point being, sometimes it doesn’t take much. Take a deep breath, climb a little higher, and make subtle changes on the sticks to regain control.

Thanks so much for sharing the experience and for the tips on the compass calibration.

It seems like there are definitely two schools of thought; One says to calibrate the compass EVERY time you launch, the other says don't calibrate compass unless the app tells you to. I guess I won't calibrate it again unless I am SURE that I am in an area with no metal or interference.

Thanks again.

 

[Traveler]

Thanks so much for sharing the experience and for the tips on the compass calibration.

It seems like there are definitely two schools of thought; One says to calibrate the compass EVERY time you launch, the other says don't calibrate compass unless the app tells you to. I guess I won't calibrate it again unless I am SURE that I am in an area with no metal or interference.

Thanks again.

A thousand perfect calibrations will never hurt you, but one bad one, well you know!

For me and many others who can attest to the same, don’t try to fix what ain’t broken.

Cheers and happy flying!

Traveler

 

[msinger]

I guess I won't calibrate it again unless I am SURE that I am in an area with no metal or interference.

It's highly unlikely that you'll be able to successfully calibrate the compass in a location where the compass is affected by a magnetic metal object. The procedure should fail and prompt you to move to a different location.

 

[BigAl07]

If you have a moment, maybe you all wouldn't mind taking a look at my take off spot (and whether the conditions I was in might have been a factor).

I was launching from that middle area that looks like grass (it was really astro turf on top of concrete). At the narrowest point, it was probably about 15 feet wide.

I did a compass calibration trying to stay away from metal as best as I could, but those are metal roofs on the building and I don't know if there was a lot of metal in the concrete below the takeoff spot or not.

I thought my compass point was correct, but as mentioned above, the app was laggy (and the app did crash later on).

Out of the frame (at the bottom) was some power lines (the drone was about 15 feet above them when I snapped this shot.

I am assuming that - in general - this is kind of a bad environment to fly in. (Yes, I have my 107 and had purchased insurance from Verifly, in case anyone was wondering). The wind was mild, but I have been fooled by the wind before...

I've taken off in much tighter and less "compass friendly" areas. We recently launched from a boat with cranes and guy wires all around. We had to ascend through a small corridor of pending disaster until we were above the machinery and scaffolding scaffolding.

We don't do a compass Calibration unless we experience some type of error. I've traveled across states and back again without doing one with no issues. Always remember, what works for one operation may or may not work for yours so develop and tweak your processes as you go along.

It's possible you just didn't have enough GPS satellites to hold a stable column and this lead to over control etc. It could happen in a blink of an eye and one small mistake can snowball quickly into an Oh CRAP situation.

I think the keep point is to (I hate to preach) be competent in flying the aircraft in any mode and attitude that might happen so when it does happen it's not a total new experience for you. It's not a matter of IF it will happen but WHEN. . . Emergencies never happen in convenient areas or at convenient times.

We teach UAS flight and after the first day of instruction the students operate almost exclusively in "ATTI" mode even for tight/precise flights like flying under and landing under an EZ-Up Canopy landing on top of a platform.

 

[Just Mark]

I've taken off in much tighter and less "compass friendly" areas. We recently launched from a boat with cranes and guy wires all around. We had to ascend through a small corridor of pending disaster until we were above the machinery and scaffolding scaffolding.

We don't do a compass Calibration unless we experience some type of error. I've traveled across states and back again without doing one with no issues. Always remember, what works for one operation may or may not work for yours so develop and tweak your processes as you go along.

It's possible you just didn't have enough GPS satellites to hold a stable column and this lead to over control etc. It could happen in a blink of an eye and one small mistake can snowball quickly into an Oh CRAP situation.

I think the keep point is to (I hate to preach) be competent in flying the aircraft in any mode and attitude that might happen so when it does happen it's not a total new experience for you. It's not a matter of IF it will happen but WHEN. . . Emergencies never happen in convenient areas or at convenient times.

We teach UAS flight and after the first day of instruction the students operate almost exclusively in "ATTI" mode even for tight/precise flights like flying under and landing under an EZ-Up Canopy landing on top of a platform.

Thanks again.

Yes, looking forward to hitting the flying field tomorrow for some testing and practice.