Flying under bridges...eek!

[Mike_Flys]

What bridge in jax??? Where I live!!

Near Deland

 

[Rodkat]

If you can line it up well from say 10m away, set your altitude and then accelerate through the gap you should be fine. Look at your metres per second speed, by the time the drone reacts to any signal loss you'll be out the other side, I'd then climb to reaquire los. Alternatively, fly under very slowly and monitor your signal strength, back out if it drops more than you're comfortable with. Remember you can set rth to hover.

 

[Brojon]

I'm sure the drone doesn't just lose connection when you fly under bridges it just drops into none GPS mode and if it is dark then into attitudes mode I've done it loads with my spark and mavic pro.

Well, mine I had just flown under the edge of the metal suspension bridge. My MP started drifting at which point I tried to back out. Instead it shot up into the bridge and down into the mud. Thankfully the battery was defective and the terminal broke saving the drone from being powered when dunked. I was able to clean it up and return to service. But no. I stay away from bridges now even though I'd love to get some passing through shots.
BTW - I was standing not 60 feet away in full sight of teh drone. I don't think it was a loss of signal issue.

 

[mackt83]

State Farm has my back!

 

[Jake 61]

Done bridges a few times, but always flying backwards so the sensors don't mess with the flight. Never lost the signal yet, also, I don't hang around under a bridge, line it up, set the height and get on with it.
Mavic Pro, not Air.

 

[El NinoPerdido]

Mavic Virgin here, My Mavic is on order. I have flown Hubsan'a and there is one bridge I would love to conquer. I lost the satilites on the Hubsan going under this bridge and thankfully when it determined that I wasn't driving anymore it did a RTH. I'm hoping I can use Lichi to set waypoints and get the Mavic Air under this bridge. The Hubsan 501 has a fixed camera but great machine to learn with around $100 for the bird, cheap to replace. Here is the video from the Hubsan: Anybody think it can be done?

 

[hqm]

I lost a mavic pro under the Marine Park bridge in Rockaway beach NY.
I believe it lost signal and then did return to home and hit the bridge. I didn't do an in depth analysis of the log, but it had lost video at the time.

 

[RadioFlyerMan]

Hi Thwyllo,
I'm new to the world of drones and just joined the Mavic Pilots group yesterday. So take my comments with that in mind. I'm just learning my way around here and noticed your post as one of the most recent and wanted to say hello and and share my two cents. As is the case with any good pilot, you are doing the right thing by pre-planning your flight into a situation that you have not experienced previously.
A couple things I would consider and / or keep in mind before giving this a try would include:

• How far away from you (and the controller) would your "Air" be from you when it went under the bridge?
  • Obviously the closer you are to the drone, the less likely it is that you will lose signal.
  • Consider your position with the controller during the adventure. Try to position yourself so that the the time the drone would not be in direct line-of-site of the controller would be minimized and of course have a Visual Observer positioned so they are in a position to monitor the bird anytime it would be out of your line-of-site.
• What are the surroundings like?
  • For example, is this in a heavily wooded area or would there be clear sky and limited (or no) obstructions around the bridge?
  • This would be important in weighing the risks. If you did lose signal and there was little or no obstructions along with clear sky above in the area, the risk involved with an automated Return to Home would be reduced some-what. Of course a RTH being initialized while still under the bridge or with other overhead obstacles nearby could potentially prove disastrous.
• Now I am definitely just thinking out loud here as I am not very familiar with the Intelligent Flight Modes on my Mavic Pro never-mind on the Air. Is there a I.F.M. that may allow you to preset your course under the bridge? It *may* give the drone a little more incentive to follow through and continue out from under the bridge into clear sky if it does lose connection to the controller. At least long enough so that if an automatically initialized RTH were to happen, it would be more likely that it would be clear of the bridge. Again...just thinking out loud as a new guy. I imagine there are far more experienced pilots that can weigh in with hands on experience with this sort of thing.

Good luck and fly safe!
- Scott

Here’s what I do at low level, close proximity flying under tree cover...

Waypoints continues with loss of signal until the end point. When in doubt, change RTH to hover, assuming you have maintained VLOS and can get closer to recover signal.

 

[Tridiver]

Yes it can be done. I fly under bridges a lot. Just don't go slow and or hover. Have some momentum and the bird won't have time to loose signal. if it does, you'll be out the other side and regain it again. I'm in the process of flhing under all the bridges in Jecksonville. 19 fo them, I'll post the vid when I'm done. Keep in mind also, just because you loose GPS signal, doesn't mean you loose RC signal!! THe RTH only activates when RC signal is lost, not GPS!

 

[irpnetgb]

In my little experience, and I know you said MA specifically, but I flew a Parrot Bebop 2 under a metal / concrete road bridge that went over a canal without any issues. I was LOS and I flew the drone away from me being about 30-40m (90-120ft) away or less. This solved the 'pilot in view' problem as well.
I think it is more about the construction of the bridge, the length of time you will be out-of-sight of GPS and your flying skills. I've seen people fly in tunnels (wood and concrete construction) without issue, but that was more than likely in OPTI mode.
Take care and fly safe!

 

[Mrmund]

Point taken, although as I said earlier, I'm only taking about a ten foot wide bridge, not a massive road bridge. I might try it on a dried up riverbed first and see how it goes.

A small bridge like you've described signal loss shouldn't be a problem because you'll want to position yourself in a location where you can see your drone fly through (like down on the river bank looking under the bridge).
I've done this many times and it's not really that hard.
1. Practice first between some trees or through a goalpost
2. Be prepared if you lose GPS. Not a big deal if you don't panic because you can see your drone and fly it well enough in attitude mode to make it through to the other side.
3. Turn your RTH setting to Hover so if you do lose signal it won't ascend up into the bridge.
4. Think about the wind. Sometimes it'll funnel under tunnels and bridges weirdly, can pick up speed or come from an unexpected direction. I'll sometimes fly right up to the entrance first, stop and just see how it reacts.
One more thing to remember is once you've figured out your altitude you'll be flying under the bridge you don't need to adjust it. Figure a height between the ground/water and the underside of the structure and then you can just steer it through.
Have fun and practice a bit first, I love to fly through places and get great shots doing. I'm sure you will too