Maximum Effort Avoidance of a Low-Flying Manned Aircraft

[MS Coast]

So, what is the best maneuver for maximum-effort avoidance of a low-flying manned aircraft that appears suddenly near our drone and presents a clear and present collision hazard? Surprisingly I don't recall seeing this specifically addressed in any instructional videos or publications.

I'm thinking that collision avoidance maneuvers are something we need to sort out prior to needing to execute them. Knowing how to respond appropriately is essential. And removing even a second from our response time might make be the difference between a collision and a near miss.

I'll toss this out as a starting point for discussion, with the assumption that the manned aircraft is at or above the drone's altitude.

An immediate movement of the left stick full back and the right stick fully in a direction perpendicular to the aircraft's flight path, along with a switch to sport mode.

It might be worth practicing to work out how to execute all three motions on the controller quickly and develop some dexterity.

Comments?

 

[GFields]

I would descend as quickly and safely as possible.

 

[@Rip]

Situational awareness is important here so as not to collide with a tree or some other unanticipated "thing".. Strong decent, Sport Mode, I think are good thoughts... Which ever direction is required to get out of the flight path a.s.a.p. .. PRACTICE with multiple direction (avoidance) strategies. I suspect the reality of it is really thinking and acting on your feet, so to speak. Back to situational awareness!

 

[MS Coast]

I would descend as quickly and safely as possible.

Yes, "An immediate movement of the left stick full back..."

Shouldn't lateral avoidance be considered, too?

 

[Yorkshire_Pud]

If you are actually looking at the drone and not the screen I think the biggest problem is going to be judging where the drone is in relation to the plane. At distance it seems difficult to judge whether alignment is due to height or distance.
I.e., with care, I can make my drone climb and fly away or descend and fly towards me yet the drone stays in exactly the same place in the sky. In the absence of other information only the drone's increasing or decreasing apparent size would tell me if the drone was flying towards me or away from me.
Meaning you probably can not tell what horizontal movement will diminish the threat.
The same thing applies to vertical movement but my first reaction would be full speed descent in sports mode.
The reason being, the aircraft is increasingly less likely to be at the drone's height as the drone descends. If really worried and there was sufficient time I'd switch the emergency motor stop option to "Anytime"/ "Always" and CSC the drone let it drop and try to restart the motors with a second CSC.

Realistically in such circumstances I think you'd have a better chance of judging alignment via the screen rather than eyes on the drone but down as fast as possible would still be my first action.

 

[mavic3usa]

Do we have a list or a source of reported near misses or near collisions with a drone vs. manned aircraft? Would be interesting to know how often this really happens.

 

[Ty Pilot]

There are way too many variables to try and settle on a single action (beforehand) in the event of a manned aircraft suddenly appearing.

Depth perception of two objects in the sky that are both moving in three dimensional space is probably the biggest challenge. And while practice with your aircraft can sharpen your sense of it's position relative to things like trees and ground, you have very little opportunity to practice against moving objects. The difference in scale and speed between a drone and even a small aircraft adds layers of difficulty to deciphering even a mildly close idea as to where they are in relation to each other.

In 45 years of RC I spent the majority of that time (over 16,000 hours) trying NOT to hit another aircraft yet I can remember at least seven (7) mid air collisions I had with other aircraft.

On the inverse of that, on numerous occasions I flew in events (not counted above), with cheap aircraft that trailed streamers where the idea was to cut each others' streamers. Mid airs occurred and were expected. Yet flying nimble Fixed wings with no worry of collision made it painfully obvious how truly little depth perception one has as a remote pilot. I scored a few ribbon cuts but only one midair in maybe 25 such events.

For this reason, my answer would be that the best defense against such an event is always be aware of what can happen and always be on your toes and keep SA throughout the flight a top priority.

 

[MS Coast]

If you are actually looking at the drone and not the screen I think the biggest problem is going to be judging where the drone is in relation to the plane. At distance it seems difficult to judge whether alignment is due to height or distance.
I.e., with care, I can make my drone climb and fly away or descend and fly towards me yet the drone stays in exactly the same place in the sky. In the absence of other information only the drone's increasing or decreasing apparent size would tell me if the drone was flying towards me or away from me.
Meaning you probably can not tell what horizontal movement will diminish the threat.
The same thing applies to vertical movement but my first reaction would be full speed descent in sports mode.
The reason being, the aircraft is increasingly less likely to be at the drone's height as the drone descends. If really worried and there was sufficient time I'd switch the emergency motor stop option to "Anytime"/ "Always" and CSC the drone let it drop and try to restart the motors with a second CSC.

Realistically in such circumstances I think you'd have a better chance of judging alignment via the screen rather than eyes on the drone but down as fast as possible would still be my first action.

Two different things. I'm thinking about an immediate need for evasive action, as when that helicopter emerges over the tree line 100 yards away. That's very different from situation where there's time to open the Fly app settings menu, navigate to the right screen, change CSC settings, close settings, execute the CSC and wait for the time delay.

There are certainly situations where the relative positions of the manned aircraft and drone are difficult to understand, but in situations where immediate action is required, there would be no time to aim the camera and find the aircraft.

In some cases, it is indeed difficult to immediately know which way to move the drone laterally. But in other cases, the best direction would be clear. For instance, where the drone and aircraft were aligned in your field of view, it wouldn't matter whether the aircraft was going toward you or away, moving to the side would be advantageous. If the aircraft is moving to one side, the drone ought to be moved in the opposite direction.

I'm remembering being taught to fly a Cessna 150 that when the engine sputters, you immediately reach for the fuel selector to be sure it's on both tanks, pull the carburetor heat on, and set the mixture to full. The instructor had me practice so that it was an automatic thing and there was no need to think or look around for the right levers and knobs. I think it's worth developing that sort of near-reflexive response to a sudden and immediate collision threat.

 

[Big Bro]

If really worried and there was sufficient time I'd switch the emergency motor stop option to "Anytime"/ "Always" and CSC the drone let it drop and try to restart the motors with a second CSC.

Really? You might want to watch some of the videos on youtube of pilots using CSC. It's not instantaneous and before that you're going to enter into the menu system and set the emergency stop option?

First off, I'm going to be paying attention, like @Rip said, situational awareness is key! I'm always scanning the sky and more importantly I'm listening for aircraft, most are very loud and can be heard from quite a distance! At the first inclination of an approaching aircraft I'm down on the left stick. I do this because while it might sound or look like an aircraft is down at or below you're 400' ceiling, most likely they are higher, part 61 pilots are taught that altitude is your friend and are not fond of being below 500' except when taking off or landing. Helicopters certainly do fly lower, but again, situational awareness. Are you in an area that helis frequent? Near a hospital, airport or anywhere there's a heli pad. If so, you might want to find a safer place to fly. If it is so apparent that I need to drop altitude to the point of needing the decent rate of CSC, then it might be better to ascend as quickly as possible. None the less, the last thing I want to do is relinquish control of the aircraft and then realize, oh $#!* I should have gone left, right or up and not have control!

 

[old man mavic]

if you are flying within the VLOS rules then all you need to do is descend in a controlled manner ,
to remove the drone from the equation ,the most likely aircraft to be in a position ,of flying in the 400ft designated zone that we fly in, are the emergency services,
or crop spraying ,and military doing low level training exercises,
and heaven forbid ,an out of control aircraft trying to get down as quickly as possible
and of course not flying in restricted airspace during emergencies, knowing full well that the likely hood of low flying manned ,or indeed SAR unmanned ,aircraft being there is highly likely,will also decrease the chances of your drone being involved in a mid air collision ,every situation will be different ,and there is no hard and fast rule ,to fit every scenario,

 

[MS Coast]

if you are flying within the VLOS rules then all you need to do is descend in a controlled manner

The drone is at 200 feet AGL. A helicopter suddenly appears over the treetops at 150' AGL and it's flight path is taking it toward a point directly under the drone. It arrives just as your drone descends vertically through 150'

Flying the drone laterally while descending might have averted contact.

 

[old man mavic]

@MS Coast a purely hypothetical example of a possible mid air collision, i did not say anything about the direction of the descent ,simply because that would depend on so many variables,i said descend in a controlled manner ,the emphasis being on descend, which is what a UAV should do first and foremost ,to avoid a collision with another aircraft
when it comes to airspace use we are on the bottom rung of the ladder

 

[@Rip]

Even Manned aircraft pilots can't see everything. When I was training in the 70's my instructor called out another aircraft and as I scanned the sky he took control and abruptly changed course. He tore my shirt that day! It was a good day... Was there another aircraft? Or was he training me to be aware.? Not sure. Never saw another aircraft. And I don't remember asking him about this. I am sure the situation would be compounded with the small size of MOST drones. In the event of a manned aircraft needing to find a spot to land in an emergency, I doubt the pilot would be concerned with a drone, after all. Nonetheless I use Anti-Collision Lights day and night. But WE should be concerned. For Sure.

That said there are a lot of helicopters and low flying private aircraft (I have considered reporting) that "buzz" the mountain here on the coast. Air National Guard, Coast Guard, etc. usually stay over the ocean..

When I talk to the Coast Guard, They are usually looking for a lost or missing person and extend their search somewhat inland, just to be sure... But those are jet powered and audible... Most helicopters are audible even over the coast on most days.. We hear the thumping... The Private planes that are out on a joy ride are less dependable. [Language removed by ADMIN]

We have to be ready to "bug out" in any direction in the event... Not looking forward to it.

BTW: I almost always use a spotter for these kinds of situations. Really Helps.

 

[AlanL]

Even Manned aircraft pilots can't see everything. When I was training in the 70's my instructor called out another aircraft and as I scanned the sky he took control and abruptly changed course. He tore my shirt that day! It was a good day... Was there another aircraft? Or was he training me to be aware.? Not sure. Never saw another aircraft. And I don't remember asking him about this. I am sure the situation would be compounded with the small size of MOST drones. In the event of a manned aircraft needing to find a spot to land in an emergency, I doubt the pilot would be concerned with a drone, after all. Nonetheless I use Anti-Collision Lights day and night. But WE should be concerned. For Sure.

That said there are a lot of helicopters and low flying private aircraft (I have considered reporting) that "buzz" the mountain here on the coast. Air National Guard, Coast Guard, etc. usually stay over the ocean..

When I talk to the Coast Guard, They are usually looking for a lost or missing person and extend their search somewhat inland, just to be sure... But those are jet powered and audible... Most helicopters are audible even over the coast on most days.. We hear the thumping... The Private planes that are out on a joy ride are less dependable. [Language removed by ADMIN]

We have to be ready to "bug out" in ant direction in the event... Not looking forward to it.

BTW: I almost always use a spotter for these kinds of situations. Really Helps.

My description of CG flying low and fast along the coast was just about in your backyard - I was shooting the Heceta Head Lighthouse in the fall with moderate winds and high surf below. The chopper came around the corner from the north at no more than 300' above the swells. He blew past my drone's position less than a second after he came into view around Heceta Head. I don't there is a maneuver I could have made that would have been helpful. Thankfully he was just far enough away from my drone that there wasn't a problem for either of us beyond me being almost in need of clean underwear. Short of a spotter on the beach north of Heceta Head I had zero warning he was going to rip past.

 

[@Rip]

I get that! I'll be there tomorrow. At least I know most of the pilots int he CG that will definitely float by.
Key words... "Short of a spotter" ... I'm too paranoid for that.
The key is to contact the Coos Bay station where they have a home base. Let them know what I am up to... Maybe they'll give me a cameo... maybe not. Yes and they do RIP!!!
EDIT: National guard is not so accessible. They do fly low , heavy and slow. (But you can hear them coming))

 

[Yorkshire_Pud]

Really? You might want to watch some of the videos on youtube of pilots using CSC. It's not instantaneous and before that you're going to enter into the menu system and set the emergency stop option?

Thanks but I have no need to watch youtubes.
Apart from anything else I have probably already watched every available one, notably the ones by "DroningOn" and "Daily Droning".

When I first read the manual for the Mavic Mini I was extremely concerned about the wording of the section that dealt with the use of the CSC to stop the motors in mid air, I think it is important to have that capability and to know how to trigger it.
Therefore I performed experiments with the Mavic Mini. Firstly with the drone held in a wobbling hand, to simulate the movements of a drone in flight, the drone fought me of course.
In all those experiments,
a) with the emergency motor stop option set to "Emergency Only", the CSC did not stop the motors of the 'airborne drone' no matter how long the CSC position was held.
b) With the emergency motor stop option set to "Anytime" the CSC did stop the motor, every time, once the CSC position had been held for what seemed to be around two seconds. Looking at the logs the delay turns out to be 1.7 seconds.

I recollect trying the same thing with a drone tethered to the ceiling, with the same results.

Finally, when I was convinced the CSC would not stop the drone's motors whilst the emergency motor stop option was set to "Emergency Only", I tested it with the drone in flight. It did not stop the drone's motors, the drone descended in a controlled helix. I then tested with the emergency motor stop option set to "Anytime", the CSC stopped the drone's motors after it had been held for around 2 seconds, again the logs showed this 'delay' to be 1.7 seconds.

I repeated the hand held experiments with an M2P when I got it, same results.

I dislike both options. As a means of stopping the motors in mid air "Emergency Only" is of no practical use and "Anytime" has too short a delay period to be safe.

Personally I prefer the arrangement that exists with the P3 Adv/Pro, where the CSC will always stop the motors after the CSC position has been held for around 3, or perhaps 5, seconds and is ALWAYS 'active'. Which ever the P3 delay period is, it was long enough for me to catch myself with the sticks in the CSC position and release the sticks without triggering a motor stop of the in flight drone. However I recollect that there were numerous complaints because of inadvertent Phantom? mid air motor stops, which is probably why DJI started to 'experiment' with how to trigger an intentional mid air motor stop and prevent accidental ones.

and before that you're going to enter into the menu system and set the emergency stop option?

I certainly agree with both you and @MS Coast that, by the time the pilot had thought to switch the option and had triggered a shut down, it would probably be too late. Which is why, in post #5, I wrote
" but my first reaction would be full speed descent in sports mode.
The reason being, the aircraft is increasingly less likely to be at the drone's height as the drone descends. If really worried and there was sufficient time I'd switch the emergency motor stop option to "Anytime"/ "Alw......"

 

[Starz]

The difficult part of this scenario is the time. In most cases the drone pilot will be attempting to figure out where the other aircraft is coming from and trying to decide which way to bail. Not a fun situation to be in and I still have the picture in my mind of the fixed wing at 300 feet AGL in a populated area. I did not have time to make a decision much less move a stick. One of DJI’s bigger drones in the air at the time and thankfully no one got hurt. I did visit the local airport and mentioned all this to the airport officials and they knew exactly who it was. When I mentioned the V-tail and the color of the culprit aircraft, that was all they needed.

 

[3rdof5]

To my knowledge, the rule is we have to give way to manned aircraft at all costs, including purposely crashing if that's what is required. Every scenario is different obviously, I'm sure there are instances where going straight up (which is faster on all models) is the safer choice.

 

[Starz]

give way to manned aircraft at all costs

If you have the time to do so. In my case, not.

 

[MAvic_South_Oz]

Let's be honest, if you are flying at 400' above ground level, and for some reason, a manned aircraft (be it fixed wing or helicopter) is flying below its normal cruising minimum alt of 500', then there will be very little time to do anything to avoid that aircraft.

That's IF you need to avoid it.

It'd be like scoring lotto 1st division once or more in your life (well, ok the reverse luck equivalent) being unlucky enough for that aircraft to be exactly on course to collide with your relatively static drone.

There are plenty of examples of much larger small sized aircraft (manned para gliders etc) almost colliding with light fixed wing aircraft, that are well into manned aircraft normal altitudes over 500'.
The lack of warning and time to react was quite evident.

If this actually happened to you once in your drone flying lifetime, I feel it would be incredibly long odds.
Not odds you want, but still the lack of such serious incidents to date shows just how miniscule the risk is.

I feel the levels of rules and compliance for drones / aircraft conflict are well and truly in place to mitigate risks adequately.
There are much higher risks of a mechanical failure, fire, bird strikes etc for manned aircraft to be concerned with in general.