Hello everyone! Is anyone here using a P4P for high rise inspections? My concern is that the wind load may be too much for this drone. Our firm is currently offering high rise inspections, but we haven't performed any yet. We have a P4P which has been great for SFR, Condos and low-rise buildings.

Second question. Which specifications of a UAS has the greatest impact on flight stability during wind? I suspect propeller size and aircraft weight will have the biggest impact, but maybe I'm missing something? I'm still very new to this, so any pointers would be great. Thank you all!

The problem is not really wind, but turbulence, and especially updrafts.    If an updraft removes most of the aircraft's weight then it can't use much power to hold position.

In good conditions there will be no problems, but you can't see the turbulence and it is very difficult to predict so you do need to take safety precautions, keep a decent distance and always keep the aircraft in sight.

Heavier aircraft with faster propellers will do better since the updrafts will remove less of their weight, so definitely a Phantom rather than a Mavic, but heavier aircraft are also more dangerous if they fall!

My question would be, how close to the high rise do you need to be? And are there any other nearby high rises? 20 MP photos are extremely high resolution images. Depending on what you’re trying to inspect you might be able to get enough information from a series of images taken from a distance safe from the effects of the wind. Using Ground Station Pro, 3D Map Point of Interest would give you just that. In fact, that’s pretty much what it’s made for.

Jeff

As mentioned already, your problem is not steady state winds, there you are good up to about 20kts.
The issue comes down to turbulence, wind shear, and increased speeds due to the Bernoulli effect, 15 to 20kt winds on the surface away from the structure or structures does not translate to the same up at altitude near the buildings.  You have to know or determine winds aloft and factor in other nearby structures to establish whether you are safe to fly.  Even a heavier drone may be challenged in those conditions.  A full sized chopper would be challenged to fly in some areas in Chicago's down town area during increased wind activity.
If you were doing a single stand alone structure, then you need to respect the down wind side as noted due to turbulence.
Bottom line, a P4P can do the job but you'll need to establish set wind restrictions for when you can operate safely.
This much is known, DJI has set a limit of 10 m/s (22.4 mph or 19.5 kts) steady state.  Considering the variables mentioned above you may not be able to fly with winds no higher than 5 to 10 mph and you will need to determine a way to gage winds aloft or ensure you are getting an accurate wx reading for your area for winds aloft.  Lastly, short of an aeronautical engineer figuring winds and turbulence for areas near other structures due to the Bernoulli effect, it will come down to a guess.  Which is all the more reason to avoid more than a light steady breeze depending on the environment you are in.

Thank you for the responses. We would be flying near stand alone buildings in some instances and downtown areas in other instances. So this would vary. It looks like I have some research to do, so thank you for pointing me in the right direction.

We have been considering an Inspire or Matrice 100 for these type of inspections. I haven't been able to find the wind resistance specs for them. At half of the Inspire top speed, that would put it at just under 30 mph. Would there be a large enough benefit to using an Inspire or Matrice over a P4P? The P4P camera resolution is plenty for inspecting sealant joints around windows and such, so we're more concerned about the performance of the aircraft.

Im no expert so i wont give a suggestion but a question instead could you not physically go to the top of the building to get a wind speed reading then divide it down as you get lower to the ground?
I know this would only be able to work with steady winds not gusts.

Nigel_ Posted at 2018-1-30 09:16
The problem is not really wind, but turbulence, and especially updrafts.    If an updraft removes most of the aircraft's weight then it can't use much power to hold position.

In good conditions there will be no problems, but you can't see the turbulence and it is very difficult to predict so you do need to take safety precautions, keep a decent distance and always keep the aircraft in sight.

FYI, bigger aircrafts has slower motors not faster

OP, it really depends of the wind speed up there. Could you give us a number?

Hellsgate Posted at 2018-1-30 18:58
Im no expert so i wont give a suggestion but a question instead could you not physically go to the top of the building to get a wind speed reading then divide it down as you get lower to the ground?
I know this would only be able to work with steady winds not gusts.

Not exactly, here's why...because of what I stated earlier.  As the winds interact with the structure they will change in direction and speed primarily in the form of turbulence.
However, noting the winds at the top of the building unobstructed would give you a clear idea of what you are dealing with as compared to the surface winds.  For that reason alone it would be a very good idea to do so and it would obviously take the guess work out of the effort.

BucklesTroy Posted at 2018-1-30 18:18
Thank you for the responses. We would be flying near stand alone buildings in some instances and downtown areas in other instances. So this would vary. It looks like I have some research to do, so thank you for pointing me in the right direction.

We have been considering an Inspire or Matrice 100 for these type of inspections. I haven't been able to find the wind resistance specs for them. At half of the Inspire top speed, that would put it at just under 30 mph. Would there be a large enough benefit to using an Inspire or Matrice over a P4P? The P4P camera resolution is plenty for inspecting sealant joints around windows and such, so we're more concerned about the performance of the aircraft.

The Inspire is a much more stable aircraft. It is heavier and the motors have a greater power. It is much more stabled toits construction and capabilities. The Inspire also offers interchangeable lenses which will give you a much better image at a greater distanced helens is glass, not plastic.

Genghis9 Posted at 2018-1-30 19:49
Not exactly, here's why...because of what I stated earlier.  As the winds interact with the structure they will change in direction and speed primarily in the form of turbulence.
However, noting the winds at the top of the building unobstructed would give you a clear idea of what you are dealing with as compared to the surface winds.  For that reason alone it would be a very good idea to do so and it would obviously take the guess work out of the effort.

Thanks for the reply i had a feeling that may have been the case.

BucklesTroy Posted at 2018-1-30 18:18
Thank you for the responses. We would be flying near stand alone buildings in some instances and downtown areas in other instances. So this would vary. It looks like I have some research to do, so thank you for pointing me in the right direction.

We have been considering an Inspire or Matrice 100 for these type of inspections. I haven't been able to find the wind resistance specs for them. At half of the Inspire top speed, that would put it at just under 30 mph. Would there be a large enough benefit to using an Inspire or Matrice over a P4P? The P4P camera resolution is plenty for inspecting sealant joints around windows and such, so we're more concerned about the performance of the aircraft.

You are kinda mixing apples and oranges here a little bit or maybe I should say you are setting up a quandary
The faster the wind speeds go the more turbulence and sheer you'll get, and of course, the higher the speeds may get still if being funneled through other buildings.
All this means is that getting some thing that flies faster funnier does not necessarily give you more ability to fly in stronger winds as a direct translation.  At best, you can use a stronger drone to ensure you can operate but in lesser conditions than it was designed for because you'll need that pad to cover the increased speeds and turbulence that you could find the higher up you go and the turbulence you could encounter.
Meaning, a P4P could be used in near ideal conditions with calm to light winds.  While a Inspire/Matrice can operate in conditions that are at the limit of the P4P but again at altitude the conditions could be at the limit of the Inspire/Matrice.  In other words you need a pad of capability to cover the range of conditions you may experience.
Regardless, no matter the size and capability you have, as already mentioned, updrafts, downdrafts, and turbulence will challenge any aircraft especially lightweight ones.

BucklesTroy Posted at 2018-1-30 18:18
Thank you for the responses. We would be flying near stand alone buildings in some instances and downtown areas in other instances. So this would vary. It looks like I have some research to do, so thank you for pointing me in the right direction.

We have been considering an Inspire or Matrice 100 for these type of inspections. I haven't been able to find the wind resistance specs for them. At half of the Inspire top speed, that would put it at just under 30 mph. Would there be a large enough benefit to using an Inspire or Matrice over a P4P? The P4P camera resolution is plenty for inspecting sealant joints around windows and such, so we're more concerned about the performance of the aircraft.

The big advantage of an Inspire is that you can use a long lens and then keep your distance from the building, turbulence issues get sort of exponentially worse as you get closer to the building so by keeping your distance you are much safer.   If you need to get close anyway to get into nooks and crannies then I suspect the P4P is preferable, partly due to its obstacle avoidance and partly that if it does crash and fall it will not do much damage when it reaches the ground.  Dropping an Inspire on someone or maybe on a car will not give a nice result.

Whatever you get, you do have to plan for the occasional crash, including the extra costs that result.  With a good pilot you can hope to not have any crashes, but that is far from certain when flying around buildings.  There is a lot that can go wrong, like loosing GPS positioning or control signals because they are blocked by the building.

Although an Inspire is heavier than a P4, I'm not sure that helps when you get close to the building because it is also a lot bigger with slower propellers (I think) and an updraft is probably more capable of taking its weight away and leaving it unable to use its power.  If you are getting close to the building then you want obstacle avoidance, you only need to accidently use it once and it will have been worth having.

Hellsgate Posted at 2018-1-30 18:58
Im no expert so i wont give a suggestion but a question instead could you not physically go to the top of the building to get a wind speed reading then divide it down as you get lower to the ground?
I know this would only be able to work with steady winds not gusts.

We can go onto the roof and get readings. We may look into setting up a weather station during the duration of the flight and having PIC/VO monitor the readings.

One of the biggest dilemmas for us is that typically, we're at the behest of attorney's dictating the schedule (which days) to us. We may have to setup this up differently for UAS inspections on high-rises. It would be costly for everyone involved to schedule an inspection day, then call it off because of wind. I think in the end, getting out on a swing stage is going to be more reliable and safer. Maybe our UAS will be for the "hard to reach" areas only.

BucklesTroy Posted at 2018-1-31 05:14
One of the biggest dilemmas for us is that typically, we're at the behest of attorney's dictating the schedule (which days) to us. We may have to setup this up differently for UAS inspections on high-rises. It would be costly for everyone involved to schedule an inspection day, then call it off because of wind. I think in the end, getting out on a swing stage is going to be more reliable and safer. Maybe our UAS will be for the "hard to reach" areas only.

If you are on the upwind side of the building in steady winds then you are pretty safe up to 20mph winds, it is what happens in the turbulence on the downwind side that is the main problem, so most of the time you can probably do half the building safely which could still save a lot of time.