Hey folks i am planning to built quad which has flight time as good as 2-3 hrs . It should be able to sustain air speed of 70-90 kms/hrs .I have been doing search from quite long but still confused .
I need Quad

• That can fly 1000-300 ft
• fly for 2-3 hrs
• sustain air/wind speed of 70-90 kms/hr
• can carry load upto 2 kgs minimum

Also wanted to know any one from Navi Mumbai or Mumbai flying quad and can give me some Quadgyan

Hello do you have good experience building and flying quads?or is this the first one? Building big quads is difficult.first try to build a small quad using kit.

I am new Bee . I am plannning to test the quad that i will build starting with kk2.1 board  as flight controller then will more to APM 2.6 .At the moment i am doing my ground search to make my quad right .

Use 8108 motors with 26" folding props and a big frame for this setup with 3x 10000mAh 6S 15C batteries, and you can get about 1.5-2hrs easily

Rahul but it has many many problems while doing such a quad...
I am into this for a quite long time and build several multis till now..
My last one was a quad with gopro gimbal and fly for about 30min
Successfully done it in my 3rd attempt and now I am getting around 29min with 5000mah 6s and 34 min with a 6000mah 6s..
But without load.. it is not a good way to lift it up..
Also flying in attitude or gps mode is the toughest job in these kind of heavy powered quads.. one we can do is move on with mannual mode flying my setting the limit and end points low.. so that we will get a stable yet long endurance quad...

My setup was something lile
700mm  motor to motor
16x5.5 cf prop
41xx motors
6s lipo also using 4s
Naza without gps

41xx is a small motor, compared to 8108 its not efficient. I had seen a youtube video of x8 with 8108 motors lifting a DSLR for 60min.
Try the 8108, i am sure u will be happy with that, but it gonna cost a lot.

You will find examples of 2hrs flight times on RCgroups but that was just hover under ideal circumstances with a lighter setup. It would be inefficient or unusable even if you were able to achieve it with hobby grade stuff given the environment you intend to use.

Sustain wind speeds of 70-90kmph! In what kind of environment are you going to fly?? Frankly its too much for a multirotor. Attached a video where you can see APM's performance in 20-30mph winds, where it struggles a bit.



The motors suggested by Rahul costs 220$ a piece, http://www.foxtechfpv.com/foxtech-motor-s8108-kv135-p-1421.html
So I think OP is aware of the the fact that its gonna cost a bomb in the end if he realizes his multirotor as planned.

Rahul I am not talking about the efficiency... but talking about the stability.. while considering bigger motors for less amp consuption keep in mind that over powering will effect it badly..
I know in r groups many of them done these kind of setup.. but franky they are struggling in many cases..
Using it for professional platform is not 100% safe option..
Overpowering and wrong gain may cause serios damage while test flight..
Also with the perfect gain setting there are chances of flipping with that huge setup..

Next is the wind resistance.. lesser the aera means more stable in wind..
 Swinging bigger props will make it hard to resist the wind..
Which ever controller you use.. not gonna help you in any case..
Anyway all the best for the build.. keep updated...

hmm guys here is one  video :http://www.youtube.com/watch?v=2ScZ8zDsVvk . he claims by adding low kv motor say 100kv motor we can gain more flight time . But again i have no idea what wind speed it can sustain, is it stable etc