You have a good voice and phrasing for narration, and even more than that, you explain things well because you understand the dynamics and organize your material logically and talk about what's important with great insight. And the icing on the cake is that you have no music soundtrack. EXCELLENT video.
Haha, thanks mate! Really appreciate the support! :) Actually some people have been commenting that I talk too much and there are no music only sections of the video... so every now and then I try to also make videos like this! :D
ArxangelRC, I just wanted you to know how much I appreciate all of the helpful information that you share with others on both on your UA-cam channel and on the RCGroups forum! I have watched and read MANY of your videos and posts and have learned so much from what you have shared. Thanks again & I look forward to following your future videos & posts! Tom
You made me a believer man, she's on my Christmas list. Another superb look and review by you. Your narration and style is like no other. Thanks for this video Nikola. What a treat bro. Cheers.
You received a beautiful gift from a place no planes have ever flown.... I trust he's doing well & although I struggle w/ this hobby I foresee a much bigger future in delivery or transportation? We'll have to wait & see but it's people like you who're evaluating the applications into this future realm...... peace
Thanks mate, appreciate it! :) These things will see a surge in use... but I doubt it will be over cities, like most people are talking about! It will be in rural areas and for hard to reach places! :)
Really not a fan of that design to be honest, at least not without landing on an airstrip and having a landing gear, which limits the use of the plane quite a bit! Landing with a front mounted gimbal in the grass fields where we do... not going to last long!
Sure, but then you will have to replace that nose cone quite often! In addition, unless it is made of a very special material and is expensive, there will be all sorts of reflections in it, which will be visible on the camera... I am not really a fan of that setup to be honest... BUT.... you are free to experiment and try to make it... see how it works out! :) If you can find short grass to land in every time, it should be fine.
So whats a fast airspeed at a known power setting, and whats the endurance time at that power setting, im trying to build a list of potential long range fpv platforms, Will post up results for asw28 v2 soon
It's really a miracle that you didn't crash the plane set it up as a wing on iNav... At the first tap on the conf. There are options for deferent aircraft.. You can also use one of the preset planes at the same tab. INav is a very simply system. You just need to get use to it... Good Luck.
Thanks! :) Actually I never even touched the flying wing preset! I had it on normal plane, then when I was loading the custom V-tail mix from Painless360 I did a mix reset, I just assumed that pitch2thr mix was enabled by default!
Have you checked my blog: arxangelrc.blogspot.com/2017/11/believer-1960mm-professional-mapping-fpv-platform-best-designed-aerial-platform.html That is about as detailed as I can get it! :)
Awesome setup mate, very interested in getting back into this myself. Incase it helps some tips... Have the antennas at 90 degrees to each other, this is the whole point of diversity receive and allows coverage of more polarisation possibilities. This i'm pretty sure of, but could use some testing... the antennas could remain inside the fuselage as the attenuation of the foam is practically nil. The above is the opposite tho for aircraft with heavy use of carbon fibre sheet, this will experience extreme attenuation. I'm off to look at your links!
Thanks Robert, and thanks for the tip, but consider the following: 90 degrees are actually needed when you fly 3D or bank very hard, because you never know where those antennas will end up, so it is a good idea to have them at an angle. However, especially when I fly long range, plane flies level all of the time and the turns are very gentle. In this situation I don't really need angled antennas because I don't do crazy sharp turns and aerobatic manoeuvres 10km or 20km away, so the best way to mount the antennas in this situation is straight vertical! As for mounting them in the fuselage vs outside, I did give this some thought, and the fact is that if I mount them inside, they would more easily get behind the battery when I turn around and face home for the return trip, and I will surely loose signal, whereas if they are mounted like they are now, it gives me a much better chance of having directly like of sight with at least one of them, if not both, at greater distance when facing home! :) I have not decided to do these things at random you know! :) Besides, my 22km distance record with the L9R does suggest that vertical installation on long range platforms is not without merit: ua-cam.com/video/XY4ZeXYK138/v-deo.html
@@ArxangelRC If flying closer distance, your assertion holds up- but at longer distance where signal attenuation is a significant issue, one would want the 90 degree offset even more. Should your plane end up in an unusual attitude 20km away, you will certainly not want that to be the deciding factor in the loss of your control. It's less of an issue at typical distances, but when dealing with weak signals at distance you want to minimize loss of signal integrity. It may be unlikely that you will intentionally initiate a high bank angle, but an outside influence could bring that situation.
Where could I go to learn more about turning this into a farm surveillance drone? I'd like to mount an IR camera in the belly and be able to observe my property for extended periods.
@@cm2973 Does the video downlink need to be HD, or will analogue video do? Also... what would be the max distance from home the plane will have to reach?
@@ArxangelRC i could be very wrong, but I suspect analog thermal wont do. I'm thinking the ability to patrol a 2Km square would be ideal. I'm not sure what capabilities exist in a price range attainable by an individual.
@@cm2973 Well... recently the DJI HD FPV system has been performing very well for a lot of people... sadly a bit pricey for me still... but if you think the expense is worth it... could be a VERY good option for getting HD video down to the ground from whatever camera you put on board!
I have the Radiomaster T16S but am unsure how to program a VTail aircraft using OpenTX. Does anyone know if the radio programming would be the same if I added a Flight Controller using Mission Planner?
Greatings Arxangel! first of all, thanks a lot for all your wonderful reviews and videos! I'm a proud patreon (under a different name) :-) i would like to ask you two questions. thanks for your time. :-) from all the different long range mapping/fpv platforms you already tried which one is you favorite? didn't you ever feel an itch to try the mini talon? :-) thanks again and please keep up with the excellent work
Well then... thank you for your support mate! :) As for the mini talon, I actually bought one a few years ago... it arrived... stayed in its box for about a year... or more and then I sold it! Some reports of tip stall behaviour really kept me from dealing with it! As for mapping/fpv... had I replied to you yesterday... my answer might have been different... today though... we are now past yet another flight with the Crosswind (goo.gl/bTfuJk), and I can tell you that this is THE plane!!! Once they start shipping it with the fixed tail it will be even better... but even with the current one... it is outstanding! Today's flights were absolutely perfect!
Hey, sorry for the delay! :) These are the motors: store-en.tmotor.com/goods.php?id=335 And these are the props: www.banggood.com/2Pcs-APC-Style-1070-10x7-DD-Direct-Drive-Propeller-Blade-CW-CCW-For-RC-Airplane-p-1056591.html?p=6L1818635832201406F2?ArxangelRC Alternatively, in the video description there is a link to my blog post, in it you will find a full parts list for this build! :)
Actually, the foam between the Believer and the Clouds is pretty much the same, but the Skywalker EVE-2000 does have denser and harder foam. Besides, the Believer is not made by Banggood, they just sell it. It is made by a company called MakeFlyEasy, and according to their website they specialise in mapping solutions.
@@MrOlezhandr Most planes are actually pretty fine with default ArduPlane params. Tuning could improve some areas, but in general on stock they fly well! Other than an autotune, I am not sure I've done much else.
Question: is there not some way to mount the antennas internal to the fuselage? Does the styrofoam mess with the propagation? If so, what about some kind of aerodynamic fairing that was rf-transparent?
Usually the foam is not a problem for RF signals, but the battery is! Putting the antennas inside the fuselage would mean that they would more easily get behind the battery and will not have clear view of the ground when flying from a large distance towards home, hence why I put them out there! The drag these two create is negligible compared to the gimbal I am planning to mount in the nose... so I really don't think I need to spend more effort on making them aerodynamic! :)
ArxangelRC thank you for the reply...im using the same target...but maybe i got the faulty unit coz my pwm 6 is not working for rudder...i disabled the uart3 in port tab...or maybe i am missing something here..
A friend had the same problem! Not sure why it wasn't working, but I wired the rudder on the 2nd aileron channel, and rewrote the mix a bit to account for that.
Thanks! Hmmm... sounds good if you ask me! I am also thinking of a Christmas gift... but since I already have this one, I am looking at something else! :)
Hard to say at this time! When I have done more extensive testing, I will do some calculations and compare them to my friend's calculations for his MTD. It may turn out both are equally efficient, but the MTD definitely has better off the shelf design for FPV, while the Believer would need some DIY in the nose to fit cameras and a gimbal, as it is much more mapping oriented.
There are plenty to be honest, but so far from my experience, the Believer is the only one that has been so purposefully designed and built for mapping purposes! There is the Skywalker Titan (goo.gl/dfWUvB), but I have not had this one, so I can't comment! Some other mapping oriented planes are: X-UAV Clouds: arxangelrc.blogspot.bg/2017/03/x-uav-clouds-it-is-simply-very-good.html MFD Nimbus: arxangelrc.blogspot.bg/2017/04/mfd-nimbus-1800-twin-tractor-well-designed-with-some-good-potential.html Skywalker EVE-2000: arxangelrc.blogspot.bg/2016/11/skywalker-eve-2000-lots-of-space-easy-take-off-long-flight-times.html
Hmmmmm... that would depend on the amount of prior knowledge you have, or have accumulated since you asked! Right now two options spring to mind: ua-cam.com/video/lUYMF4YsrnI/v-deo.html or ua-cam.com/video/EfRTde5I8V8/v-deo.html
It's a year late, but congrats on the latest addition to the Arxangel family. The baby, not the Crosswind. The falling bodies and the flying field obstacle course were priceless. Are you going to try putting the Believer in the air again? I have an opportunity to buy a new Believer kit for $200US, but now I'm not sure. Can you recommend something else?
THANK YOU! And its 2 years 2 months later! :P Yes, the Believer is flight worthy again! But as for you... depends on what you need to do with it! I consider the MFD Crosswind... the big one... a better flyer... more stable!
But why did you start in stable? Is not more common to fly this platform und make physical trim and CG Settings until it flys great before starting setting up the Flightcontroler? But nice plattform
I did not take off in any Stabilized mode! I flew the plane 2 times before I tried the angle mode for take off, and then I still didn't realize the pitch to throttle mix was actually a thing! :)
Well... depends on why you want to do that? Otherwise I don't see a problem with that if you are OK adding 150-200 grams to the plane in the form of laminate! :)
Yes, I have laminated the wings on two of my FPV Raptors, and on one of my Ranger EX planes, but that was because I needed to reinforce the wings either due to a crash, or just because they were too flexible from the factory! The only reason you would want to laminate the Believer, is to help protect the foam and make it last longer in time.
Wezley Vardy Just recently Crashed his Inav Believer. He does long range testing, and perhaps you could help him understand what may have happened. He was also using Inav.
Yes, I know, I talked to him a few days ago. To me it seems like the left V-tail fin stopped working. I could be wrong, but from watching his video that is what I think happened! Some people suggested iNav was at fault... and even though I'll admit I would gladly point my finger at it too... especially at the rate at which it is killing planes, not sure it is the culprit this time! :)
@@ArxangelRC I left him a message on his video as to my questions and theories. One of my questions was if all the servos were recovered working, and if that “gear linkage” in the V-tail looked stripped or stuck.
@@nikhayes3396 Looking at the state of the plane in the video... some of these would be hard to say! :P Servos could have suffered from the impact, same for the control linkages!
So what else have you been doing with this frame since this initial video? I waited for this video to release and was happy to hear your initial thoughts. I've been hanging out for another video after you've done a lot more flying with it. Would love to see you utilise the parachute too, since that's why I'm interested in this frame. Where I live there's lots of trees spread out everywhere with rocks and ant mounds. Very hard to take off and land with the bigger crafts. I plan on building a mapper to map 85k acres.
Well,lately I've been testing an HD video system on it: ua-cam.com/video/a_iZrMR_1j0/v-deo.html Otherwise I will absolutely not mount a parachute on it. In my mind this only ruins a plane and increases the chances of it braking.
Why are all of these planes lacking landing gear? I would really like to find a plane capable of slow stable flight with the ability to carry an under mounted camera
Well... for the most part landing gear is limiting from where you can take off and land and adds more weight and drag to a plane that usually is aimed at being optimized to stay long time in the air and needs to be efficient! Might have something to do with that! I have not seen many of these with landing gear... if any, unless they are VTOL! Only the Crosswind Mini has an option for one, but definitely not tall enough for a hanging camera!
Haven't had nearly as much flight time with this one, especially as I only recently installed the Pixhack Nano in it, but I'd yes at worst it is the same as the Clouds... but does have more potential for payload, endurance and range, plus it can easily take larger motors and props, which drastically improves efficiency!
The Tital has been confirmed to be the least efficient of all the current mapping airframes... other than that... I haven't had one in person so can't comment on other details, but for mapping flight efficiency is key as it extends flight times. The Believer holds the crown for the time being, according to what I've seen done with it! :)
What is the best mapping plane out there at the cheapest price for I am drone rich and cash poor. LOL We are wanting to map rice fields with a spectrum NDVI.
Well... best and cheapest... are not two things that usually go together... actually... they never go together! :) I am currently building a souped up version of the Believer, the Flying Dragon, and have yet to test it... but the Believer is a very good option, as well as the MFD Crosswinds... but that would depend on your specific needs for the plane!
Thanks! Hahaha... I did think of trying to get her inside, but by the time that thought had crossed my mind she was already too big, and I had already glued the wing adapters with the carbon tubes. On her first day though, she would have fit in there without any problems! :)
Love the videos. I am about to build the Believer. I chose the KDE 2814 515kv motors and will run 6s. What prop size do you recommend? The goal is to have a good efficient platform that can get home upwind if needed. Appreciate any insight you can provide as it’s difficult to find much online!
@@ArxangelRC Tnx for the response. Not sure final AUW...but plane will have the KDE2814XF-515, Hobbywing Sky Walker 60a ESCs, 4x EMAX ES3054 servos, up to 15000mah 6s LiPO battery, BN-880 gps, Dragonlink 433mhz system (dipole antennas), RMRC 800mw 1.3ghz video tx (will try dipole antenna first), and standard res camera for FPV I might try a gimble later with GoPro for fun later but predominantly I want to build this for long range endurance.
@@mateostyle Right, so it will be relatively light then! In any case these motors will be OK with an 11x7" prop at 6S. Should have plenty of power! If for some reason you feel like it could be a little faster, try 10x8" also, or do an endurance with both and see which one works best. Both should be more than OK.
@@ArxangelRC very much appreciate the response. I know it would be easy to blow off the question and claim not enough info but you are very dependable for your excellent UA-cam content as well as being a gentleman with the various questions from guys like me whose experience pails in comparison to yours in the hobby! Appreciate the time to respond.
Curious, what’s your preference between the believer and the xuav clouds? I’m seeing you tend to lean towards the clouds based on your videos. I’m debating which one to go with. Thoughts?
@@AlexanderPerez-oe1gu Well the Believer would be the better choice in this case! A lot more room to work with, and more carrying capacity for batteries, etc.
You made several comparisons to the XUAV Clouds, but I’m more curious how it compares to the MTD. I know the MTD has a tremendous amount of interior space, but I wonder how it compares in efficiency. Great video. I always love the sarcastic comments about endangering people. Have you considered stand up comedy as a back up career? 😎 Congratulations on the new kid too. Good luck on sleeping through the night. I’m sure you know what I mean by now. 😜
Thanks! As for the baby... we are actually well past the night time feeding period now, she sleeps all night and we also get to have some rest! :) The MTD featured in the video belongs to a friend of mine, but he has a pretty good idea how efficient it can be, so as soon as I get the new motors installed and the endurance flight done, we will be able to do some rough comparison of the efficiency between the two.
Question in regards to that death spiral, was that caused by CG to far back? and how do you recover from that? full opposite rudder?. thank you and great review as always!
Not sure what caused it... cannot attribute it to CG... more like wing design perhaps! You shut the motor off, and give it full down elevator and counter aileron, as soon as it stops spinning throttle up and up elevator to level off! And also switch to manual mode!
Are you not on Patreon? I need to give you money or else I'm going to feel guilty for sitting at your feet and benefiting from your incredibly great research and documentation. If I recall correctly, you are a My Twin Dream owner. Isn't she the champ for long-range endurance and efficiency in a mapping plane? I'm puzzled by why you haven't included her in your comparisons. Do you have some reservations about that plane, for some reason? Bravo, Bravo, Encore!, Geoff
Thank you very much Geoff... I have been thinking about Patreon for a while now... haven't gotten around to checking out what it is about... might give it a go now that you mention it! :) As for the MTD, I do not have one, a friend of mine does, and we do some tests with it from time to time! When I am done properly testing the Believer I will provide some comparison data on the performance of the two planes and we will see which one is better! :)
MFD is the manufacturer of the Nimbus... perhaps you are referring to the MTD? Yes, RTH was working with the Omnibus F3 Pro... it just needed a bit of setup to get it right.
They are quite different to be honest! I do not have the MTD, but I can tell you that it definitely has a lot more usable space due to the design of the body, but the Nimbus is A LOT more easier to convert to a Vtol without adding much weight, and is quite convenient with those quick attach locks for the wings and tail. It all boils down to what you need to do with the plane.
ArxangelRC i always like the idea of vertical and horizontal stabalizer, but with Nimbus it was very quick to assemble. I was looking around on few famous sites, but nothing i could find e.g BG, Ready made rc and so on.
Will you keep the omnibus/inav thingy or going to pixhawk/vector? It's possible to use the tracker with inav? Mavlink output and that's all isn't it? I was waiting for a proper review of this plane for few weeks, I love it (just from the photos!) Si you think that 11.11 will be with a good discount?
No idea about the discount... I guess you need to hold out for another day and we will know! :) As for the Omnibus, yes I will be keeping it for the time being. Any system will work with the MFD tracker as long as you also have the MFD TeleFlyPro OSD connected in there as well, as I do! :) Might have to look into getting native support for the tracker in the iNav code, would save some weight and money by not having to put the MFD board in there. No Mavlink output, i am not using the ArduTracker... that never did work for me.
Hmmm... probably not without some modifications! They were designed for another plane and wing... also... not sure if you would be able to get them separately, at least not for the time being.
Thankyou for the great review again. Can you link to the T Motor that you think would be the best fit for this model. Also the Inav Diff file from your model once dialed in would be awesome.. M
Sure thing Michael, will share the file somewhere when I finally have it dialled in. As for the T-motors, I have ordered these: store-en.tmotor.com/goods.php?id=335 Should work well on 6S with a 10" or 11" prop, and their size would allow for easier mounting in the plane. I also have ordered a set of the larger model MN3510 700Kv, but those would go on the EVE-2000. :)
Thanks! I used iNav because I had a number of F3 Pro boards lying around, and no spare Pixhawks, so thought it would be a good idea to finally see what the hype is all about! iNav is definitely not up to any mapping tasks at this point, it is still in very early development in my opinion. It should be used mostly for FPV... has nothing on the Pixhawk when it comes to mapping!
Thank you! Well... I do take breaths, but as you can probably tell, do I a lot of editing on my videos to make them sound and look good... so the breathing sounds awful in the video and I cut it out!
Hello. Is APM 2.6 recommended for this plane. Or Pixhawk is better. I’ve already ordered one from AliExpress for this Christmas. Your video help me settle on this plane.
Like I mentioned in the video, I was not able to do an endurance test during my initial review, and now I remember that I still haven't done that... so will have to get on it now that the plane is back on active duty! My idea was that in 1 hour it consumer 6000mAh, meaning it might be able to fly for 2 hours on 12000mAh pack! :)
We truly appreciate your objectiveness and detailed appreciations ... Your contribution is extremely appreciated. When you say that F3 Omnibus + Inav was not a good combination, do you mean it is not a good match for this particular aircraft? Or do you mean that you have reserves on F3 Omnibus + Inav duet ? I would like to use Inav/F3 on a Volantex ASW28 but would like to know what you think of Inav.... Thanks again for your amazin contribution ! - dan from Canada
Hey Dan, actually I meant that it wasn't a good idea to use an autopilot system that I have never used, on a brand new plane that I have never flown! :) Omnibus F3 Pro and iNav are a good combination actually, and I like it, you just need to keep in mind that iNav is still young and is developing, so there are still some bugs to be ironed out, but overall, when you take the time to really get to know it and set it up properly, it does perform rather well.
To what end? If you have a Pixhawk in there you can probably use a LIDAR for auto landings on mapping missions and possibly for low altitude terrain following, in relatively flat areas! But for general purpose FPV this would not be needed! :)
Join this channel to get access to perks:
ua-cam.com/users/c@ArxangelRC/join
You have a good voice and phrasing for narration, and even more than that, you explain things well because you understand the dynamics and organize your material logically and talk about what's important with great insight. And the icing on the cake is that you have no music soundtrack.
EXCELLENT video.
Haha, thanks mate! Really appreciate the support! :) Actually some people have been commenting that I talk too much and there are no music only sections of the video... so every now and then I try to also make videos like this! :D
ArxangelRC, I just wanted you to know how much I appreciate all of the helpful information that you share with others on both on your UA-cam channel and on the RCGroups forum! I have watched and read MANY of your videos and posts and have learned so much from what you have shared.
Thanks again & I look forward to following your future videos & posts!
Tom
Thanks Top, much appreciated! I am glad the work I do is helpful to somebody! :)
That is really a gorgeous plane! You did a great job with the flights and the narration of the video! Thanks for sharing!
Thanks mate, appreciate it! :)
You made me a believer man, she's on my Christmas list. Another superb look and review by you. Your narration and style is like no other. Thanks for this video Nikola. What a treat bro. Cheers.
And another THANK YOU to you for the continued support! Really appreciate it! :)
Love the commentary. Congrats on the birth of a new pilot.
Thanks! I do hope it will be a new pilot more than a new mall surfer... but I guess only time will tell! :D
You received a beautiful gift from a place no planes have ever flown.... I trust he's
doing well & although I struggle w/ this hobby I foresee a much bigger future in
delivery or transportation? We'll have to wait & see but it's people like you who're
evaluating the applications into this future realm...... peace
Thanks mate, appreciate it! :) These things will see a surge in use... but I doubt it will be over cities, like most people are talking about! It will be in rural areas and for hard to reach places! :)
Congratulations with this beautiful baby ... good job as well with the show demo... thanks.
Thanks! :)
As always a great review, but those drone shots make it simply awesome !
Thanks Paul! :)
Man, you have talent. You should have many more Subs. Great work, my friend. And hello from the States.
Thank you, again! :P Appreciate it...
Congrats on the new one. Excellent review as always.
Thanks mate! :)
This plane looks great, good video.
Congratulations, we already have a little Arxangel to follow the saga :)
Haha, thanks! Lets hope that is the case! :P
you're a genius at 2:50
Hahaha, thanks! I did laugh a lot while making this! :D
oh god, I'm holding my sides and crying from laughing so hard!
:D
callum white
love the humor. great review thanks
Thank you, appreciate the support! :)
dude your review on rcgroups is legit...more photos then a season of CSI Miami! top stuff!
Haha, thanks mate! :)
Congratulation my friend! Great work and great review;-)
Thank you! :)
That is already quite impressive and has possibilities. Look forward to more testing (when you have time :) )
Well... it will be more like when I have the new motors! Time has nothing to do with it... haven't had that in a long... time! :D
Great review young man! I've become a big fan of your content!
Thank you Ronnie, appreciate the support! :)
Man you are just awesome 😊😊😊 I’ve been doing FPV on sky walker and you made this video and I think I have to switch to this plane . Great plane
Thanks! The Believer really has some nice potential both in efficiency for mapping, and long range FPV! :)
I love your sense of humour :)
Thank you! :)
Great video 👍
Thank you! :)
Great video man! As always. My best wishes for your sweet baby.
Thank you! :)
Very promising for future projects! Best wishes about the babe.
Thanks mate! :)
Why not use a gimbal set into the nose like the Mavic with an optically correct dome placed in front?
Really not a fan of that design to be honest, at least not without landing on an airstrip and having a landing gear, which limits the use of the plane quite a bit! Landing with a front mounted gimbal in the grass fields where we do... not going to last long!
ArxangelRC
That’s why I was thinking to mount the whole unit behind a clear nose cone.
Sure, but then you will have to replace that nose cone quite often! In addition, unless it is made of a very special material and is expensive, there will be all sorts of reflections in it, which will be visible on the camera... I am not really a fan of that setup to be honest... BUT.... you are free to experiment and try to make it... see how it works out! :) If you can find short grass to land in every time, it should be fine.
Congratulations on the birth of your son. God Bless
Thanks mate! :) It is a girl though... :P
So whats a fast airspeed at a known power setting, and whats the endurance time at that power setting, im trying to build a list of potential long range fpv platforms,
Will post up results for asw28 v2 soon
Can't really say for this plane, did not fly it for long, and have not done tests like this!
It's really a miracle that you didn't crash the plane set it up as a wing on iNav... At the first tap on the conf. There are options for deferent aircraft.. You can also use one of the preset planes at the same tab. INav is a very simply system. You just need to get use to it... Good Luck.
Thanks! :) Actually I never even touched the flying wing preset! I had it on normal plane, then when I was loading the custom V-tail mix from Painless360 I did a mix reset, I just assumed that pitch2thr mix was enabled by default!
Bro, I love your reviews. Keep it up and I hope to use the links some day.
Thanks mate, appreciate it! :)
Where are the assembly instructions?
Have you checked my blog: arxangelrc.blogspot.com/2017/11/believer-1960mm-professional-mapping-fpv-platform-best-designed-aerial-platform.html That is about as detailed as I can get it! :)
Awesome setup mate, very interested in getting back into this myself.
Incase it helps some tips...
Have the antennas at 90 degrees to each other, this is the whole point of diversity receive and allows coverage of more polarisation possibilities.
This i'm pretty sure of, but could use some testing... the antennas could remain inside the fuselage as the attenuation of the foam is practically nil.
The above is the opposite tho for aircraft with heavy use of carbon fibre sheet, this will experience extreme attenuation.
I'm off to look at your links!
Thanks Robert, and thanks for the tip, but consider the following: 90 degrees are actually needed when you fly 3D or bank very hard, because you never know where those antennas will end up, so it is a good idea to have them at an angle. However, especially when I fly long range, plane flies level all of the time and the turns are very gentle. In this situation I don't really need angled antennas because I don't do crazy sharp turns and aerobatic manoeuvres 10km or 20km away, so the best way to mount the antennas in this situation is straight vertical!
As for mounting them in the fuselage vs outside, I did give this some thought, and the fact is that if I mount them inside, they would more easily get behind the battery when I turn around and face home for the return trip, and I will surely loose signal, whereas if they are mounted like they are now, it gives me a much better chance of having directly like of sight with at least one of them, if not both, at greater distance when facing home! :) I have not decided to do these things at random you know! :)
Besides, my 22km distance record with the L9R does suggest that vertical installation on long range platforms is not without merit: ua-cam.com/video/XY4ZeXYK138/v-deo.html
@@ArxangelRC If flying closer distance, your assertion holds up- but at longer distance where signal attenuation is a significant issue, one would want the 90 degree offset even more. Should your plane end up in an unusual attitude 20km away, you will certainly not want that to be the deciding factor in the loss of your control. It's less of an issue at typical distances, but when dealing with weak signals at distance you want to minimize loss of signal integrity. It may be unlikely that you will intentionally initiate a high bank angle, but an outside influence could bring that situation.
Where could I go to learn more about turning this into a farm surveillance drone? I'd like to mount an IR camera in the belly and be able to observe my property for extended periods.
Observe it via video downlink? And how long are those extended periods?
@@ArxangelRC 1-2hr flight time seems available. So I suppose that'd do.
@@cm2973 Does the video downlink need to be HD, or will analogue video do? Also... what would be the max distance from home the plane will have to reach?
@@ArxangelRC i could be very wrong, but I suspect analog thermal wont do. I'm thinking the ability to patrol a 2Km square would be ideal. I'm not sure what capabilities exist in a price range attainable by an individual.
@@cm2973 Well... recently the DJI HD FPV system has been performing very well for a lot of people... sadly a bit pricey for me still... but if you think the expense is worth it... could be a VERY good option for getting HD video down to the ground from whatever camera you put on board!
I have the Radiomaster T16S but am unsure how to program a VTail aircraft using OpenTX. Does anyone know if the radio programming would be the same if I added a Flight Controller using Mission Planner?
If you add a flight controller, you will not need to do the V-tail mixing in the radio, the autopilot will take care of that!
oh boy! another excellent video. great job!
Thank you! :)
Great review dude !
Thank you! :)
Third video. Excellent. Thanks. Cheers, D.
Thank you!
What’s the endurance of this aircraft, in minutes?
Some people have been able to get 5 hours out of it!
Greatings Arxangel!
first of all, thanks a lot for all your wonderful reviews and videos! I'm a proud patreon (under a different name) :-)
i would like to ask you two questions. thanks for your time. :-)
from all the different long range mapping/fpv platforms you already tried which one is you favorite?
didn't you ever feel an itch to try the mini talon? :-)
thanks again and please keep up with the excellent work
Well then... thank you for your support mate! :)
As for the mini talon, I actually bought one a few years ago... it arrived... stayed in its box for about a year... or more and then I sold it! Some reports of tip stall behaviour really kept me from dealing with it!
As for mapping/fpv... had I replied to you yesterday... my answer might have been different... today though... we are now past yet another flight with the Crosswind (goo.gl/bTfuJk), and I can tell you that this is THE plane!!! Once they start shipping it with the fixed tail it will be even better... but even with the current one... it is outstanding! Today's flights were absolutely perfect!
Can you please link to the motors and props you used? Thank you.
Hey, sorry for the delay! :) These are the motors: store-en.tmotor.com/goods.php?id=335
And these are the props: www.banggood.com/2Pcs-APC-Style-1070-10x7-DD-Direct-Drive-Propeller-Blade-CW-CCW-For-RC-Airplane-p-1056591.html?p=6L1818635832201406F2?ArxangelRC
Alternatively, in the video description there is a link to my blog post, in it you will find a full parts list for this build! :)
Thank you, I did read the blog post and realised that the parts list was in there. Looking forward to your next video.
Its on now! :)
How does it perform in strong winds?
It is OK, I've seen worse! And it also depends a lot on the settings of the autopilot, the make a difference as well!
top notch review! thank you
Thanks mate, appreciated! :)
I got mine, can you share the stl files for the t-motor mount?
Sure, drop me a message on Facebook and I will give you the files.
@@ArxangelRC ok thanks
Sent
good job, good model
Thanks!
I’m building a CLOUDS survey grade right now. They look very similar but NOT the same quality. The Banggood Believer foam looks coarse
Actually, the foam between the Believer and the Clouds is pretty much the same, but the Skywalker EVE-2000 does have denser and harder foam. Besides, the Believer is not made by Banggood, they just sell it. It is made by a company called MakeFlyEasy, and according to their website they specialise in mapping solutions.
Nice plane. Wish You explain what settings you need to do to fly on it? I Want to fly this plane too)
Thank you! Settings on what?
@@ArxangelRC Arduplane FC setting using MP?
@@MrOlezhandr Most planes are actually pretty fine with default ArduPlane params. Tuning could improve some areas, but in general on stock they fly well! Other than an autotune, I am not sure I've done much else.
Hai.. can beleiver used 14 inchi prop?
Nope! That would be too big! I think 13" can fit.
@@ArxangelRC i will start search prop 13 now
How did it go? You find any?
@@ArxangelRC i find but need to buy many.... have on shopee but they cancel my order
@@ansariflightplan5814 Damn... try APC's website?
You're using 3130 700kv motors with 6s? isn't that too high of a KV for 6s?
Nope, the motors can take it easily!
How about flying home if is one motor dead?
We've tested that, should be fine: ua-cam.com/video/i0lQp4TebKY/v-deo.html
Question: is there not some way to mount the antennas internal to the fuselage? Does the styrofoam mess with the propagation? If so, what about some kind of aerodynamic fairing that was rf-transparent?
Usually the foam is not a problem for RF signals, but the battery is! Putting the antennas inside the fuselage would mean that they would more easily get behind the battery and will not have clear view of the ground when flying from a large distance towards home, hence why I put them out there! The drag these two create is negligible compared to the gimbal I am planning to mount in the nose... so I really don't think I need to spend more effort on making them aerodynamic! :)
Hi..what is your inav firmware target for the omnibus f3 that you use?
I think its just OMNIBUS... or something like that! It was the top most of the OMNIBUSes.
ArxangelRC thank you for the reply...im using the same target...but maybe i got the faulty unit coz my pwm 6 is not working for rudder...i disabled the uart3 in port tab...or maybe i am missing something here..
A friend had the same problem! Not sure why it wasn't working, but I wired the rudder on the 2nd aileron channel, and rewrote the mix a bit to account for that.
ArxangelRC cool idea...will do that
:D
Congratulations!!!!!!!🎉🎈🎊🍾!!!!!! Awesome review!!!!!👍👍👍👍👍👍👍👍👍
Thanks Greg! :)
Hello!
how have you done to fix the mn motors in the existing 44mm existing motor mounts?
thanks!
Hi, I believe I printed out some mounts for them! :)
great vid, thinking...... of this for Xmas gift
Thanks! Hmmm... sounds good if you ask me! I am also thinking of a Christmas gift... but since I already have this one, I am looking at something else! :)
so mtd? or Believer? for just fpv very long range?
Hard to say at this time! When I have done more extensive testing, I will do some calculations and compare them to my friend's calculations for his MTD. It may turn out both are equally efficient, but the MTD definitely has better off the shelf design for FPV, while the Believer would need some DIY in the nose to fit cameras and a gimbal, as it is much more mapping oriented.
Wonderful video but can you tell me what did you use to put charge back into the battery
A charger... ISDT SC-608: ua-cam.com/video/B4R5a_FRzHg/v-deo.html
Any other mapping fixed wing drone is available
There are plenty to be honest, but so far from my experience, the Believer is the only one that has been so purposefully designed and built for mapping purposes! There is the Skywalker Titan (goo.gl/dfWUvB), but I have not had this one, so I can't comment!
Some other mapping oriented planes are:
X-UAV Clouds: arxangelrc.blogspot.bg/2017/03/x-uav-clouds-it-is-simply-very-good.html
MFD Nimbus: arxangelrc.blogspot.bg/2017/04/mfd-nimbus-1800-twin-tractor-well-designed-with-some-good-potential.html
Skywalker EVE-2000: arxangelrc.blogspot.bg/2016/11/skywalker-eve-2000-lots-of-space-easy-take-off-long-flight-times.html
Any guides for starting this hobby??
Hmmmmm... that would depend on the amount of prior knowledge you have, or have accumulated since you asked! Right now two options spring to mind: ua-cam.com/video/lUYMF4YsrnI/v-deo.html or ua-cam.com/video/EfRTde5I8V8/v-deo.html
Hii if i want to install with 6s 22000 mah..? The 2.5 kg battery
Yes, the Believer should be OK, and should carry it without any issues!
@@ArxangelRC thank u sir for the reply
@@ansariflightplan5814 You are welcome!
@@ArxangelRC any change to motor and prop if want used that batter?
@@ansariflightplan5814 Well 2820 510Kv motors and 12x12 props would be a good idea!
the majority of the links are not working anymore :(
Will look into that... :)
What motors / prop size / esc’s/ Lipo did you use? Thanks.
If you follow the link in the video description to my blog, all of your questions will be answered! :)
It's a year late, but congrats on the latest addition to the Arxangel family. The baby, not the Crosswind. The falling bodies and the flying field obstacle course were priceless.
Are you going to try putting the Believer in the air again? I have an opportunity to buy a new Believer kit for $200US, but now I'm not sure. Can you recommend something else?
THANK YOU! And its 2 years 2 months later! :P Yes, the Believer is flight worthy again! But as for you... depends on what you need to do with it! I consider the MFD Crosswind... the big one... a better flyer... more stable!
But why did you start in stable? Is not more common to fly this platform und make physical trim and CG Settings until it flys great before starting setting up the Flightcontroler? But nice plattform
I did not take off in any Stabilized mode! I flew the plane 2 times before I tried the angle mode for take off, and then I still didn't realize the pitch to throttle mix was actually a thing! :)
ArxangelRC 3:23 „check out this take off in stabilize“ thats the sentence why I thought you take off in stab mode
Yes, but that was the 3rd flight, first two were in full manual! :)
Great review. Thank you
You are welcome! :) Thanks for the support.
What’s your opinion about covering this plane with heat film?
Well... depends on why you want to do that? Otherwise I don't see a problem with that if you are OK adding 150-200 grams to the plane in the form of laminate! :)
ArxangelRC have you done the laminating thing with any of your rc planes
Yes, I have laminated the wings on two of my FPV Raptors, and on one of my Ranger EX planes, but that was because I needed to reinforce the wings either due to a crash, or just because they were too flexible from the factory! The only reason you would want to laminate the Believer, is to help protect the foam and make it last longer in time.
Wezley Vardy Just recently Crashed his Inav Believer. He does long range testing, and perhaps you could help him understand what may have happened. He was also using Inav.
Yes, I know, I talked to him a few days ago. To me it seems like the left V-tail fin stopped working. I could be wrong, but from watching his video that is what I think happened! Some people suggested iNav was at fault... and even though I'll admit I would gladly point my finger at it too... especially at the rate at which it is killing planes, not sure it is the culprit this time! :)
@@ArxangelRC I left him a message on his video as to my questions and theories. One of my questions was if all the servos were recovered working, and if that “gear linkage” in the V-tail looked stripped or stuck.
@@nikhayes3396 Looking at the state of the plane in the video... some of these would be hard to say! :P Servos could have suffered from the impact, same for the control linkages!
So what else have you been doing with this frame since this initial video? I waited for this video to release and was happy to hear your initial thoughts. I've been hanging out for another video after you've done a lot more flying with it. Would love to see you utilise the parachute too, since that's why I'm interested in this frame. Where I live there's lots of trees spread out everywhere with rocks and ant mounds. Very hard to take off and land with the bigger crafts. I plan on building a mapper to map 85k acres.
Well,lately I've been testing an HD video system on it: ua-cam.com/video/a_iZrMR_1j0/v-deo.html
Otherwise I will absolutely not mount a parachute on it. In my mind this only ruins a plane and increases the chances of it braking.
Where i can find this quick lock mechanisms? I want to buy few.
I have no idea mate! I have a feeling these particular locks were designed and made for this plane along with the other plastic bits!
Why are all of these planes lacking landing gear?
I would really like to find a plane capable of slow stable flight with the ability to carry an under mounted camera
Well... for the most part landing gear is limiting from where you can take off and land and adds more weight and drag to a plane that usually is aimed at being optimized to stay long time in the air and needs to be efficient! Might have something to do with that! I have not seen many of these with landing gear... if any, unless they are VTOL! Only the Crosswind Mini has an option for one, but definitely not tall enough for a hanging camera!
Loved the sarcasm, funny.
:D
Are you only using antenna tracker for 5.8Ghz video? What antennas are you using on ground station/?
Yes, I am using the MFD Antenna tracker: goo.gl/bAONIi
On the ground I have an 8-turn self made helical.
Nice video. Greetings from the Netherlands.
Is this still your favorite 2 motor fpv plane?
Thanks! Actually... it never was my favourite... it is very good for a purpose, but not my favourite! :) Depends what job needs doing!
Does it fly better than the Clouds?
Haven't had nearly as much flight time with this one, especially as I only recently installed the Pixhack Nano in it, but I'd yes at worst it is the same as the Clouds... but does have more potential for payload, endurance and range, plus it can easily take larger motors and props, which drastically improves efficiency!
ArxangelRC I ordered the Clouds a few days ago. If I had known this earlier, I would have got a Believer instead :(
Trust me... nobody stops at one plane... its time will come! ;)
ArxangelRC I've got another question if you got time. How would you compare the Believer to Skywalker Titans?
The Tital has been confirmed to be the least efficient of all the current mapping airframes... other than that... I haven't had one in person so can't comment on other details, but for mapping flight efficiency is key as it extends flight times. The Believer holds the crown for the time being, according to what I've seen done with it! :)
What is the best mapping plane out there at the cheapest price for I am drone rich and cash poor. LOL We are wanting to map rice fields with a spectrum NDVI.
Well... best and cheapest... are not two things that usually go together... actually... they never go together! :) I am currently building a souped up version of the Believer, the Flying Dragon, and have yet to test it... but the Believer is a very good option, as well as the MFD Crosswinds... but that would depend on your specific needs for the plane!
Thanks, great info.
You are welcome! :)
Congratulations on your new edition to your family.great review.maybe the baby could fit inside? Not!
Thanks!
Hahaha... I did think of trying to get her inside, but by the time that thought had crossed my mind she was already too big, and I had already glued the wing adapters with the carbon tubes. On her first day though, she would have fit in there without any problems! :)
I look to purchase a beleiver soon. Do you have any motor/prop combo recs or were you happy with the TM3113? Thanks and love your channel!
Hi, it depends on what the goal is? I was quite happy with those... but they are not the most efficient option out there!
@ArxangelRC have you balanced your props?
I should have... at least I did before the maiden... I always do balance them.
Love the videos.
I am about to build the Believer. I chose the KDE 2814 515kv motors and will run 6s.
What prop size do you recommend?
The goal is to have a good efficient platform that can get home upwind if needed.
Appreciate any insight you can provide as it’s difficult to find much online!
Hi, what weight will the plane be?
@@ArxangelRC Tnx for the response.
Not sure final AUW...but plane will have the KDE2814XF-515, Hobbywing Sky Walker 60a ESCs, 4x EMAX ES3054 servos, up to 15000mah 6s LiPO battery, BN-880 gps, Dragonlink 433mhz system (dipole antennas), RMRC 800mw 1.3ghz video tx (will try dipole antenna first), and standard res camera for FPV
I might try a gimble later with GoPro for fun later but predominantly I want to build this for long range endurance.
@@mateostyle Right, so it will be relatively light then! In any case these motors will be OK with an 11x7" prop at 6S. Should have plenty of power! If for some reason you feel like it could be a little faster, try 10x8" also, or do an endurance with both and see which one works best. Both should be more than OK.
@@ArxangelRC very much appreciate the response. I know it would be easy to blow off the question and claim not enough info but you are very dependable for your excellent UA-cam content as well as being a gentleman with the various questions from guys like me whose experience pails in comparison to yours in the hobby! Appreciate the time to respond.
@@mateostyle No worries mate, if I can, I always try to help out as best as I can! :)
More Believer videos please!
Will come soon! I promise!
Curious, what’s your preference between the believer and the xuav clouds? I’m seeing you tend to lean towards the clouds based on your videos. I’m debating which one to go with. Thoughts?
Well, that would depend largely on what you plan to do with it!
@@ArxangelRC Long Range. Maybe dual small cameras (Runcam front and runcam pointing down). Looking for stability and pushing long range.
@@AlexanderPerez-oe1gu Well the Believer would be the better choice in this case! A lot more room to work with, and more carrying capacity for batteries, etc.
Love the humor
Hehe, thanks, so do I! :D
What are those cameras you're using? (on the front and back at the start)
Both are listed in the video description - RunCam HD, and RunCam 2.
You made several comparisons to the XUAV Clouds, but I’m more curious how it compares to the MTD. I know the MTD has a tremendous amount of interior space, but I wonder how it compares in efficiency. Great video. I always love the sarcastic comments about endangering people. Have you considered stand up comedy as a back up career? 😎 Congratulations on the new kid too. Good luck on sleeping through the night. I’m sure you know what I mean by now. 😜
Thanks! As for the baby... we are actually well past the night time feeding period now, she sleeps all night and we also get to have some rest! :)
The MTD featured in the video belongs to a friend of mine, but he has a pretty good idea how efficient it can be, so as soon as I get the new motors installed and the endurance flight done, we will be able to do some rough comparison of the efficiency between the two.
Question in regards to that death spiral, was that caused by CG to far back? and how do you recover from that? full opposite rudder?. thank you and great review as always!
Not sure what caused it... cannot attribute it to CG... more like wing design perhaps! You shut the motor off, and give it full down elevator and counter aileron, as soon as it stops spinning throttle up and up elevator to level off! And also switch to manual mode!
Are you not on Patreon? I need to give you money or else I'm going to feel guilty for sitting at your feet and benefiting from your incredibly great research and documentation.
If I recall correctly, you are a My Twin Dream owner. Isn't she the champ for long-range endurance and efficiency in a mapping plane? I'm puzzled by why you haven't included her in your comparisons. Do you have some reservations about that plane, for some reason?
Bravo, Bravo, Encore!,
Geoff
Thank you very much Geoff... I have been thinking about Patreon for a while now... haven't gotten around to checking out what it is about... might give it a go now that you mention it! :)
As for the MTD, I do not have one, a friend of mine does, and we do some tests with it from time to time! When I am done properly testing the Believer I will provide some comparison data on the performance of the two planes and we will see which one is better! :)
Great video, I have 3 MFD and I love them, any difference between MFD and Nimbus.
Just a quick one with F3 omnibus are you able to have RTH
MFD is the manufacturer of the Nimbus... perhaps you are referring to the MTD? Yes, RTH was working with the Omnibus F3 Pro... it just needed a bit of setup to get it right.
ArxangelRC opps my bad, yes I was referring to MTD, MTD and Nimbus how are they different and which one you like
They are quite different to be honest! I do not have the MTD, but I can tell you that it definitely has a lot more usable space due to the design of the body, but the Nimbus is A LOT more easier to convert to a Vtol without adding much weight, and is quite convenient with those quick attach locks for the wings and tail. It all boils down to what you need to do with the plane.
ArxangelRC i always like the idea of vertical and horizontal stabalizer, but with Nimbus it was very quick to assemble. I was looking around on few famous sites, but nothing i could find e.g BG, Ready made rc and so on.
You mean you can't find the plane listed on those websites?
Will you keep the omnibus/inav thingy or going to pixhawk/vector? It's possible to use the tracker with inav? Mavlink output and that's all isn't it?
I was waiting for a proper review of this plane for few weeks, I love it (just from the photos!) Si you think that 11.11 will be with a good discount?
No idea about the discount... I guess you need to hold out for another day and we will know! :)
As for the Omnibus, yes I will be keeping it for the time being. Any system will work with the MFD tracker as long as you also have the MFD TeleFlyPro OSD connected in there as well, as I do! :) Might have to look into getting native support for the tracker in the iNav code, would save some weight and money by not having to put the MFD board in there. No Mavlink output, i am not using the ArduTracker... that never did work for me.
Hi, will those wing adapter attachments fit the MTD wings? I really like the quick disconnect and wish the MTD had them instead of screws.
Hmmm... probably not without some modifications! They were designed for another plane and wing... also... not sure if you would be able to get them separately, at least not for the time being.
Thankyou for the great review again. Can you link to the T Motor that you think would be the best fit for this model.
Also the Inav Diff file from your model once dialed in would be awesome..
M
Sure thing Michael, will share the file somewhere when I finally have it dialled in. As for the T-motors, I have ordered these: store-en.tmotor.com/goods.php?id=335
Should work well on 6S with a 10" or 11" prop, and their size would allow for easier mounting in the plane. I also have ordered a set of the larger model MN3510 700Kv, but those would go on the EVE-2000. :)
Can someone please make a RC airplane that look like the new Celera 500L? Thanks!
:)
Nice review! Why did you decide to use iNAV? Advantages for mapping over Pixhawk?
Thanks! I used iNav because I had a number of F3 Pro boards lying around, and no spare Pixhawks, so thought it would be a good idea to finally see what the hype is all about! iNav is definitely not up to any mapping tasks at this point, it is still in very early development in my opinion. It should be used mostly for FPV... has nothing on the Pixhawk when it comes to mapping!
Very good review.. And funny! :)
:D
Awesome and very instructive video, thank you. But , how can you speak without take any breath?. :)
Thank you! Well... I do take breaths, but as you can probably tell, do I a lot of editing on my videos to make them sound and look good... so the breathing sounds awful in the video and I cut it out!
A camera or two,
and possibly gimbal,
as I’m planning to do
Sick bars M8
Thanks! :)
Lol! fwd: FAA :)
And informative too. I'd get the believer if I wasn't already building my first double engine frame.
Thanks! What frame are you building?
Hello. Is APM 2.6 recommended for this plane. Or Pixhawk is better. I’ve already ordered one from AliExpress for this Christmas. Your video help me settle on this plane.
Hey, in general the Pixhawk is the better choice, but make sure it is one of the micro versions, as they are much better designed hardware wise.
if the battery was a 12Ah and you flew for 1 hour draining 6A it means that battery is only 6-7ah? Trash battery?
Like I mentioned in the video, I was not able to do an endurance test during my initial review, and now I remember that I still haven't done that... so will have to get on it now that the plane is back on active duty! My idea was that in 1 hour it consumer 6000mAh, meaning it might be able to fly for 2 hours on 12000mAh pack! :)
Another great video of a great product (*)
Thanks Horacio! :)
We truly appreciate your objectiveness and detailed appreciations ... Your contribution is extremely appreciated. When you say that F3 Omnibus + Inav was not a good combination, do you mean it is not a good match for this particular aircraft? Or do you mean that you have reserves on F3 Omnibus + Inav duet ? I would like to use Inav/F3 on a Volantex ASW28 but would like to know what you think of Inav.... Thanks again for your amazin contribution ! - dan from Canada
Hey Dan, actually I meant that it wasn't a good idea to use an autopilot system that I have never used, on a brand new plane that I have never flown! :) Omnibus F3 Pro and iNav are a good combination actually, and I like it, you just need to keep in mind that iNav is still young and is developing, so there are still some bugs to be ironed out, but overall, when you take the time to really get to know it and set it up properly, it does perform rather well.
I really ejoyed this one of your videos , thanks for the hard work
You are welcome! Thank you for the support! :)
Good video. What mapping camera do you use?
I don't! Never have done mapping with a plane... and don't really have any gear for it.
LiDAR?
To what end? If you have a Pixhawk in there you can probably use a LIDAR for auto landings on mapping missions and possibly for low altitude terrain following, in relatively flat areas! But for general purpose FPV this would not be needed! :)