Litchi Mission - Duration Times Inaccurate?


I was using VLM and noticed a large discrepancy between the mission duration times in Litchi Hub and the VLM in Google Earth.

Investigating, I created a two waypoint mission of 1km (ok, 999m - to ensure it wasn’t 1.5km with the .5 not being displayed.), and speed of 30km (specified as cruise speed and waypoint speed so there could be no “interference”) … and simple maths says this should be 2 minutes.

But no, Litchi Hub reports this as 3 minutes!

Perhaps they have a built in “safety battery reserve”? No idea … but at least it’s overstating the times and not understating it.

Anyone else noticed this? Or read of a reason?

(Don’t worry! I’m not really going to beat up Southampton Airport at 30m with my MP! …. 3m would be far more fun! :imp:)


Same with a longer distance … even though the MP would never last that long.

30km @ 30kph is ……. 81 minutes!!! … apparently! :stuck_out_tongue:


Could be a safety margin built in to account for small amounts of wind.

The parrot one is wildly inaccurate as well but usually under estimates as it’s hard to maintain a constant ground speed with disco.

I’ve had a 45 min flight take 1hr and 10 mins.


To take account of wind you need to know the wind speed and direction - otherwise it’s meaningless.

Let’s face it … 100mph wind in any direction and the duration calculated should be the time to circumnavigate the world. :stuck_out_tongue:


That’s true and the reason I was thinking a safety margin to account for small amounts.

Either that or someone on the dev team can’t count.


I think the latter. That’s a large margin … almost 50%.

And it’s the same on a mission that’s planned to return to WP1. It’s still near 50% on the time to get back to the start … and wind should (semi) cancel itself out.


I don’t know enough about itchy litchie Is it possible that it’s getting miles and kilometres mixed up. I’m sat in McDonalds at the moment and my head is hurting trying to figure it out. Lol
I will ask my mate tonight, I think he’s on the same shift as me, he uses litchie a lot for his MA.




I have their reply.




The web UI and the mobile app don’t actually do the same thing!

The web UI overestimates(?)!

But the mobile app is accurate!

That could be dangerous …. assuming the mobile calculation has the same “security measure” built in!!

I’ve asked them - I shall let you know there response as to why the two philosophies.


Interesting… did you have the same cruising / top speeds on both missions?


Yes - everything identical.

But over longer distance the same times. #inconsistent


5km @ 30kph … 14 mins v 13 mins

Probably closer to the usual mission distance when time could become an issue … depending upon speed, of course.


At least Litchi have responded …. “rounding error” on the 1km comparison.

I’ve suggested that this “safety feature” should be me more evident …. probably as a switch on/off mission setting … or as a “so many minutes” value.


I’ve noticed this too.

Supposed 20 minute missions taking 10-12 minutes. Nipped in to stick the kettle on only for my M2P to have done the mission and was hovering and looking at me begging for a biscuit after being a good boy!

Guess its a good thing so as not to over extend the missions and therefore the batteries!?! :slight_smile:


I have some missions I want to do, when conditions are right, that will be pushing the limit. I’m using Virtual Litchi Mission to check these and that gives an accurate time.


Is the virtual missions via Google Earth Pro? . Bet thats pretty darn cool!

I am enjoying Litchi for its ability to plan missions online. Such a great feature!


Yes - you still do the planning in Litchi Hub (either raw as you’ll be doing already, or via the exact same thing that’s embedded in VLM) … and then it creates the Google Earth data that enables you to fly the mission in 3D.

It’s Windows only - but there is a very similar plugin for Chrome browser on Mac.

An example : Flying in London! 😉


Good lord!!! that vid looks amazing. :heart_eyes:

Going to have to have a play with that feature. :+1:


Viewing it in GE is instant … rendering a video like that (from GE) takes ages, since it has to ensure all data (3D and imagery) for each frame is fully downloaded before it renders them.
But - yes - one can imagine flying all kinds of places that are either illegal or in places you’ll never manage to travel to.
Limited only by where there’s 3D data in GE, of course, which is quite extensive … and can be hit an miss. Some 3D is satellite/aerial image derived - some are where people have uploaded 3D models of buildings.
Either way - it’s quite a bit of fun.

Two of the forts (you may have seen my flights to and pics of) have 3D models that have been uploaded by someone …

The third has no 3D info …