Sign in to follow this  

XNVU for the TU154M

Recommended Posts

I just want give some headsup for those interested in navigating in a unusual way. The TU154M, made by Felis, can navigate without GPS and beacons (though you can use the installed GPS KLN90B if you want) with its NVU computer and isolated gyros. Though creating a flightplan and calculating the bearings and distances manually can be quite tedious when flying in orthodromic courses, as the NVU computer does not convert geographic coordinates itself.

Therefore I've created a tool called XNVU, which you can create a flightplan from waypoints, airways and also custom waypoints (and many other features). The flightplan can then be printed or exported to PDF, where you do read the data which is programmed in the NVU computer. The flaw with the NVU computer is that you can only program 2 waypoints at a time (to and next waypoint) in the format distance and local system bearing. That is one if the things that is important to have this flightplan directly available while flying.

Good facts to know

* Before departure, gyros are calibrated and aligned with the meridian and magnetic declination of the departure airport, no special data expect for current latitude needs to be known.

* Before arrival, even when navigating with the GPS, the gyros needs to be aligned with the arrival airport meridian and magnetic declination, preferably before TOD. The difference of degrees to align between departure and arrival airport is called FORK, which is calculated in XNVU, and gyros is manually adjusted while in straight flight by this value, hence then the navigator uses the second table of bearings to use with the computer.

* About every change of latitude while flying, the latitude instrument needs to be manually set to current latitude.

* Gyros will drift with distance and time, always be prepared when flying far stretches that navigation errors will be induced.

* If you are off course, the NVU computer can be corrected by RSBN beacons (almost the same function as VOR/DME) while in flight, and they where/are placed around eastern Europe, I think even one was placed in Sweden. Even though probably they are no more in service, they are included and working in Felis TU154M. The NVU is also capable to be manually adjusted against VOR/DME or NDB.

Currently the application does include a manual or descriptive hints, but that is planned in the future.


  • Upvote 1

Share this post

Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Thanks for the heads-up, that`s nice to read it is also possible in the Tu-154M in XPlane.

I made the manual for the Project Tupolev Tu-154B2/M a while ago and had a lot of fun with NVU navigation.

So I can only encourage to use that. I certainly will.


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this