Whilst the VOR adequately meets the accuracy to support RNAV 5, it does not provide the level of accuracy to support more demanding navigation specifications.

If we consider a Doppler VOR with an NSE of +/- 2½ ° and apply that performance using the 1 in 60 Rule, we note that the maximum range at which the VOR can meet a 1 NM performance is 23 NM.  Please note, that certification to any navigation specification is based on the Total System Error of which NSE is one part; Flight Technical Error (FTE) and Path Definition Error (PDE) are the other two.

Therefore, a Doppler VOR will not support a 1 NM lateral performance outside of approximately 15 NM. 

This is why the only Navigation Specification that uses VOR is RNAV 5.

This website or its third party tools make use of cookies to enhance browsing experience and provide additional functionality. If you want to know more or withdraw your consent to all or some of the cookies, please refer to the cookies policy. Accept