What is LNAV in aviation

What is the difference between LNAV / VNAV and LPV minimum values ​​in an RNAV approach?

There is an FAA paper on RNAV approaches that explains the differences between LP, LPV, LNAV, and LNAV / RNAV approaches. I made a table for reference, but since StackExchange doesn't allow tables (AFAIK), here is a summary:

  • LP: no vertical guidance; WAAS required; MDA for minimum
  • LPV: vertical guidance; WAAS required; DA for minimum
  • LNAV: no vertical guidance; WAAS not required; MDA for minimum values; requires RAIM integrity when WAAS is not available
  • LNAV / VNAV: vertical guidance; WAAS or Baro-VNAV required; DA for minimum; requires RAIM integrity when WAAS is not available (ie when Baro-VNAV is used); Possible temperature limitations when using Baro-VNAV

The difference between LPV and LNAV / VNAV is that, while both have vertical routing, LPV has been purposely designed to be very similar to an ILS approach with an increasingly sensitive slideway, while LNAV / VNAV is not was. Other answers include additional comments on LNAV / VNAV that were developed earlier and for other devices, which would certainly make sense.

Jan Hudec

The difference in equipment required is why LPV approaches can have lower minima. GPS with WAAS (required for LPV) gives pretty accurate altitude and requires no adjustment. On the other hand, LNAV / VNAV can only be flown with a barometric altimeter and this requires adjustment and even if it is adjusted correctly it has a system temperature dependent error so it is not as reliable and consequently the decision altitude must be higher.

Pond life

@Jobuck I just saw your answer turned into a comment which is why it popped up again for me. Sorry for repeating the same points again.