If the visibility is good but there is a low cloud deck I know I can get under, I will “dive and drive” in an attempt to get as low as possible as soon as possible. It increases pilot workload to continually level off then descend. Teaching Tangent: I personally prefer controlled descents on my LNAV approaches. It’s missing the vertical component just like localizer approaches with no glideslope. Think of LNAV-only approach minima as the equivalent to a Localizer or VOR approach. Which technique you choose is completely up to you. These are the approaches you will hear pilots argue about whether it’s best to “dive and drive”/”step-down” or do a controlled descent until you hit the next waypoint at the exact altitude. Simple Cessna 172s with steam gauges and a Garmin 430 could use these approach minimums. LNAV approaches are the most basic of RNAV approaches and as such they usually have the highest minimums. They require no special avionics except a IFR certified installed GPS receiver. Completely different, yet still under the umbrella of an RNAV approach.Įnough side-notes! Let’s break down the different types of approach minimums. Think of LPV approaches as ILS approaches and the LNAV approaches as VOR approaches. An RNAV approach to LPV minima is a very advanced approach compared to a RNAV approach to LNAV minima. You will hear me and other pilots talk as if they are separate types of approaches because they kind of are. It’s easier to call them approaches instead of the correct terminology: “RNAV approach to LPV minima.” I will go back and forth referring to them as approaches vs minimums just because it’s easier from a copy writing perspective. Just to clarify, LPV vs LNAV/VNAV vs LNAV are not types of approaches they are minimums within RNAV approaches. Let’s assume your aircraft is legally allowed to file a “/G” flight plan. It was considered an emergency procedure only. When I flew the OH-58 A/C (which was not instrument rated), we would use our GPS to fly practice RNAV approaches to LNAV minimums in case we inadvertently punched in. Why can’t you use handheld GPSs? Handhelds don’t have adequate backup power, they may drop signal at a key time, but more importantly, they don’t have Receiver Autonomous Integrity Monitoring (RAIM capability) which is an FAA requirement.Īnother side-note: you can always do practice emergency RNAV approaches to LNAV minimums if you don’t have an IFR certified installed GPS. You have to stick to VOR and ILS approaches only. I’m just saying you can’t legally file, ask ATC for, or accept an RNAV approach. I am not saying you can’t use your GPS when flying IFR for situational awareness. You won’t be able to file an IFR flight plan with the “/G” designation. Side-note: No! A handheld GPS or your iPad is not approved for GPS/RNAV approaches so don’t even go there. Go find another article to read, this doesn’t apply to you. If you don’t have an incorruptible (you can’t modify approaches) GPS installed in your aircraft (ie Garmin 430 or 530), you can’t do GPS approaches. If you don’t want to pay to update your database, you can read how to do that by clicking here. You can avoid updating the database, but it’s a pain because you have to check the lat/long points by hand. You may think you can do RNAV approaches when you can’t.įirst, an RNAV approaches are approaches using an IFR certified GPS installed in your aircraft which gets updated every 28 days. Why are some LNAV/VNAV minimums greater than LNAV minimums?īefore we get started, I want to make sure I am talking to the right audience.How do you know if you can fly one vs the other?.What is the difference between LPV, LNAV/VNAV and LNAV approach minima?.I ran into a Navy pilot the other day who had never flown an RNAV approach! I was a little shocked as I thought most experienced pilots had flown Area Navigation approaches (RNAV) before.Īpparently not, which is why I will answer the following questions in this article (plus a few more):
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