GPS Acronyms Explained | What is LPV, LNAV, LNAV+V, and LNAV/VNAV?
Vložit
- čas přidán 3. 04. 2023
- GPS approaches are everywhere, and they comes with a bunch of new acronyms for different approach minimums like LPV, LNAV, and LNAV+V. They all sound similar, but they mean different things. Here is a breakdown of them and how to keep them straight, and why it matters.
IFR Ground School isn't just for new instrument pilots. It's essential knowledge for all who want to excel in their instrument flying. Sign up today at flight-insight.com/ifr
Man, I f**ing love your channel. Every time I google something about what I'm learning, the second or third result is one of your videos. One day I wanna fly in to your base and shake your hand.
Literally the plain English to lay out all these acronyms and not just what they stand for but how to apply them. Fantastic thank you
Thank you so much for this and all your other videos. Your explanation, tone, and presentation and content make this channel a treasure of knowledge!
Thanks!. Studying for my IFR written. You VOR simulator video was excellent... All of your videos help so much! I was really stuck until I watch a few of your videos!
YOU ARE SIMPLY THE BEST MY FRIEND . I LEARN LOTS MORE FROM YOUR VIDEO .
Legit the best instrument videos on CZcams
Another EXCELLENT tutorial by FlightInsight.
Stellar video and shot at the end. Definitely took a pic of it with my phone. Thanks so much!
It did clear up TONS of my confusion :) Thank you!
Thank you for your content. You helped me pass my FAA Instrument written test.
Thanks so much, finally a basic and easy to understand breakdown...
I feel so lucky for this video to come out just before my IFR Checkride
Excellent. Well paced and clarifying.
Great insights again :) You guys rock, thanks again :)
Thanks for this explanation I have been instrument rated for quite some years (been out of currency for a while now) I am currently ATC and never knew more than the very basics of the difference between these.
You give the best explanations
SO much clearer and more concise than both the AH flight si dude and the "pink shirt" (certified for all things) dude!
Excellent presentation. Thanks
Incredible videos!
This was helpful, thanks for making it. If I could, I'd like to request a follow up about GPS errors and when you need to go missed--I'm still confused about that.
Very good explanation, thx! But in this case the difference between the LNAV and LPV is just ca. 100ft and 1/4 SM...
Dan -- Please add this video to the instrument course on your site. Very helpful. Thanks.
Fantastic, thanks so much! However, aside from baro aided LNAV/VNAV there is SBAS as well for the vertical guidance right?
Correct! Another advantage here is you can ignore the temperature constraints for the LNAV/VNAV as GPS isn’t impacted by that. However with that said, I have yet to see an approach that has LNAV/VNAV and NOT have LPV so if you are using GNSS with SBAS and have no issues, you would just fly the LPV anyway…. My comment therefore was just to help you win a round of bar trivia!
737 driver here, Great content!! You got a sub!!!
Thanks
Your videos are incredible and very informative. I've been struggling with a certain portion of this for a week now... how do you tell if your GPS is WAAS equipped? I've looked for the SBAS option in my G430 but cannot find it so I'm assuming I do not have WAAS and should therefore use the LNAV MDA. Also how do you tell if you have the GPS-Baro Nav? Thanks so much!
You should check and see if it is upgradable to WAAS.
I'm sure you've figured this out by now...but one way to go go to the PROC option, and the lowest minima available to your box will be annunciated next to the appch name
Question……if SBAS is not available would the system downgrade to a LNAV VNAV using baro VNAV and the RNP value on the HSI show L/VNAV allowing app to a DA? Assuming of course that you have the required air dat computer to give baro correction to your G1000 and required temp comp range. Your thoughts on this knowing the G1000 as well as you do. My G1000 knowledge is limited to what I see on YT.
Thanks
"I still don't understand the answer, even though it's a great video. Ok, there is an SBAS APV, but what about the SBAS CAT I (a precision LPV approach)? Are there any SBAS CAT I approaches in the US NAS? Thank you.
LP+V will pop up on LP approaches. Naturally, its the same treatment as an LNAV+V. Probably the most commonly used LP approach is the RNAV Y 27 at KSAN with WAAS equipped aircraft.
So do you need WAAS for an LNAV + V? That's the only part I'm confused about
@@AmericanGi370 airliners, very few of which have WAAS, can create vertical guidance. That said, I believe that in GA, only WAAS capable GPS units have the required sensitivity to create a vertical glidepath
@@N1120A that's interesting. I would have assumed all airliners would have waas lol. Thank you. Working on Instrument as we speak!
I Read your credentials on your web site ... Impressive !! I Fly For 20y VFR, but I don't think I am Smart Enough to Learn IFR, besides on my personal G1000 cockpit
you're smart enough
I've seen a approach plate that has lower minimum for LNAV/VNAV compared to LPV. I don't remember the name of the approach, but I wonder what would have made this unusual approach plate.
KOMN RNAV(GPS) RWY 9
@@junzhonghuang7458Oh my that's a good one... I remember Dan pointed this out in one of his videos but I don't remember which one.
Hey at my local airport F70 the LNAV MDA has lower minimums than LNAV/VNAV DA is there a specific reason the LNAV MDA is lower than the LNAV/VNAV DA?
Got this from another site I follow.... The obstacle clearance surface for the LNAV/VNAV is a sloped surface and when obstacles are encountered close in to the runway on the sloped surface, the obstacle height is projected backwards from the runway until it hits the sloped obstacle surface and the DA/H is established above this point. So it has the effect of moving the DA further back and away from the runway at a higher altitude so that the obstacle ends up being in the visual segment so the pilot can see it and avoid it. Also, with a vertically guided procedure, on reaching the DA, the aircraft is in a descent and will descend below the DA as a matter of physics and momentum. On the missed approach pull up, the obstacles in the missed approach can cause the DA to be increased so the aircraft will clear them. On an LNAV procedure, there is no descent below the MDA allowed and the aircraft is assumed to be in level flight at the missed approach point. Also the obstacle surface is a level surface at a fixed height above the controlling obstacle. Also, in some cases, step down fixes may be used for an LNAV procedure so that once the obstacle is cleared, the aircraft on the LNAV may allow descent to a lower MDA. This step down option is not available to a vertically guided procedure.
Generally, most LNAV/VNAV minimums are not lower than LNAV alone is because it is an old system that uses Baro . Most of the time you have errors, especially with temperature, and the fact that the weather reporting at the local station may be inaccurate or unavailable. You may also note that most approaches with this on the alternate minimums tell you that the RNP .3 is not authorized, and this approach in general may not be authorized for use on this airport if filing as an alternate.
In the AIM look for FIG 5−4−12. It explains this perfectly with a graphic.
It’s really interesting ICAO does not recognize GPS approaches as precision. The FAA allows it for check rides and IPC‘s in lieu of an ILS. The truth of it all is an LPV is much more accurate than an ILS and it’s not subject to the errors caused by say a vehicle or aircraft crossing in front of the glideslope antenna or radio frequency distortions.
My first approach in IMC was an LPV approach. It was easy and straightforward to follow. I'd rather take an LPV over an ILS any day
I’m pretty sure it’s not recognized due to the fact that the lateral and vertical are not combined into one navaid.
I could be wrong though
Isn’t there some lighting requirement for precision approaches, too?
I could be wrong, but that was my understanding… 🤔
@@ehuntley83 I don’t believe there is a special lighting requirement, but it does have more lights than a normal runway. You have the RAIL lights and edge lights as well as PAPI or VASI lights.. The approach slope lighting itself does not make it precision. What makes it precision is vertical and lateral guidance.
To those of us who frequently experience gps spoofing, jamming or just signal loss while overseas agree with icao’s reasoning.
If you follow the LNAV+V reference 3 degree approach to an airport with a substantially displaced threshold, or any approach with a stepdown fix between the FAF and the runway, the 3 degree reference glidepath will have you too low. In fact, there have been CFIT accidents where pilots inappropriately flew the reference glide path on a 3 degree approach angle where the approach required more than 3 degrees because obstacles were in the final segment. Be very careful flying the V+ glidepath! Remember, it is for reference only and does not guarantee obstacle clearance, or that you will make fix crossing altitudes.
I drew that map!
Idem tools for ch[ppers?
❤
Hi, I write a newsletter for a 30 person flying club. Would you mind if I use some of your graphics for my newsletter? I'll be sure to credit your site.
So, the only active precision approach in this world is ILS. Is that correct?
ILS, PAR, MLS, TLS
@@PilotFarooq they still have MLS active today? Where?
@@casilasgoaler no
GBAS "GLS" approaches with accuracy to 1 meter and eventually autoland are supposed to be FAA Nextgen approaches. See free FAA-H_8083-16B Instrument Procedures Handbook page 4-26 There are currently a few at KEWR to peruse.
FYI LNAV VNAV is not a precision approach. Only LPV is a precision one similar to ILS cat 1 minima 200ft Agl
1280 foot ceiling? Not.