Hi, I am an Airline pilot wz 15k plus hours. Nothing or nobody has made it clear for me about all this stuff like you did. Thank you so much. Keep up the good work.
Have to agree Natnael, airline guy as well, (787 Captain & C421 owner). I started before GPS, GLS, RNAV(RNP) and WAAS and the world has changed so much. It was VOR-to-VOR in a 727 back in the day. Now, my twin has more capability than I ever thought was possible in GA. We can’t even do an LPV approach at my airline, but I can in my plane. And the opposite is true with the RNP approaches, yes at work and no in my plane! Thanks for the great video!!!
This is one of the best - if not *the best, - video I’ve ever seen as a concise guide to flying approaches. Thank you so much for this!! Reviewing it before my CFII Checkride 😊
This is extremely well done. I started flying in the Air Force before GPS and later flew 737s for the White House & Congress in the Air Force. This is probably the single most well developed discussion. Thank you for this.
I am renewing my IFR, this video helped me learned so much more stuff that I already know. I understand it all, you are an amazing teacher, thank you for this video !
Hi Gary, it was nice meeting you today at SNF and thanks again for the signed book. I tuned in here to learn what LPV is since I’m not allowed to do them with at work w/ my equipment and thus had a poor understanding of what they really were. Fascinating technology! Interesting discussion on RNAV (RNP) around 19:30 though; I can do those and sometimes that is the way to go to get into a place like DCA (LNAV/VNAV is magic to keep us along the river and out of P-49!). The terminology is driving many of us bananas though since ICAO uses different nomenclature to muddy the waters further…… For example, an RNAV (GPS) XX in the states is the same as an RNP XX outside the states. An RNAV (RNP) XX stateside is equivalent to a RNP XX (AR) overseas. The RF legs usually give away what kind of procedure it is though. I would expect the FAA to merry up with ICAO naming convention in the coming years, so expect the confusion to get worse before it gets better! The point I’m confused about on the RNAV (RNP) approach you show is that you say it’s based on a “dual DME” rather than GPS. If it were using any kind of DME signal from a conventional navaid, it certainly doesn’t tell you that on the plate (would it not say “DME from XYZ and ZYX required” or something along those lines?) Honestly, I don’t think it would use DME at all to fly the RF legs-the ANP wouldn’t likely be tight enough to satisfy the RNP. It would probably be using GPS (though a suitable equipped FMS system would have many “sensors” from which the FMS automatically chooses….GPS being one of them; most likely some kind of “blended” solution such as INU/GPS. Probably not WAAS or LAAS enabled though since LPV minima aren’t provided; though you can see the RNP requirement is tighter than most stand-alone GPS approaches. As I’m sure you know, the fundamental difference between RNAV and RNP is the internal monitoring/alerting capability demanded by an RNP system that you wouldn’t necessarily have with RNAV systems. Hope that wasn’t too long winded; anyway, I love the video; great work!
Gary, at 38:00 on the LP+ V you said “If you descend below the glidepath you’re going to hit those obstacles because clearance is not guaranteed”. I think you meant, “If you descend below the MDA”.
Great educational content! Regarding RNP AR, the same held true in our Dassault Easy and Gulfstream aircraft. (FAR 91 operator) The RNP Z (RNP AR) approaches were in our aircraft’s Jeppessen approach database, but not in the Honeywell FMS database.
I believe Gary may be incorrect on the explanation of authorization not allowing the approach to be available. @ ~24:00. It’s a box capability/certification question. There are still plenty of boxes that are not certified to conduct RF legs. None of our pilots are authorized for any approaches that require the Administrator -in. However we have a UNS that can do the approach and a Rockwell that cannot.
Great video. Lot of really good information presented. I will say that I cringe when I hear folks say that pilots should rely on the the autopilot for instrument approaches. I do understand why and I did hear you add the part about maintaining proficiency without it, but from experience, it becomes a crutch. The same goes for the flight director. The airlines have pushed this so much that we don’t even practice engine failures without without using the autopilot and there really isn’t much opportunity to practice hand flying during line operations because of self induced limitations placed on us in the interests of safety. I understand we are looking at statistics and the odds of a malfunction of the systems vs how often a pilot gets distracted. I agree, use the magic, but we shouldn’t allow ourselves to become system managers and lose our pilot skills. Looking back, I still can’t believe I flew a single pilot fighter, with a single tacan nav and single uhf radio, and no autopilot flying direct point to point and dme arching approaches down to minimums without being able to carry a very much extra gas and limited divert options. But then again, times have changed and I also didn’t have to fly only referencing turn needle and ball with a single adf.
@pilotsafetyorg A couple of issues so far in the presentation. A 145/146 WAAS receiver doesn’t require a RAIM check as long as their are no WAAS NOTAM’s. If WAAS outages are in effect then RAIM is required. Next the claim that the KOMA RNAV(RNP) Z 18 is not GPS? It says GPS required right on the plate.. nothing about DME/DME required. RNP AR is based on Dual NON WAAS GPS, with dual IRU’s and dual autopilots. The technology was developed by Alaska Airlines prior to WAAS deployment, even to this day WAAS is not a option for the 737 (there is one aftermarket exception being used by Northern Air Cargo). RNP AR TERPS is also different from LPV TERPS. Where LPV is angular, RNP AR keeps its protected area the same width all the way to the runway. Also to make the blanket statement that the LPV is always better than the ILS? I have yet to run into an airport where that is the case. Also the AIRCRAFT needs to be certified from the factory to be in compliance with AC-90-101 for RNP AR.
FANTASTIC VIDEO! I'd like to clear something up, however. I think you made a mistake on your table at @8:04 but I couldn't find a definitive answer, so I'd like to bring it up.. You describe terminal, enroute, and approach phases as having "full range left to right" widths of 1, 2, and .3 nm, respectively and "deflection on one side" of half those values. You do the same with Victor Airways, having a "full range" of 8nm. I know that you're correct in describing the width of Victor Airways, but I'm fairly certain that the RNAV 2, 1, and 0.3 describe "deflection on one side" and not "full range". I.e. a full scale deflection in the enroute phase would be 2 nm left or right of centerline, not 1nm. Again, that is MY UNDERSTANDING that I've carried with me for a number of years and I couldn't find documentation clearly specifying whether RNAV 2, 1, etc. specifications describe "full range" or "deflection on one side". Everything I've seen in the past is similar to this: code7700.com/rnav_vs_rnp.htm, but this isn't exactly an approved source of information. If you could find the literature on this, I'd greatly appreciate it!
For both RNP and RNAV, the numerical designation refers to the lateral navigation accuracy in nautical miles which is expected to be achieved at least 95 percent of the flight time by the population of aircraft operating within the airspace, route, or procedure. I think you have confused yourself with your terminology. "Full range and full width" vs "full scale deflection." Full scale deflection of RNAV 1 would be a lateral error of 1 nm. Yes, the total width (what you are calling "full range") of the "path" is 2 nm wide. Another example: 0.3 nm means lateral accuracy of 0.3nm either side of centerline. It is defined as lateral accuracy, so the only way to be in error is left or right (not up or down). Compare that to 4 nm accuracy on a Victor airway (and a "full range" of 8 nm). As for where to find documentation, start in the AIM where it describes Performance-Based Navigation.
LOVE your book......Read it 4 x's so far......LOADED with GREAT Tips and solid IFR info..... Bought extras to give to my Pilot Buddies.......SAVE a LIFE and Share!!!! Thanks
This is very informative Gary. Thanks! I like how you covered the HDG vs TRK issue. I fly Internationally for a 121 carrier, and notice that most, if not all SIDS that we fly overseas call for a TRK from the Runway. According to our systems manual, the FMS will be properly coded to fly all RNAV SID procedures as published, so we are instructed to arm LNAV prior to takeoff. Just out of curiosity, do you happen to have any insight as to why the US, Canada, and Mexico choose HDG to a conditional WPT vs TRK to a fixed WPT?
Terrific video, I learned a lot. I was under the impression that by definition a "Precision" approach was based on reliable RADIO based transmitters. And that LPV, while preferable and more accurate are not considered precision because of the radio definition. Small point but curious if I learned it wrong.
Great video! I’m a CFII but still learned a lot from this. My one comment/question would be you said an RNAV Z have lower minima than an RNAV Y into the same runway. That doesn’t seem to always be the case as KRDM has an RNAV Z RWY 5 that has higher minima than the RNAV Y RWY 5. Now the big difference between these plates is the Z is RNP and the Y is GPS, any clarification with why they choose the order of the letters would be great! My assumption is that a runway that has an RNP approach will always be a Z or Y (if there are multiple RNP approaches for the same runway) before the GPS approaches are lettered
Hey I actually just learned about this the other day from my CFII. They list the approaches A,B,C ascending order for approaches that dont line you up close enough to runway heading. And Z,Y,X go descending order and will usually line you up runway heading. For example the RNAV A into KSPK is a circling approach that dumps you into a high left downwind for runway 30. And the RNAV Z and Y put you lined up for runway 12.
Awesome! Thanks! And I have 25,000 hours. On the other hand... While there are dozens of different approaches... On most of the planes I fly (big ones) there are just two buttons on the Mode Control Panel. I mean, I either press this button or I press that button. I tell my F/Os, it is either that button or this button. What is going on in the computers out there in the Universe... from my point of view it is this button (usually labeled APP) or that button (usually labeled VNAV). (Okay, and on a 737 you have IAN but that can be flown as a LNAV/VNAV.)
I missed your webinar on this the other day and I wanted to thank you for sending me the link to this presentation of it! I enjoyed, and learned a lot from it.
If you fly a LNAV only CDFA approach using an advisory glide path created by the FMS/GPS, then you should not level off at the MDA, you should add a buffer of 30-50ft above to create a Derived Decision Altitude, at this point if not visual you should go around. Proceeding on heading until the missed approach point before making any turns required by the missed approach procedure. The LNAV/VNAV approach uses a Decision Altitude, so you must make your decision to go around at the DA, again no level off, and climb straight ahead to the missed approach point before making any required turns.
Thanks for making this available for those of us that couldn't attend. It really drove home the differences between the RNAV approaches... and other than we need to keep up our localizer skills, etc. why would anyone fly anything but an LPV?! Thanks Gary.
Going through CFII training now and I wish that there were references for some of the stuff on the video so I could prove it to my instructors. Having a hard time finding the information to cite.
Such an informative video and such a measured and composed delivery. Thank you, possibly one of the best videos I come across thus far, as part of my ongoing search for content to support my Microsoft Flight Simulator experience.
Quite possibly the best explanation of the various aeronautical approaches that are available that I've ever watched. I use the TDS GTN 750XI software product that uses the 750XI Garmin Trainer in Microsoft Flight Simulator, the Gramin trainer drives the autopilot in the simulator and is a fantastic learning tool. Such an outstanding video, I learned so much, thank you! :)
First and foremost, I LOVE your material and your vast expertise!!! I have some feedback that is just my opinion (and I am not even a pilot, to take this with a HUGE grain of salt)...the "90 degrees or less turn to final" example at 29:51 (and the one earlier at 26:42) is a bit awkward to observe... The 29:51 example, just looking at it from a geometry point of view, seems to be an angle LESS THAN 90 degrees. I think it should maybe better be described as "Do you have to change your inbound heading by > 90 degrees" and then it seems a bit more clear that I am changing from maybe an inbound heading of approximately 40 degrees to a final approach heading of 146 degrees - which is > 90 degrees. The slide description on the bottom also seems to be missing some text as well. I propose "Is the heading change > 90 degrees to the final approach course, if so, a PT will (almost) always be required". Thoughts?
Thank you so much from overseas is 91 operation we have To know and I understand both systems as an FAA AND ICAO As everybody know private jet they could fly anywhere is on the ward any time
I always do the 30 day VOR check at the same time as I do the GPS database update. I'm fortunate to have a VOR near the field to do the check on the ramp.
From a metrology perspective it may be a bit missleading to state the simple "accuracy" of the various GPSS systems. There are probability factors(combined accuracy, variance, and repeatability of all components combined) and acceptable levels of "known uncertainty" that all must be met, then combined with sampling rate and averaging algorithms in the receiver software. If a pilot were to take only the simple statement of "accurate +/- 9.5ft" they might believe that they are safe doing somthing as long as they give it at least 10ft clearance. But(numbers made up for example), the location measurment may be off by 30ft 2% of the time, and to acheive an acceptable one in a billion level of confidence the buffer allowance may need to be 100ft. The common Garmin GA units sample the GPS signal 5 times per second, even excluding dropped samples a plane at 100kts travels 35ft between samples. Further this distance does not include the lag time the unit adds to process and display the sample or the pilots reaction to the displayed result. And even that 100ft signal-variance buffer doesn't consider the buffer required for a pilot to react to a complete failure of the receiver and switch to some fallback action. All of these considerations are incorporated within the limits of published FAA procedures. For example, to state that LPV is better than ILS because it has narrower full scale deflection at the threshhold is poor logic. (LPV might be better, but just not for the reasoning given.) It may be that a narrower full scale deflection is required to accomidate a larger secondary obstacle buffer zone. In other words, it is not about how close you are on average to the centerline of the primary flightpath, it is about how far away the obstacle needs to be when at the edge of the flightpath, and the size of the secondary buffer needs to meet the signal uncertainty requirements of the equipment. (In the case of LPV, the standard width at threshhold is able to be narrower than ILS because of limits in the way an ILS antennea is positioned at the departure end of the runway and tuned for different runway lengths while still being a reasonable width 5-10 miles out. LPV stops narrowing at the threshhold while ILS continues to narrow down the full runway. It really isn't because one is inherently more precise or reliable.)
Hello really appreciate you elaborating on this learnt a lot would you be in position to point in the direction for official/FAA references for the same I am ask so that my students will be in a position to use it on a checkride if needed Thank you
When going over RNP at 7:00, isn’t the terminal RNP 1NM to either side of center, as opposed to 1NM wide total? Meaning a full-scale deflection would be = to 1NM instead of 1/2NM? And same with enroute (2NM either side of center?) Genuinely curious to make sure I’m studying the right thing. Or is this something different than basic RNP? Loving this video!
Hi, I've got a question. In 8:00 you mentioned that full range deflection in GPS approach is .3NM, but is it correct? From my understanding, GPS approaches have RNP 0.3 which would mean that the full range deflection is actually 0.3 * 2 = 0.6NM. Could you please clarify it to me? Thanks for video though, it is very informative!
Hey Gary, i`m new to the Channel, just subscribed. AMAZING video, I`m working on my CFII, hopefully going for checkride in a couple weeks. Thank you for the Video!
Watching this video before my exams. First of all very great explanation! You clarified a lot of things! I'm a little bit confused right now on the part of the difference btw RNAV (GPS) and RNAV (RNP) about the fact that you can fly the first without authorization and the second one only with it. I'm from Italy so maybe the things are different or they changed in the last few months. If you look for any approach chart for italian airports and look at the GPS procedures there are only procedures called "RNP Approach" without any authorization required. I've recently studyed that the procedure requiring authorization there's an "AR" after RNP (so e.g. RNP AR RWY18, and the books state that because they have curved paths) So, my confusions comes that in this video you say that RNAV (GPS) do not require authorization but RNAV (RNP) requires it, while in Italy there are only RNP approaches and the books states that for the "special procedures" they are called "RNP AR". I'm not saying that you are wrong because your carrerer is really amazing and congrats of that, but maybe they've just changed things after the publication of this video or here in Europe the terminology are different (i've also read that some states calls these procedures in another ways). Thank you for this video!
If you think you're confused, imagine how US pilots get mixed up! You are correct! Every RNAV approach by definition is RNP. Thee FAA chose to name GPS based approaches RNAV(GPS) and decided to name Authorization Required approaches for the airlines using dme based RNAV as RNAV(RNP) and put an AR(Auth Require) note on the chart to try and make it easy for GA pilots to know what they could and could not fly. Unfortunately, it does create a lot of confusion... Thanks for being part of the team!
Sorry, but in reference to your example about IF/IAF, I can’t think of any situation where I would be cleared direct to CUMUM without the phrase “cleared for approach”, simply, the course reversal is not necessary if you are arriving from the NW sector where the turn is less than 90. If you are arriving from the SE and cleared for the approach, you simply follow the depicted course reversal in which case CUMUM then becomes both the IAF and IF.
LPV is NOT a precision approach... It is allowed to be substituted for the purpose of the ACS if the DA is lower than 300 feet. PRECISION APPROACH PROCEDURE- A standard instrument approach procedure in which an electronic glideslope or other type of glidepath is provided; e.g., ILS, PAR, and GLS. GLIDESLOPE- Provides vertical guidance for aircraft during approach and landing. The glideslope/glidepath is based on the following: Electronic components emitting signals which provide vertical guidance by reference to airborne instruments during instrument approaches such as ILS; or, Visual ground aids, such as VASI, which provide vertical guidance for a VFR approach or for the visual portion of an instrument approach and landing. PAR. Used by ATC to inform an aircraft making a PAR approach of its vertical position (elevation) relative to the descent profile. Those definitions eliminate LPV approach as precision approach as GPS calculates a glide path, and is not based on emitting signals. Also the table at 9:28 has some errors, Refer to the instrument flying handbook 9-44 thru 9-45 for GPS-RNP. EX: (Terminal is NOT 1/2 NM with Full Scale deflection on one side, its 1NM with a total of 2NM Full Range from Left to Right. If I am mistaken, please cite FAA source with correction Thanks.
Hi, great video. Question: I have a plane with the G950 with a AP 550. My plane can only do LNAV approaches. WHAT to I have to put on the plane to execute an LNAV/VNAV app? So I can lower my MDA. Thanks
Thanks for explaining I have got a clear understanding of GNSS approaches but also with few doubts 1.WAAS gps receiver is more accurate than non-WAAS gps receiver, how LNAV/VNAV has DA ?
In AIM 1-1-17, the "Procedures for Accomplishing GPS Approaches" section describes the width of the Enroute CDI as +/- 5 NM either side of centerline, within 30 NM of the airport as +/- 1 NM, and 2 NM from FAF smoothly changing to +/- 0.3 NM. This indicates the full-scale deflection is 5 NM, then 1 NM, then 0.3 NM. This video gives these full-deflection distances incorrectly as 1 NM, 0.5 NM, and 0.15 NM.
So what's the point in getting the training and all that for an RNP approach if its just worse than an LPV. Was talking to an ALA pilot the other day about how they used RNP a lot but I didn't understand why.
Question on your questions at the end, with the Lnav/Vnav, I consulted with my instructors ( I have some prev instructors and the one I have now) with my understanding and they said I am correct. LNAV/VNAV requires WAAS, and if it does not have WAAS, then it cannot have a DA, it would have an MDA (unless its an ILS but this is about GPS (WAAS) Apchs). How did you come up with the answer to that question that its C?
Hey Gary, cheers for the video really helped me. But I got confused at 1:00:30. Isn't LNAV/VNAV is a non WAAS approach with Advisory Vertical guidance that only takes you to MDA?
Amazing content. I have a question regarding approach plates that show “RNP APCH”. L35 shows RNP APCH next to the notes for RNAV (GPS) RWY 26. KSNA on the other hand does not show RNP APCH next to the notes for the RNAV (GPS) Y RWY 20R. Clearly in both cases you need the Required Navigation Performance for the approach you plan to fly. So why the difference?
1. LPV Non Precision or Precision? Re: Instrument Procedures Handbook; pg. 4-63 (203 of 312) "Approach minima as low as 200 feet HAT and 1/2 SM visibility is possible, even though LPV is not considered a precision approach." 2. A Designated Examiner (Alaska-2023) had been using LPV in lieu of ILS for pilot instrument rating certifications; until the local FAA caught wind...something approaching (no pun intended) 100 pilots had to be rechecked by FAA examiners to fulfill the ILS 'Precision Approach' requirements for an Instrument Rating.
Just started to watch and got confused: at 1:31 I see that GPS accuracy is 26 ft, but at 6:47 I see the different figures of lateral (9.5ft) and vertical (14ft) accuracy. Are they related somehow to each other? Thanks for the great aggregation of info though!
I’m just starting my instrument training. Love the videos. My question is I’ve heard that atc will more than likely change your direct flight plan . Is this true?
I think your explanation of full scale deflection is incorrect. From center to one side is 1 mile in terminal not 1/2 mile. Enroute is 2 miles from center to one side and App mode is .3 from center to one side, Your graphics are showing half of this sensitivity.
At minute 31:00 you explain LNAV +V You say that the Advisory vertical guidance is created by WAAS GPS. If I have a WAAS GPS in a country without WAAS, does the GPS generate the Advisory glide path ??
The U.S DoD does not own GNSS, it owns the GPS satellite network which is a PART of the GNSS network … GNSS is a (future) network of satellites comprised of several countries satellite networks including (potentially) Russian GLONASS, Chinese BeiDou-2, European EGNOS (Galileo), Indian IRNSS, Japan QZSS etc. Current GNSS includes GPS (WAAS) + EGNOS and are SBAS capable.
@@maaitah1991 Correct, not currently because their programs are still in development, however per National Defense Authorization Act 2020, United States Secretary of Defense in consultation with Director of National Intelligence will designate NavIC (IRNSS) and QZSS as allied navigational satellite system for (potential) inclusion in GNSS. Current GNSS includes USA GPS and European EGNOS … both SBAS capable 👍
WAAS ground relay station sends signal to A satellite or satellites that transmits correction, but not to all NAV satellite in constellation do this. The NAV satellites do not know correction. In other words correction is coming from other satellite that accepts unlink and relays it back.
So RNAV(GPS) approach AND RNP approach are both GPS Approaches bases on internal computation of aircraft and gps . But the difference is RNP needs On board performance monitoring and alerting system for more accuracy . Am I right? Please clarify?
I am building a home built and have no plans for VOR receivers. It seems to me the likelihood of a total failure is pretty darn unlikely, but I am now wondering if having a handheld VOR receiver might be a reasonable backup. Anyone else doing this? Or is the feeling that GPS is reliable enough that this isn’t necessary?
So at 40:00, I tried this advice today. On my garmin GNS430, keeping the first altitude before the stepdown and waiting for the glidepath. It does appear, but when it appears I am two dots above it and have to then dive on the GP. Tried again with the "dive and drive", I get the GP from below. So with respect, it seems to vary with equipment types?
Can one fly LNAV/VNAV with a non-waas GNS430? Some sources say no because most GA aircraft don't have baro aiding installed. Other sources say yes because the GPS still can produce a glideslope, just less accurate than WAAS. Which is correct?
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Hi, I am an Airline pilot wz 15k plus hours. Nothing or nobody has made it clear for me about all this stuff like you did. Thank you so much. Keep up the good work.
try asking your dispatcher. Not all of them know, but most do.
Have to agree Natnael, airline guy as well, (787 Captain & C421 owner). I started before GPS, GLS, RNAV(RNP) and WAAS and the world has changed so much. It was VOR-to-VOR in a 727 back in the day. Now, my twin has more capability than I ever thought was possible in GA. We can’t even do an LPV approach at my airline, but I can in my plane. And the opposite is true with the RNP approaches, yes at work and no in my plane! Thanks for the great video!!!
Same here! Finally all of this makes sense. Excellent presentation. Thank you for sharing.
How is it good he talks about these approaches in the first 10 minutes but never explains what they actually mean terrible
I think I've watched this about a half-dozen times during my IFR training. Thanks Gary!
I just jumped into A320 FO duty, and I am so lucky to see your video that none of my previous training ever discussed them so well.
That's really cool, great to meet you! Hope you love the airbus.
MCDUDU
The most clear and concise explanation of GPS approaches. Thank you!
Incredible how aviation is always about learning new things everyday. Thanks Gary !
I have 0 hour flying experience but I found your videos very very detailed, informative and helpful. Big thanks.
This would have saved me tons of confusion during IFR training. Forwarding this to all my II friends. So well done - Thanks so much!
This is one of the best - if not *the best, - video I’ve ever seen as a concise guide to flying approaches. Thank you so much for this!! Reviewing it before my CFII Checkride 😊
This is extremely well done. I started flying in the Air Force before GPS and later flew 737s for the White House & Congress in the Air Force. This is probably the single most well developed discussion. Thank you for this.
I am renewing my IFR, this video helped me learned so much more stuff that I already know. I understand it all, you are an amazing teacher, thank you for this video !
Thank you very much. You don't know how valuable this training is for me. Morris-Ground instructor. This is a place to renew the knowledge.
Hi Gary, it was nice meeting you today at SNF and thanks again for the signed book.
I tuned in here to learn what LPV is since I’m not allowed to do them with at work w/ my equipment and thus had a poor understanding of what they really were. Fascinating technology!
Interesting discussion on RNAV (RNP) around 19:30 though; I can do those and sometimes that is the way to go to get into a place like DCA (LNAV/VNAV is magic to keep us along the river and out of P-49!). The terminology is driving many of us bananas though since ICAO uses different nomenclature to muddy the waters further……
For example, an RNAV (GPS) XX in the states is the same as an RNP XX outside the states. An RNAV (RNP) XX stateside is equivalent to a RNP XX (AR) overseas. The RF legs usually give away what kind of procedure it is though. I would expect the FAA to merry up with ICAO naming convention in the coming years, so expect the confusion to get worse before it gets better!
The point I’m confused about on the RNAV (RNP) approach you show is that you say it’s based on a “dual DME” rather than GPS. If it were using any kind of DME signal from a conventional navaid, it certainly doesn’t tell you that on the plate (would it not say “DME from XYZ and ZYX required” or something along those lines?)
Honestly, I don’t think it would use DME at all to fly the RF legs-the ANP wouldn’t likely be tight enough to satisfy the RNP. It would probably be using GPS (though a suitable equipped FMS system would have many “sensors” from which the FMS automatically chooses….GPS being one of them; most likely some kind of “blended” solution such as INU/GPS. Probably not WAAS or LAAS enabled though since LPV minima aren’t provided; though you can see the RNP requirement is tighter than most stand-alone GPS approaches.
As I’m sure you know, the fundamental difference between RNAV and RNP is the internal monitoring/alerting capability demanded by an RNP system that you wouldn’t necessarily have with RNAV systems.
Hope that wasn’t too long winded; anyway, I love the video; great work!
Gary, at 38:00 on the LP+ V you said “If you descend below the glidepath you’re going to hit those obstacles because clearance is not guaranteed”. I think you meant, “If you descend below the MDA”.
So glad I discovered your channel! I'm a 160hr PPL starting instrument training and this was incredibly helpful! Thanks!
Awesome! It's really nice to meet you.
Great educational content! Regarding RNP AR, the same held true in our Dassault Easy and Gulfstream aircraft. (FAR 91 operator) The RNP Z (RNP AR) approaches were in our aircraft’s Jeppessen approach database, but not in the Honeywell FMS database.
I believe Gary may be incorrect on the explanation of authorization not allowing the approach to be available. @ ~24:00. It’s a box capability/certification question. There are still plenty of boxes that are not certified to conduct RF legs. None of our pilots are authorized for any approaches that require the Administrator -in. However we have a UNS that can do the approach and a Rockwell that cannot.
Great video. Lot of really good information presented. I will say that I cringe when I hear folks say that pilots should rely on the the autopilot for instrument approaches. I do understand why and I did hear you add the part about maintaining proficiency without it, but from experience, it becomes a crutch. The same goes for the flight director. The airlines have pushed this so much that we don’t even practice engine failures without without using the autopilot and there really isn’t much opportunity to practice hand flying during line operations because of self induced limitations placed on us in the interests of safety. I understand we are looking at statistics and the odds of a malfunction of the systems vs how often a pilot gets distracted. I agree, use the magic, but we shouldn’t allow ourselves to become system managers and lose our pilot skills. Looking back, I still can’t believe I flew a single pilot fighter, with a single tacan nav and single uhf radio, and no autopilot flying direct point to point and dme arching approaches down to minimums without being able to carry a very much extra gas and limited divert options. But then again, times have changed and I also didn’t have to fly only referencing turn needle and ball with a single adf.
I’m a simmer and this is going to help me 10 fold!!! Thank you!
Me too
You make learning Fun! I think I will impress my CFII tomorrow after watching this 😁
@pilotsafetyorg A couple of issues so far in the presentation. A 145/146 WAAS receiver doesn’t require a RAIM check as long as their are no WAAS NOTAM’s. If WAAS outages are in effect then RAIM is required. Next the claim that the KOMA RNAV(RNP) Z 18 is not GPS? It says GPS required right on the plate.. nothing about DME/DME required. RNP AR is based on Dual NON WAAS GPS, with dual IRU’s and dual autopilots. The technology was developed by Alaska Airlines prior to WAAS deployment, even to this day WAAS is not a option for the 737 (there is one aftermarket exception being used by Northern Air Cargo). RNP AR TERPS is also different from LPV TERPS. Where LPV is angular, RNP AR keeps its protected area the same width all the way to the runway. Also to make the blanket statement that the LPV is always better than the ILS? I have yet to run into an airport where that is the case. Also the AIRCRAFT needs to be certified from the factory to be in compliance with AC-90-101 for RNP AR.
Wow, this may have been the best training I’ve ever received about this topic. Very well explained thank you!
Thanks! I'm so glad to meet you
FANTASTIC VIDEO! I'd like to clear something up, however. I think you made a mistake on your table at @8:04 but I couldn't find a definitive answer, so I'd like to bring it up..
You describe terminal, enroute, and approach phases as having "full range left to right" widths of 1, 2, and .3 nm, respectively and "deflection on one side" of half those values. You do the same with Victor Airways, having a "full range" of 8nm. I know that you're correct in describing the width of Victor Airways, but I'm fairly certain that the RNAV 2, 1, and 0.3 describe "deflection on one side" and not "full range". I.e. a full scale deflection in the enroute phase would be 2 nm left or right of centerline, not 1nm.
Again, that is MY UNDERSTANDING that I've carried with me for a number of years and I couldn't find documentation clearly specifying whether RNAV 2, 1, etc. specifications describe "full range" or "deflection on one side". Everything I've seen in the past is similar to this: code7700.com/rnav_vs_rnp.htm, but this isn't exactly an approved source of information. If you could find the literature on this, I'd greatly appreciate it!
For both RNP and RNAV, the numerical designation refers to the lateral navigation accuracy in nautical miles which is expected to be achieved at least 95 percent of the flight time by the population of aircraft operating within the airspace, route, or procedure.
I think you have confused yourself with your terminology. "Full range and full width" vs "full scale deflection." Full scale deflection of RNAV 1 would be a lateral error of 1 nm. Yes, the total width (what you are calling "full range") of the "path" is 2 nm wide.
Another example: 0.3 nm means lateral accuracy of 0.3nm either side of centerline. It is defined as lateral accuracy, so the only way to be in error is left or right (not up or down).
Compare that to 4 nm accuracy on a Victor airway (and a "full range" of 8 nm).
As for where to find documentation, start in the AIM where it describes Performance-Based Navigation.
"W" Key West Florida RNAV GPS RWY 9 has a "W" noted. Been there and didn't know what the "W" was till I saw your presentation
That last comment was the gift. I asked my ii .. what about partial panel? No VAC.
Ans: use Foreflight only
Golden Sir Golden
im refreshing my instrument knowledge studying for CFII and this is extremely helpful. Thanks
What an absolute outstanding Video! I learned so much from it, crazy - Thanks for this brilliant work!
Using KLUD and KADM is awesome. I fly there a few times a month.
LOVE your book......Read it 4 x's so far......LOADED with GREAT Tips and solid IFR info..... Bought extras to give to my Pilot Buddies.......SAVE a LIFE and Share!!!! Thanks
This is very informative Gary. Thanks! I like how you covered the HDG vs TRK issue. I fly Internationally for a 121 carrier, and notice that most, if not all SIDS that we fly overseas call for a TRK from the Runway. According to our systems manual, the FMS will be properly coded to fly all RNAV SID procedures as published, so we are instructed to arm LNAV prior to takeoff. Just out of curiosity, do you happen to have any insight as to why the US, Canada, and Mexico choose HDG to a conditional WPT vs TRK to a fixed WPT?
Great content and presentation. I refreshed and learned a lot. I have a 20 year military flying background and hold an ATP.
Terrific video, I learned a lot. I was under the impression that by definition a "Precision" approach was based on reliable RADIO based transmitters. And that LPV, while preferable and more accurate are not considered precision because of the radio definition. Small point but curious if I learned it wrong.
GPS is radio based
Excellent instructional video. Thank you for breaking down all the approaches at one time. I'm keeping this as my go to reference.
Great video! I’m a CFII but still learned a lot from this. My one comment/question would be you said an RNAV Z have lower minima than an RNAV Y into the same runway. That doesn’t seem to always be the case as KRDM has an RNAV Z RWY 5 that has higher minima than the RNAV Y RWY 5. Now the big difference between these plates is the Z is RNP and the Y is GPS, any clarification with why they choose the order of the letters would be great! My assumption is that a runway that has an RNP approach will always be a Z or Y (if there are multiple RNP approaches for the same runway) before the GPS approaches are lettered
Hey I actually just learned about this the other day from my CFII. They list the approaches A,B,C ascending order for approaches that dont line you up close enough to runway heading. And Z,Y,X go descending order and will usually line you up runway heading. For example the RNAV A into KSPK is a circling approach that dumps you into a high left downwind for runway 30. And the RNAV Z and Y put you lined up for runway 12.
Awesome! Thanks! And I have 25,000 hours.
On the other hand...
While there are dozens of different approaches...
On most of the planes I fly (big ones) there are just two buttons on the Mode Control Panel.
I mean, I either press this button or I press that button. I tell my F/Os, it is either that button or this button. What is going on in the computers out there in the Universe... from my point of view it is this button (usually labeled APP) or that button (usually labeled VNAV).
(Okay, and on a 737 you have IAN but that can be flown as a LNAV/VNAV.)
I missed your webinar on this the other day and I wanted to thank you for sending me the link to this presentation of it! I enjoyed, and learned a lot from it.
If you fly a LNAV only CDFA approach using an advisory glide path created by the FMS/GPS, then you should not level off at the MDA, you should add a buffer of 30-50ft above to create a Derived Decision Altitude, at this point if not visual you should go around. Proceeding on heading until the missed approach point before making any turns required by the missed approach procedure. The LNAV/VNAV approach uses a Decision Altitude, so you must make your decision to go around at the DA, again no level off, and climb straight ahead to the missed approach point before making any required turns.
Thanks for making this available for those of us that couldn't attend. It really drove home the differences between the RNAV approaches... and other than we need to keep up our localizer skills, etc. why would anyone fly anything but an LPV?! Thanks Gary.
Because Like he said the GPS F'ed up.
Going through CFII training now and I wish that there were references for some of the stuff on the video so I could prove it to my instructors. Having a hard time finding the information to cite.
Good explanation about this issue. Is there any videos talking about Converging Runway Operations?
Such an informative video and such a measured and composed delivery. Thank you, possibly one of the best videos I come across thus far, as part of my ongoing search for content to support my Microsoft Flight Simulator experience.
Quite possibly the best explanation of the various aeronautical approaches that are available that I've ever watched. I use the TDS GTN 750XI software product that uses the 750XI Garmin Trainer in Microsoft Flight Simulator, the Gramin trainer drives the autopilot in the simulator and is a fantastic learning tool. Such an outstanding video, I learned so much, thank you! :)
Absolutely fantastic video! Thanks Gary!
Glad you enjoyed it
Outstanding video on GPS! You cleared up the few misunderstandings for this Double-I. 👍🏼👍🏼👍🏼👍🏼
Glad it was helpful!
First and foremost, I LOVE your material and your vast expertise!!! I have some feedback that is just my opinion (and I am not even a pilot, to take this with a HUGE grain of salt)...the "90 degrees or less turn to final" example at 29:51 (and the one earlier at 26:42) is a bit awkward to observe... The 29:51 example, just looking at it from a geometry point of view, seems to be an angle LESS THAN 90 degrees. I think it should maybe better be described as "Do you have to change your inbound heading by > 90 degrees" and then it seems a bit more clear that I am changing from maybe an inbound heading of approximately 40 degrees to a final approach heading of 146 degrees - which is > 90 degrees. The slide description on the bottom also seems to be missing some text as well. I propose "Is the heading change > 90 degrees to the final approach course, if so, a PT will (almost) always be required". Thoughts?
Thank you so much from overseas is 91 operation we have To know and I understand both systems as an FAA AND ICAO As everybody know private jet they could fly anywhere is on the ward any time
I always do the 30 day VOR check at the same time as I do the GPS database update. I'm fortunate to have a VOR near the field to do the check on the ramp.
This is a great idea!!!
From a metrology perspective it may be a bit missleading to state the simple "accuracy" of the various GPSS systems. There are probability factors(combined accuracy, variance, and repeatability of all components combined) and acceptable levels of "known uncertainty" that all must be met, then combined with sampling rate and averaging algorithms in the receiver software. If a pilot were to take only the simple statement of "accurate +/- 9.5ft" they might believe that they are safe doing somthing as long as they give it at least 10ft clearance.
But(numbers made up for example), the location measurment may be off by 30ft 2% of the time, and to acheive an acceptable one in a billion level of confidence the buffer allowance may need to be 100ft. The common Garmin GA units sample the GPS signal 5 times per second, even excluding dropped samples a plane at 100kts travels 35ft between samples. Further this distance does not include the lag time the unit adds to process and display the sample or the pilots reaction to the displayed result.
And even that 100ft signal-variance buffer doesn't consider the buffer required for a pilot to react to a complete failure of the receiver and switch to some fallback action.
All of these considerations are incorporated within the limits of published FAA procedures.
For example, to state that LPV is better than ILS because it has narrower full scale deflection at the threshhold is poor logic. (LPV might be better, but just not for the reasoning given.)
It may be that a narrower full scale deflection is required to accomidate a larger secondary obstacle buffer zone. In other words, it is not about how close you are on average to the centerline of the primary flightpath, it is about how far away the obstacle needs to be when at the edge of the flightpath, and the size of the secondary buffer needs to meet the signal uncertainty requirements of the equipment.
(In the case of LPV, the standard width at threshhold is able to be narrower than ILS because of limits in the way an ILS antennea is positioned at the departure end of the runway and tuned for different runway lengths while still being a reasonable width 5-10 miles out. LPV stops narrowing at the threshhold while ILS continues to narrow down the full runway. It really isn't because one is inherently more precise or reliable.)
Excellent! Great explanations even a helicopter pilot can understand!
Hello really appreciate you elaborating on this learnt a lot would you be in position to point in the direction for official/FAA references for the same I am ask so that my students will be in a position to use it on a checkride if needed
Thank you
Thank you so much for making it EASY!
I’ve been teaching instrument for a while. Feel dumb as a box of rocks after this video. Thanks 🤭
SBAS means “Satellite Based Augmentation System” not Space Based?
Great explanation of differences between these procedures 👍
Glad you think so!
Great video. Not sure if I’m a nerd or that was funny, but I laughed pretty hard at “GPS or Garry’s Pink Shirt”.
I'm 100% sure I'm a nerd, cause I thought it was funny!
When going over RNP at 7:00, isn’t the terminal RNP 1NM to either side of center, as opposed to 1NM wide total? Meaning a full-scale deflection would be = to 1NM instead of 1/2NM? And same with enroute (2NM either side of center?) Genuinely curious to make sure I’m studying the right thing. Or is this something different than basic RNP? Loving this video!
Congratulations Gary on the 2019 award, a little too late, but you deserved!!!
Hi, I've got a question. In 8:00 you mentioned that full range deflection in GPS approach is .3NM, but is it correct? From my understanding, GPS approaches have RNP 0.3 which would mean that the full range deflection is actually 0.3 * 2 = 0.6NM. Could you please clarify it to me? Thanks for video though, it is very informative!
My New favorite channel , thank you for your passionate devotion to teaching and introducing some of us to great info !!!
Thanks for your time and those valuable information.
My pleasure!
Hey Gary, i`m new to the Channel, just subscribed. AMAZING video, I`m working on my CFII, hopefully going for checkride in a couple weeks. Thank you for the Video!
Welcome aboard!
Watching this video before my exams.
First of all very great explanation! You clarified a lot of things!
I'm a little bit confused right now on the part of the difference btw RNAV (GPS) and RNAV (RNP) about the fact that you can fly the first without authorization and the second one only with it.
I'm from Italy so maybe the things are different or they changed in the last few months.
If you look for any approach chart for italian airports and look at the GPS procedures there are only procedures called "RNP Approach" without any authorization required.
I've recently studyed that the procedure requiring authorization there's an "AR" after RNP (so e.g. RNP AR RWY18, and the books state that because they have curved paths)
So, my confusions comes that in this video you say that RNAV (GPS) do not require authorization but RNAV (RNP) requires it, while in Italy there are only RNP approaches and the books states that for the "special procedures" they are called "RNP AR".
I'm not saying that you are wrong because your carrerer is really amazing and congrats of that, but maybe they've just changed things after the publication of this video or here in Europe the terminology are different (i've also read that some states calls these procedures in another ways).
Thank you for this video!
If you think you're confused, imagine how US pilots get mixed up! You are correct! Every RNAV approach by definition is RNP. Thee FAA chose to name GPS based approaches RNAV(GPS) and decided to name Authorization Required approaches for the airlines using dme based RNAV as RNAV(RNP) and put an AR(Auth Require) note on the chart to try and make it easy for GA pilots to know what they could and could not fly. Unfortunately, it does create a lot of confusion...
Thanks for being part of the team!
@@PilotSafetyOrg thank you!
Just seen this and subscribed immediately, how did I never know about your account
Sorry, but in reference to your example about IF/IAF, I can’t think of any situation where I would be cleared direct to CUMUM without the phrase “cleared for approach”, simply, the course reversal is not necessary if you are arriving from the NW sector where the turn is less than 90. If you are arriving from the SE and cleared for the approach, you simply follow the depicted course reversal in which case CUMUM then becomes both the IAF and IF.
i really would love to see the sources on the accuracy of the LPV vs. the ILS and where you get that info!
I agree lol
You should add references to FAA/AIM for your instructions (You had a few mistakes and false information).
LPV is NOT a precision approach... It is allowed to be substituted for the purpose of the ACS if the DA is lower than 300 feet.
PRECISION APPROACH PROCEDURE- A standard instrument approach procedure in which an electronic glideslope or other type of glidepath is provided; e.g., ILS, PAR, and GLS.
GLIDESLOPE- Provides vertical guidance for aircraft during approach and landing. The glideslope/glidepath is based on the following:
Electronic components emitting signals which provide vertical guidance by reference to airborne instruments during instrument approaches such as ILS; or,
Visual ground aids, such as VASI, which provide vertical guidance for a VFR approach or for the visual portion of an instrument approach and landing.
PAR. Used by ATC to inform an aircraft making a PAR approach of its vertical position (elevation) relative to the descent profile.
Those definitions eliminate LPV approach as precision approach as GPS calculates a glide path, and is not based on emitting signals.
Also the table at 9:28 has some errors, Refer to the instrument flying handbook 9-44 thru 9-45 for GPS-RNP. EX: (Terminal is NOT 1/2 NM with Full Scale deflection on one side, its 1NM with a total of 2NM Full Range from Left to Right.
If I am mistaken, please cite FAA source with correction
Thanks.
Hi, great video. Question: I have a plane with the G950 with a AP 550. My plane can only do LNAV approaches. WHAT to I have to put on the plane to execute an LNAV/VNAV app? So I can lower my MDA. Thanks
Great video, very informative and detailed. Thanks for sharing =)
Thanks for explaining
I have got a clear understanding of GNSS approaches but also with few doubts
1.WAAS gps receiver is more accurate than non-WAAS gps receiver, how LNAV/VNAV has DA ?
In AIM 1-1-17, the "Procedures for Accomplishing GPS Approaches" section describes the width of the Enroute CDI as +/- 5 NM either side of centerline, within 30 NM of the airport as +/- 1 NM, and 2 NM from FAF smoothly changing to +/- 0.3 NM. This indicates the full-scale deflection is 5 NM, then 1 NM, then 0.3 NM. This video gives these full-deflection distances incorrectly as 1 NM, 0.5 NM, and 0.15 NM.
Very nice to have you and sharing the knowledge. GBU!❤❤❤
So what's the point in getting the training and all that for an RNP approach if its just worse than an LPV. Was talking to an ALA pilot the other day about how they used RNP a lot but I didn't understand why.
What a great lesson! Thank you
Glad you liked it!
I enjoyed this, and learned a few things too. Thank you sir
Question on your questions at the end, with the Lnav/Vnav, I consulted with my instructors ( I have some prev instructors and the one I have now) with my understanding and they said I am correct. LNAV/VNAV requires WAAS, and if it does not have WAAS, then it cannot have a DA, it would have an MDA (unless its an ILS but this is about GPS (WAAS) Apchs). How did you come up with the answer to that question that its C?
Hey Gary, cheers for the video really helped me. But I got confused at 1:00:30.
Isn't LNAV/VNAV is a non WAAS approach with Advisory Vertical guidance that only takes you to MDA?
@PilotSafetyOrg
LPV is not considered Precision Approach by FAA . even though its as accurate as ILS. only ILS is precision .
Thank you. Got my ii ride soon this helped!
Amazing content. I have a question regarding approach plates that show “RNP APCH”. L35 shows RNP APCH next to the notes for RNAV (GPS) RWY 26. KSNA on the other hand does not show RNP APCH next to the notes for the RNAV (GPS) Y RWY 20R. Clearly in both cases you need the Required Navigation Performance for the approach you plan to fly. So why the difference?
All RNAV approaches are RNP(ReqNavPerf) but as to why the FAA chose to use that note on some and not others baffles me too!
Thx for watching.
GPS
1. LPV Non Precision or Precision? Re: Instrument Procedures Handbook; pg. 4-63 (203 of 312) "Approach minima as low as 200 feet HAT and 1/2 SM visibility is possible, even though LPV is not considered a precision approach."
2. A Designated Examiner (Alaska-2023) had been using LPV in lieu of ILS for pilot instrument rating certifications; until the local FAA caught wind...something approaching (no pun intended) 100 pilots had to be rechecked by FAA examiners to fulfill the ILS 'Precision Approach' requirements for an Instrument Rating.
Thank you so much! You made it too clear! So useful!
Just started to watch and got confused: at 1:31 I see that GPS accuracy is 26 ft, but at 6:47 I see the different figures of lateral (9.5ft) and vertical (14ft) accuracy. Are they related somehow to each other? Thanks for the great aggregation of info though!
I’m just starting my instrument training. Love the videos. My question is I’ve heard that atc will more than likely change your direct flight plan . Is this true?
I think your explanation of full scale deflection is incorrect. From center to one side is 1 mile in terminal not 1/2 mile. Enroute is 2 miles from center to one side and App mode is .3 from center to one side, Your graphics are showing half of this sensitivity.
I had the same thought. AIM 1-1-17 is where the guidance is on this.
At minute 31:00 you explain LNAV +V
You say that the Advisory vertical guidance is created by WAAS GPS.
If I have a WAAS GPS in a country without WAAS, does the GPS generate the Advisory glide path ??
Dude you are an awesome teacher
I appreciate that!
Great video. Sharing with my students 👍🏼
The U.S DoD does not own GNSS, it owns the GPS satellite network which is a PART of the GNSS network … GNSS is a (future) network of satellites comprised of several countries satellite networks including (potentially) Russian GLONASS, Chinese BeiDou-2, European EGNOS (Galileo), Indian IRNSS, Japan QZSS etc. Current GNSS includes GPS (WAAS) + EGNOS and are SBAS capable.
Galileo UK only? No European (Germany, Italie, France etc…) ! and by the way NOT mainly from UK.
EGNOS is an EU SBAS system and Galileo is an EU satellite network. After Brexit, the U.K. participates in neither.
@@bjorn2625 Yep, true that 👍 Brexit not what it was sold to us all 😕 … I will update my post
The Indian IRNSS and the Japanese QZSS are not considered GNSS! They are SBAS’s (Satelite Based Augmentation Systems).
@@maaitah1991 Correct, not currently because their programs are still in development, however per National Defense Authorization Act 2020, United States Secretary of Defense in consultation with Director of National Intelligence will designate NavIC (IRNSS) and QZSS as allied navigational satellite system for (potential) inclusion in GNSS. Current GNSS includes USA GPS and European EGNOS … both SBAS capable 👍
This video is incredible, thank you very much
Great class, thanks!
Hi, Garry. Where do I find any information about to fly a “Coventional” procedure such as VOR, or a SID based in VOR/DME in OVERLAY?
After getting stumped on the IFI question, you may be tempted to fly direct to the WTF fix. ;-/
Thank you so much. This helped immensely!
Alternate Airport without a published approach? YES - As long as you get descend from MEA to the Airport in VFR conditions.
Great presentation. Thanks
WAAS ground relay station sends signal to A satellite or satellites that transmits correction, but not to all NAV satellite in constellation do this. The NAV satellites do not know correction. In other words correction is coming from other satellite that accepts unlink and relays it back.
So RNAV(GPS) approach AND RNP approach are both GPS Approaches bases on internal computation of aircraft and gps . But the difference is RNP needs On board performance monitoring and alerting system for more accuracy . Am I right? Please clarify?
I am building a home built and have no plans for VOR receivers. It seems to me the likelihood of a total failure is pretty darn unlikely, but I am now wondering if having a handheld VOR receiver might be a reasonable backup. Anyone else doing this? Or is the feeling that GPS is reliable enough that this isn’t necessary?
How did you do the GPS app? Is it on an Ipad or computer? Does it cost to get that? I'd sure like to learn with it.
So at 40:00, I tried this advice today. On my garmin GNS430, keeping the first altitude before the stepdown and waiting for the glidepath. It does appear, but when it appears I am two dots above it and have to then dive on the GP. Tried again with the "dive and drive", I get the GP from below. So with respect, it seems to vary with equipment types?
Can one fly LNAV/VNAV with a non-waas GNS430? Some sources say no because most GA aircraft don't have baro aiding installed. Other sources say yes because the GPS still can produce a glideslope, just less accurate than WAAS. Which is correct?