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Collins FMS-3000 - always use APPR mode ?
RE: ProLine 21 / Collins FMS-3000
NOTE: Still learning the system, nice and slow, one day at a time, know my limits. With that said : Getting some different opinions, regarding when/whether to use NAV mode or APPR mode when executing an IFR approach. The 2005 Rockwell Collins FMS-3000 guide, issued by the manufacturer, says "all approaches should be flown in APPR mode" (p.91), however a few guys at my place advocate NAV mode: LNAV only Approach, RNAV with MDA, VOR Approach, anything with MDA is NAV mode APPR mode: anything with a DA What are the various opinions on this ? I prefer simple versus hard |
If the book says always use approach mode, then why the debate?
Modern FMS units are smart enough to know what type of approach you're flying. (You have to program the box with the procedure, right?) In the two types of aircraft I fly (both with Collins systems), you select a directed mode and the box/autopilot sensitivities change based which mode you've chosen. In your case, selecting nav instead of approach for a procedure where the FMS is actually using GPS as the primary means of navigation (via an approved overlay), might reduce your safety margins or add slop into the course line. It might also prevent you from being able to properly sequence or use FMS derived VPATH information. |
What FlyerJosh said. To expand, if you don't select APPR mode on non-precision approaches, the system will never transition to approach lateral and vertical deviation sensitivity, nor will the course deviation display scaling change appropriately. You should see the "NO APPR" PFD annaunciatior in those situations as well.
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good points, thats why I asked
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FMS 3000 (525B)
DA - Approach MDA - Nav VOR (if green needle) *must be flown in approach mode. Localizer (no gs) - Nav Backcourse - BC |
Originally Posted by GrummanCT
(Post 1204267)
FMS 3000 (525B)
DA - Approach MDA - Nav VOR (if green needle) *must be flown in approach mode. Localizer (no gs) - Nav Backcourse - BC and why |
PM sent. ;)
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Originally Posted by satpak77
(Post 1204290)
where does it say this
and why VOR approaches must not be conducted in the NAV mode of the flight director. Use the APPR mode, or manually track the approach course using the HDG mode.this limitation applies to both flight director only and utopilot coupled operation. Autopilot coupled operation is prohibited during any portionof a VORapproach in which the VOR is located behind the airplane more then 15 miles, unless the HDG mode of the flight directoris being used to manually trackthe approach course. As to why I would not fly everything in approach mode....What if you are descending to an MDA? Autopilot and or Flight Director will fly right through the altitude. The appropriate mode would be Nav / VS or Nav / VNAV |
ok clearly different schools of thought exist on this.....
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Don't forget the equipment and/or certifications might be slightly different. We're talking a King Air and Citation here. Even though PL21 may be similar, they may not be authorized to do the same thing...
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Originally Posted by GrummanCT
(Post 1204267)
FMS 3000 (525B)
DA - Approach MDA - Nav VOR (if green needle) *must be flown in approach mode. Localizer (no gs) - Nav Backcourse - BC CJ3/CJ4 driver; I agree with the above. Only thing I'd add is to be in APPR when shooting a LOC to get it to auto-sequence to green needles, then once it's sequenced to green needles, go back to NAV so it won't possibly pick up an errant GS and blow through your MDA (I think the book, at least the FSI training manual, has words to this effect). |
Originally Posted by Mink
(Post 1204788)
CJ3/CJ4 driver; I agree with the above. Only thing I'd add is to be in APPR when shooting a LOC to get it to auto-sequence to green needles, then once it's sequenced to green needles, go back to NAV so it won't possibly pick up an errant GS and blow through your MDA (I think the book, at least the FSI training manual, has words to this effect).
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Originally Posted by GrummanCT
(Post 1204938)
Refresh my memory...will the switch to green needles only happen when in apprch? I can't recall ever doing a stand alone localizer approach sine flying the airplane.
Edited to add that the Loc will NOT auto-tune unless your Nav Source is FMS to begin with. |
What aircraft is this on?
As another person mentioned, there can be significant differences from one aircraft or manufacturer to another. I'd suggest checking with your training provider or the aircraft manufacturer on this. In the King Air, you fly a precision approach in APP or APP/VNAV. Non-precision approaches are flown in NAV or NAV/VNAV. Also, the PL21 in the King Air only has green needles.....green for FMS, green for VOR/LOC. None of that silly color coded stuff so you can tell when a change happens. Confusing, huh? |
Originally Posted by trafly
(Post 1206849)
What aircraft is this on?
As another person mentioned, there can be significant differences from one aircraft or manufacturer to another. I'd suggest checking with your training provider or the aircraft manufacturer on this. In the King Air, you fly a precision approach in APP or APP/VNAV. Non-precision approaches are flown in NAV or NAV/VNAV. Also, the PL21 in the King Air only has green needles.....green for FMS, green for VOR/LOC. None of that silly color coded stuff so you can tell when a change happens. Confusing, huh? If PFD1 & 2 are looking at the same Nav source, such as both on VOR1 or both on FMS w/a single FMS then they'll be green and yellow. But I know what you mean! :p |
Originally Posted by KingAirDriver
(Post 1207014)
Unless you've got a single FMS. :D
If PFD1 & 2 are looking at the same Nav source, such as both on VOR1 or both on FMS w/a single FMS then they'll be green and yellow. But I know what you mean! :p |
Ha, I know, right? :D
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You guys have two FMS Units in the King Air? Not a Garmin 500 that the manufacturer labels FMS II, but x 2 FMS 3000's?
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Originally Posted by KingAirDriver
(Post 1204961)
Must have FMS as active Nav Source AND have APPR selected for the Nav-to-Nav transfer to occur.
Edited to add that the Loc will NOT auto-tune unless your Nav Source is FMS to begin with. |
Originally Posted by GrummanCT
(Post 1209404)
You guys have two FMS Units in the King Air? Not a Garmin 500 that the manufacturer labels FMS II, but x 2 FMS 3000's?
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Originally Posted by GrummanCT
(Post 1209404)
You guys have two FMS Units in the King Air? Not a Garmin 500 that the manufacturer labels FMS II, but x 2 FMS 3000's?
Originally Posted by KingAirDriver
(Post 1209650)
Optional, not sure which models are standard though, if any.
USMCFLYR |
Follow the manual!
There are NO tricks to this. FOLLOW THE MANUAL. Approach mode uses tighter tolerances to drive the flight director and hence you or the autopilot. On non precision approaches add the VNAV and you’ll have vertical guidance rather than “dive and drive”. NEVER take anecdotal information over the manual. Be safe!
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General advice!
Plane coffee |
Originally Posted by Avanticaptain
(Post 2856066)
There are NO tricks to this. FOLLOW THE MANUAL. Approach mode uses tighter tolerances to drive the flight director and hence you or the autopilot. On non precision approaches add the VNAV and you’ll have vertical guidance rather than “dive and drive”. NEVER take anecdotal information over the manual. Be safe!
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The Collins guidance issued by flight safety for the KingAir 350 (although it doesn’t specify type) says: MDA use NAV, DA use approach.
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Originally Posted by EMAW
(Post 2856463)
The Collins guidance issued by flight safety for the KingAir 350 (although it doesn’t specify type) says: MDA use NAV, DA use approach.
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Originally Posted by EMAW
(Post 2856463)
The Collins guidance issued by flight safety for the KingAir 350 (although it doesn’t specify type) says: MDA use NAV, DA use approach.
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I’ve been flying PL21 for 10 years and have never read, heard, or been taught to always use approach mode for all approaches.
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Hey, guys and gals- New here, but I do have a question on this:
I agree that the proper procedure is the procedure recommended by the manufacturer. However, in a non-precision approach, using Nav/VNAV to the MDA creates a couple other workload issues: 1) You're gonna have the MDA altitude set in the window and will need to start twisting for the MA altitude at the highest workload phase of the flight (though I agree this is not a huge issue if you "just fly the airplane" on the miss and conduct a SNAP checklist). 2) In A/P mode, the plane is gonna level and stall if you don't have your head out of your butt at MDA, in any case. So, whether you're flying in Appr/VNAV, Nav/VNAV or Nav/Pitch (dive and drive), you're gonna have to know the MDA and when you're approaching it. That done, it just seems to me, there's two alternatives: NAV Mode: Go missed, power up, clean up, SNAP APPR/VNAV Mode: Go missed, power up, clean up, SNAP (with the "A" part already set for you, greater precision on the Approach Profile and a single Manual of Arms from Approach to Approach) What am I missing here? Input welcome. |
APPR/VNAV Mode: Go missed, power up, clean up, SNAP (with the "A" part already set for you, greater precision on the Approach Profile Can you provide a reference for it? In our old AP, it did have tighter tolerances for the AP, but if the PL21 manual reads to use NAV mode for non-precision approaches (like a VOR/DME SIAP for example), then if APPR mode did give greater precision on this approach why would they dictate NAV mode? |
Originally Posted by P180 Jockey
(Post 2866905)
Hey, guys and gals- New here, but I do have a question on this:
I agree that the proper procedure is the procedure recommended by the manufacturer. However, in a non-precision approach, using Nav/VNAV to the MDA creates a couple other workload issues: 1) You're gonna have the MDA altitude set in the window and will need to start twisting for the MA altitude at the highest workload phase of the flight (though I agree this is not a huge issue if you "just fly the airplane" on the miss and conduct a SNAP checklist). 2) In A/P mode, the plane is gonna level and stall if you don't have your head out of your butt at MDA, in any case. So, whether you're flying in Appr/VNAV, Nav/VNAV or Nav/Pitch (dive and drive), you're gonna have to know the MDA and when you're approaching it. That done, it just seems to me, there's two alternatives: NAV Mode: Go missed, power up, clean up, SNAP APPR/VNAV Mode: Go missed, power up, clean up, SNAP (with the "A" part already set for you, greater precision on the Approach Profile and a single Manual of Arms from Approach to Approach) What am I missing here? Input welcome. Level at the MDA, set the missed altitude then hit the GA and start a climb straight ahead to the MAP then SNAP. |
Originally Posted by P180 Jockey
(Post 2866905)
Hey, guys and gals- New here, but I do have a question on this:
I agree that the proper procedure is the procedure recommended by the manufacturer. However, in a non-precision approach, using Nav/VNAV to the MDA creates a couple other workload issues: 1) You're gonna have the MDA altitude set in the window and will need to start twisting for the MA altitude at the highest workload phase of the flight (though I agree this is not a huge issue if you "just fly the airplane" on the miss and conduct a SNAP checklist). 2) In A/P mode, the plane is gonna level and stall if you don't have your head out of your butt at MDA, in any case. So, whether you're flying in Appr/VNAV, Nav/VNAV or Nav/Pitch (dive and drive), you're gonna have to know the MDA and when you're approaching it. That done, it just seems to me, there's two alternatives: NAV Mode: Go missed, power up, clean up, SNAP APPR/VNAV Mode: Go missed, power up, clean up, SNAP (with the "A" part already set for you, greater precision on the Approach Profile and a single Manual of Arms from Approach to Approach) What am I missing here? Input welcome. |
greater precision on the Approach Profile Does it? Can you provide a reference for it? how do you think that technique is going to work while on the final approach segment, a stiff tail wind, and then the need to start maneuvering for the landing runway? (circle approach) My only point here is that a consistent sequence, across approach types, seems to me to be a desirable thing. Whether it's an ILS or a GPS you are required to reconfigure at DA/MDA. If you don't on an ILS, you're going to auger in; if you don't on a GPS or VOR, you're going to stall...and auger in. So, knowing that you MUST take action at (or approaching MDA), why not fly the (more stabilized) VNAV toward the MDA, initiating the GA decision when applicable? Just like an ILS. Same procedures. Same sequence. I realize we're talking King Air's here and I'm interloping with discussion of the P180. But I can tell you, the P180 does NOT provide very much forward visibility in the "Drive" portion of a Dive and Drive approach. Here's a great article on why that type of sequence is no longer in favor: From Non-Precision to Precision-Like Approaches I don't find it curious that Beech might have a different manual of arms on this issue than does Piaggio. Perhaps the P180 is not as well suited to a Dive and Drive approach configuration. Perhaps it simply demonstrates that the experts differ in opinion also. That would mean nobody is wrong. ;-) |
Originally Posted by P180 Jockey
(Post 2867491)
According to Flight Safety, it does for a VOR or GPS approach. You can check with them. I just did.
I submit the exact same sequence might be used; only difference is the MDA/DA will be at the published Circle to Land altitude, which is designed to allow for maneuver to the Landing Runway. VNAV will get you there; Dive and Drive requires you to assure you'll arrive in time to Drive. My only point here is that a consistent sequence, across approach types, seems to me to be a desirable thing. Whether it's an ILS or a GPS you are required to reconfigure at DA/MDA. If you don't on an ILS, you're going to auger in; if you don't on a GPS or VOR, you're going to stall...and auger in. So, knowing that you MUST take action at (or approaching MDA), why not fly the (more stabilized) VNAV toward the MDA, initiating the GA decision when applicable? Just like an ILS. Same procedures. Same sequence. I realize we're talking King Air's here and I'm interloping with discussion of the P180. But I can tell you, the P180 does NOT provide very much forward visibility in the "Drive" portion of a Dive and Drive approach. Here's a great article on why that type of sequence is no longer in favor: From Non-Precision to Precision-Like Approaches I don't find it curious that Beech might have a different manual of arms on this issue than does Piaggio. Perhaps the P180 is not as well suited to a Dive and Drive approach configuration. Perhaps it simply demonstrates that the experts differ in opinion also. That would mean nobody is wrong. ;-) The airports that I frequent for evals/training all have at least one RNAV (GPS) approaches. I can fly most of these approaches blindfolded. I experiment with the LNAV MDA, LP minima. Pretty much 100% of the time I can acquire the runway environment sooner and be in a better position to land using NAV and VS (1000 fpm max) versus NAV/VNAV. I prefer that my new guys I teach/evaluate use the full automation (VNAV). Guys, that I give PIC rides to will have at least one approach limited to VS. I really throw them for a loop when I dim the FMS brightness full down and tell them to execute me an ILS raw data ;-) |
Then there is the question is MDA MINIMUM descent altitude or is that just an advisory thing only? Would you stake a type ride on selecting APPR to the MDA? |
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