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Flying below VAPP - What to do ?

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Flying below VAPP - What to do ?

Old 14th Aug 2015, 11:22
  #61 (permalink)  
 
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With all due respect sir, pilots still routinely need to move between types, and they deserve to know the truth about what they're seeing, and why

There was a friend who flew with Air Belgium many tears ago. There he flew a mix of B734 & A320 in the same week. That sounds a handful. Is it possible today under EASA? It seems fraught with 'an incident waitting to happen.'
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Old 14th Aug 2015, 16:50
  #62 (permalink)  
 
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Answer to CM's question

CM, the answer to your question is that many can, and it has been demonstrated many times. The big jets are typically tested well beyond the values shown in the AFM or FCOM to be sure they are robust, and that they exhibit no adverse behavior in the event that conditions are unexpectedly or unknowingly somewhat worse than the values published for routine use. In fact if you look closely at these AFMs and FCOMs for some types, you will note that the autoflight limitations posted clearly additionally state the qualifier "when landing minimums are based on their use". So that in many instances, where reported visibilities are reported as above Cat III minima, but actual conditions are nonetheless equivalent to Cat III, such as in a driving rainstorm, or blowing snow, or even with a landing landing into a blinding sunset with bright reflections off the runway, these AL systems are beneficially and effectively used as an aid, sometimes in wind and gust conditions even beyond the value cited above.

As to the relative performance of the AT in the latest modern big jets, have you even used those systems in stressful conditions, to be able to make a relative comparison of their performance???

Regarding your comment about RNP and ANP, you noted capability during GNSS "SA OFF" operation, during normal ops, as for a GNSS approach. But this is hardly any indication at all of the suitability of your aircraft for RNP capability, which deals with containment in normal, rare normal, and non-normal ops. So even if the equivalent of ANP or EPE for your jet on a GNSS straight in approach was reasonable, that in no way addresses or assures its LNAV and VNAV ability to deal with RNP containment or useful RNP capability, especially at the lower RNP values down to RNP .1. It also says nothing of the overall AFDS and related system's ability to safely fly the necessary paths for departure, for RNP based RF Legs during approach, or for RNP paths on an E/O MAP approach initiated from the TDZ. To do so, the FMS/FMS and related systems like the redundant IRUs, standby electrical system, AP and FD, and map displays, in combination need to be demonstrated to be capable to achieve the specified robust normal, rare-normal, as well as non-normal performance, in designated conditions, including having adequate FTE for all the designated control modes to be used. In short, to date, there is no evidence so far that the jet you mention has or can demonstrate any of this, even for RNP procedures that have now been in beneficial and safe use globally now, dating back to before 1994. Perhaps you could jumpseat on a flight someday in a real RNP capable aircraft, into NZQN, PAJN, or CYLW or equivalent, and see this RNP capability used first hand, to better see how much more significant capability other jets now have, and why AT performance alone is only a limited part of an overall aircraft's operational capability, regardless of how good the AT might be? Which is just one more reason why this Vapp thread is quite important and significant, to those who are legitimately trying to understand and deal with these important questions and issues.
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Old 14th Aug 2015, 17:40
  #63 (permalink)  
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What a lot of waffle. The answer to your question is yes, currently and in the past.

I'm interested in your definition of "real RNP capable". It seems like an odd statement seeing as the Embraer has a better ANP performance than the NG I currently fly. Have you ever operated the Embraer to allow you to make your comparisons?
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Old 15th Aug 2015, 00:44
  #64 (permalink)  
 
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@CM reference your questions

Sir, ANP level alone matters little, as long as it's less than the needed RNP with adequate FTE margin (e.g., the reason for having features like NPS), and is predicted to stay less than RNP for any relevant non-normal conditions. Instead, it is the low RNP capability that really matters for an aircraft, and having it able to support RNP based LNAV and VNAV suitably, for any leg type combination needed, including for RF legs down low, while fully satisfying all the rare-normal, and non normal conditions that must be addressed in the FHA and FMEA. Yes, I am intimately familiar with that particular autoflight system, including even for the pending E2 design, and have seen no evidence whatsoever that so far it is capable, or will be capable of safely flying the real RNP procedures that I cited earlier, even for normal operations, let alone for rare-normal, or non-normal operations down to the TDZ and back out, even in the event of a first E/O, and first Nav failure, or any relevant system failure, such as a lightening strike bus trip back to stby power, while maintaining RNP capability (per relevant criteria such as in AC120-29A, which was the basis for RNP approvals for aircraft and airlines now doing [real] RNP).

Last edited by 7478ti; 15th Aug 2015 at 00:54.
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Old 15th Aug 2015, 01:24
  #65 (permalink)  
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The point about ANP is that the ANP of the Embraer is accurate enough to carry out GNSS only, RNAV and VNAV/LNAV approaches and it has done so for years which, obviously, means it meets the relevant RNP. You're unaware of this?

I am intimately familiar with that particular autoflight system
Wizard, but that was not the question.

Still, the AT system is more intuitive and better in an operating environment than both the two types mentioned above.
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Old 15th Aug 2015, 03:04
  #66 (permalink)  
 
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@CM ...Not so

CM,... Not so. The fact that a system may have an ANP adequate to fly a "GNSS only" approach means absolutely NOTHING in an RNP world. ANP must always be less than, and be predicted to stay less than, the specified level of RNP (even for non-normals) for the specific RNP based procedure to be flown, with adequate FTE margin. Further, your assertion about "RNAV approaches with LNAV and VNAV minima" has nothing whatsoever to do with RNP based RNAV procedures (e.g., NZQN RNAV(RNP) RWY23). This discussion relates purely to those kinds of RNP based procedures, and is a subject for which no current BizAv based avionic system, as typically used in any RJ presently flying, comes anywhere close to meeting RNP.1 capability, for the leg types and configurations of the RNP based approaches noted, or duplicating the key capability needed to address rare normal and non-normal conditions for those procedures, as I cited earlier. I'm not aware of ANY RJ currently capably of flying RNP based procedures at low RNP values near or at RNP .1, such as needed at NZQN or PAJN, let alone for meeting the VEB related to the vertical RNPs associated with those procedures. In fact from what I've seen in recent months for design specifications for AFDS and FMS system improvements in the RJ fleets, and for even a few new designs in development in that class, this full equivalent RNP capability that has been flying in the big jets for years isn't likely to happen at any time soon in the RJ fleet, in even the intermediate future. Further, even the basic fundamental avionics architecture is weak in some of these RJ designs, potentially even permanently precluding beneficially combining use of modes for LAND 3 using GLS, also with low RNP capability.
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Old 15th Aug 2015, 05:12
  #67 (permalink)  
 
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Would the last person please turn out the lights when they leave.
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Old 15th Aug 2015, 18:30
  #68 (permalink)  
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I think what you're saying is that because the Embraer is not approved, but is capable, of RNP 0.1 then the AT system is useless.

Right.
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Old 15th Aug 2015, 20:05
  #69 (permalink)  
 
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Which RNP .1???

Sir, ...You say your RJ is "Capable of RNP .1". But Which RNP .1??? Straight-in??? It isn't adequate to just have some measure of accuracy under normal conditions, to fly some limited brief LNAV "straight-in" segment and claim RNP.1 capability. Instead, you need to be able to fly ALL the LEG TYPE combinations needed at RNP .1 (which there is NO evidence yet that any RJ can meet), ...meeting both the lateral and vertical RNP requirement based constraints, including for speeds, and later RTAs.

Further, this discussion isn't esoteric.

In fact, it is a core issue and key to any successful and economic and capable future evolution of the entire global ATS system. Unless these RNP based trajectories can be appropriately flown 3D and later 4D, with relevant speed and eventually RTA, NET, and NLT constraints, using many if not most procedures with LNAV and VNAV RNP based RF legs at low RNP, then there is no hope of economically and successfully solving NextGen or SESAR.

This is the fundamental reason why RJs are now causing such enormous pain in the entire present ATS system, and for ANSP ATS system evolution globally. Because no known RJs so far can safely, reliably, and with redundancy fly these kinds of accurate RNP based procedures, and especially not with evolving RTA elements. That is why coordinating mutually exclusive efficient RNP based flight paths into, and out of places like KSEA, KSFO, KORD, and KMDY, and KLAX, and KDFW, and KLGA and KJFK and KEWR is so terribly (and unnecessarily) difficult.

Bottom line is that no known RJs can yet do this. AT performance inherently relate to lateral and vertical profiles, and that interaction matters. And until RJs can do Real RNP at the needed low values, then successfully and economically solving and evolving ATS, at any affordable cost to users, and with the needed capacity increases, and ability to address WX deviation flexibility, is virtually hopeless.

As to "lights out", ...understanding why all this matters, may be key to your future operator and employment survival, let alone safety, ...in particular for those who may be following this thread, and who are not already retired...

Q.E.D.
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Old 15th Aug 2015, 20:56
  #70 (permalink)  
 
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Ozymandias gave you the absolute correct answer.
Adv the Throttles as needed just forward of CLB detent till back on VAPP, then return them back to CLMB detent and everything "managed again"


Or pull the Speed knob and increase speed to "selected" for the auto-thrust to increase THR to the new selected speed.
You can also disconnect the ATHR, and be careful you are clear with that procedure or it may bite you.
Airbuses are not dead busses, they tend to scare pilots which are not proficient on the stated procedures in the FCOM/FCTM.
I have flown both 320 & 767 and like the both, they are just different and the airbus is less forgiving on "sloppy pilots" period.

Last edited by A320 CURSED; 15th Aug 2015 at 21:24. Reason: typoe
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Old 15th Aug 2015, 21:15
  #71 (permalink)  
 
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This discussion relates purely to those kinds of RNP based procedures, and is a subject for which no current BizAv based avionic system, as typically used in any RJ presently flying, comes anywhere close to meeting RNP.1 capability
Huh? Numerous business jets today are fully certified for RNP 0.1 approaches (including those with curved segments). E.g., Gulfstreams equipped with Honeywell Primus, Bombardier Global series (with Rockwell Collins), and Cessna Citations (Garmin) all include full RNP 0.1 approach capability available as options. Some, like Cessna, include RNP 0.3 as a standard feature.

So it's not a technology issue but whether or not specific customers require (and is willing to pay) for the capability. The reality is that new business jet avionics tend to be superior than your typical airline fleet avionics.

In Europe, trial RNP curved approaches were conducted on a CRJ-1000NG operated by Air Nostrum.

Since you mentioned PAJN, note that Horizon has been flying curved RNP 0.1 approaches there on their Q400s, mere turbo-props!

And in any case the refreshed regional jets coming up (Embraer E2, Bombardier CSeries, etc) are all orderable with RNP 0.1 as options.
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Old 15th Aug 2015, 21:57
  #72 (permalink)  
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Originally Posted by peekay4 View Post
Since you mentioned PAJN, note that Horizon has been flying curved RNP 0.1 approaches there on their Q400s, mere turbo-props!
With no AT!
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Old 15th Aug 2015, 23:44
  #73 (permalink)  
 
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Those examples have significant use constraints or limitiatons

Not all RNP .1 is equal. Those aircraft types and procedure examples you cited come with significant RNP related procedure operating constraints or limitations. I can cite specific examples, having tried and failed to make some of those systems work for both OEMs or operators. Even the excellent work done by Horizon (led by Perry S and Steve B... ) on their Q400s, to make an otherwise seriously deficient box at least try to mimic real RNP, to some extent, and partially work, is only very primitively successful. For example, NONE of those types or avionic systems have yet demonstrated capability for suitably flying any of the kinds of real RNP procedures that I cited earlier, such as at NZQN, etc. A few of them are reportedly going to potentially try, with still "in the future" attempts to be modified to evolved versions of those avionic systems, but NONE currently can yet can perform these cited RNP procedures adequately. Just because they have a magazine ad promoted PR label, claiming RNP capability, or even "RNP .1", doesn't necessarily mean they actually can safely fly any of these real RNP based procedures, and particularly not when addressing the needed rare-normal or non-normal conditions. In fact a few OEMs are now getting a rude awakening by purchasing some of those systems for their new types thinking they're getting comparable systems to the big jets, only to find those BizAv related systems have serious RNP related shortfalls, to actually be able to do the job, even if they advertise RNP capability.
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Old 16th Aug 2015, 01:31
  #74 (permalink)  
 
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You've lost all credibility with your post there, 7478ti.

There are dozens of business jet operators today flying RNP AR on a regular basis.

In the US, Part 91 and 135 operators with LOA are authorized to fly all published FAA RNP AR procedures down to RNP 0.1 limits depending on the aircraft's capabilities. Every single one of them, as the authorization is not "per approach".

Unless you're suggesting FAA RNP AR approaches are not "real" RNP.
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Old 16th Aug 2015, 02:36
  #75 (permalink)  
 
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Quite a bit off the track here. As far as i know a subsidiary of ours was certified to fly the curved RNP AR approaches into Innsbruck and Salzburg with their E190, same as we did with our 737-700s. Whereas our A320 fleet is still not certified for anything below RNP 0.3 and is not RNP AR capable. Not no mention that the autoland crosswind limit on our newest just delivered A321 is still only 20 kts, which is even less than our 10 year old 737s who can do 25kts in fail operational approaches.

Quite honestly, the E-Jets are pretty nifty with their autoland capable autoflight system, even more so if equipped with the dual HUD setup.
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Old 16th Aug 2015, 09:55
  #76 (permalink)  
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Remember not all RNP 0.1 is equal. I suspect your curved approach won't be curvy enough to satisfy 7478ti.
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Old 16th Aug 2015, 11:41
  #77 (permalink)  
 
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Frightened!

That anyone is even having this discussion is frightening.
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Old 18th Aug 2015, 11:45
  #78 (permalink)  
 
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Know Your Airplane!

1. Learn how to Hand-Fly your airplane.
2. Pay attention to the instruments AND the visuals.
3. If you need to go faster, PUSH a little;
4. If you need to go slower, PULL a little.
5. Practice a few times and you can learn how to Hand-Fly almost anything.
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Old 18th Aug 2015, 12:55
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NFZ:

Agree with 1. 2. and 5.,

but 3. and 4. don't work like that in a FBW Airbus, which I think is the point.
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Old 18th Aug 2015, 16:52
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I wonder how long before FBW cars are the norm. Car goes faster/slower, but accelerator pedal doesn't move; same with brakes. I wonder if the pedals will still exist, but there has to be a 'manual' over-ride. Side stick, central, FBW steering. It is all technologically possible and possibly, once certified & produced to a suitable economy of scale it will financially viable. There is already active cruise control that includes braking sensors; there is automatic parking, auto wipers & lights, massage seats and voice controlled radios & phones. You could have 'scream activated brakes'
In 20 years we may be having similar discussions about the degradation & dilution of driving skills. However, I suspect there will be many more smoking holes before they realise that all is not well and the basics are still the basics and should be taught with a vengeance.
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