JARDesign A320 : a TransaTvia.com studygf3.myriapyle.net/aero/Fichiers/Transition_au_JAR.pdf · A320 VER 2.2 r1 : a TransaTvia.com study (paper version : 07/09/14) 07/04/14 ... Perform

A320 VER 2.2 r1 : a TransaTvia.com study (paper version : 07/09/14) 07/04/14

JARDesign A320 : a TransaTvia.com study

The A320neo is a simulation for X-Plane 10 by the JARDesign GroupEugeny “JAR” Romanov – cockpit texturing, flight model, aircraft systemsAndrey “Dron420” Belov – 3D modelling (cockpit, vehicles, landing gears), texturing (vehicles, landing gears)Andrey “Felis” – 3D modelling & texturing (external 3D, cabin), liveries, paint kit.Viatcheslav “Slava” Shleniov – cockpit textures & tuning.The VERSION 2.2 r1 has been used in this paper.

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JARDesign a320neo Forum:

http://forums.x-plane.org/index.php?showforum=158

Background story

Hi everyone,

I am considering myself a new user of the A320. Actually strictly speaking of putting an hand on a joystick, it was back in 1993 that I did place my very first hand on a F-4 Phantom simulated joystick. I more recently started serious airliner flight simming a decade ago with the Wilco/Feelthere Airbus A320 on FS2004. However I transitioned later to better evolved simulations in terms of accuracy in MSFS (lateral and vertical navigation accuracy). Thus I quitted the Bus. I've spent the last few years mastering the advanced modelisation of the iFly 737 in FS2004. This Boeing 737 modelisation is so accurate (RNP AR capability) that it brings in its last version the differences between fail operational aircraft and fail safe aircraft ! I have so much practiced the Boeing that I know in the detail which very pump has an effect on which particular system in the mechanical background. Now it's time to resume A320 studying with the JARDesign model in X-plane! At least I will try.

Disclaimer

In this study we assume that you understand the principle of the instrumented flight rules, along as basic principles of the handling of an airliner. The concept of the FMGS/FMS, airport minimums, aircraft minimums, engine %N1, ILS, RNP approaches, minimal descent altitude or decision height, managed or selected guidance among other things will not be reviewed. The purpose of this paper is to focus on the particularity of the simulated A320 by the JARDesign Group to asses it's consistency.

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Objectives

• Determine the handling (complete a basic A320 qualification) and operational procedures of the A320 ;

• Spot JARDesign Group limitations/restriction to the real world ;

• Test the RNAV(GNSS) lateral and vertical modes.

I have made a comprehensive study of the RNAV(GNSS) (ie RNP and RNP AR) approaches last year. It covers a range of simulations in MSFS from the Wilco/Feelthere Airbus to the iFly 737. The results with the Wilco were not good in terms of navigation accuracy in NAV mode and final approach. Now I will try and experiment that with the JARDesign A320 on X-Plane

https://www.ssl-url....RNP_APCH-en.pdf (direct access to PDF)

https://www.ssl-url.....com.en.php#rnp (RNP section on my website)

My intentions are to update my comprehensive study of the so-called RNAV(GNSS) approaches with the X-plane data.

Related reviews

http://asn-xp.aerosoft.com/?tag=jardesign

In one of the interviews linked in the page above we can spot the following :

What's not yet programmed in the MCDU?

Quite a few things haven’t been. From functionality, including missed approach, the second flight plan, time and speed constrains, database hold (we have only computed hold now), offset and alternate functions, F-PLN discontinuity - this is the main list.

ASN REDUX 2.0 review :

With this section I’ve tried to combine the many flights I did to one overview. I did ILS landings as well as GPS APPROACHES and the aircraft's behavior was exactly as expected and as written in the official manuals. For those who want to go even further, there’s the possibility of making an ILS RAW DATA landing.

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https://www.ssl-url.net/gf3.myriapyle.net/aero/Fichiers/Tuto_RNP_APCH-en.pdf

http://asn-xp.aerosoft.com/?tag=jardesign

https://www.ssl-url.net/gf3.myriapyle.net/aero/transatvia.com.en.php#rnp


Checks to be done

Objective

Determine the operational procedures of the A320 and enlight JARDesign Group A320neo limitations/restriction to the real world.

List of checks

INIT

Perform preflight and produce a fuel estimate from Airbus tables.

Pressurization system : check that the semi-auto mode is selectable and that in manual mode, outflow valve can be operated (impact on systems ? Visual depiction ?).

TAXI

N1 set at 40% for taxi

T/O

Set 60% N1, then check SRS (for runways with ILS), lateral bar should appears, replaced by the FD vertical bar after T/O.

Maintain stick pushed forward until reaching 80 knots.

Check guidelines for PACK operations and APU usage (FCOM).

CLIMB

Check that the ToC is displayed (white arrow).

CRUIZE

Check that ATHR engaged and throttle below CL detente is possible as in the reality. In this case the sole effect must be the limitation of the N1 to the throttle settings.

Check that F-PLAN constraints are seen in a page names VERT DEV.

HOLD : check the effectiveness of HOLD function if enough fuel and altitude set (FL). Is it depicted on the ND ?

DIR TO functions is limited to the F-PLAN waypoints. No extra entry of a waypoint is allowed. Check what the real FCOM says.

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https://www.ssl-url.net/gf3.myriapyle.net/aero/Fichiers/Payload-fuel_A320.ots


DIRECT LAW : have a quick review about Normal law and direct law section in the FCOM. Does direct low deactivate auto trimming ? What are the conditions of engagement ?

DESCENT

Check that the ToD is displayed (white arrow) and magenta deceleration point is displayed and handled.

Review the DES mode engagement. OP DES ? DES ? Automatic descent or pilot action required to initiate ?

APPROACH

Plan a Flaps 3 approach. Check if GPWS Flaps 3 option is simulated, if not, “Too low flaps” should be heard upon a FLAPS 3 approach.

Retrieve some information in the FCOM about Fail-Operational and Fail-Safe.

MDA and DH : mutually exclusive normally, however a value pops up in certain case in the JARDesign airbus (DH50, DH20). Check behavior. Is it at second AP engagement ? What does become the previously set MDA ? Check that in regard to AUTOLAND or manual landing.

LANDING

Disengage manually the spoilers to retract'hem. Check if display on DU.

POST-FLIGHT

Check remaining fuel in regard to the initial estimate in preflighting.

EXTRA QUESTIONS

HYDRAULICS

All pumps off on ground, does it prevent the flaps to deploy ?

All pumps off in flight, same question ? Does the RAT deploys in this very case (the RAT does deploys if no APU nor Engines are available).

Report the HYD scheme.

In contrast to the Boeing, FD (the brain) must be engaged to allow A/P engagement (the muscle). Check the logic in the FCOM.

VOR1 and VOR2 simplified : JARDesign A320 is “one side only” in contrast to the QPAC.

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Flight parameters

Flight parameters are provided to ensure the reproducibility of the flight.-(FPL-IDENT-IS -1A320/M -SDFHIRGWY/EB2 -LFBO 0000 -M078F310 AMOLO UT24 FJR UL127 ROVOT UY373 ABLAK -LFMN 0036 LFML -PBN/A1B1C1D1)

[flightplan]title=LFBO to LFMNdescription=LFBO, LFMNtype=IFRroutetype=3cruising_altitude=31000departure_id=LFBO, N43* 38.10', E001* 22.06', +000200.00departure_name=LFBO Toulouse Blagnac 499 ftdestination_id=LFMN, N43* 39.91', E007* 12.88', +000200.00destination_name=LFMN Nice/Cote d'Azur 12 ftwaypoint.0=LFBO, A, N43* 38.10', E001* 22.06', +000200.00,waypoint.1=MEDAP, I, N43* 55.30', E002* 01.30', +001000.00,waypoint.2=AMOLO, I, N43* 49.66', E002* 34.71', +001000.00,waypoint.3=DEGOL, I, N43* 46.83', E002* 51.11', +001000.00,waypoint.4=FJR, V, N43* 34.70', E003* 58.46', +001000.00,waypoint.5=ROVOT, I, N43* 20.21', E004* 55.73', +001000.00,waypoint.6=MTG, V, N43* 23.16', E005* 05.20', +001000.00,waypoint.7=ABLAK, I, N43* 30.08', E005* 26.30', +001000.00,waypoint.8=ABILI, I, N43* 34.06', E005* 40.48', +001000.00,waypoint.9=AMFOU, I, N43* 35.75', E006* 06.06', +001000.00,waypoint.10=TIPIK, I, N43* 30.23', E006* 26.06', +001000.00,waypoint.11=MUS, V, N43* 23.06', E006* 36.36', +001000.00,waypoint.12=LFMN, A, N43* 39.91', E007* 12.88', +000200.00,

Flight distance is 263 nautical miles, expecting an Estimated Elapsed Time of 0036 for the aircraft 1A320/M. Eurocontrol validator response is “no errors”.LFBO 041330Z AUTO 28013KT 9999 FEW031/// BKN066/// BKN100/// ///CB 21/18 Q1014LFMN 041330Z 04007KT 9999 FEW033 FEW066CB SCT110 BKN130 24/18 Q1013 RETS NOSIGLFML 041330Z 16020KT CAVOK 29/17 Q1011 NOSIG

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Cockpit briefing / Flight order YARTBriefing Part : OFP, 04-07-2014 LFBO LFMNDISPATCH BRIEFING TEL:--------- --------- --------- --------- --------- --------- --------- -OFP 8 04Jul14 WX PROG xxxx xxxx xxxx

03:58 PM OBS xxxx xxxx xxxx CRZ SYS 40GND DIST 263

FLIGHT N0 TRT2739 LFBO LFMN AIR DIST 26104Jul14 I-MMAT 1638 1722 AVGG W/C -3A320 CFM56-5B4 SHARKLET CTOT:1638 STA xxxx AVG ISA NA

Slot 1633→|1648 F-F FACTOR NARunway or climb TOW limitation : 84000 kg

MAXIMUM ZFW NOT AVAI LAW 66000 TOW 77020 structuralESTIMATED ZFW 41300 LAW 45860 TOW 47829ACTUAL ZFW . . . LAW . . . TOW . . .

kg--------- --------- --------- --------- --------- --------- --------- -TRIP 1704 3757 0044 1 800 EET 0044CONT 85 188 0002 100 EnduranceALTN LFML 930 2050 0021 900 0227FINAL 1814 4000 0050 1 900ADDNL 0 0 0000TANKERING . . . . . . . . .PLN TOF 4533 9994 0157EXTRA 1814 4000 0030 1 800 Dispatch in fuel tanks :TOF 6348 13994 6 500 L and R → 7 606 3 450TAXI 363 800 400 Center → 0 0BLOCK 6711 14794 6 900 Total →15 212 6 900

KG LBS lbs kg--------- --------- --------- --------- --------- --------- --------- -

REASON EXTRA FUEL 30 MINUTES HOLD LFMN :1815 EXTRA° CREW-QUALIFICATION ° ATC-AIR TRAFFIC CNTRL ° WXR-WEATHER--------- --------- --------- --------- --------- --------- --------- -

COMMANDER NAME : F. Bregier SIGNATURE : xxxxx--------- --------- --------- --------- --------- --------- --------- -FROM : LFBO ELEV 192 TO : LFMN ELEV 12 ALTN : LFMLATC C/S : CIMAVIA2739 AVG ISA : NACO-ROUTE : unkn AVG TT : xxx FMC-RES 4,6 (SI)FMC-RES-FUEL : 4560 (10050,0359446198 lb) AVGG W/C -3CRZ ALT : 31000 FL310 …/...CRZ SYS : 40 FL200 …/...unkn LFBO AMOLO UT24 FJR UL127 ROVOT UY373 ABLAK LFMN--------- --------- --------- --------- --------- --------- --------- -DESTINATION ALTERNATE LFMLEXTRA GND DIST 89 EXTRA TIME 0021--------- --------- --------- --------- --------- --------- --------- -Landing distance autobrake MED Flaps FULL : DRY 520 m WET 600 m without reversersToD 97 nm at 2100ft/min CFM56-5B/ N1 near of 80,7% for FLEX TEMP 60

LFBO 3500m LFMN 2700m

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Results

Green arrow means test passed, read arrow means tested failed.

Blue star means “topic of interest” to the handling of the A320.

The NO GO item buble points an item that is incorrectly simulated, or not simulated at all that would be a major flaw for the hardcore simmer (but maybe not for the casual simmer).

INIT

Perform preflight and produce a fuel estimate from Airbus tables.

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NO GO ITEM

https://www.ssl-url.net/gf3.myriapyle.net/aero/Fichiers/Payload-fuel_A320.ots


System version is 2.2R1 with a NavDataPro navigation databank CYCLE 1406.

Estimate from Airbus tables (not FMGS) is 6900 kg (total fuel required)

FLAPS/THS set to 1/UP0.9

Predictions made by the FMGS itself are concordant with our own estimates :

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TRIP FUEL is 1.86 . 1000 kg (FMGS) against our 1.80 . 1000 kg (dispatch briefing).

Pressurization system : check that the semi-auto mode is selectable and also that in manual mode, outflow valve can be operated from the cockpit (impact on systems ? Visual depiction ?).

Manual mode is selectable and thus outflow valve can be operated from the cockpit (seen on DU and visual depiction on the exterior model) while landing altitude stays in AUTO.

Manual mode is selectable and thus outflow valve can be operated from the cockpit (seen on DU and visual depiction on the exterior model) while landing altitude is switched in MAN.

From automatic mode, landing altitude can be switched in MAN therefore coming into semi-automatic mode.

TAXI

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N1 set at 40% for taxi

With Empty aircraft like us (6 people) 30% N1 is sufficient to taxi so 40% seems credible with a more loaded ACFT.

T/O

Set 60% N1, then check SRS (for runways with ILS), lateral bar should appears, replaced by the FD vertical bar after T/O.

Runway 32R at LFBO Toulouse Blagnac is equipped with the ILS–DME TD 108.35 (per charts). And indeed 108.35 / CRS323 is tuned by the FMGS.

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FLEX TEMP ATHR is engaged and N1 is set by the FMGS at 86,0% instead of our pre-calculated 80,7% (our own data). So our data is not very accurate. That's our fault. With a CFM56-7B (B737) we would have selected 90% N1 for Assumed Temperature 60°C, which would have been better.

SRS is engaged and lateral bar appears :

It is replaced by the FD then.

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Maintain stick pushed forward until reaching 80 knots.

Argh, don't you always forgot to do that one ? Maybe there is a chapter in the FCOM that would explain why, precisely.

Check guidelines for PACK operations and APU usage (FCOM). Not done.

Correct CLB vertical mode engagement after SRS ?

Yes :

CLIMB

Check that the ToC is displayed (white arrow).

Yes, it is !

However, it is not dynamically updated (it seems at least).

It has been an update of the Wilco/Feelthere model in its time, to bring dynamic ToC. This model is less accurate system speaking, but better when it comes to FBW and lateral accuracy than the Wilco one.

Which mode are engaged ?

Initial flight level set in the FCU is captured from CLB in NAV with ALT* then ALT.

To resume climb, press the altitude knob1.

At first sight I couldn't find any way to display CLB (managed) (push the knob) and not OP CLB (selected) (pull the knob) on the FMA. I knew I was missing something and a post on the X-plane forum help me to find the different clickspots to activate either managed climb or selected climb as seen in the picture below.

1 This has the same effect as the ALTITUDE INTERVENTION button on a Boeing 737 mode control panel.

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S for selected, M for managed and 3 for another clickspot in the neighborhood.

Then ALT CRZ when reaching ToC.

For CLB / OP CLB clickspots I had the answer from here :

http://forums.x-plane.org/index.php?showtopic=73272&hl=climb :One finger a little bit beside the Alt button means Managed descent, "DES" will appear in the FMA on the PFD. Open hand directly on the Alt button means Open descent, "OP DES" will appear in the FMA on the PFD.

And as always, just to comfort you in what you already know, think of it as:

Finger pointer = push for managed climb/descent respecting flight plan constraints.

Open hand pointer = pull or grab to selected (OP CLB / OP DES).

The same clickspots applys for the VS/FPA button. However, here pushing the knob has no relation with managed functions. VS/FPA cannot be managed. Pushing the knob will level-off the aircraft2.

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http://forums.x-plane.org/index.php?showtopic=73272&hl=climb


ALT Selected (green), ALT knob managed (red), VS knob selected (green), Altitude Hold (red), and other clickspot in yellow from the captain perspective.

CRUIZE

Check that ATHR engaged and throttle below CL detente is possible as in the reality. In this case the sole effect must be the limitation of the N1 to the throttle settings.

Yes, it is possible

but the effect not that clear in term of limitation.

You won't do that during normal operation anyway.

Check that F-PLAN constraints are seen in a page names VERT DEV.

2 This is the same as the ALT HOLD button found on a Boeing 737 Mode Control Panel.

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ABILI CSTR is +12000 (ie FL120 or ABOVE) and F-PLN page states accordingly passing ABILI at FL249.

HOLD : check the effectiveness of HOLD function if enough fuel and altitude set (FL). Is it depicted on the ND ?

Yes it is drawn, COMPUTED HOLD only, because the computer defines the last allowable exit in terms of fuel.

DIR TO functions. Check what the real FCOM says.

In the simulation DIR TO functions is limited to the F-PLAN waypoints. No extra entry of a waypoint is allowed.

FCOM 4.03.20

Pressing the "DIR" key under the MCDU screen brings up this page. The [ 1L ] key on thispage is the DIR TO key. The pilot presses it to modify the flight plan by creating a directleg from the aircraft's present position to any selected waypoint.[ 1L ] DIR TOPressing this key activates the DIRECT TO function, routing the aircraftfrom present position to the waypoint inserted in the scratchpad.The pilot can identify the waypoint to be inserted by using its

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identifier, its latitude and longitude, place/bearing/distance, orplace-bearing/place-bearing.Line 2 to Line 6These lines display the active flight plan with time/speed/distance predictions.Pressing any key activates the DIRECT TO function from presentposition to the waypoint adjacent to that key.

DIRECT LAW : have a quick review about Normal law and direct law section in the FCOM. Does direct low deactivate auto trimming ? What are the conditions of engagement ?

Yes, in the real aircraft direct low deactivates the auto trimming. Direct law is triggered with triple failure cases. However GROUND LAW is also a control law in direct law.

NORMAL LAW

- VERTICALIN FLIGHTWhen the PF performs side stick inputs, a constant G-load maneuver is ordered, andthe aircraft responds with a G-Load/Pitch rate.Since the aircraft is stable and auto-trimmed, the PF needs to perform minorcorrections on the side stick, if the aircraft deviates from its intended flight path. AT TAKEOFF AND LANDINGThe above-mentioned pitch law is not the most appropriate for takeoff and flare,because the stable flight path is not what the PF naturally expects.Therefore, the computers automatically adapt the control laws to the flight phases:• GROUND LAW: The control law is direct law• FLARE LAW: The control law is a pitch demand law.

Operational Recommendation:Takeoff and landing maneuvers are naturally achieved. For example, a flarerequires the PF to apply permanent aft pressure on the side stick, in order toachieve a progressive flare. Whereas, derotation consists of smoothly flying thenosegear down, by applying slight aft pressure on the side stick

- LATERAL When the PF performs a lateral input on the side stick, a roll rate is ordered andnaturally obtained.

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Therefore, at a bank angle of less than 33 , with no input on the side stick, a zero̊

roll rate is ordered, and the current bank angle is maintained. Consequently, theaircraft is laterally stable, and no aileron trim is required.

ALTERNATE LAWIn some double failure cases, the integrity and redundancy of the computers and of theperipherals are not sufficient to achieve normal law and associated protections. Systemdegradation is progressive, and will evolve according to the availability of remainingperipherals or computers.

Alternate law characteristics (usually triggered in case of a dual failure):- In pitch: same as in normal law with FLARE in DIRECT- In roll: Roll DIRECT- Most protections are lost, except Load factor protection.

At the flight envelope limit, the aircraft is not protected, i.e.:- In high speed, natural aircraft static stability is restored with an overspeed warning- In low speed (at a speed threshold that is below VLS), the automatic pitch trim stopsand natural longitudinal static stability is restored, with a stall warning at 1.03 VS1G.In alternate law, VMO setting is reduced to 320 kt, and FLOOR is inhibited. (Onα

A318, MMO setting is also reduced to M 0.77.)OPERATIONAL RECOMMENDATION:The handling characteristics within the normal flight envelope, are identical in pitchwith normal law.Outside the normal flight envelope, the PF must take appropriate preventive actionsto avoid losing control, and/or avoid high speed excursions. These actions are thesame as those that would be applied in any case where non protected aircraft (e.g. in case of stall warning: add thrust, reduce pitch, check speedbrakes retracted).

DIRECT LAWIn most triple failure cases, direct law triggers.When this occurs:

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• Elevator deflection is proportional to stick deflection. Maximum deflection depends onthe configuration and on the CG• Aileron and spoiler deflections are proportional to stick deflection, but vary with theaircraft configuration• Pitch trim is commanded manuallyThe aircraft obviously has no protections, no automatic pitch trim, but overspeedor stall warnings.

Editing the F-PLAN page content

Here, the JARDesign is also simplified. While there should be Temporary pages to edit the flight plan, or immediate modification, triggered with two different kind of action, here there is only one, and it is a mix between the two real actions. Also the lack of DISCONTINUITY is a big miss to the Airbus FMGS philosophy. The Wilco model was better in this department.

Here in the JAR, to add a waypoint : write it in the scratchpad, then upselect it to the LEFT (for instance 2L a waypoint AFTER current waypoint in 2L).

In the real world, you have to upselect to tho the right to be inserted before the waypoint selected. And clear the discontinuity. Or use the temporary mode, clicking to the left button and then, only then, add it via the Lateral Revision page, then accept it, then clear the discontinuity.

DESCENT

Check that the ToD is displayed (white arrow) and magenta deceleration point is displayed and handled.

Yes for both. And also an early round magenta and hashed point (LIM) where the plane slow to the limitation, often set like 250 below the FL100. D point : effectively commands further reduction of managed speed to 177 knots.

Review the DES mode engagement. OP DES ? DES ? Automatic descent or pilot action required to initiate ?

Pilot action is required to initiate descent.

You might have struggled like me to find how to engage a managed descent instead of a open descent. Without constraints a managed descent would mimics an open

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descent. However this is not the same as there are constraints on the planned route. So I did grab and pull the knob without being able to find a way to push it instead into managed status.

To start the managed descent, remind you of the clickspots below.

TIPIK CSTR is strictly FL120. How will-it be handled ?

ABLAK CSTR set manually to -20000, FL245 is then displayed in F-PLAN. While FL280 before.

During Preflight, ABLAK CSTR has been set manually to -FL200 or above. The ToD has then been recalculated by the FMGS but FL245 was then displayed in F-PLAN with the above profile. While FL280 before.

This has to be worked again before to write any observation here.

ILS APPROACH

Plan a Flaps 3 approach. Check if GPWS Flaps 3 option is simulated, if not, “Too low flaps” should be heard upon a FLAPS 3 approach.

GPWS Flaps 3 mode is simulated. CONF 3 in APPR page of the FMGS has also been set. Abnormal operation will not be tested.

Retrieve some information in the FCOM about Fail-Operational and Fail-Safe.

The crew should plan the approach using the best approach capability. This would normally be CAT III DUAL with autoland, depending upon aircraft status. The crew should then assess the weather with respect to possible downgrade capability.

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CAT 3 SINGLECAT 3 SINGLE is announced when the airborne systems are fail passive which meansthat a single failure will lead to the AP disconnection without any significant out oftrim condition or deviation of the flight path or attitude. Manual flight is thenrequired. This minimum DH is 50 ft.CAT 3 DUALCAT 3 DUAL is announced when the airborne systems are fail-operational. In case ofa single failure, the AP will continue to guide the aircraft on the flight path and theautomatic landing system will operate as a fail-passive system. In the event of a failurebelow the AH (Alert Height, 100 ft for single aisle airbus family), the approach, flare and landing can be completed by the remaining part of the automatic system. In that case, no capability degradation is indicated. Such a redundancy allows CAT III operations with or without DH.

MDA and DH : mutually exclusive normally, however a value pops up in certain case in the JARDesign airbus (DH50, DH20). Check behavior.

MDA This field displays the minimum descent altitude with associated brackets. The flight crew inserts the value, which it can modify at any time. If the flight crew makes an entry in [ 3R ] or changes the approach, it clears this figure.

DH lf the flight plan includes an ILS approach, this field displays "DH" and empty brackets. The flight crew inserts the decision height. The system will accept an entry of "NO". If the flight crew inserts an MOA or an MDH, this erases the decision height, and this field reverts brackets. The DH range is 0 to 700 feet

For CAT1 ILS, the crew will insert DA/DH values into MDA (or MDH if QFE functionis available) field on the MCDU PERF APPR page, since these values are baro

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referenced.For CATII or CATIII ILS, the crew will insert DH into DH field on MCDU PERF APPRpage, since this value is a radio altitude referenced.

MDA has been set to 280 according to the chart because of a CAT1 ILS landing planned on single autopilot.

However, with the JARDesign model, during an ILS approach and when APPR is depressed (ie comes green to activate APPR mode) DH200 pops in along with CAT1 SINGLE. Around 2000 feet AMSL, a new DH50 pops up along with CAT3 SINGLE. No matter which minimums have been previously selected by the crew !

ILS APPROACH : a new DH50 pops up along with CAT3 SINGLE.

From FCOM we have :

CATEGORY III Fall PASSIVE STATE (SINGLE)Minimum decision height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 feetAt least one autopilot must be engaged in APPR mode, and CAT 3 SINGLE or CAT 3 DUALmust be displayed on FMA.A/THR must be used in selected or managed speed .

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So the DH50 value that pops up along with the CAT3 SINGLE FMA indication is related to the aircraft minimums.

So the simulation simply sets the aircraft and system certified minimums. But what if the airport minimums are greater ? IT CHANGES MY SETTINGS WITHOUT MY PERMISSION !

From FCTM :

For CAT1 ILS, the crew will insert DA value into MDA field on the MCDU PERF APPR page, since these values are baro referenced.For CATII or CATIII ILS, the crew will insert DH into DH field on MCDU PERF APPRpage, since this value is a radio altitude referenced.

ALL APPROACHES, REACHING THE MINIMADecision to land or go-around must be made at MDA/DH at the latest. Reaching theMDA/DH, at MINIMUM call out:• If appropriate visual reference can be maintained and the aircraft is properly

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NO GO ITEM


established, continue and land.• If not, go-around.The MDA/DH should not be set as target altitude on the FCU. If the MDA/DH wereinserted on the FCU, this would cause a spurious ALT*.

NON PRECISION APPROACHES :When approaching MDA, the pilot flying should expand the instrument scan to includeoutside visual cues.Reaching MDA, ”MINIMUM” is either monitored or called by the crew. The currentaltitude value becomes amber.If the required conditions are not met by MDA, a missed approach must be initiated.When the required visual conditions are met to continue the approach, the AP must bedisconnected, the FDs selected off, Bird ON and continue for visual approach.

PRECISION APPROACHESCAT II and CAT III approaches are flown to very low DH (or without DH) with very lowRVR. The guidance of the aircraft on the ILS beam and the guidance of the aircraftspeed must be consistently of high performance and accurate so that an automaticlanding and roll out can be performed in good conditions and, the acquisition of visualcues is achieved and the aircraft properly stabilized. Hence,• The automatic landing is required in CAT III operations including roll out in CAT IIIB.• The automatic landing is the preferred landing technique in CAT II conditions• Any failures of the automated systems shall not significantly affect the aircraftautomatic landing system performance• The crew procedures and task sharing allow to rapidly detect any anomaly and thuslead to the right decision

LANDING

POST-FLIGHT

Check remaining fuel in regard to the initial estimate in preflighting.

Landing with 4,4 tons of remaining fuel after a go-around. Would have been between 4,6 and 4,8 without the go-around so it's perfect !

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Another try : FOB at gate at LFMN : 4330 kg. The final fuel in LFBO was stated 4,33 tons. Strange that it is so close (equal to what was planned, to the kilogram).

EXTRA QUESTIONS

HYDRAULICS

All pumps off on ground, does it prevent the flaps to deploy ?

Noooooo and I am really upset ! Don't you ?

All pumps off in flight, same question ? Does the RAT deploys in this very case (the RAT does deploys if no APU nor Engines are available).

Not done yet.

Ref. for HYD is FCOM 1.29

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In contrast to the Boeing, FD (the brain) must be engaged to allow A/P engagement (the muscle). Check the logic in the FCOM.

FCOM 1.22.30

The Flight Guidance (FG) part of the FMGS controls the :- Flight Director (FD)

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- Autopilot (AP)Autothrust (A/THR).

The Flight Director (FD) displays guidance commands from the Flight Management andGuidance Computer (FMGC) on the Primary Flight Display (PFD).You may manually fly the aircraft , following FMGC guidance commands, or crosscheck the FMGC orders when the autopilot is engaged.

AP ENGAGEMENTThe flight crew can engage AP1 or AP2 by pressing the corresponding pushbutton on theFCU if the aircraft has been airborne for at least five seconds. When one AP is engaged, the corresponding FCU pushbutton comes on and AP1 (or 2) is displayed on the FMAs.

- One AP can be engaged on the ground if the engines are not running. It disengages when one engine is started.- Two APs may be engaged at a time (APT active, AP2 in standby), when the localizer/glide-slope or roll out or go-around mode is armed or engaged. Only one AP can be engaged at a time in other cases.- If one AP pushbutton is set to on with both FDs off, the AP engages in HDG V/S or TRK FPA mode, depending upon which the pilot has se/ected on the FCU.- If one AP pushbutton is set to on with at least one FD already on, the AP engages in the current active FD modes.- AP engagement increases the break out force on the side stick controllers and on the rudder peda/s.

If one AP pushbutton is set to on with both FDs off, the AP engages in HDG V/S or TRK FPA mode, depending upon which the pilot has se/ected on the FCU ?

No, all settings selected, impossible to reproduce that in the simulation.

In the simulation FD off = AP off.

VOR1 and VOR2

VOR1 and VOR2 simplified : JARDesign A320 is “one side only” in contrast to the

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QPAC A320. And again I am quite upset ! But that's fair enough for daily operation.

User-reported spurious SID and STAR waypoints. Confirmation ?

Confirmed, often spurious.

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NO GO ITEM


Accuracy of lateral and vertical modes in RNP app.

Objective

In the second part of this paper we are testing the RNAV(GNSS) lateral and vertical modes.

Definitions

RNAV is not the only performance-based navigation (PBN). RNP are the other category of PBN procedures. RNP approaches are set up all over the world since the ICAO A37-11 resolution from October 2010.

The main difference between RNAV and RNP is that RNP requires a performance monitoring system. The aircraft must be equipped with a system that checks the integrity of input signals (satellites, navaids) and alert the crew if integrity or required performance is lost.

Presently there are two different types of RNP approaches : RNP APCH (basic RNP) and RNP AR APCH (with special authorization for crew and aircraft). In the later type, only radius to fix (RF) legs (a special way of turning around a fix) and track to fix (TF) legs are part of the path whereas basic RNP APCH have only straight segments along with more leg types allowed (exactly 9 of 23). On French civil aviation authority charts, RNP approaches are designated by the RNAV (GNSS) mention. RNP AR would be designated by RNAV(RNP).

In order to test the accuracy of the managed lateral mode of the simulation, we will however begin with a VOR approach, flown in RNAV OVERLAY with the FMGS instead of displaying and tracking the raw data (ie the VOR radial and DME).

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PBN

RNAV RNP

RNAV5 RNAV1 RNP APCH RNP AR APCH

En route Terminal Classicalapproach

APVapproach

Specialapproach


VOR approach with RNAV overlay

VOR 36R LFLL, unpublished RNAV overlay

All constraint are reviewed in the MCDU. All constraints were AT or ABOVE. They are changed manually to AT constraint to be the exact value written on the approach chart.

Vertical navigation accuracy reveals itself to be perfect with vertical managed mode with those “AT” constraints.

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However the lateral guidance provides a slight offset to the left of the runway axis ! But that 's not that bad ! Disconnecting the autopilot leads to a successful approach.

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RNAV(GNSS) approaches

This kind of approach if often referred as RNAV(GNSS) on the approach charts, and RNP in the official ICAO terminology.

RNAV(GNSS) y runway 26 at LFLC

APPROACH GUIDANCE FOR RNAV APPROACHTwo different approach strategies are available to perform RNAV approaches :1. Lateral guidance, managed by the FM, and vertical guidance selected by the crew :NAV-FPA (or NAV-V/S) modes.This strategy applies, when LNAV ONLY (Lateral Navigation only) RNAV approach isintended.2. Lateral and vertical guidance, managed by the FM : FINAL APP mode.This strategy applies, when LNAVVNAV (Lateral and Vertical Navigation) RNAVapproach is intended.In all cases, the recommended flying reference is FPV, which should be selected duringthe initial approach.

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Monitor VDEV and FPV (on the PFD) and XTK error (on the ND).The second strategy (vertical guidance managed) has been tested because we want to test the vertical accuracy of the simulation.

Adopting this strategy we should check that FINAL APP mode is used as seen in the left part of the figure below.

We begin by selecting the approach in the FMGS. However here we have got a problem linked to the JARDesign Group A320neo. This simulation is not able to read correctly the SID and STAR database (using the NavDataPro Cycle 1406) and provide the good sequence on the flight plan ! SID and STAR are spurious with totally wrong conditional waypoints and other erratic fixed waypoints. This has been reported to me by an user and I later confirmed it on several occasions. We are going to illustrate it here.

From the MCDU we select an RNV26-Y via RIMOR approach.

The sequence of this approach is RIMOR, LC406, LC408, MAPT1, RW.

The result is quite different. What are those FA1492, CF89 and BELEP spurious waypoints seen below ?

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So we edit the flight plan in to remove all those waypoints. An this is a very disappointing part of this simulated A320, not being able to read the SID/STAR/ARRIVAL databank correctly.

In the end, after removing the spurious waypoints to establish the correct sequence we've got the following results after RIMOR :

We check all the constraints according to the charts they are OK !

All the waypoint of the approach are present from LC406, with correct altitude constraints.

Another thing we have to do during an RNAV(GNSS) approach is to monitor the accuracy as seen in the upper part of FCOM illustration below :

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However here, there is no way to enter a new RNP for the approach. RNP will stay at 1.00 and the accuracy will stay at HIGH, with no estimated value :

The lower part of the figure from the FCOM above is the need to press the APPR pushbutton on the FCU if the managed vertical guidance strategy has been adopted in order to display the VDEV scale on the PFD and the magenta circle representing the computed vertical glide path (and normally the cross track error on the ND, not simulated here).

Once the APPR button has been pressed, APP NAV is displayed on the ND. And FINAL is armed on the second FMA line below DES. The descent respects the constraints written in the procedure however I cannot get FINAL APP active so the final glide path is always too steep and sends me into the terrain. The lateral deviation is very good however and this can be checked against the localizer of the runway 26.

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NO GO ITEM


This approach is published as LNAV only and not LNAV/VNAV. Maybe this is the reason and at some place in the internal databank it changes something for the FMGS.

However, from the 3 kinds of approaches below, the LNAV only should normally be flyable with VNAV ! (called managed descent in the Airbus).

• LPV (APV SBAS) Localizer Performance with Vertical Guidance (APproach Procedure with Vertical Guidance and Satellite Based Augmentation System). Lateral navigation and vertical navigation use the GNSS signal and SBAS signal. SBAS is provided by another constellation of satellites (constellation EGNOS in Europe).

• LNAV/VNAV (APV BARO VNAV) APproach Procedure with Vertical Guidance (this is an ABAS procedure : Aircraft Based Augmentation Systems). Vertical guidance is provided by aircraft VNAV

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system with Baro reference set to local QNH.

• Non precision with LNAV only. Vertical guidance is made like a VOR/DME or NDB approach, with V/S or FPA (or VNAV, but VNAV is Baro-dependant).

To test the execution of an officially approved Baro VNAV/LNAV approach we use the RNAV approach for runway 03 in Nantes (LFRS). At RS708 the plane should initiate its 5,2% descent (illustration 44). Crossing OSBEN fix he should be at or above 1300 feet.

Same result here, the FINAL APP mode can't be activated. It stays blue on the second line of the FMA. The VS mode pops up however. In the picture below we can see that a VS of -300 fpm has suddenly appeared during the RNV03 LFRS approach ! But why ?

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X


Let's check the correct approach sequence :

It seems that we don't do anything wrong but FINAL APP is never triggered !

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NO GO ITEM


What if the APPR pushbutton is not pressed ?

The lateral path is very good and guide us toward the runway axis without deviation however the vertical guidance is erratic :

1. RNV APPR is still displayed on the ND and there is no computed flight path.

2. The glide path is horrible and leads us into the terrain (CFIT).

3. The magenta circle is not shown.

In the picture below, the ILS has been displayed on the ND, only for reference as it is not used in this approach. We can spot that the aircraft is on the LOC but way below the reference glide-slope of the ILS.

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RNP AR approach with RF-leg

This kind of approach if often referred as RNAV(RNP) on the approach charts, and RNP AR in the official ICAO terminology.

The lateral accuracy of NAV was very good during the RNAV(GNSS) approaches. We try to further experiment and test the approaches with RF-leg even if we couldn't achieve correctly a RNAV-GNSS approach because of the FINAL APP not coming up in LATERAL+VERTICAL managed guidance strategy.

RNAV (RNP) Y RWY 28R

By selecting the RNAV(RNP) approach to Runway 28R at KSFO we expect the sequence GUTTS DONNG JOSUF FABLA to the runway 28R. But the two critical RF-legs waypoints JOSUF and FABLA are escaped by the JARDesign Group MCDU.

RNP AR approaches with RF-leg are not simulated in this model. That's it !

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2 5 0 0

8 0 0

( . )( 7 )

2 8 4

8 446

320

GPS required. RF required.


Conclusion of the second part about RNP/RNP AR

This is the statement on the JARDesign Group front web page :

Among other things reported as simulated are NPA approaches. However, while Non Precision Approaches like VOR approaches are clearly achievable with the Airbus, that's not the case with other Non Precision Approaches like RNAV(GNSS).

The developer stated in an interview that the FPA mode was not currently programmed with an exception made for the bird, displayed when FPA is activated. Maybe the fact that FPA (and, therefore, an unknown part of the airbus vertical guidance modes) has currently not been made, has something to deal with the missing triggering of the FINAL APP mode during a RNAV(GNSS) approach conducted in fully managed strategy. This is an hypothesis. So FINAL APP is replaced by a sudden trigger of the VS mode with some value in fpm.

We also saw that RF legs are not taken into account. The VERSION 2.2 r1 has been used in this paper.

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General conclusion

Obviously a lot of work has been done on this simulator add-on. A lot of systems are emulated, and a lot of very good “environmental goodies” are here like the oral checklists, the stairs, the pushback truck, the fuel truck, the very good virtual cockpit, a custom MCDU improving over each update release. The accuracy of the lateral flight path is accurate, once the flight path has been correctly defined. But there are also a lot of items to improve ! On top of them is the incorrect exploitation of the navigation databank that leads to spurious SID ans STAR or the MDA/DH management during ILS approaches. I will keep en eye on the project development and maybe give it another try when a version 3 will come. From the angle of the hardcore simmer, the system simulation is not presently as perfect as we would wait for with a $59,95 product.

For the casual simmer, this is a very good simulation, with a relatively nice fly-by-wire simulation and immersive side-goodies. The PFD, the ND and the MCDU are a step farther in system modeling than the default X-plane FMC. Apart from the SID and STAR problem, the presence of an updatable databank is a good point. Such a databank is mandatory for me because it usually signs an add-on with evolved system modeling. For the casual simmer, this Airbus is a good start to enhance his understanding of the real handling of an airliner, and an airbus airliner by the way. The FBW is very fun to discover and experiment, in particular if you come from the Boeing world like me.

Some of the tests made in this second part here (RNP) are usually stringent in the world of flight simulation add-ons. They are good discriminants between the very first-class add-ons and the also very good second class others. The casual simmer will not encounter the flaws reported in the second part of this review at first. But in the end, a number of limitations have been spotted in the whole review. They all-in-all made the product a bit overpriced.

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Documents

JARDesign A320 : a TransaTvia.com studygf3.myriapyle.net/aero/Fichiers/Transition_au_JAR.pdf · A320 VER 2.2 r1 : a TransaTvia.com study (paper version : 07/09/14) 07/04/14 ... Perform