Issue 1/ After lab test, a delta max of 100ft is observed between estimated ZSTD (ZSTDxBYPSx) and ZSTDx.\r\n\r\nAs this result is superior to the half of the level detector (150/2) this is not compliant, even if no monitoring has been triggered.\r\n\r\nDefect opened for improvement.\r\n\r\n================\r\n\r\nSimilarly, the delta max observed between VCAS from ADR and VCAS estimated is higher than the expected value (2kts instead of 1kts). This should also be analyzed\r\n\r\n \r\n\r\nIssue 2/ From ELACE-4247: Threshold need to be reviewed to improve robustness of the consistency monitoring while ensuring that the error on parameters provided to FCL are within the acceptable values. \r\n\r\n \r\n\r\nIssue 3/ Open items from ELACE-4088 : \r\n * Does the 2vs2 need to be part of the NAV IAS fault definition ?\r\n * Reduce the tconf of the revalidation principle on the Vcasbup when 3 Vcas are usable to 1s (as already done when there are 2 usable vcas)\r\n\r\n \r\n\r\nIssue 4/ Requirement improvement:\r\n> req on consistency monitoring to be improved\r\n\r\n \r\n\r\n+*Analysis*+\r\n\r\n+Issue 1/ Defect EST-1217+\r\n\r\nAs the result obtained during DO analysis are different from the result obtained by Lab, investigation are carried out by DO which show that the difference between Lab/DO results and the fact that the delta max is higher than the expected are mainly due to two points:\r\n> Computation step, which underestimated the variation of ZSTD(PSTAT) & VCAS(PSTAT, MACH)\r\n> Truncation & rounding of values\r\n> The method used for linearization which is also questioned as the criteria to choose the points is the number of points allowed instead of the max error, this method consists in choosing at first n point evenly spaced and then reposition them in function of the derivative. This method still answers the needs as the ZSTD (ZSTDxBYPSx) and ZSTDx are more or less linear, so it will be kept.\r\n\r\nFor ZSTD(PSTAT), it is decided to review the level detector instead, its value is chosen based on the engineer judgment but as there is no need to have a LD more tight than the narrow monitoring. Additionally, as we can see in issue 2, the threshold of these monitoring can be defined based on the max error provided to FCL which will increase its values.\r\n\r\nFor VCAS(PSTAT, MACH), it is decided to re-compute the value with a correct step computation and having a better resolution (4 digits after the decimal point). Then at the same time align the LD of the EVA VCAS monitoring to the LD of narrow monitoring (4kts)\r\n\r\nWith all this update the max delta for:\r\n\r\n> ZSTD(PSTAT) is 104.59 ft  (same as before)\r\nCf [^delta_ZSTD_interpol_v2.png] for errors plotting\r\n\r\n> VCAS(PSTAT, MACH) is 1.039 kts\r\nCf [^delta_VCAS(Pstat)_interpol_v2.png] & [^delta_VCAS(MACH)_interpol_v2.png] for errors plotting\r\n\r\n \r\n\r\n+Issue 2/ Threshold analysis+\r\n\r\nThe purpose of the consistency monitoring is to provide a mean to detect ARINC failure that can affect MACH, PSTAT and ZSTD while the VCAS remains correct (triplex monitoring does not triggers). The threshold used on this consistency monitoring are chosen in the first time to be tighten to ensure that any smart failure where MACH/PSTAT are incorrect while the computed VCAS=f(Mach, Pstat) and computed ZSTD = f(PSTAT) remains consistent.\r\nAfter review with expert, this strategy is exagerated as we already have the narrow triplex monitoring which will allow us to detect and unhide this type of failure and the consistency monitoring does not differ from the triplex monitoring in a sense that they have the same purpose which is ensuring that the data provided to FCL does not exceed the maximum acceptable erroneous values.\r\n\r\nThis is why an analysis is performed to justify the element given by the expert and to review the threshold on the consistency monitoring to improve robustness while fulfilling the max error objectives for Flight Control Law.\r\n\r\nThe detailed analysis is available here: [https://docs.google.com/document/d/15doWjePV74x50Nm_J1L93zDdmLXNIoRFvHiP_Eqi4pw/edit|https://docs.google.com/document/d/1LwljLE4dHxhr347UAVkI66oY5NxF753VdQpIz8QV6PY/edit]\r\nOr in the pdf attached to this change card: [^Consistency monitoring analysis.pdf\r\n\r\nFrom these analysis, \r\n> to ensure a max error of PSTAT on FCL side (+/-30mbar), the threshold on the ZSTD consistency monitoring should be lesser than or equal to 1400ft (taken into account the table inaccuracy of 200ft (+100% margin))\r\n> for MACH, the performed analysis on the SSIN shown that the threshold used on the VCAS triplex (16kts) is sufficient to guarantee an acceptable max error of MACH on FCL (already detailed in SSIN) as the two parameters are linked. Therefore and with a table inaccuracy on VCAS of 2kts (+100% margin), the threshold on the VCAS consistency monitoring should be lesser than or equal to 14kts\r\n\r\nThese new values should be implemented.\r\n\r\n \r\n\r\n+Issue 3/+ \r\n\r\nPoint 1: The purpose of the NAV IAS fault alert (class2 warning) is to display a message in ECAM in case of IAS parameters is failed (rejected by a monitoring in ELAC) without law degradation to keep the pilot informed and for maintenance purposes. In case the VCASPUB is available, a VCAS from a source can be rejected by the 2v2 monitoring so it should be also included in this alert.\r\n\r\nPoint 2: The confirmation time used to recover the VCASBUP is reduced when 2 VCAS are usable, but not the case when 3 VCAS are usable which delay the 2v2 monitoring activation which does not make sense. Need to update the condition to reduce the confirmation time by including the case where 3 VCAS are usable\r\n\r\n+Issue 4/ Requirement improvement+\r\n\r\n \r\n\r\n+*Solution*+\r\n\r\nA502090_C: New values are implemented for VCAS(PSTAT,MACH):\r\n|Mach\\Ps|100.0|141.4257|195.7374|261.0086|336.1865|420.5879|513.7315|615.2507|724.8523|842.3023|967.4065|1100.0|\r\n|0.1|20.7837|24.7153|29.0743|33.571|38.0967|42.6069|47.0836|51.5197|55.9131|60.2643|64.5749|68.8469|\r\n|0.2315|48.3592|57.4941|67.6143|78.0442|88.5291|98.965|109.3084|119.5421|129.6602|139.6631|149.5538|159.3363|\r\n|0.3622|76.3084|90.6855|106.5912|122.9548|139.3715|155.6739|171.7914|187.6944|203.372|218.8234|234.0518|249.0625|\r\n|0.4916|104.8338|124.5103|146.234|168.5269|190.8268|212.8997|234.6454|256.0208|277.0096|297.6094|317.8248|337.663|\r\n|0.6193|134.122|159.1671|186.743|214.9478|243.0553|270.7618|297.9367|324.5249|350.5062|375.8801|400.6552|424.8449|\r\n|0.745|164.3427|194.8312|228.2867|262.3658|296.172|329.3316|361.6869|393.1749|423.7776|453.5026|482.3694|510.404|\r\n|0.8686|195.6481|231.6528|271.0003|310.8878|350.246|388.6352|425.8779|461.9124|496.7328|530.3643|562.8463|594.2258|\r\n|0.99|228.1676|269.7509|314.9787|360.5738|405.2965|448.651|490.4527|530.6547|569.2762|606.3713|642.0098|676.2677|\r\n\r\n \r\n\r\nA515033: Update VCAS consistency monitoring threshold (14kts in flight instead of 8kts)\r\nA515073: Update ZSTD consistency monitoring threshold (1400ft instead of 1000ft)\r\n\r\nA502001: the 2vs2 monitoring added to the NAV IAS fault definition \r\n\r\nA515021: create a boolean set to true when 2 or 3 VCAS are usable (confirmed)\r\nA51503K: reduce the confirmation to recover the VCASBUP when  2 or 3 VCAS are usable confirmed, instead of only 2 VCAS usable\r\n\r\n \r\n\r\n+Requirement (to be updated)+\r\n\r\nCDF_L3_PP_PAR_820 (add/update table)\r\n\r\nCDF_L3_PP_PAR_822 (update threshold + improve req)\r\n\r\nCDF_L3_PP_PAR_823 (update threshold + improve req)\r\n\r\nCDF_L3_PP_PAR_562 (add 2v2 VCAS monit)\r\n\r\nCDF_L3_PP_PAR_273 (2 or 3 VCAS usable confirmed)\r\n\r\nCDF_L3_PP_PAR_284 (add 3 VCAS usable to reduce conf time on PUB recup)