Cold temperature corrections on LNAV/VNAV minima
Hey guys,
I cannot really come to an end weather it's necessary or not to apply cold temperature corrections to minimum altitudes when performing RNAV GNSS apch using LNAV VNAV minima on A320/330.
According to the latest 2015 issue of Getting to grips with cold weather operations :
5.2.1 Low* altitude* temperature* corrections Corrections* on* an* indicated* altitude* have* to* be* applied* on* the* published* minimum altitude,* except* when* the* criteria* used* to* determine* minimum* flight* altitudes* are* already published* and* take* into* account* low* temperature* influences. (Reference to LFBO 14L RNAV GNSS Baro-Vnav minimum temperature is made).
On the other hand ICAO and EASA reminds crews to apply temperature corrections in APV approaches (regardless if the Baro-Vnav system incorporates or not a VPA auto compensation system or not):
ICAO PBN MANUAL DOC9613
6.3.4.2.12 Temperature compensation.* For aircraft* with* temperature* compensation* capabilities, approved* operating procedures may allow* pilots to disregard the* temperature* limits on RNP AR* APCH procedures if the operator provides pilot training on* the use of* the temperature compensation function. Temperature compensation* by* the system is applicable* to the baro-VNAV* guidance* and is* not a substitute* for the* pilot compensating* for the cold temperature effects on minimum altitudes or the DA. Pilots should be familiar* with* the* effects of* the temperature* compensation* on intercepting the compensated path described in EUROCAE ED-75B/ RTCA DO-236B Appendix H.
6.3.5.3.2 k) temperature compensation —* pilots* operating* avionics systems* with* compensation* for altimetry* errors introduced* by* deviations from ISA may disregard the temperature* limits on RNP AR APCH procedures, if* pilot training* on* the use of the temperature compensation* function* is provided* by* the operator and the compensation function is* utilized* by* the crew. However, the training* must also recognize the temperature compensation* by* the system is applicable to the* VNAV guidance and is not a substitute for* the pilot compensating for the cold* temperature effects on minimum altitudes or the DA.
6.4.2.11.3 The effect of extreme* temperature (e.g. extreme* cold* temperatures, known local atmospheric or* weather phenomena, high* winds, severe turbulence) on barometric* altitude* errors on the* vertical path is mitigated through the procedure* design* and crew* procedures,* with an allowance for* aircraft that compensate for this effect to conduct procedures regardless of the* published temperature limit.* The effect of* this error on minimum segment altitudes and the DA is addressed in an equivalent manner to all other approach operations.
EASA AMC 20-27A, Appendix 4* par.1.2:
For* APV* BARO-VNAV* operation,* pilots* are* responsible* for* any* necessary* cold temperature* compensations* to* all* published* minimum altitudes/heights.* This* includes: a)*** the* altitudes/heights* for* the* initial* and* intermediate* segment(s); b)*** the* DA/H;* and c)*** subsequent* missed* approach* altitudes/heights. APV* BARO-VNAV* procedures* are* not* permitted* when* the* aerodrome* temperature* is below* the* promulgated* minimum* aerodrome* temperature* for* the* procedure,* unless* the RNAV* system* is* equipped* with* approved* cold* temperature* compensation* for* the* final approach.
What's your or your operator idea?
Txs for sharing.