Oh not again,
the winter is coming...
Are there any opinions about the DEFINITION / MEANING of the word
compensation in this one
EASA Air-OPS paragraph?
Reference: AMC2 SPO.OP.116 Performance-based navigation — aeroplanes and helicopters
MONITORING AND VERIFICATION
(d) Altimetry settings for RNP APCH operations using Baro VNAV
(2) Temperature compensation
(A) the flight crew should not commence the approach when the aerodrome temperature is outside the promulgated aerodrome temperature limits for the procedure unless the area navigation system is equipped with approved temperature compensation for the final approach;
(B) when the temperature is within promulgated limits, the flight crew should not make compensation to the altitude at the FAF and DA/H;
(C) since only the final approach segment is protected by the promulgated aerodrome temperature limits, the flight crew should consider the effect of temperature on terrain and obstacle clearance in other phases of flight.
In the
(B) above, what are the arguments that the word
compensation stands for either
- a feature of the airborne equipment (i.e. activating a temperature compensation algorithm of the FMC)
- a pilot's cognitive task (i.e. applying a temperature correction additive to a published value)
In the search for an answer myself, below is what I found in the regulation. I am reasonably certain the list is exhaustive, all appearances of words
correction / compensation / temperature in the context of Baro VNAV.
Originally Posted by AMC1 CAT.OP.MPA.145(a) Establishment of minimum flight altitudes -CONSIDERATIONS FOR ESTABLISHING MINIMUM FLIGHT ALTITUDES
(b) The operator should also consider: [...] (1) corrections for temperature and pressure variations from standard values;
Originally Posted by AMC1 SPA.PBN.105(b) PBN operational approval FLIGHT CREW TRAINING AND QUALIFICATIONS
(b) Ground training [...] (2) General concepts of RNP AR APCH operation [...] (ii) [..] should include [...] in particular [...]
(K) the temperature compensation: Flight crew members operating avionics systems with compensation for altimetry errors introduced by deviations from ISA may disregard the temperature limits on RNP AR APCH procedures if flight crew training on use of the temperaturecompensation function is provided by the operator and the compensation function is utilised by the crew. However, the training should also recognise if the temperature compensation by the system is applicable to the VNAV guidance and is not a substitute for the flight crew compensating for the temperature effects on minimum altitudes or the DA/H
Originally Posted by AMC2 SPA.PBN.105(d) PBN operational approval - FLIGHT CONSIDERATIONS
(a) Modification of flight plan [...] not be authorised to fly a published RNP AR APCH procedure unless [...]
The only other acceptable modification to the loaded procedure is to change altitude and/or airspeed waypoint constraints on the initial, intermediate, or missed approach segments flight plan fixes (e.g. to apply temperature corrections or comply with an ATC clearance/instruction).
(j) Temperature compensation
For aircraft with temperature compensation capabilities, the flight crew may disregard the temperature limits on RNP procedures if the operator provides pilot training on the use of the temperature compensation function. It should be noted that a temperature compensation by the system is applicable to the VNAV guidance and is not a substitute for the flight crew compensating for temperature effects on minimum altitudes or DA/H. The flight crew should be familiar with the effects of the temperature compensation on intercepting the compensated path as described in EUROCAE ED-75C/RTCA DO-236C Appendix H.
The threads on the topic so far:
Cold temperature corrections on LNAV/VNAV minima,
Cold temp corrections on LNAV appr,
LNAV/VNAV BAROVNAV APPROACH,
Temperature correction on Baro-VNAV approach,
RNP approaches. A question about the APV version and low temperature