What does the understanding of the CDFA concept include according to the safety assessment topics?

The understanding of the CDFA concept includes use of the MDA/H as DA/H.

GM7 NCC.OP.110 Aerodrome operating minima -- general

Q: What did the two independent analyses conclude about the safety of using MDH as DH in CDFA operations compared to traditional step-down and level flight NPA operations?

The analyses concluded that a CDFA using MDH as DH without any add-on is safer than the traditional step-down and level flight NPA operation.

Q: What was the basis for comparing the safety level of using MDH as DH without an add-on in CDFA operations?

The comparison was made with the well-established safety level resulting from the ILS collision risk model (CRM).

Q: What design limit of the ILS approach design must be observed for the CDFA to keep the validity of the safety comparison?

The maximum glide path (GP) angle of 3.5 degrees must be observed for the CDFA.

Q: Is it necessary for each operator to conduct similar safety assessments to those already performed for CDFA operations?

No, it cannot be expected that each operator is able to conduct similar safety assessments, and this is not necessary.

Q: What circumstances do the already performed safety assessments for CDFA operations take into account?

The safety assessments take into account the most demanding circumstances at hand, like the most tightly designed NPA procedures and other 'worst-case scenarios'.

Q: What must operators assess regarding their cockpit procedures and training in the context of CDFA operations?

Operators must assess whether their cockpit procedures and training are adequate to ensure minimal height loss in case of a go-around manoeuvre.

Q: What are the suitable topics for the safety assessment required by each operator for CDFA operations?

Suitable topics include: understanding of the CDFA concept including use of the MDA/H as DA/H; cockpit procedures that ensure flight on speed, on path and with proper configuration and energy management; cockpit procedures that ensure gradual decision-making; and identification of cases where an increase of the DA/H may be necessary because of non-standard circumstances.

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GM7 NCC.OP.110 Aerodrome operating minima — general

ED Decision 2022/012/R

USE OF DH FOR NPAs FLOWN USING THE CDFA TECHNIQUE

The safety of the use of MDH as DH in CDFA operations has been verified by at least two independent analyses concluding that a CDFA using MDH as DH without any add-on is safer than the traditional step-down and level flight NPA operation. A comparison was made between the safety level of using MDH as DH without an add-on with the well-established safety level resulting from the ILS collision risk model (CRM). The NPA used was the most demanding, i.e. most tightly designed NPA, which offers the least additional margins. It should be noted that the design limits of the ILS approach design, e.g. the maximum glide path (GP) angle of 3,5 degrees, must be observed for the CDFA in order to keep the validity of the comparison.

There is a wealth of operational experience in Europe confirming the above-mentioned analytical assessments. It cannot be expected that each operator is able to conduct similar safety assessments, and this is not necessary. The safety assessments already performed take into account the most demanding circumstances at hand, like the most tightly designed NPA procedures and other ‘worst‑case scenarios’. The assessments naturally focus on cases where the controlling obstacle is located in the missed approach area.

However, it is necessary for operators to assess whether their cockpit procedures and training are adequate to ensure minimal height loss in case of a go-around manoeuvre. Suitable topics for the safety assessment required by each operator may include:

— understanding of the CDFA concept including use of the MDA/H as DA/H;

— cockpit procedures that ensure flight on speed, on path and with proper configuration and energy management;

— cockpit procedures that ensure gradual decision-making; and

— identification of cases where an increase of the DA/H may be necessary because of non-standard circumstances, etc.

Details

Source-Title: GM7 NCC.OP.110 Aerodrome operating minima -- general View latest amendments

Erulesid: ERULES-1963177438-19677 Compare versions

Domain: Air operations

Applicabilitydate: 30 October, 2022

Entryintoforcedate: 1 July, 2022

Regulatorysource: ED Decision 2022/012/R Navigate

Regulatorysubject: Part-NCC

Typeofcontent: GM to IR (Guidance material to implementing rule)

Parentir: NCC.OP.110 Aerodrome operating minima -- general

Origin: EASA

Category: EAR