Aerodrome operating minima - use of data in commercially available charts

Ednei Amaral • 11 July 2022

in community Air Operations

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Hi all,

I'd like to understand how it is expected to be, in practice, the determination of aerodrome operating minima (AOM) by operators, when they use charts provided by commercial organizations (eg. Jeppesen).

From the rules, I understand that CAT.OP.MPA.110 and associated AMCs stablish acceptable methods to determine AOM. And the new "GM7 CAT.OP.MPA.110 Aerodrome operating minima' says the operator is responsible for ensuring the AOM are in accordance with the methods in operator's manual Part C.

On the other side, the organization which publishes charts (which could be commercial or governmental) does these charts for every operator, and may use methods different from that of AMCs associated to CAT.OP.MPA.110, and that may vary for each country (eg, TERPS, for US; or a specific method for a smaller country).

In this scenario, how is it expected the operator to comply with the rules?
1) is it acceptable that the operator includes, in its OM Part C, these different methods used by the chart providers for each country, so that - once the authority has approved these methods [per the new CAT.OP.MPA.110(d)] - the operator can use the charts provided?
2) Or is it required that the operator uses always the same method (as provided in AMCs associated to CAT.OP.MPA.110)? In this case, is it required the operator adapts - or requires from the chart provider an adaptation of - the charts so that they present AOM in accordance with the method of that operator? Or would it be possible to keep the charts as they are, and the operator would ignore the minima intormation in the charts, and would publish the operator's AOM elsewhere?

My main doubts are on feasibility of these solutions. In the first scenario, in doubt if the operator would have access to how the commercial organization (or State of aerodrome) determine AOM, in the same level of detail as AMCs associated to CAT.OP.MPA.110; and whether it would be practical to have a different method for set of different countries. In the second scenario, in doubt if the provider (specially States) would do these adaptations; and also with the risk of confusion if the operator uses the charts provided, but not their minima, which should be consulted elsewhere.

Thanks for any thoughts on this issue.

Comments (3)

Robert Gottwald • 1 year ago

The whole point of CAT.OP.MPA.110 is to require operators to establish their own operating minima specifically for their operation. These minima consider the minima in the AIP (as in the old point (a) and new point (b) (12)) and they must never be lower than these (unless specifically approved). Operator AOM must also account for all these factors specific to the type of and risk inherent in the operations being conducted by the operator.
To make these minima available in an accessible and usable way, most operators contract chart providers such as Jeppesen or Lido to develop and produce charts with these operator-specific (and usually also aircraft-specific) minima as part of the OM-C for them.

None of this has been changed. The new CAT.OP.MPA.110 merely clarifies the safety objective of ensuring "separation of the aircraft from terrain and obstacles and to mitigate the risk of loss of visual references during the visual flight segment of instrument operation operations". The list of items has been reworded to be more ICAO-aligned and more general.
I do think that the new version lacks the clarity of the previous point (a) stating "These minima shall not be lower than those established for such aerodromes by the State in which the aerodrome is located, except when specifically approved by that State.", which I think lead to this question.

Ednei Amaral • 1 year ago

Thanks, Robert!
From your answer, I understand the scenario 2 would be the practice, with chart providers adapting their material in accordance with operator's method. I have only seen Jeppesen charts for general use, and did not know they also provide operator-specific charts (for example, taking the US airports minima, based on TERPS, and recalculating the minima based on CAT.OP.MPA.110 methods).

Finally, I understand this point that the minima shall not be lower than those promulgated by the State of the aerodrome, and I agree it seems less clear now. It appears in AMC3 CAT.OP.MPA.110 as "the published approach procedure DH or minimum descent height (MDH) where applicable;" and "the published approach procedure MDH where applicable;", for example, but it seems not so clear for visibility/RVR now.
However I don't think it was the focus of my previous message.. My doubt was more in the practical side: when the operator minima is higher than State minima, how would this operator minima be put on the chart?

Robert Gottwald • 1 year ago

There is no standardized way to depict operator-specific AOM. Jeppesen will label them as "Tailored", whereas in Lido charts they are labelled "Company".
For most operators though, most of the minima will be the standard values as the operator would have the method used to derived these approved.

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