NPA to JAR-OPS 3

[JimL]

Stinger,

As I hinted in my first post, the introduction of Exposure with its associated Appendices resulted from NPA-8 (in 1998); the proposals do not, in respect of Battersea, change anything at all. It is my understanding that existing operations are permitted by the CAA under the ANO, or under JAR-OPS 3 with exemptions. UMS (when exposure is permitted) has been a JAR-OPS 3 requirement for the last seven years.

For elevated heliports, the need for AEO HOGE performance - both for PC2 and 3 - is based upon a practical consideration that delta power above that required for hover in ground effect will be required if a dynamic procedure is to be used; even if a pull-and-go is used (for example in a single) the erosion of the ground cushion would result in a dangerous condition if sufficient power is not available to arrest the descent. (Those who operate S76As from the North Sea rigs will understand this only too well.)

With the proposal for the introduction of ground level exposure to 200ft, operations to limited areas which require steep or vertical climbs are envisaged - hence there is a need to introduce AEO HOGE performance to the rule under such conditions. (For PC2 there is also the base line requirement for second segment climb performance (150ft/min at Vy, 1000ft above the take-off surface).)

The conditions are not tied to the requirement for AEO HOGE performance but Exposure per se - the additional requirement for AEO HOGE has always been present in guidance but (with the proposal for the introduction of ground level exposure) it was considered that it would be better inside the rule.

EESDL,

I fear that my point (also made by others) may not have been well enough stated; with the understanding of how operations to Battersea are permitted (for which the condition of use have not changed for seven years - and in substance will not change with the introduction of NPA OPS-38 - i.e. the CAA permit operations by exemption) you may go about your business exactly as you do today. If however, you wish to take advantage of the introduction of ground level exposure (which was graphically described by CRAZYBROADSWORD above) which is proposed, you will need to apply the mitigating clauses.

The need for the provision of a safe-forced-landing - which derives from ICAO Annex 6 Part III - has always driven the requirement for operations from open areas; the proposed amendment to ICAO and to JAR-OPS 3 permits the State(s) to accept operations with Exposure (without the provision of a safe-forced-landing) when they are appropriately risk assessed. The JAA, in the explanatory text of NPA OPS-38, explains how ground level operations with exposure can be permitted to the existing safety target providing the engine achieves the reliability figure of one failure in 100,000 flight hours. One of the elements for the achievement of such a reliability figure is that certain events are eliminated or captured (to be appropriately dealt with).

UMS can assist in the achievement of this reliability figure in that it can prevent ‘hot starts’ (which change the structure of the crystals in the turbine blades) and inculcate a more considered approach to engine management (along with power assurance checks and improved maintenance procedures).

However, if you wish to continue to operate as you do today and not take (commercial) advantage of operating with ground level exposure, do so and there is no penalty.