Impact Engineering Working Group

Report from the Impact Engineering Working Group

We had several very interesting topics presented at this IBSC meeting. Rather than pull them into a separate session they were woven into the fabric of related sessions.

Birdstrike tolerance is the last line of defence. It is the requirement which is added when all other means of preventing birdstrikes result in a level of risk that is still deemed higher than acceptable and therefore unsatisfactory. By its nature then, the risks of a birdstrike in excess if the requirement are deemed acceptable. Change is inevitable as we all know and what was acceptable yesterday is not necessarily acceptable today.

We have all heard about incidents/accidents as evidence of the need to increase birdstrike resistance. There is no question, birdstrike resistance can be increased. It is primarily just an issue of demanding that specific birdstrike tolerance requirements be designed into the structure, verifying that the desired capability is actually available, recognizing that birdstrikes exceeding the design requirements are likely to cause consequences beyond that deemed acceptable at the design conditions, AND, that this is acceptable. This is not meant in any way to minimize the task. It is a complex and costly task and is never implemented without serious attention to the consequences of making/not making a change to the requirements. Highly specialized risk analysis tools, design tools, and materials are available as are also the tech experts who are competent in their application.

Increasing the tolerance requirement typically adds cost, a logistics cost tail, and may add weight. The consequences of this will be traded-off against the cost consequences of not increasing the tolerance capability. This trade-off will be heavily influenced by the availability of operational statistics and it is for this reason that the community must continue to encourage the recording of birdstrike events.

Those who are in support of, as well as those who are against, any increase in requirements will draw from the same pool of operational statistics. If you become involved in either side of the argument about revising a tolerance requirement, I suggest that you review my presentation about the art of influencing decisions—Decisions are NOT made in the best interest of those that are either for or against any change, BUT rather, the decisions are made in the best interest of the one(s) that are responsible (accountable) for living with the consequences of making, or not making, the change.