Aircraft C ontrollability& Certification With All Engines Failure
Hi,
25.671 FAR (d): The airplane must be designed so that it is controllable if all engines fail. Compliance with this requirement may be shown by analysis where that method has been shown to be reliable.
I am wondering about the meaning of this regulation especially the bolded words on the context of this regulation. For example what’s the meaning of:
a)controllable: being able to control the aircraft and land at airport only or any place (field, water,..), or it means something different?
b)All engines fail: wondering if it includes birds strike, ash volcano, heavy rain/hail, maintenance mistakes, fuel mis-management/exhaustion,…etc or it means only failures that are related directly to engine such continuous surge, no/low pressure oil,…etc
c)May be shown: I guess a confusing word. If aircraft manufacturer can’t show this requirement by analysis, what’s the other alternative?
d)Analysis: What kind of analysis?
What’s the JAR that’s equivalent to FAR 25.671(d)?
What do you think about this regulation (FAR 25.671(d) or the equivalent JAR especially while looking at the past or recent incidents/accidents after all engines failures? FYI FAR 25.671(d) was issued on 04/01/1970.
Feedback appreciated
Regards