Helicsa S61 - Tenerife - Prelim report
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Helicsa S61 - Tenerife - Prelim report
Prelim report on S61 Tenerife crash published last month. MRB failure of Black Blade highlighted, with indications that BIM system/refilling valve on that Black Blade were leaking days before accident, and that maintenance as per MM carried out.
20 mins into the flight, the Cockpit BIM lights up, we know this because the Pilot announces "Look we are at BIM PRESS"and nothing more is heard of relevence on the CVR until the Black Blade lets go 30 mins later. My reading of this is that everyone assumes it is the unreliability of the monitoring system rather than a fatigue crack. Hence the blade lets go with the inevitable consequences.
Blade had 6750 hrs on it. I suppose we shall never know, outside a courtroom, what advice was going to and from UTC and Helicsa about the reliability of the BIM system.
20 mins into the flight, the Cockpit BIM lights up, we know this because the Pilot announces "Look we are at BIM PRESS"and nothing more is heard of relevence on the CVR until the Black Blade lets go 30 mins later. My reading of this is that everyone assumes it is the unreliability of the monitoring system rather than a fatigue crack. Hence the blade lets go with the inevitable consequences.
Blade had 6750 hrs on it. I suppose we shall never know, outside a courtroom, what advice was going to and from UTC and Helicsa about the reliability of the BIM system.
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response to Toolguy
It was going 120kts just before the radar trace was lost, and no prior speed is given in the report.
Arguably, they could have done an emergency stop in Tenerife, and if the light had been a one-off, then for sure. But the context and build up to this accident seem to show that a properly diagnosed leak from the refilling valve, temporarily repaired as per MM, was the suspected cause of the inflight BIM alert. However, they were sadly wrong: Justified "confirmation bias".......I just do not know!
Arguably, they could have done an emergency stop in Tenerife, and if the light had been a one-off, then for sure. But the context and build up to this accident seem to show that a properly diagnosed leak from the refilling valve, temporarily repaired as per MM, was the suspected cause of the inflight BIM alert. However, they were sadly wrong: Justified "confirmation bias".......I just do not know!
