Clues. CPLS or TANS
I have not seen a shred of evidence to show that CPLS was even switched on the day of the crash.
The RACAL report has the SUPERTANS working to a high spec until it was "Powered Down" some 32 secs before impact. The power switch was found by Mr Cable to be in the Off Position at impact.
Some contend that impact knocked the switch to off. I have used several varieties of TANS and find this to be unlikely. If switched On the massive G of impact would certainly dislodge the switch but it is designed to fall back to its original position.
Can I be certain of this? Of course not. Crashes do strange things.
But a combination of the 32 Sec Powerdown and the Switch in the Off Position suggest Switch Off by the crew at 32 Secs to impact.
But the RACAL analysis says the crew had just completed the (three?) button pushes to do a Manual Waypoint change. Why use the kit then switch it off?
I have never been a Chinook operator but I can think of experiences on other
aircraft which would force me to ditch a good accurate piece of Navigation equipment.
Tornado (80's version). Double Generator Failure Drill.
You have a couple of minutes before the engines accelerate to oblivion. The more load you shed, the longer you get to deal with the emergency.
C130. Mains AC failure. Not as critical as on the Tornado, but all non essentials are switched off. If you are VFR then TANS is not essential.
So crew distracted by a critical drill? Who knows, but at least the availabable evidence points to the possibility.
Last edited by dalek; 22nd Jun 2011 at 11:55.