Mountain wave?

That Flightpath data exert indicates XWD got down as low as 2,592' then down to 2,411' whilst the other aircraft WVV stayed around the 3,900' mark.
May be there was a aircraft problem.
Does anyone know what height the mount is?

Captain Google says 2,600’

Has all the hallmarks of scud running and getting it wrong - the other aircraft is 1000' higher and gets through...........nothing much more to say.

Departing the city for Ulupna (as reported), if cloud base was an issue then it is a mystery to me why they chose to go via the hills rather than the Kilmore Gap, only a few miles to the west and pretty much on track. RIP.

Even to this day we would not wear our shoulder harnesses in the 212/205/Huey as we are mostly doing external load and with the shoulder straps on you cannot lean all the way out in the bubble window. About 5 years ago we bought the "tilt" seat and now we are able to wear them. Some of the "old School" pilots still refuse however.

Were either pilot instrument rated & were the helicopters IF equipped? Was the second pilot flying on top or in IMC & flew himself out safely?

The descent rate in the final 20 seconds of flight appears to be in excess of 4,000fpm if the surveillance data is accurate.

4000 fpm is basically impossible in free fall, an object would need to be powered to fall that fast. A dropped brick falls at only about 120 mph. I hope my maths hasn't gone too astray!

It's only 45 MPH Nigel, 5280 fpm is 60 MPH. A brick would be far higher than 120 MPH, which is what a skydiver in belly to earth falls at, on average, they use weights and tight/loose clothing to adjust free fall speeds relative to one another, Grand Slam and Tall Boy bombs of WWII impacted at some 750 MPH, only power required was an aircraft to drop them from.

Some passenger jets climb at in excess of 3,000fpm.

4.000 fpm decent is easy possible - had it on the VSI more than once - but deliberate ;-)

Without going too far OT, the BK117 managed 4,000fpm RoC back in the last century, passenger jets way more than that. RoD for most helicopters would be >2,000fpm in an auto although some come down like the proverbial brick: the Wasp/Scout was 3,500-4,000fpm in a 'normal' auto. 360* autos in a Squirrel can reach the 3,000fpm RoD, too, within the error of FR24 readouts.

Back On topic, the Kilmore Gap sort of made it easier to get through the low cloud around Disappointment and the Macedon Ranges, is it still local knowledge or has the Magenta Line overruled such options? I haven't seen any mention of a mechanical failure, but it can't be discounted until the initial report comes out.

Unless the debris field is well spread , which might indicate an in-flight break up of some sort, there probably won't be enough left to reach much of a conclusion about mechanical failure.

Was always too scared to look John, besides, was too busy scanning the potential crash site. :p

Didn't the ROC max out at 2000 fpm?

C'mon, don't spoil the dit :p

One story is that the ROC is limited to 2000fpm because if the engine quit, the aircraft would keep going up for a while and by the time the ROD was sufficient to turn the blades in autorotation, the RRPM was too low for it to work.

However, that might be a load of horsefeathers.

If I remember rightly, the 407 has a 2000 FPM ROC limit for that reason.