sea-plane crash hawkesbury river nsw

[Happyflyer]

Exactly...it’s not the fact that the wings are no longer horizontal that causes the lower wing to stall first...it’s the fact that it has slightly lower airspeed because it is on the inside of the turn...

Wrong. Angle of attack stalls a wing, not airspeed.

 

 

[Awqward]

Wrong. Angle of attack stalls a wing, not airspeed.

Yes...that’s true...in this case the angle of attack is higher because the horizontal component of the relative air is reduced on the inside wing...ie lower airspeed....while the component normal to the plane of the wing is the same....thus the resultant airflow over the inside wing is at a higher angle of attack...so not wrong...just not a full an explanation.

 

 

[Bats]

I see the prelim report is out; little if anything new there and as expected, stall warning devices are on the further investigation list. Sydney Seaplanes bottom line must have taken quite a hit, shutting down operations at peak season and doubling up crew when they did restart. Could easily have been the end of a smaller operator.

 

Investigation: AO-2017-118 - Collision with water involving a de Havilland Canada DHC-2 Beaver aircraft, VH-NOO, at Jerusalem Bay, Hawkesbury River, NSW on 31 December 2017

 

 

[Oscar]

Yes, there is little if anything that is unexpected so far in the report, at least for those with knowledge of the area.

 

The pilot's credentials are pretty much impeccable, I would most certainly have flown in the thing with him as pilot without any hesitation. Why he ended up where he did - when the standard flight path (figure 1 in the ATSB report) would, I believe, in the prevailing conditions have produced an entirely incident-free result, is possibly a mystery that may never be solved.

 

However, there are some seriously important messages (overt and implicit) even in the preliminary report.

 

First amongst those, I consider, is the indication that the 'general area' wind forecast is NOT a reliable indicator of local wind direction in a topographically complicated area. Those who were closely familiar with that particular area know this well.

 

I quote from the report: The aircraft was observed to enter the bay at an altitude below the height of the surrounding terrain (Figure 2).... At 1500 on the day of the accident, the Terrey Hills AWS recorded the wind at 13 km/h (about 7 kt) from the north-east. The Gosford station recorded the wind at 20 km/h (about 11 kt) from the east-north-east. Witnesses positioned in Jerusalem Bay generally indicated that the wind was directly into the bay at various strengths,5 which would have resulted in the aircraft experiencing a tailwind at the time the aircraft entered Jerusalem Bay.

 

 

From personal knowledge of the area, I will state with certainty that any local area wind with a decent Northerly component, results in a curl-over from the terrain to the north side of Jerusalem Bay. Therefore, the vertical component of that wind is descending.

 

So you have a situation of flying at very low altitude into a very topographically tight area, with the terrain accelerating towards you (due to the tailwind) and your climb gradient materially reduced (due to the curl-over).

 

The photograph of the wreckage recovery ( Figure 5 in the report), shows very graphically both how tight the area is, and how steep and completely unavailable is any option for a minimal-impact result on the land; trying for the water is the ONLY option. The geography of Jerusalem Bay would preclude any chance of a nominally 'straight-ahead' landing being an option particularly when it was crowded with moored boats. You might achieve it in a Drifter.

 

Perhaps, more answers will come from the ATSB final report.

 

 

[Yenn]

An alternative to the black box is to use Ozrunways and I assume also Avplans tracking system.

 

I attended a seminar at Narromine where Ozrunways explained how they found the crashed chopper at Curtis Island. They had his flight path documented very well.

 

That chopper pilot was the man who convinced me to use the electronic flight bag.

 

 

[Chinaplate]

For mine, it all hinges on the left hand turn from the original climb out path. This is crucial and what happened in Jerusalem Bay is a distraction imho.

 

 

[onetrack]

Bottom line is, the pilot deviated from the designated flight path, into a much tighter landlocked bay - and I don't think the reason for that will ever be known.

 

It could have been a pax viewing request that he decided he would accommodate - thinking he would be able to easily climb out of Jerusalem Bay.

 

Once in Jerusalem Bay, it's possible he realised he would not have the climb ability to go straight ahead out of the Bay, and made the fatal and sudden decision to do a tight turn and head back.

 

One hopes the pax's recording devices such as phones or cameras will reveal something to assist the investigators.

 

IMO, despite the impeccable record and the high hours in command of the pilot, I see something in the pilots behaviour that is common with extensive experience - complacency, coupled with familiarity. It kills a lot of people.

 

 

[Oscar]

Statement from Sydney Seaplanes: Sydney Seaplanes says crash pilot's actions were 'totally inexplicable'

 

Usual inaccuracies from the media here re the 'standard flight path'.

 

 

[Bats]

Interesting observation re the impact of a wind with some northerly in it, Oscar. I'm not very familiar with the area, but have experienced a similar scenario elsewhere and it creates a fair amount of torque on the sphincter until you fly clear. I've always considered time in some form of unpowered aircraft a bonus in these situations. It will be interesting to read the final report and see what other pax and witnesses have to say; was this a regular deviation or a spur of the moment decision.

 

 

[Gravity]

This sad event may very well go down as unsolved. Plenty of highly experienced pilots flying well maintained machines have left us all way too early. If the final report finds no mech fault then we shall just have to accept that the answer lies with the deceased driver. RIP to all involved.

 

 

[Camel]

Preliminary report released.

 

Investigation: AO-2017-118 - Collision with water involving a de Havilland Canada DHC-2 Beaver aircraft, VH-NOO, at Jerusalem Bay, Hawkesbury River, NSW on 31 December 2017

 

 

[Happyflyer]

Preliminary report released. Investigation: AO-2017-118 - Collision with water involving a de Havilland Canada DHC-2 Beaver aircraft, VH-NOO, at Jerusalem Bay, Hawkesbury River, NSW on 31 December 2017

Is that the same one as post #153?

 

 

[bexrbetter]

It does look like it's as simple as he was distracted and thought the far wall was Cowan point and turned left, realised it, and tried to turn back around.

 

You would think that so soon after lifting off a few of the Pax had videos going that will be recovered. "Sources of recorded information" is on their investigation list.

 

Oscar would know better I guess, but sadly looks like he had the option and room to land again, then turn it around and go again?

 

 

[Camel]

Is that the same one as post #153?

Yes, sorry to repeat.

 

 

[Old Koreelah]

...despite the impeccable record and the high hours in command of the pilot, I see something in the pilots behaviour that is common with extensive experience - complacency, coupled with familiarity. It kills a lot of people.

I suspect you've nailed it, Onetrack. Even the best human can sometimes relax his professionalism enough to make a silly spur of the moment decision. Maybe a phone cam will reveal he decided to satisfy the sudden whim of a paying customer.

 

 

[Bats]

Oscar would know better I guess, but sadly looks like he had the option and room to land again, then turn it around and go again?

Quite possibly not, the footage at the time showed the whole area littered with anchored craft. Getting in there without hitting a mast or hull somewhere along the line would have been a big ask.

 

 

[geoffreywh]

Saw a report last night on BBC that said it had been confirmed by ATSB that the engine was functioning correct and all control cables were in place. Eyewitness and video footage reports that the aircraft had entered a 80 - 90 degree bank!...That is REALLY steep.....I was shocked. .......Plus the Aircraft owners say that the pilot did not have permission to be in that area....Poor buggers....

 

 

[Oscar]

That whole area is extremely cluttered with boats during the Christmas-New Year period. lt is just around the corner - as it were - from Pittwater, where there are literally many thousands of boats. I had every year a holiday with my kids from Boxing Day through to NY day just 'hanging out' in Refuge Bay - just to the NE of Jerusalem Bay - and I kid you not, there were hundreds of boats there. Rafted up for the holiday, as many as ten-fourteen hanging off one mooring!. PARTY-time - major.

 

Pretty much the same for Jerusalem Bay; it is a lovely place to just relax. Anybody in that area (bar the odd dickhead on a Waterski) understands that it is chill-time and you are likely to find kids in tiny inflatables, kayakers, people fishing from tinnies, people just swimming around, everywhere. You go with the flow.. and you do NOT expect there to be a need for stricken aircraft to need a clear landing path.

 

I am going to make a wild postulate here, that is MOST unlikely to be ever confirmed, but I could imagine it to be a possibility.

 

IF the passengers - in a mellow mood after a great lunch in wonderful surroundings - had asked if they could view some more of the area... and there was no immediate booking for a flight after their return, the Pilot might have thought: why not? If you know the area, it is almost impossible to be untouched by the sheer wonder that it exists so close to a large and rather unlovely city..

 

IF distracted, it is not impossible that the pilot actually meant to fly to the mouth of the Hawkesbury River into Broken Bay (which does not show on the ATSB map reproduced) and turn left up the Hawkesbury River to fly over Brooklyn. In the prevailing conditions, that would have been entirely safe and afforded an opportunity to traverse Brerowa Waters Inn, another Sydney Seaplanes destination and one of the most celebrated dining establishments in the Sydney area. Only accessible by water. Iconic. Google it to appreciate.

 

I would like to think that the turn into Jerusalem Bay, which by any objective analysis was a HUGE mistake - was not any sort of 'hot-dogging' by the pilot but a momentary lapse of spatial cognisance. I've had them; who has not?

 

 

[thearb]

Still under investigation: 'aircraft weight and balance'

 

The ATSB must have an idea by now what the weight of the aircraft was on take-off, even if it isn't clear about the distribution. Richard Cousins wasn't a small guy and tragically one of the victims was an 11 year old child.

 

Whether he diverted into Jerusalem Bay in error or deliberately, the aircraft may simply not have had the performance to exit even if operating at 100% capability. There have been numerous incidents in the Rockies in North America where a pilot has flown into a valley with no way of exit due to increasing surrounding height terrain and narrowness making a safe turn impossible.

 

As already mentioned, with a tailwind the point of no return may have swept up on the pilot before he fully realised it.

 

 

[thearb]

You will of course have to make your own mind up whether the pilot intentionally entered Jerusalem Bay or not. To me, it seems highly unlikely that a proficient pilot who had been there many times before would mistake that small bay for the normal route.