sea-plane crash hawkesbury river nsw

[facthunter]

Sailing and flying overlap. Surface winds exist are not predictable. Planes do not run on rails. Like a sailboat they respond to wind they encounter.. Local knowledge is the key for many situations. Anabatic and katabatic winds, standing waves, mechanical turbulence Dust devils etc as examples Nev.

 

 

[old man emu]

There are a few facts surrounding this incident that we do know.

 

1. The pilot had approx 9000 hours total time, of which about 8000 were on floats, and a lot of that in the Canadian bush

 

2. He had flown for Sydney Seaplanes for a few years, then had about two years overseas, and had been back here working for Sydney Seaplanes for about the past two years.

 

3. The aircraft are well maintained, both at their water base and at Bankstown.

 

4. The internal control cables were gal wire, with stainless used down to the floats. Inspection of the cables is included in the maintenance schedule for the 100 hourly.

 

5. The plane entered the water vertically.

 

6. The floats did not bring the plane to the surface as one would expect if it went into water 40 feet deep.

 

7. The seating arrangements were:

 

Row 1 - Two individual seats, Pilot + one seat

 

Row 2 - Bench seat, 3 Pax

 

Row 3 - Hammock seats, 2 Pax.

 

The disposition of the pax has not been released.

 

8. The flight was a 20 minute milk run in VFR conditions.

 

The only difference I can see in the wind pattern is that on the day of the incident, the wind around the time was changing from a generally southerly direction towards the east (slightly), whereas the usual afternoon winds are north easterlies, but I haven't got the data for the time of incident.

 

 

[Methusala]

Coincidence is unpredictable (by definition). Ever come to an intersection on a slow day when roads are all but deserted? Suddenly there are two cars approaching from opposite directions and a couple of bike riders as well. As you drive away the roads are again deserted. Funny thing, the law of (im)probability.

 

 

[Oscar]

In any Easterly, we would always anchor off the East side of the mouth of Jerusalem Bay, as close as prudent to the East side of the bay, where (if you look at the topography) there is a high and steep escarpment. In anything with an Easterly component, most of Jerusalem Bay has become useless as an anchorage, due to the sedimentary run-off from the Northern Freeway out of Hornsby. I have had personal experience of being dragged on anchor almost onto the upper end of Jerusalem Bay, several times, when the wind changed to a moderate Easterly. Makes for a disturbed night.

 

An aircraft taking off from Cottage Point and then turning left for a run up Jerusalem Bay rather than right to head for the open area of Broken Bay past the mouth of the Hawkesbury would suddenly run into the rapidly descending and slowing air of the curl-over from the Eastern escarpment. Thus both dropping the turn options due to the tight terrain limits and also reducing airspeed - particularly when suddenly encountering downwind conditions.

 

I would imagine that the situation for the pilot was therefore having to make what equates to a low and slow final turn into a downwind with a significant descending vertical component rather than into wind with a reasonably constant vertical component with no options to alter course due to the proximity of the hills around.

 

I do not have any experience that would allow me to make a judgement as to whether a float-equipped Beaver has the power to simply pull it out of such a situation.

 

There is such a thing as a 'danger envelope' - determined by airspeed, height, power and load etc. Maneouvering area has to be added to this.

 

I believe that only an intimate knowledge of the local area wind patterns under all circumstances would provide a pilot with the necessary information to make judgement of where NOT to go at a given moment of time and low height. I can say with some certainty, that the wind at Cottage Point at T/O, would NOT be a reliable indicator of local conditions based on conscious experience from around 1952 through to at least 2002. I doubt that the wind has changed characteristics in the last 15 years.

 

As nomadpete suggested above, this was most likely a case where all the holes in the Swiss cheese lined up against the pilot.

 

Sometimes, we should be ready to accept that 'shit happens'. It hurts us all as aviators when it does, and I agree that any useful information that MIGHT prevent a recurrence should be exposed - but Fate is Fate, in the ultimate reckoning.

 

 

[Chinaplate]

Oscar that makes a lot of sense. I have some experience sailing there. I am very surprised that the plane would turn left into Jerusalem Bay rather than continue to climb out to the NE and then eventually turn right to head south. The prevailing at the time of the incident at Gosford was moderate NE. So turning left would immediately reduce airspeed. If the pilot recognised a problem at this stage, any hard right would already be on the edge of stall speed. I am always amazed watching those planes and feel that they dont have a lot of margin.

 

Does that mean that their normal mode of operation is a left into Jerusalem Bay and then climb out over the highway? That surprises me.

 

 

[Guest extralite]

"The prevailing at the time of the incident at Gosford was moderate NE. So turning left would immediately reduce airspeed."...let me get some popcorn before the discussion starts. . Story from someone claiming to have had a previous rough trip. ‘I thought I was going to die’ Very tragic accident for the families.

 

 

[facthunter]

I don't accept the fate stuff or trust luck.. The more you do to anticipate, the bigger the margins and the more risk averse you are the luckier you become in this aviation game. The idea planes fly themselves. (They CAN but they usually don't) is misleading. If some catastrophic event like a component failure happens it could be you have no control over your fate.. When things go pear shaped, keep at it and you have a fighting chance. You can't get someone up there to help. You are it.. Nev

 

 

[bexrbetter]

CNN International reporting a C208 Caravan crashed in Costa Rica killing 10 passengers and 2 crew.

Sadly a similar loss of families, a family of 5, Mum, Dad, 3 sons, and a family of 4. Mum, Dad, Son and Daughter.

 

 

[facthunter]

As is frequently the case. A connected group. Often a football team or such. Tragic . event. Nev

 

 

[Oscar]

Some further information has emerged in a report in the Sydney Morning Herald, that I believe raises some issues.

 

"The aircraft took off in a north-easterly direction, followed by a turn to the north-west, then a subsequent right hand turn prior to impact," Nat Nagy, an executive director of the Australian Transport Safety Bureau, said.

 

It seems to me that that flight path - if one places it over a picture of the topography - is inimical to the basic concepts of minimisation of risk in the case of an EFATO. The initial turn to the north-west was towards steeply rising ground with absolutely no area for a safe forced landing ahead other than perhaps the water, which was crowded with boats at the time and from reports and video evidence, done at around 200 feet or so. That there was room to initiate a turn to the right surely suggests that the previous left-turn had been quite tight.

 

Beavers have without doubt an almost legendary capability, but I wonder what margin of safety for an EFATO was left in this case? I think it would not be outside the realm of possibility for an expert investigator to match up flight performance against the topography to make such an evaluation.

 

 

[facthunter]

Perhaps someone wanted to fly near/over a particular locality? Nev

 

 

[Chinaplate]

Some further information has emerged in a report in the Sydney Morning Herald, that I believe raises some issues."The aircraft took off in a north-easterly direction, followed by a turn to the north-west, then a subsequent right hand turn prior to impact," Nat Nagy, an executive director of the Australian Transport Safety Bureau, said.

 

It seems to me that that flight path - if one places it over a picture of the topography - is inimical to the basic concepts of minimisation of risk in the case of an EFATO. The initial turn to the north-west was towards steeply rising ground with absolutely no area for a safe forced landing ahead other than perhaps the water, which was crowded with boats at the time and from reports and video evidence, done at around 200 feet or so. That there was room to initiate a turn to the right surely suggests that the previous left-turn had been quite tight.

 

Beavers have without doubt an almost legendary capability, but I wonder what margin of safety for an EFATO was left in this case? I think it would not be outside the realm of possibility for an expert investigator to match up flight performance against the topography to make such an evaluation.

Yep, I reckon the investigation will focus on why that first turn took place.

 

 

[Birdseye]

From a quick view of Mr Nagy's LinkedIn profile, I don't see much flying experience.

 

 

[Oscar]

Perhaps someone wanted to fly near/over a particular locality? Nev

Nev - you may well be correct, though what is 'particular' about Jerusalem Bay beyond the fact that it is part of the Kuringai National Park I cannot think, and I know it like the back of my hand. It is a lovely place - I have anchored there nearing hundreds of times - but there is no natural feature that is outstanding by comparison with anywhere else on Cowan Creek, and absolutely no man-made features at all.

 

I have no issues with Sydney Seaplanes wanting to provide visitors here with a deep appreciation of the wonderful area that is the Kuringai National Park - I think it is almost a wonder of the modern world that such an area can be found in such close proximity to a city of 2M people. I used to, whenever possible, take my visiting international friends on a cruise on my boat around Pittwater and into the KNP and without exception their reaction to the immense change from the urban sprawl to the graceful peace of that area was amazing to them and a matter of national pride to me. I think that many, many visitors to Sydney have come away from a Sydney Seaplanes flight in the KNP with deep affection for the beauty of the area - and that is an admirable achievement, they are to be applauded for that.

 

BUT - the laws of physics are not modified by emotion.

 

There will be an ATSB investigation and pending that it is probably a good time to suspend supposition of the circumstances of this sad occurrence.

 

 

[facthunter]

Perhaps I broke my own rule going there.

 

Regarding the requirement to have a stall warning device, that's still not come out. ALL Cessna's, Pipers Beech etc had them at that time. I can't recall any going off above about 6 inches off the ground, unless practicing or teaching stalls. I'm not against having them there . They wanted one fitted to the DH 82 at one time and I was part of the charge to resist that, on the basis there is no electrical system and it's stall is conventional with pre stall buffet, But why wouldn't a thing like a Beaver have one? Nev

 

 

[djpacro]

A stall warning switch on one wing is of limited value in some scenarios where it really matters. I can demo a skidded turn in one direction with my airplane - nil warning and an aggressive spin entry. In the standard practice stall it has the required warning 5-9 kts prior.

 

 

[facthunter]

Yes that's true. I'm not arguing the merits of one, more of a consistency of policy issue, but it's not a hazard to have one except like many warnings, it can be distracting when you KNOW you are trying to get the absolute limit out of the plane. because that's the situation you have put yourself in. I guess if I was designing one I would use about 5-9 knots buffer.. Nev

 

 

[Hargraves]

A terribly sad day for all concerned and just awful news to hear about for everybody. Looking at the recovered wreckage leaving the water, in particular the floats it looks like it may be just about impossible to determine their pre takoff condition in regards to one or others watertight integrity, which possibly may be a factor if indeed it was a low speed stall that occoured to such a safe and very experienced pilot.

 

 

[Awqward]

The prevailing at the time of the incident at Gosford was moderate NE. So turning left would immediately reduce airspeed.

Oh dear...

 

 

[ozbear]

Sailing and flying overlap. Surface winds exist are not predictable. Planes do not run on rails. Like a sailboat they respond to wind they encounter.. Local knowledge is the key for many situations. Anabatic and katabatic winds, standing waves, mechanical turbulence Dust devils etc as examples Nev.

Not to forget Rotors on the lee side of hills Nev probably wouldn't worry sail boats but aircraft close to stall speed and low to the ground something to be wary of.

 

 

[Oscar]

Actually, there is a fairly close correlation between the effect of a rotor behind a steep hill for yachts and for aircraft, but you have to think in horizontal rather than vertical.

 

You can be comfortably broad-reaching across the line of the shore in the true wind, which at that point is an off-shore breeze. Then, sail into the rotor, and suddenly you are in an on-shore breeze, and having to tack off the (now) lee-shore. And if you've been somewhat scraping along on that reach with a spinnaker or large Genoa up, you really have to scramble at times to get that off and things re-set for the tack away... I have seen West Head from WAY too close for comfort, in exactly that situation in a WNW breeze, and I was very conscious that it could happen.

 

 

[Sluf7]

Doing a plus 30 degree turn at MAUW will induce a stall has happened many times

 

 

[facthunter]

The real issue in turns is the extra drag associated with increasing the bank angle.. If you have limited power available your only safe way to maintain a safe speed (margin over stall) is to lose height.( Potential energy)if you have the room to do that. Nev

 

 

[Oscar]

A turn effectively crosswind would reduce the climb gradient, with rising ground ahead adding to the dicey situation; the subsequent turn back into wind should have helped BUT you have the three factors of a tight turn causing further loss of height, even more steeply rising ground, and increasingly limited maneouvering area. IF there was any curl-over, and the eastern shore of Jerusalem Bay is a prime location for that - suddenly, it would be all cards in the deck stacked against the unfortunate pilot.

 

If you look at the photos here:

 

Google Maps

 

You can see just how steep the sides of Jerusalem Bay are ( the east side is the left-hand side in the photos)

 

 

[SDQDI]

The prevailing at the time of the incident at Gosford was moderate NE. So turning left would immediately reduce airspeed.

Is that really how it works? Maybe I need to refresh my understanding of physics but I would have thought if a plane is flying balanced and turned downwind it would NOT change airspeed any more than turning upwind.

 

Doing a plus 30 degree turn at MAUW will induce a stall has happened many times

Unless this comment relates to specifics of this particular plane i have trouble understanding it. I am guessing you mean 30degrees angle of bank rather than just turning 30 degrees left or right, but I don't understand how passing the 30 degree mark somehow induces a stall? Again assuming a balanced turn I would say it would increase your stall speed but to say that would induce a stall i find a bit simplistic.