Coulson 737 Fireliner Accident near Ravensthorpe Western Australia 6th February 23

[Student Pilot]

The LATs or light air tankers when loaded are close to their max operating weight and performance suffers. The VLAT that was in Oz a few years ago was carrying 40,000 litres and still well below max weight and performed very well with a full load. The operating cost was only just more than the LAT's and delivered nearly 4 times the load. LAT's say loads from 10,000 to 15,000, usually their drops are around the 10,000. 
My experience is the LAT's loads are delivered not heavy enough, they string the loads out and don't get enough coverage. Many times SEAT's (single engine air tankers) are called to reinforce retardant lines or to tackle where fires have burnt through lines. Never had to do that with the DC10.

[RFguy]

So combine oxygen depleted region.... with localized DA  increase of perhaps 6000 feet... (at 60 deg C at sea level)  a. anyone who has ever been in a fire fighting helicopter knows it is a BBQ above the firefront . 

 

The DA and humidity thermocline  is so steep that radio waves over a firefront get diffracted and cannot pass without high loss. 

 

In 2019/20 I was able to watch the DC10 tankers  land, fuel, takeoff from the window of my workshop  (Canberra)  , the departure performance was impressive. 

Edited February 12, 2023 by RFguy

[Carbon Canary]

ATSB initial report now out.

 

Too low, too slow, nowhere to go.

[spacesailor]

Just Happy the crew made it out ! .

 

'' Both pilots escaped with minor injuries before most of the huge plane was destroyed by fire, with Premier Mark McGowan describing their survival as a "miracle".

  Investigators from the ATSB found the pilots attempted to pitch the plane up from the low-altitude drop before its engines could accelerate, seconds before it hit the ridge line.

  "Flight recorder data shows the throttles were advanced and the engines had accelerated just before the aircraft struck a ridge line with the stick shaker activating," ATSB Chief Commissioner Angus Mitchell said.

  "The aircraft then cleared a small line of foliage, before impacting the ground a second time and sliding to rest.
        
            Cabin door stuck

  "Both pilots were unable to open the cabin door as it had buckled and the co-pilot was unable to open the right-side window," the report read.

  Realising the plane was on fire, the captain managed to open the left side window on a second attempt, allowing the pair to escape.

  Crews believed the pilots were trapped inside the aircraft and dropped retardant on the tanker, before the duo were rescued by helicopter with minor injuries. ''

spacesailor

[Garfly]

 

[facthunter]

They are pretty lucky to still be with us. There has to be fairly large forces involved to distort the sliding windows. They are an EMERGENCY exit.   There's a coil of rope in a panel above the window to Lower yourself down t ground level.  Nev

[Garfly]

 

Juan Browne comments on the ATSB report:

 

 

 

[Blueadventures]

On rare occasions when thermaling in gliders I would feel a lift in the tail when going through a thermal slowly.  The tail being light would be lifted in the rising air mass.  May be what caused the bump he refers to.

[facthunter]

The plane was well and truly stalled and that's a high drag situation with the inevitable result if high thrust is not available and perhaps even if it had been. On calm days the HOT air over the end of a sealed runway makes planes fallout of the sky somewhat. The sort of oxygen depleted hot air near bushfires is a real challenge for lift and power as well as turbulence..  Nev

[Old Koreelah]

Op

34 minutes ago, facthunter said:

The plane was well and truly stalled and that's a high drag situation with the inevitable result if high thrust is not available and perhaps even if it had been. On calm days the HOT air over the end of a sealed runway makes planes fallout of the sky somewhat. The sort of oxygen depleted hot air near bushfires is a real challenge for lift and power as well as turbulence..  Nev

I’ve watched local water bombers working a fire on a ridge above us while listened to their radio exchanges.

Bluddy dangerous work; they get hammered and so do the airframes. Not a good place to be low and slow.

[facthunter]

They are old and fatigued planes as well and operating unpressurised and well out of their design envelope. A designed for Purpose firefighter won't have swept wings All control movements create extra drag and so does turbulence.. When all the holes line up you fall out of the sky.  Nev

[Old Koreelah]

Totally true. It intriges me how so many swept-wing airliners get used for low, slow water bombing. Designed for a totally different role. I guess the main reason is so many are available cheaply and there are plenty of pilots with experience in them. 

Several purpose-built water bombers have been developed, but we don’t see many of them.

[facthunter]

It's all about COST but it's also lives potentially. A normally  endorsed B737 pilot wouldn't operate these planes without a fair bit of specialised training and they'd also have to WANT to.. Nev

[Garfly]

Another interesting fire bomber conversion - the Grumman Tracker to the CALFIRE S2-T

 

 

https://en.wikipedia.org/wiki/Grumman_S-2_Tracker

 

 

 

 

Edited May 7, 2023 by Garfly

[Student Pilot]

Interesting yes, not so practical. Oz did have a heap of these from the Navy, they sat for years corroding away until they were finally sold for scrap. Just to convert to turbine power 3 million plus, another million to install a 4000 litre hopper and for the CASA paperwork. The delay in CASA processing add another million and 5 years. 
When they become operational they cost 3 times what an 802 cost to operate and deliver only 500 to a thousand litres more than an 802. You have spent maybe 5 million per aircraft compared to the cost of an 802 at 2 million. Top that off with nobody being prepared to cover the cost of any of this the government would have to pay bringing into play another level of bureaucracy and delay. Todays fleet of 802's are all privately owned and available at no cost to the tax payer, only call when needed or on contract standby cost.

I am no fan of large air tankers, I am a big fan of very large air tankers. The current fleet of lat's in Oz from Herc's to 737's usually only drop up to 11,000 litres. They say they drop 15,000, they don't. 11,000 is still a good load when used rightly. Personal experience is few LATs drops are effective, too light, too high.