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Convair 340 (C-131D) ZS-BRV crash Pretoria, South Africa

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Convair 340 (C-131D) ZS-BRV crash Pretoria, South Africa

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Old 16th Jul 2018, 16:58
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Did a little time on Curtiss C46. Engine failure if you could start chucking the freight if you couldn’t pick a field. But they we’re controllable & great fun to fly. Different times different rules. To be honest that experience stood me in very good stead with the big jets. Imho the pilots in this incident were some of the best so there for the grace of God.
Hope they recover.
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Old 16th Jul 2018, 17:00
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Originally Posted by The Ancient Geek
With both pilots alive they should be able to give a good account of what happened to the enquiry, they should be out of hospital soon. There may well be other contributing factors such as problems with the gear or flaps.
They got the gear up very early while still being over the runway. That shows that they where aware of the situation pretty soon.
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Old 16th Jul 2018, 19:36
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Anyone know if #1 prop was feathered at any point,and, if the aircraft used water/water-meth. injection...?
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Old 16th Jul 2018, 20:41
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They got the gear up very early while still being over the runway. That shows that they where aware of the situation pretty soon.
Hmm, could be, but my recollection of flying in the piston era was that the gear coming up early was fairly standard.
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Old 16th Jul 2018, 20:41
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Originally Posted by EDML
They got the gear up very early while still being over the runway. That shows that they where aware of the situation pretty soon.
You'd select gear up as soon as you had a positive indication of climb. That's usually over the runway.
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Old 16th Jul 2018, 23:28
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I remember the instructor for my initial Convair class saying that the gear retract speed was the fastest of any of its generation aircraft specifically to improve the engine out performance.
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Old 17th Jul 2018, 01:33
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Originally Posted by sycamore
Anyone know if #1 prop was feathered at any point,and, if the aircraft used water/water-meth. injection...?
On a South African forum it was reported that they had planned to use water/meth for this take off. Apparently this was infamous for causing backfiring leading to the auto feather engaging so many crew didn't arm the auto feather. The use of water/meth could well explain the popping we hear on take off. They also had a habit of exhaust system fires aft of the engine.

Looking at the vid from the Cessna I would guess that they had both engines running until they turned onto base considering the speed they were doing. Something happened on the base leg for them not to turn onto final. May be they shut down the engine and it wouldn't feather.
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Old 17th Jul 2018, 02:20
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Most likely Cylinder head cracked then blew off thus constant smoke out one exhaust on that cylinder side. If it dropped a valve it will maintain power at 30 inches or barometric but will PUFF Smoke not stream smoke. If smoke trailing from both exhausts it is a blown supercharger drive seal or broken supercharger drive the later will have the engine stop and windmill, if it breaks the front reduction gearbox gear may end up with a run away prop.
With blown off cylinder head you can in emergency keep running the engine at higher power (or barometric if its banging to much with the blown cylinder ) which is what you maybe seeing going on from the Cessna video and the takeoff. It shakes like hell for few minutes but will put out until the piston comes apart, breaks the rod at which time you feather it . Sometimes will run 1 minute sometimes 2-3mins dependent where the cylinder head comes off. Had 8 failures myself with R1830-92 and R2800-CB16s. 1 Master rod, 1 rod, 2 dropped valves the others were cylinder head blew off some through the cowl. When these big radials stop suddenly from seizure other things break and shear it is a lot of mass and moving parts
All my failures on takeoff or first stage power reduction. All at sea level and that was bad enough. Just some technical thoughts but the investigators will advise later.

They did a good job with what they were given on the day, speedy recovery to all..
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Old 17th Jul 2018, 02:23
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Originally Posted by A Squared
You'd select gear up as soon as you had a positive indication of climb. That's usually over the runway.
I do know that. However, seeing the very shallow climb I seriously doubt they had a positive indication on the VSI. They where desperate to reduce the drag ASAP.

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Old 17th Jul 2018, 03:58
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Originally Posted by EDML
I do know that. However, seeing the very shallow climb I seriously doubt they had a positive indication on the VSI. They where desperate to reduce the drag ASAP.



So, how much experience do you have flying recip airliners from that era? I have quite a few thousand hours in them. Different airplane, same engine. I can tell you a couple of things, one is that on a hot day, in good VFR conditions it was absolutely normal to make a very shallow initial climb. The reason being that you wanted to build airspeed rapidly, to increase the cooling airflow over the cylinders, which will be hovering around redline very quickly, and also to more quickly reach the airspeed at which you make the first power reduction and also allows you to turn off the ADI, which causes the fuel air mixture to enriched. And yeah, you most certainly do get a positive rate indication on your instruments with a very shallow climb like that. Gear retraction at my airline was called as soon as the VSI was above zero and the altimeter was showing positive movement. That would be pretty much what you saw in the video. There's aren't turbine aircraft, they don't fly like turbine aircraft, you don't fly them like turbine aircraft, and they don't look like turbine aircraft when you're watching them.

Last edited by A Squared; 17th Jul 2018 at 14:21.
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Old 17th Jul 2018, 07:32
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Originally Posted by 4 Holer
Had 8 failures myself with R1830-92 and R2800-CB16s. 1 Master rod, 1 rod, 2 dropped valves the others were cylinder head blew off some through the cowl. When these big radials stop suddenly from seizure other things break and shear it is a lot of mass and moving parts
.
amazing, 8 failures would give you grey hair, thank goodness for the jet age
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Old 17th Jul 2018, 08:32
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Originally Posted by EDML


I do know that. However, seeing the very shallow climb I seriously doubt they had a positive indication on the VSI. They where desperate to reduce the drag ASAP.

Sorry to be pedantic but at, or soon after rotate the VSI, depending on the type of aircraft may well give erroneous readings. As correctly pointed out above, a positive climb is reliably indicated by the altimeter.
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Old 17th Jul 2018, 11:13
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Apparently this was infamous for causing backfiring leading to the auto feather engaging so many crew didn't arm the auto feather.
Sounds like an Old Wives Tale. Flying the Convair 440 I have used ADI on hundreds of occasions. Not once did I experience back-firing on take off. Certainly we experienced occasional rough running due to spark plug fouling with 115/145 Octane fuel but it usually cleared itself during initial climb. As far as I recall autofeather was armed for every take off. .
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Old 17th Jul 2018, 11:17
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Positive Climb

Originally Posted by Dan_Brown
Sorry to be pedantic but at, or soon after rotate the VSI, depending on the type of aircraft may well give erroneous readings. As correctly pointed out above, a positive climb is reliably indicated by the altimeter.
I do not dispute the point regarding erroneous VSI indications, however the call often is "Positive Rate, Gear Up"
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Old 17th Jul 2018, 12:33
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Originally Posted by A Squared
So, how much experience do you have flying recip airliners from that era? I have quite a few thousand hours in them. Different airplane, same engine. I can tell you a couple of things, one is that on a hot day, in good VFR conditions it was absolutely normal to make a very shallow initial climb. The reason being that you wanted to build airspeed rapidly, to increase the cooling airflow over the cylinders, which will be hovering around redline very quickly, and also to more quickly reach the airspeed at which you make the first power reduction and also allows you to turn off the ADI, which causes the fuel air mixture to enriched. And yeah, you most certainly do get a positive rate indication on your instruments with a very shallow climb like that. Gear retraction at my airline was called as soon as the VSI was above zero and the altimeter was showing positive movement. the would be pretty much what you saw in the video. There's aren't turbine aircraft, they don't fly like turbine aircraft, you don't fly them like turbine aircraft, and they don't look like turbine aircraft when you're watching them.
Only airplane with a radial engine I have ever flown was a T-6/Harvard (also in South Africa). Of course that is no airliner and it has plenty of power.

Anyways, from your experience would you rate the climb while over the runway (and of course still accelerating) as normal for these kind of aircraft? Of course the density altitude of at least 5,000ft (not sure about the OAT that day) plays a big role, too.

I am just interested if they still had power from the left engine at that point. There is no visible yaw and no bank towards the "good" engine but unfortunately you can't see the rudder on the video or any of the pictures after lift-off.

Does anybody know the blue line speed of a CV-340?
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Old 17th Jul 2018, 14:14
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Originally Posted by Centaurus
Sounds like an Old Wives Tale. Flying the Convair 440 I have used ADI on hundreds of occasions. Not once did I experience back-firing on take off. Certainly we experienced occasional rough running due to spark plug fouling with 115/145 Octane fuel but it usually cleared itself during initial climb. As far as I recall autofeather was armed for every take off. .
I had never heard of ADI causing backfiring either, at least not a properly functioning system. I did have one incident where I rejected a takeoff due to backfiring and it turned out to be a ruptured diaphragm in the ADI regulator. However that problem made itself evident as soon as the throttles were pushed up far enough for the ADI flow to start. WE didn't arm auto feather, but it was only required for takeoffs over 100,000 lb, and our operations were relatively short legs so were were always landing weight limited, so never needed to depart over 100,000lb.
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Old 17th Jul 2018, 14:29
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Originally Posted by Old Fella
I do not dispute the point regarding erroneous VSI indications, however the call often is "Positive Rate, Gear Up"
Meaningless semantics. A Positive Climb is inherently also a positive rate of climb. The SOP call at my current airline is "Positive Climb"
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Old 17th Jul 2018, 14:42
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Post WWII most piston airliners were certified on 115/145.

On 100LL derates have to be applied. Engine out performance on 100LL will be less than on 115/145.
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Old 17th Jul 2018, 14:44
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Originally Posted by A Squared
Meaningless semantics. A Positive Climb is inherently also a positive rate of climb. The SOP call at my current airline is "Positive Climb"
Same as in my company: I believe it's an Airbus standard call out. Also in our SOP, the '' Positive Climb'' call out is based on RA, not on VSI or altimeter as both will increase while the main gear are still on the ground.
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Old 17th Jul 2018, 14:45
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Originally Posted by EDML
Anyways, from your experience would you rate the climb while over the runway (and of course still accelerating) as normal for these kind of aircraft? Of course the density altitude of at least 5,000ft (not sure about the OAT that day) plays a big role, too.
My time radial engined airplanes was all in far northern climates at close to sea level. Given that this was, as you say, a much higher elevation and possibly warmer OAT I wouldn't consider the low initial climb extraordinary.

Originally Posted by EDML
I am just interested if they still had power from the left engine at that point. There is no visible yaw and no bank towards the "good" engine but unfortunately you can't see the rudder on the video or any of the pictures after lift-off.
As someone else noted earlier, it is quite possible for an engine to have a cylinder failure and still be producing a substantial amount of power.

Originally Posted by EDML
Does anybody know the blue line speed of a CV-340?
I haven't flown the Convairs, but I'd expect that it didn't have a blue line, but rather V speeds which were calculated based on takeoff weight, altitude and OAT. Blue-line is more light twin figure. It's possible though, that era was kind of a transitional period for aircraft performance theory.
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