Skippers Aviation Cessna Conquest makes forced landing on highway

[Cloudee]

https://www.pprune.org/pacific-general-aviation-questions/606056-skippers-aviation-cessna-conquest-makes-forced-landing-highway.html

The previous thread about this incident was closed, perhaps for too much conjecture. The report is out, perhaps some of the conjecture wasn’t far off.

https://www.atsb.gov.au/media/5779722/ao-2018-019-final.pdfWhat the ATSB foundDue to water contamination in the fuel tanks, the aircraft’s fuel quantity gauges were significantly over reading on the day of the occurrence and on previous days. The water contamination had existed for some time without being detected by multiple pilots’ fuel quality testing.

Although the pilot routinely compared indicated versus calculated fuel quantities, and indicated versus flight-planned fuel quantities, the pilot did not routinely conduct two other methods stated in the operator’s procedures for cross-checking fuel quantity gauge indications.

In addition, although the operator had specified multiple methods of cross-checking fuel quantity gauge indications for its C441 fleet, there were limitations in the design, definition and/or application of these methods. The primary method used (indicated versus calculated fuel) was self-referencing in nature, and not able to detect gradual changes in the reliability of fuel quantity gauge indications. Pilots also did not record (and were not required to record) sufficient information on flight logs to enable trends or patterns in fuel quantity gauge indications to be effectively identified, and pilots did not routinely cross-check information from fuel quantity gauge indications with information from the independent fuel totaliser.

The FUEL LEVEL LOW annunciators likely illuminated approximately 30 minutes before the fuel was exhausted in each tank, and when the aircraft was still within range of suitable alternative airports. However, the pilot disregarded the annunciations, and relied on the (erroneous) fuel quantity indications and continued to Broome until the engines lost power, at which point a forced landing on a highway was the only remaining option.

[Bend alot]

https://www.pprune.org/pacific-general-aviation-questions/606056-skippers-aviation-cessna-conquest-makes-forced-landing-highway.html

The previous thread about this incident was closed, perhaps for too much conjecture. The report is out, perhaps some of the conjecture wasn’t far off.

https://www.atsb.gov.au/media/5779722/ao-2018-019-final.pdfWhat the ATSB foundDue to water contamination in the fuel tanks, the aircraft’s fuel quantity gauges were significantly over reading on the day of the occurrence and on previous days. The water contamination had existed for some time without being detected by multiple pilots’ fuel quality testing.

Although the pilot routinely compared indicated versus calculated fuel quantities, and indicated versus flight-planned fuel quantities, the pilot did not routinely conduct two other methods stated in the operator’s procedures for cross-checking fuel quantity gauge indications.

In addition, although the operator had specified multiple methods of cross-checking fuel quantity gauge indications for its C441 fleet, there were limitations in the design, definition and/or application of these methods. The primary method used (indicated versus calculated fuel) was self-referencing in nature, and not able to detect gradual changes in the reliability of fuel quantity gauge indications. Pilots also did not record (and were not required to record) sufficient information on flight logs to enable trends or patterns in fuel quantity gauge indications to be effectively identified, and pilots did not routinely cross-check information from fuel quantity gauge indications with information from the independent fuel totaliser.

The FUEL LEVEL LOW annunciators likely illuminated approximately 30 minutes before the fuel was exhausted in each tank, and when the aircraft was still within range of suitable alternative airports. However, the pilot disregarded the annunciations, and relied on the (erroneous) fuel quantity indications and continued to Broome until the engines lost power, at which point a forced landing on a highway was the only remaining option.

Water contamination and both motors stop at the same time - good independent fuel and indication systems!

Still how did the aircraft depart the scene legally?

[Cloudee]

Water contamination and both motors stop at the same time - good independent fuel and indication systems!

Still how did the aircraft depart the scene legally?

From the report:
Post-occurrence actions and maintenance
On the day following the occurrence (3 March 2018), a fuel drain was conducted and a significant but unquantified amount of water was drained. The aircraft was then refuelled with 650 lb of fuel from sealed drums and the subsequent fuel drain did not contain a significant amount of water. The engines were ground run and no fuel leaks were evident. The fuel pump pressure low and fuel level low annunciators were checked to be operating as satisfactory.
Based on this evidence, and an assessment that both engines had likely lost power due to fuel exhaustion, the Civil Aviation Safety Authority (CASA) issued the operator with a special flight permit to allow the aircraft to be flown to Broome.

[Duck Pilot]

Whatever happened to the paste or syringe pill tests? If I ever get evidence of water in any tanks, I just open the fuel drain and let it drain out until the water disappears, particularly in a bug smasher. Dash 8, let the engineers deal with it and I’ll call the flight attendant for another black coffee!

[Bend alot]

From the report:
Post-occurrence actions and maintenance
On the day following the occurrence (3 March 2018), a fuel drain was conducted and a significant but unquantified amount of water was drained. The aircraft was then refuelled with 650 lb of fuel from sealed drums and the subsequent fuel drain did not contain a significant amount of water. The engines were ground run and no fuel leaks were evident. The fuel pump pressure low and fuel level low annunciators were checked to be operating as satisfactory.
Based on this evidence, and an assessment that both engines had likely lost power due to fuel exhaustion, the Civil Aviation Safety Authority (CASA) issued the operator with a special flight permit to allow the aircraft to be flown to Broome.

3rd of March being a Saturday.

Hello Casa on a Saturday.

Aircraft was disturbed following the "emergency" and NO detail of water quantity recorded.

Stick in fuel (it indicated it had fuel prior) and ground run it.

No fuel leaks - No surprise it did not have enough before the noise stopped. IT WAS NOT A FUEL LEAK ISSUE!

With that "evidence" issue a Special Flight Permit.

No filter changes or checks of the engine fuel system or any real fuel system maintenance checks.

Yep nothin fishy here.

CASA again on a Saturday!!!!!! nothin fishy here.

[Lead Balloon]

If fuel exhaustion was, in fact, the cause of the problem, what else could usefully be done to render the aircraft airworthy, other than to add fuel?

The aircraft flew away. Has it subsequently suffered any fuel system problem?

[neville_nobody]

Whatever happened to the paste or syringe pill tests? If I ever get evidence of water in any tanks, I just open the fuel drain and let it drain out until the water disappears, particularly in a bug smasher. Dash 8, let the engineers deal with it and I’ll call the flight attendant for another black coffee!

Not only that but how could you do a fuel drain and not notice that water was coming out and not fuel?? It's obvious when it happens. I've experienced it numerous times both with AVGAS and Jet-A1. Honestly if I was the ATSB I would have been pumping the pilots about whether they really were doing the fuel drains. After seeing it few times for real I cannot believe that you could be doing the fuel drains and not know.

[compressor stall]

If there was as much water as they say then the whole drain would be homogenous. It was drilled in to me early in that if there is no evidence of water (immiscible liquids) then check that the whole lot isn’t water. Smell it, touch it etc.

[Bend alot]

If fuel exhaustion was, in fact, the cause of the problem, what else could usefully be done to render the aircraft airworthy, other than to add fuel?

The aircraft flew away. Has it subsequently suffered any fuel system problem?
Yes the fuel was exhausted but not the fluid!

Know what happens to a diesel engine (and its fuel pump) when it swallow's water not diesel?

"Water contamination is one of the chief enemies of any diesel-fueled equipment. All fuels contain some water in suspension, but unlike gasoline, diesel fuel is less refined and will hold a much larger amount. This water can cause severe problems with water separators on the equipment. It can also cause the fuel injector tips to explode, resulting in expensive repairs. In fact, slugs of water in the fuel can cause sudden cooling in the engine and may result in shortened engine life."https://www.forconstructionpros.com/equipment/fleet-maintenance/article/10667628/water-in-diesel-fuel-can-wreak-havoc-in-engines

So it is OK to run this aircraft experimental?

Point/Fact there is not a AMM procedure for this event.

[Lead Balloon]

I wasn’t aware there was a diesel engined version of a Conquest.

How did it make it safely to Broome?

Presumably you reckon the aircraft should still be at the location of the forced landing, or taken to Broome by truck?

It would help if you could provide more detail around the conspiracy you’re alleging. Is it that Skippers got special treatment from CASA in the form of an ‘after hours’ ‘quick and dirty’ SFP, or that the ATSB has told fibs about the existence of an SFP in its report? Nothing would surprise me!

[Cloudee]

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/1791x1343/25ebdda6_b21d_4fde_88ce_5aa7a4c7f532_eb9f27768e332d565a3ebf3 fce120e27cbb13b9f.jpeg


Picture of the panel, I wonder if the rest of the aircraft looked as good.

This was a scheduled passenger service with 9 passengers in a ME turboprop aircraft that ran out of fuel! With some piloting skill and lots of good luck no one died or even got injured. The organisation that operated this aircraft and under whose watch this happened then goes out to the aircraft, drains an unrecorded amount of water from the tanks, checks it out and calls CASA who say sure, take off from the highway and take it home, we’ll look at it later. On a Saturday.

I personally would have thought quarantining the aircraft until an on-site CASA visit occurs might be warranted.

[Lead Balloon]

How long would it have taken and how much would it have cost for CASA to go to the site, and what deep insights and wisdom would CASA have brought to the technical issues?

Don’t get me wrong: I reckon it’s ‘waaay dodgy’ all round. But Australia is, after all and as they say, the only third world aviation nation where you can drink the tap water. I despair when there are calls for the CASA Keystone Kops to ‘do’ more, when that usually entails delay, cost and amateur hour analysis.

[Bend alot]

I wasn’t aware there was a diesel engined version of a Conquest.

How did it make it safely to Broome?

Presumably you reckon the aircraft should still be at the location of the forced landing, or taken to Broome by truck?

It would help if you could provide more detail around the conspiracy you’re alleging. Is it that Skippers got special treatment from CASA in the form of an ‘after hours’ ‘quick and dirty’ SFP, or that the ATSB has told fibs about the existence of an SFP in its report? Nothing would surprise me!

You Lead Ballon, simply do not get it!

I never ever said there was a diesel version of the Conquest - but I do know there are written procedures to allow it's use in the Garrett engine.

The point is you have zero idea (nor do I) of what damage was done to the engines if any - even though it made a short flight without "further" incident.

It could have effects on the fuel nozzle that torch the turbine to extent that it showered Broome with blade fragments killing several people or simply clog the fuel system and fail the engine again after X minutes of running.

I doubt either the engine or airframe manufacturers would say simply add fuel and go - but what would they know.

On piston engine aircraft water blocks the nozzles & requires a fair amount of work to remove it once ingested.

[megan]

but I do know there are written procedures to allow it's use in the Garrett engineNot in the Conquest it's not, what TPE331 installations allow diesel?

[Lead Balloon]

You Lead Ballon, simply do not get it!

I never ever said there was a diesel version of the Conquest - but I do know there are written procedures to allow it's use in the Garrett engine.

The point is you have zero idea (nor do I) of what damage was done to the engines if any - even though it made a short flight without "further" incident.

It could have effects on the fuel nozzle that torch the turbine to extent that it showered Broome with blade fragments killing several people or simply clog the fuel system and fail the engine again after X minutes of running.

I doubt either the engine or airframe manufacturers would say simply add fuel and go - but what would they know.

On piston engine aircraft water blocks the nozzles & requires a fair amount of work to remove it once ingested.So the aircraft should have been dismantled and transported in major subassemblies to a laboratory for extensive examination and testing.

That didn’t happen.

Oh the humanity.

You’re starting to sound like the scaremongers who shut down Glen Buckley.

[industry insider]

Way more questions than answers here for me. Interesting to know where the fuel pickups are located. Surely if there was enough water to affect the fuel quantity indications and water sinks to the bottom, why didn't the problem show up on first start? I know from operating in the Kimberly that water in fuel is a constant threat and one that any pilot operating there should be really aware of and double check.

[Capt Fathom]

It ran out of fuel and landed undamaged on the highway. After the initial investigation, fuel was added and it was flown out.

An official investigation followed and many recommendations made. So why do people continue to make a big deal of it.

If you have questions and there are no answers for you in the ATSB report, get hold of a Conquest pilot and ask them!

[machtuk]

Water = ice at Alt, that's the biggest worry!

[lucille]

You want to ensure pilots do “generous” and frequent fuel drains? Simply make sure they’re poor and they drive old diesel engined vehicles.

[Ixixly]

You Lead Ballon, simply do not get it!

I never ever said there was a diesel version of the Conquest - but I do know there are written procedures to allow it's use in the Garrett engine.

The point is you have zero idea (nor do I) of what damage was done to the engines if any - even though it made a short flight without "further" incident.

It could have effects on the fuel nozzle that torch the turbine to extent that it showered Broome with blade fragments killing several people or simply clog the fuel system and fail the engine again after X minutes of running.

I doubt either the engine or airframe manufacturers would say simply add fuel and go - but what would they know.

On piston engine aircraft water blocks the nozzles & requires a fair amount of work to remove it once ingested.

If there had been a lot of damage would not the ground runs have shown this pretty quickly? Wouldn't they have seen evidence of severe damage even with just a basic check of the fuel nozzles etc...? Also I'm sure this isn't the first time someone has managed to do this, undoubtedly the Engineers have either seen it themselves or knew someone they could contact that have seen it happen.

[SIUYA]

but I do know there are written procedures to allow it's use in the Garrett engine

ATSB – AO-2013-183 - Investigation into an accident involving an Ayres Thrush TPE331 variant

Fuel
The operator reported that the fuel being used in JAY was a 70/30 blend of diesel and aviation turbine fuel, and included a fuel additive. The manufacturer of the fuel additive advised that the purpose of the additive was to offset the potential adverse effects of using diesel fuel in turbine engines. A fuel sample was taken from the operator’s refuelling equipment and sent to a National Association of Testing Authorities-approved laboratory which reported that the chemical composition was consistent with a predominantly diesel blend. The engine manufacturer advised the ATSB that the TPE331-5-252M engine was not approved to use diesel, nor were they aware of a supplemental type certificate allowing it. They also advised that, in general, running on diesel fuel instead of aviation turbine fuel will lead to:

• Increased carbon build-up on the fuel atomizer and combustor due to the higher distillation end point

• Increased fuel system deposit or gum formation as fuel thermal stability and gum formation are not controlled in diesel fuel

• Decreased altitude relight envelope due to lower volatility

• Poor cold weather starting due to higher fuel viscosity

• Poor cold weather operation due to higher fuel freeze point

• If the diesel was ultra low sulfur diesel it would typically have poor lubricity (unless lubricity additives were added) which could degrade fuel pump life

• If the diesel was high sulfur, it could degrade turbine coatings • Diesel fuel can contain bio-diesel…currently not approved in jet fuel

• Diesel fuel can contain any number of additives which are not approved for aircraft gas turbine engines, and the effect on the engine is unknown

In addition, the engine manufacturer stated that none of their engines were approved to use the fuel additive reported to be in the fuel blend. On 26 May 2014, CASA issued Airworthiness Bulletin 28-0155 relating to the use of diesel fuel.

This bulletin stated that the use of diesel fuel in turbine engines was only acceptable if the fuel was approved by the manufacturer and the fuel conformed to a specification detailed in their approved data.

Diesel Fuel | Civil Aviation Safety Authority (casa.gov.au) (https://www.casa.gov.au/files/015pdf-3)

Even though the ATSB found that the engine was producing significant power at impact, and which indicated that the engine was unlikely to have been adversely affected by the use of unapproved fuel, it seems pretty clear that Garrett doesn't approve the use of diesel fuel OR additives in its engines.

[Ixixly]

Why are we even talking about Diesel engines here?

[Dookie on Drums]

Why are we even talking about Diesel engines here?
Exactly...this is farcical

[megan]

Why are we even talking about Diesel engines here?You need to read post #9 by Bend alot. Diesel is legal in some turbine powered aircraft depending on the jurisdiction.

[27/09]

We are talking about a turbine engine not a recip diesel engine.

The quote in post 9 by Bendalot is about diesel engines which is of no relevance here.

The effects of water on both engines will be very different. I very much doubt the diesel engine problems Bendalot is worried about are a concern for a turbine engine. For a start there are no injectors in a turbine.

[Ixixly]

You need to read post #9 by Bend alot. Diesel is legal in some turbine powered aircraft depending on the jurisdiction.

Yeah, but what does diesel have to do with this incident?!?!

[KeepItStraight]

Yeah, but what does diesel have to do with this incident?!?!
Nothing what so ever, except for one poster who tried to show the problems water creates in JetA1 by quoting an article which talked about the problems caused by water in diesel when the diesel is used in reciprocating engine. Chalk and cheese. I fail to see the relevance but apparently someone did.

[Capt Fathom]

Regardless the subject, some posters just love the sound of their own keyboard.

[Propstop]

During the northern winter in the Arctic I know the Twin Otters run on the same diesel as everything else. It is approved for PT6 but I am not sure about the TPE331.

[megan]

Regardless the subject, some posters just love the sound of their own keyboardA rather ironic statement to make, as is this.