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CASA Safety Notice warns against stalling Bristell aircraft - 19 Feb 2020


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https://www.raa.asn.au/storage/safety-notice-bristell-lsa-20-feb-2020-00000002.pdf

 

SAFETY NOTICE

Pilots and operators of Bristell light sport aircraft (LSA) are strongly advised to avoid



conducting any manoeuvre that may lead to an aerodynamic stall of the aircraft - either

intentionally or unintentionally. This includes any flight training for stalls.

The manufacturer has previously declared to CASA that the Bristell LSA meets the

applicable certification requirements for LSA.

Recent information received by CASA from the aircraft manufacturer shows that the

aircraft may not meet the LSA standards as it does not appear to have been adequately

tested (as required by the certification standards) for its ability to recover from spins.

Worldwide, a number of Bristell aircraft have been involved in fatal accidents following

unrecovered spins.

Further investigation and discussion with the manufacturer is ongoing and an update

will be provided as new information becomes available.

SAFETY ISSUES

 

Light Sport Aircraft are required to meet a range of international standards for certification. The

 

 

manufacturer has declared that the aircraft meets the standards published by ASTM International. The

 

 

standard (ASTM Standard F2245, section 4.5.9) specifies the spinning performance requirements,

 

 

including the ability to recover from a spin.

 

 

CASA has been engaging with the aircraft manufacturer, BRM Aero which is based in the Czech Republic,

 

 

seeking to confirm that the four variants presently operating in Australia meet the standard. We are

 

 

concerned that contrary to the formal declarations made by the manufacturer, the aircraft may not have

 

 

been adequately tested for compliance with the ASTM standard for spin recovery.

 

 

There have been several fatal accidents worldwide (including in Australia) where Bristell aircraft have

 

 

entered a spin (including during stall flight training) and failed to recover.

 

 

BACKGROUND

 

Manufacturers of LSA (either registered with CASA or otherwise) are able to certify or make a selfdeclaration,



 

 

that the aircraft meets accepted standards, such as the ASTM standards when making

 

 

application to CASA for a special certificate of airworthiness (COA) as an LSA.

 

 

This scheme, which has been adopted internationally, lowers manufacturer compliance costs, reduces the

 

 

time to bring a design to market, and enables a more timely response to design and technology change. It

 

 

is less rigorous than schemes which require a manufacturer to hold a production certificate issued by a

 

 

National Aviation Authority such as CASA, EASA, or the FAA.

 

 

BRM Aero has previously declared that the Bristell variants meet these standards, however, subsequent to

 

 

investigations which followed a number of fatal accidents involving these aircraft the manufacturer has

 

 

been unable to provide satisfactory evidence that the design is compliant with the requirements of the

 

 

ASTM standards applicable to light sport aircraft.

 

 

FURTHER INFORMATION

 

CASA continues to engage with BRM Aero in relation to this issue and is considering a range of



 

 

proportionate safety related actions designed to mitigate the identified safety risks and will provide more

 

 

information as it becomes available.

 

 

If you have any urgent questions, please contact: [email protected]

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So why do CASA wait until there have been "several" fatals, before they take any action? When qualified instructors are killed in them during training, alarm bells should be ringing, and action taken immediately.

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Only larger planes have CVR's and FDR's. Before you react IF you are the "Authority" you need to have a fair amount of good "evidence". (Generally)

To digress slightly I don't think the Jabiru fiasco achieved that and they got a certain amount of egg on their faces. not before a lot of damage was done. . Regarding styled "plastic fantastic" the fin and rudders look more for style than best function. ie Look good on a desk as a model. Even the Mustang ended up with a dorsal fin as did many designs. The horizontal stab and elevators can shield the fin and rudder in a spin situation. THAT problem is not new.. Nev

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According to the report after investigations into several fatal crashes Bristel has been unable to produce evidence of compliance. After the Jabiru fiasco when CASA used raw data & claimed 40 failures that ended up being 12 I would hope the lesson would have been learned.

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IF there's an issue with a planes controllability it should be resolved. Many planes have gone through evaluations after incidents/ accidents or reports.. It's an ongoing thing in the industry, Sometimes they get cleared as is. Other times they get compulsory mods or techniques restrictions of Flap setting, Cof G etc or they sit on the ground for years eg Boeing. "Airworthiness" is what it's called. Nev

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Bristell could do what has been done before. Fit a Ballistic Chute and advertise like mad that it is a great safety feature.

If they must not be taken near a stall, how do you land them?

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Bristell could do what has been done before. Fit a Ballistic Chute and advertise like mad that it is a great safety feature.

If they must not be taken near a stall, how do you land them?

Simples - Pull the chute and drift down (always thought the Bristellls & their ilk were a bit too sexy/good to be true)

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I have heard a theory that because the chute is forward of the firewall, those without tend to have a more rearward centre of gravity and therefore possibly different spin characteristics. I believe neither of our local incidents had a chute. Which begs the question when the manufacturer did thier tests did they demonstrate recovery configured at the rearmost limit. If I were to guess I would suspect this is the question casa is asking.

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I am surprised at the lack of hysteria wrt this aircraft. If it was a Jabiru all would be grounded immediately. CASA have a different approach to this problem. They were happy to kick the local product on shadowy statistics.

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BlurE that is an interesting theory. Each plane has a basic weight and index which should take account of the situation re the chute installation. The permissible Cof G is fixed from a datum and is the same range on the chord of the wing regardless of what the basic Cof G is. Same is if you put on a heavier prop or moved a battery around. It would mean that a different max load could be in the rear locker in reality, but if you went by the POH for that "particular" plane if would be looked after. Fuel tank location can produce potential risks if tanks are a fair distance from the Cof G range. ALL planes should be individually weighed and the Cof G established when put into use.. Nev

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You are right there, Jab sure did get the 'jab' in the ribs! Researching Jab engine issues it appears (to me) that poor maint and poor pilot operation was a common denominator!

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BlurE, Just to add to my previous post above, the stall speed is demonstrated with the most rearward Cof G permitted.

Any movement to the rear of the ACTUAL CofG will make spin recovery more difficult as will placing any weight)s) at the extremities of the fore and aft axis.( Make it more inclined to flat spin.) A FLAT spin is the most difficult to recover from.. Nev

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I've seen photos of both the Australian incidents. There was little if any forward speed at impact.

This C of G thing is just a theory I've head thrown around, but seems to loosely fit some of the circumstances. It's very likely the European testing was done the the chute in place so it would have probably required deliberate ballast to be added if you did intend to spin test at the rear limit. Maybe it was done, maybe it's not even required under LSA.

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When you change anything on a plane you should assess the possible change of W & B. If the weight changes by a certain amount, I forget the exact figure, but it is a percentage of empty weight, then you have to do a re weigh and work out the new C of G figures. This applies to GA aircraft, but I am not sure about RAAus planes. If the Bristell is CASA approved, then I would think the W&B would have to be done to planes, with and without a chute.

Chutes are not the be all and end all of safety. One of the first Cirrus chute saved aircraft resulted in massive injuries to the pilots vertebra. It laded in a dam and because the wing hit the water, with no slowing down by the wheels hitting ground first, it stopped in a very short distance.

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You are right there, Jab sure did get the 'jab' in the ribs! Researching Jab engine issues it appears (to me) that poor maint and poor pilot operation was a common denominator!

Ask anybody who has worked on Jabs for any length of time, they will tell you the problem is usually not the people who are operating the engine. The likes of fitting pistons in from the factory with the piston pin offset around the wrong way. Anybody know why that was done?

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