Bunnings aero

[shafs64]

I was having a read of RAA incident reports. And read that someone had replaced some springs on a rudder they got from a new shop called aero Bunning's.

 

And these aircraft are used for training and suffered from jammed rudder in flight.

 

 

[BLA82]

They are great to work for that company

 

 

[Bruce Tuncks]

It just might be that the springs from Bunnings were from the same source but 1% of the cost of the aviation ones.

 

I would need more details about this. What was it about the springs which wasn't right? Maybe they were not the right size...

 

My point is there needs to be an objective reason for the shortcomings of those springs.

 

 

[robinsm]

Is that like supercheap auto aero?

 

 

[cooperplace]

sorry, was that "supercheap aero store"?

 

 

[storchy neil]

aero bearing service for steering rod for storch s neil

 

 

[Jaba-who]

Bunnings and super cheap etc never buy their stuff from the same factories -maybe the same company in some cases but usually not - but they don't make them in the same place because the aviation stuff has more steps in the pathway. And the quality of the stuff that they sell is not comparable to proper aviation stuff.

 

Apart from the quality control of the manufacture ( which costs money) the aviation manufacturers also have to have paper trails and admin quality controls which also cost money.

 

Places like Bunnings - Even their tools are not the same quality as the apparently same tool sold in more expensive tool shops. I questioned a guy in an expensive tool shop as to why his exact same drill was twice the price as Bunnings and he enlightened me. Firstly it is not the same drill. It looks the same but if you look at the serial model numbers they have slight differences -eg same number but with an added letter or one digit different.

 

Many proper manufacturers ( tools, hardware, and consumables actually make their proper product and a " Bunnings" grade of product. Made with lower quality base ingredients and parts - in case of hardware with low grade steel without hardening or stabilising alloy and with no quality control on individual items as they go into the packaging. In the case of tools - made with plastic bushes instead of bearings etc.

 

You have to seriously remember that you don' t get anything for nothing and if you pay cheap prices for something then you are getting a cheap inferior product. You can not get an expensive aviation product for a cheap Bunnings price.

 

 

[Yenn]

The Bunnings products may also be exactly the same as the more expensive products, but they advertise that they will equal any lower price for the same object. They then say that it is not the same object as the number is different.

 

 

[pmccarthy]

My $19.99 Bunnings 4 inch angle grinder is used every week or two and still going strong after ten years. But I agree with what you say!

 

 

[Jaba-who]

It just might be that the springs from Bunnings were from the same source but 1% of the cost of the aviation ones.I would need more details about this. What was it about the springs which wasn't right? Maybe they were not the right size...

My point is there needs to be an objective reason for the shortcomings of those springs.

Getting back to the question posted - what was the issue with the springs?

 

 

[shafs64]

The issue with the springs is they where not the same as the ones fitted to the aircraft. And a person flying back for a private hire flight suffered a jammed rudder and had to land it crossed controlled

 

 

[Jaba-who]

MMmm. Well thats the worst combination of all the problems that could be envisioned. Not using right parts, substituting poor quality ones (assuming they are bunnings sourced) and then them being the wrong size as well.

 

And then on top of that being a for hire/training aircraft (s0 I assume its a factory build and subject to only LAME or L2 maintenance) so the owner/maintainer has broken the law as well.

 

Did this reported to CASA or ATSB because it sounds like it is required that it should be.

 

I mean, do what you like with your own aircraft that only you fly..... but different story if you are going to rent it to someone who has a right to expect it has maintained properly.

 

 

[shafs64]

That's what concerns me. I hire aircraft and would like to think schools are doing the right thing and not cutting corners. it happened twice and they ended up grounding the Aircraft. I will see if I can find the report.

 

 

[shafs64]

The below happened on the 29/03/15 and 30/03/15

 

On returning from a cross country flight PIC experienced a sudden yaw (rudder) to the right hand side. The aircraft subsequently went into a right hand turn and PIC was unable to correct with left rudder however gained enough control of the aircraft (with crossed controls). PIC declared an emergency and side slipped onto runway 30, landing without incident. LAME discovered that someone had changed the tensioning springs that were part of the rudder pedals to nose wheel link that returned the pedals to centre after a rudder input. The replacement spring had a much lower tension. LAME took the springs off the Ballarat Sierra and fitted them to the Bravo. The test flight with the CFI following the swap of springs resulted in perfect flight handling. There was no record of the springs being changed in the logbook and no one is aware of any modifications however explains why the aircraft was flying perfectly for years and then suddenly displayed abnormal behavior. Aircraft owner Repco, Bunnings Aerospace and other automotive suppliers.

 

Completing a check flight after inspection. Aircraft was on downwind RWY18 85 kts, straight and level. The aircraft rolled and yawed to the right without warning. PIC applied full left rudder and full power and the aircraft shuddered and recovered. Recovery was not instant but did return to level flight. Rudder required a lot of pressure to move much more than normal. Lost about 200 feet. Completed circuit and made a full stop landing without further incident. The Aircraft had suffered a similar incident on Sunday 29/3/2015. . Aircraft Grounded until fault identified and repaired. LAME discovered that someone had changed the tensioning springs that were part of the rudder pedals to nose wheel link that returned the pedals to centre after a rudder input. The replacement spring had a much lower tension. LAME took the springs off the Ballarat Sierra and fitted them to the Bravo. The test flight with the CFI following the swap of springs resulted in perfect flight handling. There was no record of the springs being changed in the logbook and no one is aware of any modifications however explains why the aircraft was flying perfectly for years and then suddenly displayed abnormal behavior. Aircraft owner Repco, Bunnings Aerospace and other automotive

 

 

[SDQDI]

Do you have a link to the reports for that Shafs64?

 

They don't make a lot of sense, first one says test flight was fine and the next one says it failed on a check flight? Not to mention the "owners"

 

 

[shafs64]

here you go. you might have to scroll thought it.

 

https://www.raa.asn.au/storage/accident-incident-summaries-2015.pdf

 

 

[Bruce Tuncks]

So the difference was in the spring constant. The same mistake could have been made with any springs, aviation-grade or not. But I agree that a mistake was made .

 

I would not have thought that those springs were safety-critical, but as an excuse for a bad landing they sufficed I guess.

 

Here's a confession from a cheapskate toolaholic... I just love how cheap Chinese tools have enabled me to own things like a table-saw that I only lusted after before.

 

 

[aro]

I heard about the incident, but I'm not convinced by the diagnosis.

 

How do weak springs cause the rudder to jam to one side?

 

My suspicion is something more along the lines of a badly adjusted bellcrank going over centre - although that also requires something to initially move the rudder. If the rudder moved without pilot input there is something going on aerodynamically...

 

 

[M61A1]

I heard about the incident, but I'm not convinced by the diagnosis.How do weak springs cause the rudder to jam to one side?

My suspicion is something more along the lines of a badly adjusted bellcrank going over centre - although that also requires something to initially move the rudder. If the rudder moved without pilot input there is something going on aerodynamically...

I have to agree...there is way more to this than buying non OEM springs.

 

 

[djpacro]

The Aviat Husky has springs on the rudder pedals for the same purpose - it can suffer rudderlock, which I have experienced on a new airplane with too much friction.

 

 

[Bruce Tuncks]

I've never seen a rudder mechanism where there was anything like an over-center possibility to lock a full rudder deflection. That would be an appallingly bad design, and I don't believe it has been done.

 

A rudder with too much aerodynamic balance ( area in front of the hinge ) could be designed to behave like this, but I bet that hasn't happened either.

 

Was that Husky really set up properly djpacro?

 

 

[SDQDI]

In My reading of those two reports I think that it is just one incident that has had a duplicate report.

 

On the second supposed report the LAME states that there was no record of the springs ever being changed which is identical to the report from the day before, if the LAME had done it the day before then he would have definitely had a different story the day after!

 

And as for Bunnings aero, the report states that the owner was concerned about l2s (wording seems to suggest a worry about a general trend across the board rather than a specific part in the related incident) sourcing their replacements from Bunnings repo ect.

 

IMO this is a prime example of where we could improve our reports with an update column to be filled out maybe a month after the incident (maybe as simple as a quick phone call to the person who reported it originally for a up to date version which could be much more accurate) which would have more info rather than the guesstimates that happen in the heat of the moment.

 

 

[geoffreywh]

The springs sold in Bunnies in individual white plastic packets are as good as any springs I have ever used. Made in USA. I have used them on many projects to great effect. Just get the right

 

ones ! There is a HUGE selection of diameters/lengths and spring wire thicknesses. Just because something is cheap does not neccesarily mean that it's bad. i.e. Trelleborg tyres on Jabs'. Miccro air radios, I could (and often do) go on....

 

 

[Jaba-who]

The springs sold in Bunnies in individual white plastic packets are as good as any springs I have ever used. Made in USA. I have used them on many projects to great effect. Just get the rightones ! There is a HUGE selection of diameters/lengths and spring wire thicknesses. Just because something is cheap does not neccesarily mean that it's bad. i.e. Trelleborg tyres on Jabs'. Miccro air radios, I could (and often do) go on....

I think you are being a bit too lax with your comparison there.

Using Bunnings stuff is not like using trelleborg tyres or a micro air. These are just the cheaper of the range of things that are designed and built for the task for which they are applied.

 

Using Bunnings stuff in an aircraft is more like using those cheap Chinese wheelbarrow tyres you buy in Bunnings and putting them on your trailer or your Nissan micro - just because they happen to be the same size- and driving on the roads. Not designed for the task, not legally approved for the task and no way on earth you could ever know or have faith it would survive the usage.

 

 

[djpacro]

Was that Husky really set up properly djpacro?

Straight off the production line, things just a bit too tight, not uncommon with a new Husky on initial flight doing the sideslip check. Would happen with Nomad too.

Using Bunnings stuff in an aircraft is more like using those cheap Chinese wheelbarrow tyres you buy in Bunnings ..... not legally approved...

Some years ago one of my friends told me that a Bunnings tyre was much better than the standard tyre for the Scott tailwheel on a Decathlon. Fortunately Scott taken on by Alaskan Bushwheels and a much better tyre is now available for 10 times the price.