Building a Jabiru J400 from a first-time builder's perspective

Federal lawsuit filed against JabiruUSA and Jabiru Aircraft Pty Ltd.
Current Status - 11/07/2008

I've had a few people emailing me to see what I've decided to do since the crash so here's an update. I decided to file a federal lawsuit in TN against JabiruUSA and Jabiru Aircraft Pty Ltd. to see what the law can do for me. It was filed back on 5/08 and has been pending. It's a bummer it's come to this but I don't think brakes with short pistons and such should be on any aircraft...but that's just my opinion thus far.

The lawsuit is based on several principles some of which are product liability and gross negligence. You can look up the Case No 4:08-cv-44 if you're interested.

J400 CRASHES AT END OF RUNWAY - BRAKE FAILURE
4/22/2008

I've had a lot of people contacting me lately asking me how the aircraft is going... well, not so good... i figured i'd post an update here since the last update was over a year ago.

Yes, it's true it crashed. I had a brake failure at Santa Monica Airport on 1/13/2008 See the NTSB report here.

We were on TV too.. See FOX LA clip here

Unfortunately, the aircraft was substantially damaged although nobody was seriously injured (I seem to have chronic back problems since though). After recovering the aircraft back to CO from CA, I examined the brakes and found that the brake rotors had brake pad material all over them. Furthermore, it appears that the caliper piston overextended and resulted in a hydraulic failure. See pictures below.

Brake Assembly Pics

Aircraft Recovery Pics
btw, the reason the aircraft is tilted 45 degrees in the truck is because the tail is too wide for the truck.

It was a day trip to Catalina Island

This was the last landing before the crash landing in Santa Monica. It was uphill and into the wind. In hindsight, it was all luck wasn't it? It certainly could have been worse with cliffs on both ends there.

Three Jabiru Brake Design Flaws (in my analysis)

1. Brake pad material all over both rotors (melted) due to overheating
• See pics #3, #6 above... it's hard to snap a photo of the material on the rotors but i think those pics reveal enough to see...both rotors on both sides are like that
• See the grooved pad pics #2, #5 that are grooved because of the material on the rotors... rotor acted like a grinder against those pads apparently
• Blueish discoloration
2. Short caliper piston
   • see pic #1... if you look at the caliper piston, you will see that the O-ring has partially popped out resulting in a hydraulic leak... and it didn't retreat back into the housing because the o-ring jammed it leaving it in its current position.
3. Brake pad plate flexing
   • The brake pad backing plate that the piston pushes against bent. It could have prevented an overextension of the piston. In pic #1 you can see that it is no longer straight (compare to pink line)... it essentially gave way to the piston and allowed the piston to overextend...

My reports to NTSB and FAA

The bulk of my findings can be found in the reports to the NTSB and FAA. Essentially, it's an overheating and short piston flaw combination.

1. Email #1 to NTSB and FAA
2. Email #2 to NTSB and FAA

Jabiru Australia & JabiruUSA's reaction

So I had a fairly long conversation (argument really) with Doug, the engineer at Jab Australia Manufacturer, followed by Pete of JabiruUSA.

Essentially they are saying that the brake failure was a result of lack of maintenance and thus claim denied. I'm going to keep it short here for now so I won't be discussing all that was discussed.

This is what Doug said in one of the emails.

"Regarding the brake design of the J400, as you most likely now know we have updated the design significantly from the system fitted to your aircraft. Currently, any Jabiru aircraft which has a MTOW above 550kg has a “dual caliper” system – which consists of 2 calipers (similar to the ones you already have), a thicker, wavy brake disk and a stainless steel plate between the pads and the calipers. The pad material has also changed, though yours looks to be reasonably current. So at first glace the new system looks like 2 of what you have currently, but there’s a little more to it in the detail. The new system can handle a couple of crash stops without fading excessively. In addition, Pete (and all our other US dealers) have been offering Matco brake packages for some time to meet the particular demands of the North American market."

Actually, I didn't know that the brakes were redesigned. There was no notice anywhere. Furthermore, I wasn't offered any Matco brake packages and what does he mean by "demands of the North American market"? Why was there such a significant brake design 'upgrade' if my version was adequate according to him (considering the extra weight)? And why does this 'upgrade' apply to MTOW above 550kg only (including the J400)?

This is what the brake assembly instructions say:

Assemble outer brake pad mounting plate by inserting two AN4-16A bolts and placing return spring (PX0029N) on each bolt

The correct bolt was on there. It said to use AN4-16A and that's what I did.

Nowhere did it say I need to shorten bolts, add washers, or tighten the bolts as the brake pads wear for fear that the piston will overextend. I don't know of any other brake assembly where this is necessary either. It doesn't really make any sense if you asked me. Why not just design the brakes so that the piston is long enough to start with? From what I understand, the tightening of bolts is to adjust the handbrake travel before it engages. It wasn't to make up for a short piston. I didn't know anything about a short piston. One has nothing to do with the other. Do other vehicles suffer from this problem? Is this common knowledge?

My dad was an auto mechanic for 30 years or so... and he said he's never seen or heard of a piston overextending on any brake assembly (trucks, cars, motorcycles) with the exception of errantly reworked rotors (lathed). So at least we know it's not a common problem in cars, trucks, or motorcycles.

Here's what it says in the maintenance manual

5.8.6 Brake Pad Adjustment
Brake Pads may be adjusted by remove the Main Wheel Spats and tightening the brake pad attaching bolts and nuts until the wheel just rotates freely.

It says 'may' and it doesn't refer to any critical short piston that you'd think is worthy of mentioning. I know if I had a non-standard brake design I'd be sure to put a notice. Actually, I wouldn't have left such a flaw to start with as the real solution to a short piston is a long enough piston. There is no other acceptable solution in my opinion. Especially on an aircraft with one hydraulic system. In my opinion, the piston needs to be long enough so that the brakes go 'metal on metal' without any hydraulic leaks. Just like the requirements on certified aircraft from what I understand.

Take a look at this TSO example Certified Aircraft document View #1 or Original. Either way it just seems prudent to me.

5.4.1 Overpressure Test: The brake with actuator pistons extended to simulate a maximum worn condition must withstand hydraulic pressure for at least 3 seconds, equal to the following
a. For airplanes, 2.0 times the brake rated maximum pressure (BRPMAX).

More from Doug:

"The photo supplied showed the nuts on the through-bolts with about 1.5 threads showing, leaving about 3mm of adjustment available by tightening the nuts, without adding extra washers. The maintenance manual for the aircraft is already quite clear – it calls up an inspection and adjustment of the brakes every 50 hours, or whenever something is noticed in the pre-flight inspection. However we take the point that the instructions could be improved and will consider updating them in the future. "

He's essentially saying that to prevent a hydraulic failure I had to tighten the bolts over time. But what kind of brake design is that? And 'clear' is quite debatable if you've seen this manual (see above for excerpt). So which is it? Is it "clear" or as he also says "instructions could be improved"? Furthermore, I don't have any other vehicles that require tightening of bolts as the brake pads wear to prevent hydraulic failures. Do I? So how would I know that the piston is short if they don't tell me? It's certainly not obvious as you need a caliper to measure and see.

They've made it very clear that they won't be doing anything about it. I'm on my own. I certainly don't think maintenance was the cause for damaged rotors nor does it make up for a critical short piston. You can read what I think it needs in detail in the NTSB emails above.

I could understand the maintenance claim if I crashed because the brake pads were completely worn and there wasn't any pad remaining to stop me. But this wasn't the case. There was brake lining remaining on both wheels after the crash.

There's a lot more to be discussed but this is where I'm going to leave the update for now. There's two main questions in which I haven't heard acceptable answers to yet.

1. Why was there brake pad (lining) material all over (melted on) both rotors? And what maintenance could I have done to prevent it? What specifically caused such buildup?
2. Why wasn't the caliper piston long enough for complete pad wear?

I've gotten many emails asking about more details on the crash itself and what happened. I really should have put the details up earlier but anyway, here they are.

Santa Monica Airport is class D and thus is manned with a control tower. Entering the airspace the controller indicated that we enter a right downwind for runway 21. There was also a Hawker and he was on left downwind for the same runway. The controller was going to put the Hawker in first but instead corrected and advised that we cut the pattern short (a short final) and land first. So we did.

Because we cut the pattern short and because there was a tailwind in the pattern (relative to direction of landing... wind was calm on the runway), we had excess altitude. So we did what you normally do which is use flaps, slip, and burn off the excess speed before you touch the runway. So that's what we did. After floating and burning off the excess speed, we touched "somewhere about half way on the runway plus or minus". This is what I told the NTSB which apparently I was put on with practically instantly after the crash (the officer passed the cell over to me a few minutes after arriving). However, since it was dark, what I actually went by was that we had all the amber lights (ILS amber lights are 2000 ft) plus a significant amount of white from the pilot seat perspective. This corresponds with my "touched about half way plus or minus" as that runway is about 5000 ft long. So without a doubt, half way on the runway after you burn off all the excess speed is about 2500 ft of braking distance. This is certainly not a problem is it for an aircraft in which has a landing distance of less than 1000ft according to the manufacturer?

Anyway, as I was braking there was an unusual vibration in the handle and what seemed to be like grinding. The brake handle/lever shortly started to slide (it's supposed to be firm and met with resistance) and my impression was that the pads were being worn at a rapid pace? Not sure... After another second or two, all tension was instantly lost on the brake lever and all braking was irretrievably lost (both sides of course).

The first thing of course that came to mind was to cut the engine. That's why the prop is intact in those pictures even though the nose is on the ground. That certainly helped. Then I unlatched the door... then I pondered for a split second whether it's best to keep straight ahead or turn and risk either tipping the aircraft (and striking the wing on the ground as I've seen this happen or even turtling it) or striking runway lights or aircraft at the sides of the runway. Because of darkness and bright end of runway lights, I couldn't really tell what was beyond the end of the runway... (nor did I have the time to gaze at it)... could be grass, gravel, etc. It just seemed darkness... (I knew it wasn't a cliff of course)... It turned out to be an embankment. I did actually start to make the turn but in fact wasn't abrupt enough because of course there was a bit of hesitation not knowing what lies beyond or which course to follow. If I had known, maybe it would be different? It's hard to say. Certainly, crashing into airport structures or other aircraft where there's a sudden impact is worse for the occupants than a gradual embankment.

According to the FAA inspector who inspected the aircraft (the day after the crash) and spoke to the tower manager, the tower manager indicated that I had about 3000 ft of runway remaining at touchdown. This could be... I said plus or minus halfway which is about 2500 ft. He's probably got a better angle than me to judge although it being dark perhaps the real answer is somewhere between 2500-3000 ft remaining? Either way, I don't think that makes any real difference because the real problem was the resulting brake failure. This is obvious from the brake assembly photos above.

Regarding the "heavy braking" which I seem to get questions about. This is a relative term to my usual braking which is actually pretty light. It does not mean cranking the handle as hard as one can. Clearly if you are half way on a runway you are going to brake significantly more than if you touched right at the beginning of it. There was no skidding, there was no hard braking even compared to short field landings on a cessna (which sometimes produces skidding)... This wasn't a short field landing first of all... it was just harder than usual considering you are where you are.

Of course, if you take a look at the photo with the hydraulic failure it pretty much tells most everything I think.

Complete photo gallery added for the entire build (see left menu)... the photos will eventually get matched to the log entries on the left but until then you can browse the gallery

It flew in exactly one year to the day of picking up the crate. First flight was on 9/2/06

I don't know exact numbers since I'm still working out some electronics issues but I can give you ballpark figures...
top speed is about 131kts plus or minus 3 .. gps ground speed is about this too
climb is about 800fpm at 8000 with 170lbs pilot only (maybe half tank?)... about 600fpm at 10000

i'm still trying to figure out economy figures out... overheating issues are still being worked out and prevents me from doing certain speeds.. there's a lot of these issues... if you join the yahoo jabiru engine forum you'll see it in detail... however, yesterday i did 6:30hr flight (this seems to be the endurance limit with 30min fuel) into a headwind burning about 4.9gph... ground speed was about 80-95kts... i had to put it into economy to make the fuel stop with a stiff headwind.. i'm guesstimating it was doing about +-115kts plus or minus 3 maybe

I have a ton of photos I have yet to put on the site.. pretty much photos for each day of construction... just haven't had the time to finish the website up... the plane has about 70hrs now

The two biggest problems are
1) poor manual ... i'm sure you'll see me complaining in the log there all the time... including flying without airdam in the airducts that contributed to lots of overheating... saw someone else's airducts from a newer engine and they are still not there nor in the manual
2) overheating issues... but it's still running well so I can't complain... maybe the figures in the manual are outdated too as some have mentioned in the jabiru forum

One other thing... definitely not a 600hr build... at best it's 1000hrs ....took me at least 1200 and still working out issues but some of these are electronics... i did do everything including paint, instrument panel, upholstry (still working on this one) though

Since there's a year of photos and log entries it's going to take time to update this website completely... the log is nearly complete on here but the photos haven't been matched yet...will get to it