Goolwa Hangar 1: Jabiru 0 30/12/21

[onetrack]

Maybe it was still bouncing, as it reached the hangar? It certainly seems to have hit the wall of the hangar, whilst it was in the air.

[facthunter]

There could have been a twister. You just don't know.  Nev

[RossK]

From the RAAus database;

"The aircraft took off, completed three circuits and departed the circuit area for flight over Hindmarsh Island to Murray Mouth then returned overhead Clayton. The joined mid downwind 01, completed downwind checks, landed long but had fully landed and deployed brakes when they lost control, veered from the end of the runway and collided with the rear of a hangar as well as a water tank and the door support of a second hangar. The pilot tried to avoid the collision by firstly applying power to power out of the situation but there was not enough lift available so braked again and aimed as well as they could for the gap between a water tank and the door support of a hangar, such that the wings would take the brunt of the force. The aircraft continued on and came to rest in the rear wall of a hangar."

[onetrack]

That report is quite deficient as regards weather conditions and other important contributing factors. Was it an instructor and student on board, or a qualified pilot with a passenger?

"They lost control" - why? There's no reference to wind direction, gusts, temperature, wind shear, and sudden wind direction change.

Why did they land long? - was it because the PIC was a student, and was still trying to get a grasp on landing techniques?

It's a pretty poor report, and doesn't help anyone else trying to learn something from the adverse event.

[kgwilson]

This is only an extract from the report which is under review. RA-Aus don't investigate these incidents specifically and are reliant on the information provided. The "Under Review" status indicates they have requested additional information which will be published when they have the details.

Edited January 13, 2022 by kgwilson

[nick_reese]

From what I have read, it was a son and father - son flying. Unconfirmed eyewitness on the scene said the aircraft bounced a few times on landing (which will explain the 'landing long') - sounds like he then lost directional control when applying brakes (worried about running out of runway?) - then applying power while veering left at low speed would only exacerbate the pull to the left (similar accident happened in the US last year) and increase the speed of impact - the guy did well to slot the aircraft into that space ...

[facthunter]

Assuming he had any real say in it. . Brakes put weight on the nose wheel. The whole thing is getting pretty uncoordinated. IF you eventually crash into something power added adds to the energy of impact.   There might be a time to just ride out what you have on your plate and slow up as much as possible.  Nev

[nick_reese]

Strange comment Nev. Of course he had a say in it - he was pilot in command. Brakes put weight on the nose wheel? That shouldn't be a problem if hold the yoke / stick back and apply the correct amount of braking - like I said - sounds like he may have been concerned about running out of runway. It still looks like he lost directional control, and, too late, decided to go around, and adding power only exacerbated the situation when the aircraft was likely below Take Off Safety Speed - 1.2 x Vs. 

[RossK]

When you read the report and look at the position of the hangar relative to the runway, it's hard not to think that this was a failed go around.

When you pile on full power the nose is going to pitch up, probably beyond the critical angle if you don't control it ("not enough lift") and it's going to pull to the left ("veered from the end of the runway"). The impact site is level with the end of the runway 70m off centre line, so the veering must have happend well before then.

[440032]

News just in:

Apparently Trevor Jacob was the pilot, and bailed out long before leaving the runway.

[turboplanner]

Runway layout

[Flightrite]

And to think some instructor signed him off? Now that’s a worry! The amount of plane drivers out there who can’t fly to save themselves is astonishing!

[kgwilson]

You cannot use brakes in a Jabiru for directional control like you can in an aircraft with differential brakes. I never liked the hand operated brake that only provides braking equally to both main wheels. The only directional control you have is the rudder which become less effective as you slow. 

 

I've had to stand on one brake to avoid an object on the runway and then on the opposite brake to get back on to the runway, all the time slowing from 50 knots or so in an Archer a long time ago. Worked a treat at the time. That is one reason when I built the Sierra I spent an extra 2k for Matco wheels and disc brakes designed for an aircraft weight double what mine is. If necessary I can even lock a wheel. Only done once in testing & locked up both on asphalt but that gave me the confidence in my brakes that I wanted.

[spenaroo]

can we all just agree that the jabiru brakes is a poor design.
I disliked them when I trained in a J160. get to choose if you want a hand on the throttle or a hand on the stick - because you cant activate the brakes with a hand on both. the work around was putting your wrist through the middle of the split stick.... okay taxing but would hate to try and pull up fast on a landing like that. the alternative is no hand on the throttle - which is fine until the need to go around

[RFguy]

Do the nylon tubing brake lines 'stretch', reducing the applied force ?

[Keenaviator]

Wheel barrowing is entirely pilot induced. If you do this you have lost all the stability  of a tricycle and created a one wheel tail dragger. Differential braking will not help the incompetent pilot. 

[turboplanner]

13 minutes ago, Keenaviator said:

Wheel barrowing is entirely pilot induced. If you do this you have lost all the stability  of a tricycle and created a one wheel tail dragger. Differential braking will not help the incompetent pilot. 

Yes, there's not much point trying to use it at high speed to get out of something you just described, but taking what KGWilson said, followed by Spenaroo's post, KGWilson gave an example of a successful action at 50 knots with all wheels planted, (and there are advantage all the way down the speed range from there to an ability to pivot into a tight parking spot) and Spennaro covered the ergonomics, and in addition to this the brake control lever is too short to make full use of braking. It would be great if Jabiru could bring out an upgrade kit for split toe brakes with leverage to  be able to get braking just under lockup; it would be a different aircraft around the terminal. 

[RFguy]

Turbs, how about just dual cylinder, dual level,  splitting the brake levers ? (IE  like a pair of throttle levers you can grab both ) that would be a simpler modification. 

and or a vac booster and metal lines.

[Flightrite]

There’s a zillion of these Jab thingy’s driving around, the brake setup, though primitive must work otherwise these pages would be full of accidents like this fool had! Fix the real problem, pilot training and checking, the later severely lacking! 

[RFguy]

yeah I was more commenting about general jab brake improvements. But agree !

[turboplanner]

1 hour ago, RFguy said:

Turbs, how about just dual cylinder, dual level,  splitting the brake levers ? (IE  like a pair of throttle levers you can grab both ) that would be a simpler modification. 

and or a vac booster and metal lines.

There's already an ergonomic issue with a single lever as Spenaroo pointed out, so ideally that cold do with elimnating in the next models. Split levers would require a new skill to be sure of operating both after landing and the correct one afterwards, albeit tractors for years have had differential foot braking. However, toe brakes are familiar to a lot of pilots and instinctive to operate.

[turboplanner]

59 minutes ago, Flightrite said:

There’s a zillion of these Jab thingy’s driving around, the brake setup, though primitive must work otherwise these pages would be full of accidents like this fool had! Fix the real problem, pilot training and checking, the later severely lacking! 

Fix training is No1 as you say.

 

As the thread has gone along the discussion drifted towards lower speed taxying control. The Jab brakes are fine for landings, but you could land shorter with the Cherokee system and make tighter turns in confined spaces using 1 wheel brake + power.

[RFguy]

The Cowra club Brumby has differential  brakes. super nice. 

[kgwilson]

The other differential option is heel brakes. Not my cup of tea but some people like them. I guess it is what you get used to.

[Yenn]

Heel brakes I do not like. Toe brakes are good, but there is no need for the ability to lock a wheel at 50kts. That leads to nose unders, not nose overs. Brakes in a plane are for control at taxiing speeds.