borne Trikes in South Africa

[Guest Cloud Warrior]

Just for interest - all Airborne trikes in South Africa (9 of them apparently) have been grounded following a accident last week where pilot and pax were killed after an Airborne XT912 suffered "wing failure". The local CAA and Airborne are investigating the accident.

 

 

[eastmeg2]

It will be very interesting to see if any real conclusions can be drawn as to the cause of the wing failure. Is it known if there were any witnesses?

 

There was a fatal XT-912 crash near Cessnock NSW in Jan 2006 which we still don't know the real cause of and failure of the outboard section of the wings leading edge spar was a possible cause, but it's still not known what caused the spar to fail.

 

 

[Guest dracer]

so its definetly the kite thats malfunctioning?

 

what is it wizard?

 

soryy im only learning.

 

brad

 

 

[Guest Cloud Warrior]

From a photo it appears to be a Streak wing. More info here

 

http://www.microlighters.co.za/viewtopic.php?t=6840

 

and here

 

http://www.microlighters.co.za/viewtopic.php?t=6751

 

Wing has been recovered and will be inspected by a local wing manufacturer.

 

 

[eastmeg2]

It seems there were witnesses, a quote from the 2nd link which is rather disturbing . . .

 

"From the bit of news from the scene, it appears the wing folded on one side. Maybe a leading edge or spreader bar. We will know more after CAA have completed their investigation."

 

I think I'll be checking more closely for signs of fatigue on my own leading edge spars and practicing my quick draw technique for my ballistic chute handle.

 

Rgds,

 

Glen

 

 

[Guest Crezzi]

There was a fatal XT-912 crash near Cessnock NSW in Jan 2006 which we still don't know the real cause of and failure of the outboard section of the wings leading edge spar was a possible cause, but it's still not known what caused the spar to fail.

The ATSB report into the Cessnock crash (& a couple of similar accidents) is available here - http://www.atsb.gov.au/publications/investigation_reports/2006/AAIR/aair200601173.aspx

 

John

 

 

[ZULU1]

Statement on Misasa web site

 

This was tragic news, I copy the posting on Misasa web site:

 

"Hi Folks after the fatal accident at Groblersdal last weekend I as safety officer of MISASA have requested CAA to "ground " all Airborne Edge aircraft till we have clarity re the wing failure on Kevin Manions Airborne XT.

 

CAA and the manufacturer are busy trying to find a solution. I have recovered the wreckage and "re assembled " the wing on my premises and are waiting for Jenya and a visit from CAA to determine the way forward .

 

I would suggest you have a competent AP inspect your wing/ leading edges to determine if it shows any signs of fatique / stress before you decide to fly again. CAA committed to contact the 9 remaining owners of Airborne products re the above issues

 

Should you know someone who owns one please contact them with urgency to inspect the plane before further flights are undertaken

 

CAA - Andre Swanepoel can be contacted re this matter . Its a life threatening situation , and I feel it should be treated as such , Leprachaun."

 

 

[eastmeg2]

Hi John,

 

I'm pretty sure I've seen the report before and it still does not make any conclusions about what caused the leading edge spar to fail.

 

I'm hoping that this accident may have had competent witnesses who can provide their input to the investigation.

 

While I appreciate the concern of MISASA, it seems a bit of an over reaction to ground all Airborne Edge aircraft in South Africa until the cause can be determined. By my reckoning there must be approx 200 Edge XT's and probably in excess of 1000 Edge X's flying in various parts of the world.

 

This accident becomes probably the 4th attributable to possible leading edge spar failure, which we know is possible if the flight envelope is exceed, but the question remains whether it was in each instance . . .

 

Rgds,

 

Glen

 

 

[Guest Crezzi]

Yes I suspected you would have already seen the report Glen. Apologies for nitpicking your post but its actually pretty clear about the cause of the spar failures - negative-g. To be fair, the report title suggests that the ATSB were asked specifically to look at the structural side things and thats what they have done. What it doesn't answer is the circumstances that led to that & this should be in an RAA or HGFA accident report. I can appreciate that thats pretty hard to reach a conclusion though especially since the the outcome is invariably fatal. The UK AAIB investigated a similar case with a British trike years ago but never reached a definitive conclusion either. Maybe the RSA investigation will be more successful but I wouldn't be too optimistic.

 

I agree that grounding them all seems excessive especially if the 9 examples don't all have the same wing as in the accident . One of the instances cited in the ATSB report was in 1996 so it wouldn't have been an Streak 3 or a Cruze).

 

Cheers

 

John

 

 

[Guest Crezzi]

According to the RSA forum (http://www.microlighters.co.za/viewtopic.php?t=6840) , the investigation conclude the "wing strut" (I guess this means the leading edge) broke on impact - presumably with the ground. Sounds as if the control bar went through the front strut.

 

John

 

 

[Guest Perry]

Folks,

 

The Airborne Units are pretty tough machines - I had flown an Edge for some time and sold it after many hours of use without any issue. It would be really beneficial to get the views of Aerodynamic Engineers with a bent toward flex wing aircraft?

 

A Couple of things come to mind:

 

1. All of the signs seem to point to -ve g component being exceeded. This may be pilot error but it may also be a case of being able to get into this condition with this trike without being aware of such or just plain flying beyond the envelope - note that the outer wing on all trikes are not braced (not just an Airborne). The manufacturer is specific about not going into -ve g.

 

2. When the ATSB report was issued, for my own peace of mind as to my trike, I inspected a number of different wings including the streak. I found that the outer wing sections do differ somewhat between manufacturers and some leading edge sections have multiple sleeves on the outer section whereas some only have a single sleeve for taper (as with the Airborne). The failure described by the ATSB indicated failure at the leading edge taper sleeve due to point stress. As a result, I now regularly check the inner part of the outer wing very carefully to confirm that there are no signs of stress at these points - this is where -ve g can cause failure.

 

Perhaps it may be worth insisting that trike wings are dynamically tested to failure? Most European manufacturers are mandated to do such (at great expense), which is not the case in the USA and Australia. This may yield clues as to whether there are indeed any structural deficiencies at high load areas under unusual conditions. This may also lead to improved wing design as an advantage to trikers.

 

It is really important to properly establish the cause of failure so as to avoid a repeat of the same if it were due to a systemic failure mode.

 

Regards

 

Perry