Jab 450 down in Thailand

[Birdseye]

Phuket News: Investigation underway into Phuket light aircraft crash

[winsor68]

Is anyone flying a Jabiru as a 4 seater with 4 POB in Australia?

 

 

[SDQDI]

I don't know about four big Aussies but I have seen a few four seater Jabs. I had looked at them as an option for the family 2adults and 2 kids would be perfect for them.

 

There are three different reports in the link. It is impossible to tell but if all the eyewitnesses are to be believed it was a combination of a few things strong wind reduced power? Tree? stall?

 

“The aircraft took off the ground at 10:05am. The aircraft then flew around the airpark. Ten minutes later as the aircraft was going to land the wind got stronger so the captain decided to fly around. A strong wind blew causing the aircraft to fall, the captain tried to raise the aircraft up again but finally the aircraft crashed into the ground,” the report stated.

 

Speaking to The Phuket News from the scene, Maj Gen Teerapol said, “After talking with witnesses we have learned that the aircraft was trying to land. The aircraft failed to land as the wind was very strong. The aircraft then went back into the air but the engine stalled causing the plane to fall.

 

Pitchayathida Pitchayodaecha, 40, a local resident who lives in the nearby Plernjan housing estate told The Phuket News, “I saw the aircraft flying round, which is normal. Not long ago I saw the aircraft again with a strange noise coming from the engine. The aircraft looked as if it was out of control as it was flying slower and slower. The aircraft first hit the top of a tree and then hit the ground so I called for help.”

 

 

[onetrack]

The Thai's are generally only small-framed people - 4 Thai's combined weight, would probably be still be less than 3 Westerners.

 

The Americans have done a major study on Thai military personnel stature and weight, and have taped and weighed them extensively. The average weight for a Thai male in their military is 56kgs.

 

The 18 yr old girl was probably only around 45 kgs, and the 18 yr old boy wouldn't be a lot more - say 55kgs maximum.

 

The two older Thai men in the front seats would have been a maximum of around 65 kgs each - so around 280kgs in total weight between all 4 on board.

 

The Jab 450 specs say 700kg MTOW, a useable load capacity of 347kgs - and the aircraft carries 140L of fuel, so 101kgs of fuel when full - leaving 247kgs for pax and luggage.

 

They'd be right for MTOW at 2/3rds fuel - full tanks puts them 34 kgs over MTOW.

 

 

[Super Cub]

Looking at the photo, one blade of the prop looks intact.

 

 

[Jaba-who]

Is anyone flying a Jabiru as a 4 seater with 4 POB in Australia?

Yep I have one.Don’t fly with 4 often but do fly it with four. With my wife and her two young teen kids it’s fine with fuel fuel. But with four adults I have to consider the amount of fuel I have and also need to keep the heaviest two in the front seats.

 

I have flown as a pax in Jabiru’s original demonstrator (VH-BNP) in the early 2000s and we got 4 big burley blokes in and did circuits a Bundaberg. I was impressed by how it could even get off the ground let alone perform as well as it did.

 

 

[Jaba-who]

The Thai's are generally only small-framed people - 4 Thai's combined weight, would probably be still be less than 3 Westerners.The Americans have done a major study on Thai military personnel stature and weight, and have taped and weighed them extensively. The average weight for a Thai male in their military is 56kgs.The 18 yr old girl was probably only around 45 kgs, and the 18 yr old boy wouldn't be a lot more - say 55kgs maximum.

 

The two older Thai men in the front seats would have been a maximum of around 65 kgs each - so around 280kgs in total weight between all 4 on board.

 

The Jab 450 specs say 700kg MTOW, a useable load capacity of 347kgs - and the aircraft carries 140L of fuel, so 101kgs of fuel when full - leaving 247kgs for pax and luggage.

 

They'd be right for MTOW at 2/3rds fuel - full tanks puts them 34 kgs over MTOW.

Except that the 700 kg is an administrative MTOW for Australia. They are approved at 760 kg in many countries without any changes to the aircraft. So even if it were strictly overweight that is an administrative overweight not and real overweight.

Jabs 430s are a handleful in strong gusty winds and I’d guess ( without being certain) that the bigger wing of the 450 would increase the buffeting and instability. I’d be thinking that is a major contributor to the crash.

 

 

[Jaba-who]

Looking at the photo, one blade of the prop looks intact.

That’s difficult to interpret what that means.I’ve seen several jabs (6 cylinders) that had prop strikes (including my own back in 2009 and they went from full noise to full stop and only had one prop blade damaged. The wooden blades are very low inertia and the engine is high compression and stops very quickly.

 

So one intact and one broken blade could mean - could be already stopped at and broken at impact or stopped by the impact. Not sure it helps much in its own.

 

The statements”the engine stalled” is a worthless bit of evidence. I’ve heard it many times before because non-aviators know nothing about wings stalling and assume for a plane to stall it has to be the engine that stops. And the only term they have for an engine stopping is “stalling”. Others hear the word “stall” from someone who means aerodynamic stall but they think it refers to the engine.

 

So all in all unless it comes from a pilot - ignore the statement.

 

Same thing about engines sounding unusual. Most non aviators have no idea what an engine can sound like and still be normal. He may have been throttling up and down trying to maintain a descent profile - sudden changes in headwind etc. the Jab engine responds very rapidly to adjustments of the throttle and to changes in wind,climb and descent. Sounding odd can be anything from something bad to something normal given the conditions.

 

I’m not sure how good or transparent the Thai aviation investigators are but waiting for something from them is the only avenue for possibly reliable information.

 

 

[coljones]

That’s difficult to interpret what that means.I’ve seen several jabs (6 cylinders) that had prop strikes (including my own back in 2009 and they went from full noise to full stop and only had one prop blade damaged. The wooden blades are very low inertia and the engine is high compression and stops very quickly.So one intact and one broken blade could mean - could be already stopped at and broken at impact or stopped by the impact. Not sure it helps much in its own.

 

The statements”the engine stalled” is a worthless bit of evidence. I’ve heard it many times before because non-aviators know nothing about wings stalling and assume for a plane to stall it has to be the engine that stops. And the only term they have for an engine stopping is “stalling”. Others hear the word “stall” from someone who means aerodynamic stall but they think it refers to the engine.

 

So all in all unless it comes from a pilot - ignore the statement.

 

Same thing about engines sounding unusual. Most non aviators have no idea what an engine can sound like and still be normal. He may have been throttling up and down trying to maintain a descent profile - sudden changes in headwind etc. the Jab engine responds very rapidly to adjustments of the throttle and to changes in wind,climb and descent. Sounding odd can be anything from something bad to something normal given the conditions.

 

I’m not sure how good or transparent the Thai aviation investigators are but waiting for something from them is the only avenue for possibly reliable information.

For most people - at least those that drive manual cars - their understanding is based up "he dropped the clutch, it kangaroo hopped and then stalled, right next to a policeman at the lights"