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Posted

A Jabiru 230 crashed shortly after takeoff from Runway 26 this afternoon. Two people were on board and were injured. They were both walking when the ambulance got there so that is very good news. The aircraft is a writeoff. The engine bay area was destroyed. The firewall peeled back and was under the aircraft so the occupants were looking out onto the empty paddock when it finally came to a halt. The left wing was destroyed but the right was untouched.

 

At this stage we do not know what happened but the wind was east to north east and fairly light so the takeoff was down wind. One possible explanation and I stress that this is purely speculative, is that the aircraft stalled in the turn and there was insufficient height to recover. The flaps were retracted. The spinner was intact but there was only about an inch or 2 of wood left of the prop indicating the engine was reving pretty high at impact and it impacted fairly flat.

 

This is another example of the strength of the Jabiru airframe.20161012_144951.jpg.55829af7e1da417661273696b7e5381a.jpg

 

20161012_144935.jpg.df0b74bda3e65f5d46421266edad360b.jpg

 

 

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Posted

Crikey there's not much left of the front end and luckily the motor peel underneath and didn't end up on their laps, glad to hear the 2 people in the Jab were walking and not too seriously hurt I hope.

 

 

Posted

A testament to probably the best survivable airframe in the recreational aviation fleet

 

Cannot doubt how many have survived Jab incidents

 

 

  • Agree 5
Posted

That's one pilot who won't try to save a few minutes by taking off (or landing) down wind again.

 

OME

 

 

Posted

A bit early to link a take off with a slight down wind with the incident isn't it? Downwind take off will mean it takes longer to get in the air and climb angle will be less. If he got airborne and was climbing at the normal airspeed the wind direction becomes irrelevant unless he failed to clear an obstacle.

 

 

  • Agree 7
Posted
That's one pilot who won't try to save a few minutes by taking off (or landing) down wind again.OME

OME

 

The 230 is good for about 6kts of downwind on take off just stay in ground effect until you get the speed you need then all good, landing is about the same just don't bang it on the ground with the higher ground speed you might pop a tyre also need to watch loss of directional control with the higher speed.

 

Aldo

 

 

Posted

Aldo,

 

That might be quite correct, and there may be situations where a down wind take off is required (eg one-way strips). However, I'm of the opinion that if there is a choice, use the free air speed provided and take off and land into wind. Early in my flight training, I did a downwind take off and the wind dropped. New Y-fronts required.

 

OME

 

 

  • Agree 1
Posted
Aldo,That might be quite correct, and there may be situations where a down wind take off is required (eg one-way strips). However, I'm of the opinion that if there is a choice, use the free air speed provided and take off and land into wind. Early in my flight training, I did a downwind take off and the wind dropped. New Y-fronts required.

OME

I agree. Once you are in the air though the downwind issue is irrelevant so long as you have sufficient airspeed. The issue is more psychological as you are travelling over the ground at a much higher speed than if you have taken off in to wind and that may lull you in to a false sense of security. You need to keep a good eye on the ASI not just the environment. Airspeed is your friend.

 

 

  • Agree 1
Posted

Yes if the wind dropped on a downwind takeoff that would be a nice thing giving you extra airspeed. Of course if the wind picked up once you got above ground affect that will be annoying but you can have the same experience whe taking of into wind and the gust does off, the only difference is your speed over the ground. As Kg said it is all about airspeed once airborne.

 

 

  • Agree 2
Posted
Yes if the wind dropped on a downwind takeoff that would be a nice thing giving you extra airspeed. Of course if the wind picked up once you got above ground affect that will be annoying but you can have the same experience whe taking of into wind and the gust does off, the only difference is your speed over the ground. As Kg said it is all about airspeed once airborne.

But if he was on a conveyor belt...........074_stirrer.gif.5dad7b21c959cf11ea13e4267b2e9bc0.gif

 

 

  • Haha 3
Posted
But if he was on a conveyor belt...........074_stirrer.gif.5dad7b21c959cf11ea13e4267b2e9bc0.gif

Turning which way?075_amazon.gif.0882093f126abdba732f442cccc04585.gif

If you are in an aircraft like a Drifter, with a relatively narrow envelope, one needs to be wary of the gradient. The same gradient that gives an apparent increase in airspeed with a headwind, as you climb out, will give you an apparent decrease in airspeed with a tailwind.

 

 

  • Haha 1
Posted
Aldo,That might be quite correct, and there may be situations where a down wind take off is required (eg one-way strips). However, I'm of the opinion that if there is a choice, use the free air speed provided and take off and land into wind. Early in my flight training, I did a downwind take off and the wind dropped. New Y-fronts required.

OME

OME

 

I'm not advocating downwind take off's or landings are what you should be doing to save a couple of minutes but sometimes you may need to and if you do providing it's not outside the performance of the aircraft they should present no problem.

 

Not sure why you were worse off if the wind dropped on a downwind takeoff that should have made it better.

 

Aldo

 

 

  • Agree 1
Posted
Turning which way?075_amazon.gif.0882093f126abdba732f442cccc04585.gif

 

If you are in an aircraft like a Drifter, with a relatively narrow envelope, one needs to be wary of the gradient. The same gradient that gives an apparent increase in airspeed with a headwind, as you climb out, will give you an apparent decrease in airspeed with a tailwind.

If you remove the word "apparent" I think I can agree with you ...

and my 2c worth is always about the airspeed vs apparent speed which is actually the groundspeed you can misapply to flight with upwind/downwind flight that exposes the pilot to the risk of responding to perceived speed from ground rather than airspeed.

 

Not saying it happened here but I can see how in a thought process of a downwind takeoff with an increasing downwind speed through wind gradient can visually mislead a pilot as to airspeed and you might respond by pulling back on the controls as you make the initial turn ... and you can then follow through to the end. Its a risk and we need to be aware of it.

 

 

  • Like 1
Posted

1. Ok lets get real - downwind takeoff of say 6 kts quoted above is no problem on normal strips, not short strips. And within aircraft limits lets say.

 

2. Its easy to pick up 10kts or more over the strip before going into a climb - so no problems.

 

3. If WIND DROPS during takeoff and no more gusts, THATS GOOD.

 

4. If you get a gust up your rear that's BAD.

 

5. As long as the gusts are light say max 10kts should prove no problem if initial climb out speed is 10 to 15 kts above climb out speed but will produce a flatter climb angel (less rate of climb). Expect (always) to get some turbulence up the rear if you are climbing over trees at end of runway. (keep nose down or flat more speed) till your up ,around 700ft or more.

 

6. Any person that does a downwind takeoff on a long strip with no more than 10 kts on a Jab etc will not have any major problems just keep speed up and is useful to do some training only FOR (just in case)

 

7. Any one doing this all the time is really asking for an accident, and in this PC world is not using common sense and asking for it.

 

8. This is all based on general comment that strip length is sufficient and long.etc. Common sense must prevail.

 

9. Anyone using one-way strips, or when gusty is asking for it sooner or later and not legal in AUS (for GA? from memory) but yes I have done it more than once.

 

10. Low performance aircraft or HEAVY AIRCRAFT, TWO UP, FULL FUEL just don't do it, its not worth the risk of your pax being injured for the sake of going to the other end.

 

 

Posted
If you remove the word "apparent" I think I can agree with you ...and my 2c worth is always about the airspeed vs apparent speed which is actually the groundspeed you can misapply to flight with upwind/downwind flight that exposes the pilot to the risk of responding to perceived speed from ground rather than airspeed.

Not saying it happened here but I can see how in a thought process of a downwind takeoff with an increasing downwind speed through wind gradient can visually mislead a pilot as to airspeed and you might respond by pulling back on the controls as you make the initial turn ... and you can then follow through to the end. Its a risk and we need to be aware of it.

Fair enough...remove "apparent" and substitute "actual". Not sure why I used the term "apparent", but I am home with a cold and full of meds. To be clear...I never use "apparent speed" in place of "groundspeed".

I have done some little experiments in the Drifter after a post somewhere about turning with a tailwind, and how dangerous it was. The outcome was as expected, but yes, you can see how someone who's angle (RoC remains the same) of climb has just got a whole lot shallower, and the ground and trees are going past way faster than usual, might be tempted to keep pulling back despite the lack of airspeed.

 

 

Posted

Down wind ops of a few knots (not large numbers) is not unheard of at larger airports e.g. my local Townsville.

 

Naturally the duty RW is changed after a certain limit (which I forget).

 

You don't have to accept it if you are concerned, but I suspect your clearance would be somewhat delayed if you wanted to operate opposite to arriving and departing traffic. I have never heard anyone refuse it, you are generally (possibly always?) asked if it is acceptable.

 

But with a 6000ft RW, in a light aircraft, just fly the numbers and you wouldn't know. There is of course a 3000ft cross RW as an option as well - often requested in high Xwinds.

 

 

Posted

Another thing to take into consideration with take off direction is where do I go if the engine fails.

 

I always take off uphill and with a tailwind at Rodds bay if the wind is less than about 8kts. There is nowhere nice to go with an engine failure on 31, but open paddocks on 13.

 

 

  • Like 1
Posted

The takeoff direction was towards open space and flat land. Takeoff on 08 is over trees, houses, major roads and the Clarence river. This may be one of the factors that influenced the decision to take off on 26 even though it was downwind. I have no further information on the progress of pilot & passenger. I imagine they are pretty sore but by all accounts initially, were very lucky & nothing was broken (apart from the plane) as far as I know.

 

 

  • Informative 1
Posted

One thing you can count on with a downwind take-off is that the wind gradient (change with increasing height) isn't going to help you climb. If you aren't used to it your apparent speed will tend to make you lift the nose and it's airspeed you need. Nev

 

 

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