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Goolwa Hangar 1: Jabiru 0 30/12/21


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On 31/12/2021 at 10:51 AM, FlyBoy1960 said:

Why is the Jabiru such a difficult plane to fly?

 

Seems to require above average pilot skills for what is generally a low performance aircraft by comparison with some others.

It needs more development in the area of handling qualities.

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The only reason the Jab can be a difficult plane to fly is lack of flying ability, of the pilot. Really how can anyone say it is difficult with a straight face.

My only time in jabs has been when I have done BFRs in them, because I fly a single seater. No problems shutting the throttle on downwind and landing cleanly. Possibly the C172 is easier to fly but not planes like Thrusters or Skyfox.

The problem seems to be that the ground roots of RAAus was flying planes that were difficult to fly, but plastic fantastics have taken over leaving us with a number of pilots who are not up to scratch.

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On 31/12/2021 at 10:57 AM, Yenn said:

Surely if you land with extra speed to allow the nose to come up, you are not landing, you are practically taking off. You need the nose up to get the speed down, not speed up to get the nose up.

Hi Yenn; The extra speed I mentioned is a little more above the recommended final speed and in this instance was due to not enough weight in the tail.  This was identified by a flight with a verify experienced Jab 230 pilot who identified lost elevator authority at round out and he knew this was not acceptable. It was not a fault of the aircraft just a lack of attention to specification detail in the final checks of the build of this particular aircraft.  The recommended addition of weight to the tail sorted the balance and then it was a delight to land; I am told on good authority.

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43 minutes ago, Yenn said:

The only reason the Jab can be a difficult plane to fly is lack of flying ability, of the pilot. Really how can anyone say it is difficult with a straight face.

My only time in jabs has been when I have done BFRs in them, because I fly a single seater. No problems shutting the throttle on downwind and landing cleanly. Possibly the C172 is easier to fly but not planes like Thrusters or Skyfox.

The problem seems to be that the ground roots of RAAus was flying planes that were difficult to fly, but plastic fantastics have taken over leaving us with a number of pilots who are not up to scratch.

Or incorrectly trained. If you had a student would you train him to push the stick forward to lower the plane to runway level?

 

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15 hours ago, horsefeathers said:

I must be missing something basic here. I've put over 500 hours on my Jab 160, with (I suppose, 6-700 landings, and I assume the same number of takeoffs), and it has been stable every time. I genuinely  don't understand the comments about the Jab. 

Now, to put that into context, I previously flew a Streak Shadow (you want to talk about understrength nosegear??) and when landing I would religiously keep the nosewheel off the deck till the last possible moment, at which point it would give a quick shake, and the straighten up.

But I have never seen behaviour as described in this thread with my Jab. And sheet, I've made my fair share of mistakes, but intrinsic problems with the Jab?  As Pauline Hanson would say, "Please Explain"

 

I admit that if you land with the nosegear first, you are in for a whole world of hurt. But that is the same for any tricycle aircraft.

 

I trained for my RAA in a 160 and learnt very quickly you have to keep the weight off the nose wheel for as long as possible when landing, I had one time early on in my training where I was trying to chase the yippy dance with the rudder to no avail, all was required was pull the stick back and the plane behaved very well.

I have seen many instances over the years a Jab dance just after touchdown, it’s not the planes fault.

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I don't think I've called the Jabs 'difficult".  and I'm certainly NOT a JAB basher. .Landing on the back of the mainwheels is good advice for nearly all tricycle gear planes.. I was a bit fortunate in that I got some clues from a very experienced LSA 55 owner that covered it in one take off, but he verballed the lot.  I've plenty of time in Heavy rudder types so I don't have lazy feet. Alf above sums it, nicely.. Possibly the mainwheels are a fair way back . Cessna's are quite light on the nosewheel when the  of G is at aft limit. Just KNOW your aeroplane.  They do vary a bit.   Nev

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Most of my life in PA-28s has made me insensitive, if not lazy, as they are so forgiving. I have to re-educate myself whenever I fly something different.

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The BIG 3 have engineered them to be docile and easy to fly because that is a marketing advantage. It was in keeping with their "ANYONE can FLY a plane "  (who can drive a car). I'm a bit inclined to question that, but then I always was a sceptic about sales people. Nev

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Here's how it's done in a Piper Warrior, one of the most docile aircraft around.

The Warrior has a high lift wing and is landed with the stick back, nosewheel high in the air and staying up as the wings are used as an airbrake in ground effect. Doing that, the landing is so smooth the passenger won't feel the wheels touch the ground.

 

This pilot, as with most of the wheelbarrow merchants, has decided to point the nose down aiming for where he wants not land; no need to guess which wheel hits first.

 

 

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You know I have put a lot of thought into the many Jabiru issues. And after carful consultation with many pilots and aircraft designers i have concluded that all of the Jabiru issues can be quickly and easy solved by flying a Tecnam.... 

 

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I've flown Technams, both Sierra and Papa, and they are almost too easy to fly. The J-170 does take a bit of concentration from the round-out to give that satisfied glow. Does this mean that the Technam is a 'better trainer' than the Jab? Apart from the round-out, no problems with the handling of either. Don

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Blueadventures says that a lack of attention to the specs in the final build of the aircraft was the cause of his problem.

Was the aircraft ever checked out for weight and balance compliance? it would seem not. in which case the pilot should be really called a test pilot. Surely with a new plane everything should be checked and verified as being correct.

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Big Jabirus (170/230) are easy to land. They just need the right airspeed, and the right amount of throttle. Too much RPM and they will keep flying when the body is within half  a wing height of the ground.... . And I mean 100 RPM too much can be too much

The 6 cylinder, much more so than the 4 cylinder, it has alot of prop ! Big and pitchy.   There is still alot of thrust at 1100 RPM ish. The 6 cyl will idle lower happily compared to the four. It might sound rough but mine will idle down to 400 RPM (I set at 850 on ground stationary).

If she doesnt land, ensure the throttle is at low idle, either wait, pulling on a teensie winsy little be of tail to push the tail down and bleed airspeed and  so mains go first, or go around. 

Edited by RFguy
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Wow, that’s gotta be an unauthorised Jab wing folding mod….Gald I wasn’t sleeping in the hangar! Lots of armchair flying here, so I’ll add my bit, watching a lot of Oshkosh arrivals, seems holding the nose off on landing is becoming a forgotten art….but no doubt the “land on the whatever colour dot” has contributed to  slight forcing it on.

 

I agree, flying speed with throttle, glide slope with attitude, can lead to a “wheelbarrow” landing.

 

I’m a big believer in a nose wheel is only there to attach a tow bar to. Get it up ASAP on take off, better rudder response and yes, make sure you don’t over rotate, as you could get airborne at a high AoA in ground effect, then you’re going nowhere fast…, select climb attitude only. This can be challenging, as you need to relax that back pressure as the aircraft accelerates and elevator effectiveness increases.

 

On landing, hold it off as long as possible. This leads to effective aerodynamic braking immediately after touch down too. 

Another thing, you don’t always need to go around. Most of our landings are on runways with plenty of room, a good burst of power, fly back up ten feet, level the nose, slowly reduce power and just re-fly the landing. 
 

“All this office talk…..!

DC330209-DBA9-456C-90FB-86DB8FE0055D.thumb.jpeg.4bc0215c59fee8d3e352ea0d6a055378.jpeg 

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When in ground effect the idling jab is pretty clean. A slight tailwind or downslope can make things interesting. One chap I used or "encounter" at places regularly shut the engine off  with his 230 in tight places. at the flare. Of course one would have to ensure a landing was  "assured" but you don't need a rocket scientist for that..Nev

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Maybe just treat Jabiru landings like a tail dragger three point, ie, minimum air speed on landing and keep the stick all the way back during the roll out. The nose wheel will settle when it's ready. In the mean time use your feet to keep it straight.  That's how I do it.  Laurie

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I would like to add, on takeoff,  lifting the nose early, and holding it slightly lifted  (as to be nice to the nosewheel) , in my experience, and the math suggests, will extend the  minimum takeoff distance as the wing with some AoA will be additional drag and hence will reduce acceleration. At least for short chord, lifty wings.  If the ground is unpleasant, then yeah certainly lifting the nose wheel early will preserve it, assuming you have the strip distance to use up. 

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5 hours ago, RFguy said:

I would like to add, on takeoff,  lifting the nose early, and holding it slightly lifted  (as to be nice to the nosewheel) , in my experience, and the math suggests, will extend the  minimum takeoff distance as the wing with some AoA will be additional drag and hence will reduce acceleration. At least for short chord, lifty wings.  If the ground is unpleasant, then yeah certainly lifting the nose wheel early will preserve it, assuming you have the strip distance to use up. 

You've got on to a different subject now. I wouldn't call the Jab nosewheel weak at all.

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I dont know anyone who has damaged a Jabiru nosewheel. My instructor instilled early to  be careful with nose wheels of aircraft gneerally, they vary in strength and durability.

 

Yes back to topic- 

 

Has anything yet come out of what actually happened at Goolwa , putting all our idle speculation aside ?

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14 minutes ago, RFguy said:

I dont know anyone who has damaged a Jabiru nosewheel. My instructor instilled early to  be careful with nose wheels of aircraft gneerally, they vary in strength and durability.

 

Yes back to topic- 

 

Has anything yet come out of what actually happened at Goolwa , putting all our idle speculation aside ?

No, not a thing; the people were in hospital, so it may take some time. RAA may also put it in the Accidents section. It's not unusual at a busy airport to see an aircraft handing off a fence or having hit something. We weren't speculating about that aircraft in particular, just about aircraft that spear off the runway while landing, because there are valuable lessons to be learned.  

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I reckon the SK was quite hard to control on the ground when going fast. The 230 is much easier I reckon, but then that accident was a 230...

Once, a fellow pilot passenger ( but he was over 80 ) lost control of my SK on take-off. I had to take over.  He was not using the rudder enough.

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Floating in ground effect is a common issue on many aircraft and exacerbated with a low wing if idling speed is a bit high. At 1000 rpm my Jab 3300 powered low wing Sierra won't land at all on our 1200 metre strip. I had to cut power & dead stick land a few times when I was getting the setup right during test flying. The idle is now 800 rpm & it is fine.

 

If this hangar incident was initially due to a bit much power and a high flare over a good distance and add in a bit of crosswind then by the time the wheels touched there would be little directional control so inexperience could easily lead to a complete LOC.

 

Check out this one. Lands OK then veers left, corrects, over-corrects, applies power & then crashes into a hangar while trying to use aileron for directional control. Inexperience and then probably panic & loss of logic.

 

 

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Gee, that poor guy got it badly wrong….seems to me he applied incorrect rudder at first, the dreaded soapbox downhill race car instinct? Then power was the one good thing, but by then he had lost it. Yes the desperate aileron steering attempt was amusing as such. But by then he was destined to become a UTube star! Poor old 172, looks very sad in the last pic. You gotta wonder, was he really fit solo?

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Going back to the original photo of a parked Jab. I wonder how they got it into the hangar, which is about 300mm above the surrounding ground, with no damage to the gear leg. The only reason I thought it was not a staged photo, was because of the emergency vehicles there.

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