Couple of Jabiru Questions

[Guest Pioneer200]

Yeah ,,back flying after 2 month break!!! I was doing a few circuits in the Jab 160 at the weekend and was getting lots of float on landing(50 metres + from intended touchdown point)

 

This was with one up and only half flap selected.

 

My only explanation was approach speed prob 5 knots to quick.

 

Q. What approach speed do you use in the 160,do you see a big floating difference with only one up, and do you use full flap?

 

Also for all you guys and girls who have flown most of the Jabiru types, which is your fav and least fav and why.

 

My early training was in Alpi Pioneer 200, then switched to 160 which I found quite a hand full at first.

 

After now doing about 40 hours in the J160 I find it a brilliant aircraft to fly

 

Well done Jabiru:keen:

 

 

[Guest drizzt1978]

Well they say if you can land a Jabiru you can land anything....

 

Seriously tho....When I floaty its usually flare too much too soon,

 

Im sure you will get ten reasons why tho....

 

Did you have a head wind??

 

 

[Harthy]

Landing

 

I did over 300 hours in a Thruster, and they say if you can land a Thruster you can land anything, and they are not too bad. I certainly have not heard that said about Jabiru's.

 

Jabiru's are a complete peace of cake compared to a Thruster, but very different of course.

 

Jabiru's will float if you don't use full flap on landing, but watch your airspeed doesn't drop off to much with full flap. They can drop if you flare to soon and they are too slow. (Full flap is recommended to be used in the flight manual)

 

 

[Deskpilot]

I was taught to use both half and full flaps, dependent upon length of runway. Never had a float problem of any sort, but yep, watch the speed, it bleeds off quick and you're more likely to experience a heavy landing than a floaty.

 

 

[Guest Ken deVos]

I aim to come in at around 50 - 60 kt over the fence. As for the "floaty" thing, try and raise the nose a bit more just after rounding out, that usually fixes it for me. With the flaps, I vary it between 1 stage and full flap depending on the conditions and payload on the dayI have just clocked up 100 hours in the 170!

 

Kev

The J160C has a quoted stall speed of 53knt (clean -no flap) and 48knt (dirty - full flap) at 540kg MTOW. Take care at coming in too slow with this aircraft because it will sink very quickly. You may also have trouble flaring without some power and nose wheels have been damaged as a result.

 

I hold 70knt @1800rpm with one stage of flap until mid-final, then generally apply full flap at 65knt. Over the fence at 65knt (60knt short field), then reduce power after the flare. If its gusty or a strong cross wind, then I generally do not use full flap.

 

 

[Guest brentc]

Better check that figure Ken, remember the stall speed for RA-Aus is 45 knots or less!

 

 

[Guest Ken deVos]

Better check that figure Ken, remember the stall speed for RA-Aus is 45 knots or less!

Brent, check the Jabiru website. I do not know how the Jabiru Company managed to certify the J160C with a 48knot full flap stall speed. The Australian LSA regs require 45knt full flap whereas, the USA regs specify 45knt clean. Hense, the J170 was designed for the US market and stalls at 40knt full flap and 45knt clean.

 

The following is from the J160 POH...

 

2.3 AIRSPEED INDICATOR MARKINGS

 

 

 

 

 

 

 

 

The airspeed indicator markings in the table below are based on airspeed calibration data from

 

 

 

 

 



Section 5.

 

 

 

 

 

 

MARKING

 

 

 

 

 



IAS VALUE or

 

 

 

 

 



RANGE

 

 

 

 

 



SIGNIFICANCE

 

 

 

 

 

 

White Arc 48 - 84

 

 

 

 

 

 

 

 

Full Flap Operating Range. Lower limit is the maximum

 

 

 

 

 



weight stalling speed in the landing configuration. Upper

 

 

 

 

 



limit is the maximum speed with flaps fully extended.

 

 

 

 

 

 

 

[Guest brentc]

That's easy then, the White arc is not the stall speed, it's the flap extension speed. I'd say it's just poor documentation as it's definitely not above 45 knots. Why am I not surprised with that :-)

 

At a really rough guess it would be maybe 44-45 knots. Mine stalls with the same wing at 45 knots at 544 kg's, so perhaps around the same because of the wing.

 

 

[Guest Ken deVos]

That's easy then, the White arc is not the stall speed, it's the flap extension speed. I'd say it's just poor documentation as it's definitely not above 45 knots. Why am I not surprised with that :-)At a really rough guess it would be maybe 44-45 knots. Mine stalls with the same wing at 45 knots at 544 kg's, so perhaps around the same because of the wing.

The fine print in the POH states:

 

Full Flap Operating Range. Lower limit is the maximum

 

 

 

weight stalling speed in the landing configuration. Upper limit is the maximum speed with flaps fully extended.

 

 

 

 

 

 

 

We are talking of the KIAS and not KCAS. For KCAS, the POH further states:

 

 

 

 

 

 

 

 

 

 

5.2 APPROVED DATA

 

 

 

 

 

 

 

 

 

5.2.1 Airspeed Indicator System Calibration

 

 

 

 

 





 

 

 

 

 

Conditions:

 

 

 

 

 

 

Power:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As required for level flight or maximum rated RPM as appropriate.

 

 

 

 

 

 

 

 

 

 

KIAS KCAS

 

 

 

 

 

 

 

 

 

 

Flaps UP Flaps Take-off Flaps Landing

 

 

 

 

 

 

 

 

 



47 - - 45

 

 

 

 

 





 

 

 





 

 

 

 

 

....

 

 

 

 

 

 

....

 

 

 

 

 

 

 

 

NOTE

 

 

 

 

 

 

 

 

 

Indicated airspeed assumes zero instrument error

 

 

 

 

 

 

 

 

[Burlc]

My approach speed is 70kts. Better to be faster then too slow.

 

You should also vary your flap setting and not just do the same thing all the time.

 

One day your electric flaps may blow a fuse and not work so you need to practice in all landing configurations.

 

In strong crosswind or known mechanical turbulance conditions you want to come in faster and with less to no flaps to limit being blown offcourse or to fall out of the sky close to the ground due to loss of lift from the gusting wind.

 

You can limit float by approach angle, shallower approach less float.

 

 

[Yenn]

Harthy. What options do you have speed wise in a Thruster. I have a little bit of experience in one, but i could never approach at 70kts or 40kts. I agree they are not the easiest to land but speed control is not really a problem as they have a very small speed envelope.

 

I once got mine up to 70kts, but that was at about 40 degrees downslope. All I ever needed was to remember 50.

 

 

[Guest brentc]

Here you go Ken, this is interesting.

 

Jabiru J160-C

 

It says in the brochure what you are saying (48), but 8 lines below says the following:

 

Stall speed with flaps at Gross Weight 45 KIAS

 

They need to tidy up their figures!

 

Sorry for the thread drift however we don't want someone thinking it's lower than it actually is.

 

 

[Guest Ken deVos]

Here you go Ken, this is interesting.Jabiru J160-C

 

It says in the brochure what you are saying (48), but 8 lines below says the following:

 

Stall speed with flaps at Gross Weight 45 KIAS

 

They need to tidy up their figures!

 

Sorry for the thread drift however we don't want someone thinking it's lower than it actually is.

Interesting it is indeed Brent. I would trust the official aircraft POH document over the marketing hype though. However, also interesting is that the POH does not show the Vs1 speed of 53knt, whereas, it is shown on the marketing hype.

 

Pilots of the J160 and of the J170 need to make a clear distinction between the two models when deciding their approach speed. If in any doubt, please ask your instructor.

 

 

[Guest Pioneer200]

Good answers guys and girls,, What about the other question, Favourite and Least favourite Jabiru model and why?

 

I am sure a few of you Aussies have flown nearly all models built so far:off topic:

 

 

[Guest Ken deVos]

Good answers guys and girls,, What about the other question, Favourite and Least favourite Jabiru model and why?I am sure a few of you Aussies have flown nearly all models built so far:off topic:

That's the easy question Pioneer200...

 

The 55(lsa) is the fun machine that teaches you great pilot skills, but I would not want to travel long distances in it because it can be fatiguing.

 

The J160 is my least favourite because it seems to need encouragement to fly, but I would use a 160 over a 55(lsa) for long trips.

 

The J170 is a true joy to fly, but perhaps a little slow.

 

The J230 is a J170 with more grunt. Pity the LSA regs prevent it being loaded more than 600kg MTOW.

 

 

[Guest brentc]

J400, of course, the fastest model they ever had. It doesn't have the climb of the 230 or 430 but leaves it in its' wake!

 

 

[jcruffle]

What sort of TAS are you talking, Brent (and what power setting)???

 

John

 

 

[bushpilot]

My approach speed is 70kts. Better to be faster then too slow.You should also vary your flap setting and not just do the same thing all the time.

One day your electric flaps may blow a fuse and not work so you need to practice in all landing configurations.

 

In strong crosswind or known mechanical turbulance conditions you want to come in faster and with less to no flaps to limit being blown offcourse or to fall out of the sky close to the ground due to loss of lift from the gusting wind.

 

You can limit float by approach angle, shallower approach less float.

I dont really understand this: Why limit flap in turbulence? Isn't it better to still use flap but maintain IAS at the higher end of the full-flap range? Say 70kts approach and ease to 60kts late late final..

 

I use this approach in all conditions and never use more than 50% of my 640m one-way strip..And do not pound the undercarriage

 

 

[quentas]

I find 65kts on final with full flap does the trick in my 230. I have run out of brakes doing just 10 kts more. Also full flap is required to maintain a clear view of the runway ahead as no or some flap tends to get the nose quite high on the flare before touchdown.

 

 

[Guest brentc]

What sort of TAS are you talking, Brent (and what power setting)???John

I don't have one of those gucci fancy Dynon's so I don't know my exact TAS unless I attempt some rough calculations (hmmm where's that theory book hiding).

 

Indicated airspeed on your average day I'm disappointed if I don't get 122 at 2,800rpm (1,000ft approx), but if I'm in a rush I'll zip along at 130'ish.

 

Where are you Derby with your carbon prop, back me up here

 

Unlike the 230 and 430 the 400's don't have an issue hitting VNE and they do it quite comfortably without shaking and vibrating and bouncing around. Remember that the 230 has 5 foot more wing hanging off the ends which definitely makes a difference!

 

Look closely under your wing struts on a 230 and you'll see a metre or so long alloy strip riveted under there. That's to stop your wings falling off when you get near VNE (true!)

 

 

[quentas]

I guess us 230 drivers are lucky our planes hardly get anywhere near vne so our wings cant fall off.

 

 

[Relfy]

I always wondered what those strips were when I was pre-flighting. Is it something to do with harmonic vibration at or near vne Brett?

 

 

[Derby]

Hi Brent, You are right my J400 will get to vne very easily at 1500 to2000 ft.

 

It will cruise at 120 or one or two knots better IAS on a good day, and never below 118 at above alt's. The three blade prop is brillant, it's the same as Brent's

 

The cruise speed is at about 2800 to 2850 rev's.At or near vne the controls get very heavy.(only tried in smooth air the plane was still accelerating but slowly), I stoped at 138 knots which is vne for a J400.There were no vibrations at all. It ran out of forward trim, ie nose down trim. Rory

 

 

[Guest brentc]

Thanks Rory. Sounds very similar to mine, particularly the trim and heaviness in the controls.

 

The strips were added when the wings were extended for the 230 / 430 model. I'm of the belief that they stop harmonics within the airframe. It does seem a little strange to have them fitted as they are treating the symptoms and not the cause of the issue.

 

We had an SP6 with some vibration at 110-115 knots at Jabiru advised to add these strips, but otherwise I'm not really sure what they are there for.

 

 

[DKM1]

Hi Brent

 

400 vs 450 you might know what is the difference is, as there is not much info around on the net for the 400.

 

Thanks Daniel