Jabiru 160 Flight Manual speeds
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Jabiru 160 Flight Manual speeds
Request the following recommended indicated airspeeds from the manufacturer's Pilot Operating Handbook for the Jabiru 160
Lift-off speed during take off run.
Climb speed clean.
Best glide speed - clean and with flap.
Final approach speed for landing with full flap and flaps up.
and
Manufacturer's before landing checks.
Note: Each flying school usually has its own company speeds and checklists which may differ from the manufacturer's recommendation. The request above is for information published in the manufacturer's POH for type - not individual flying schools technique.
Do the speeds vary between all the types of Jabiru? Examples please
Thanks.
Lift-off speed during take off run.
Climb speed clean.
Best glide speed - clean and with flap.
Final approach speed for landing with full flap and flaps up.
and
Manufacturer's before landing checks.
Note: Each flying school usually has its own company speeds and checklists which may differ from the manufacturer's recommendation. The request above is for information published in the manufacturer's POH for type - not individual flying schools technique.
Do the speeds vary between all the types of Jabiru? Examples please
Thanks.
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All the manuals are available on line. For the J160, see:
http://www.jabiru.net.au/Manuals/Pil...on0-9_Rev3.pdf
http://www.jabiru.net.au/Manuals/Pil...on0-9_Rev3.pdf
Flew a Jabiru for 45 minutes dual about 15 years ago. I recall the instructor was quite vague about what speed to reach before getting airborne. I can now see why. Having now read the POH courtesy Pprune correspondents I was puzzled at the take off technique that says:
Rotate...................................................... 30 – 40 KIAS raise nosewheel clear of ground
Take Off Safety Speed ............................ 66 KIAS
Accelerate to Climb Speed ...................... 70 KIAS
The POH also says to lift off to arrive at 66 knots at 50 feet. There is no mention of desired lift off (rotation?) speed though. It says above that you raise the nose-wheel clear of the ground at between 30-40 knots. With full throttle the stalling speed is going to be a lot lower than a conventional power-off stall speed.
Forgive my ignorance but having a "raise the nose-wheel airspeed" of say 30 knots, wouldn't that risk a premature lift off into ground effect as well as considerable increase in induced drag? To what nose attitude does the pilot raise the nose to at 30-40 knots? All the manual says is that the nose-wheel should be raised clear of the ground. It is impossible to know in most light aircraft when the nose-wheel is clear of the ground since there are no nose attitude figures published.
I recall the first of several DH Comet accidents where the manufacturers recommended take off technique was to lift the nosewheel clear of the ground at around 80 knots with the aircraft getting airborne once the wings sensed sufficient lift which was around 105 knots?. The accidents happened at night where the pilot had to guess the attitude that equated to 80 knots nose-wheel lift off - but not aircraft flying speed lift off. It was later revealed that the 80 knot deliberate raising of the nose-wheel clear of the ground resulted in stalled wings and a huge drag increase.
In the case of the Jabiru, as for some reason the manufacturer chooses not to include a desired lift off speed, it seems up to the pilot to decide for himself when to lift off. Quite tricky for a new student. In turn, that is quite imprecise compared to an aircraft like the Cessna 172 where the POH is quite clear when it states: Elevator Control - lift nose-wheel at 55 knots and climb at 70-80 knots.. In other words leave the nose-wheel on the ground until reaching 55 knots and then rotate for lift off (55 knots).
Maybe one is making a mountain out of a mole hill but as someone used to once operating jet transports where VR speeds are precise and safe, it puzzles me that LSA like the Jabiru have rather vague advice on speeds for take off. I can just imagine a student being puzzled.
Rotate...................................................... 30 – 40 KIAS raise nosewheel clear of ground
Take Off Safety Speed ............................ 66 KIAS
Accelerate to Climb Speed ...................... 70 KIAS
The POH also says to lift off to arrive at 66 knots at 50 feet. There is no mention of desired lift off (rotation?) speed though. It says above that you raise the nose-wheel clear of the ground at between 30-40 knots. With full throttle the stalling speed is going to be a lot lower than a conventional power-off stall speed.
Forgive my ignorance but having a "raise the nose-wheel airspeed" of say 30 knots, wouldn't that risk a premature lift off into ground effect as well as considerable increase in induced drag? To what nose attitude does the pilot raise the nose to at 30-40 knots? All the manual says is that the nose-wheel should be raised clear of the ground. It is impossible to know in most light aircraft when the nose-wheel is clear of the ground since there are no nose attitude figures published.
I recall the first of several DH Comet accidents where the manufacturers recommended take off technique was to lift the nosewheel clear of the ground at around 80 knots with the aircraft getting airborne once the wings sensed sufficient lift which was around 105 knots?. The accidents happened at night where the pilot had to guess the attitude that equated to 80 knots nose-wheel lift off - but not aircraft flying speed lift off. It was later revealed that the 80 knot deliberate raising of the nose-wheel clear of the ground resulted in stalled wings and a huge drag increase.
In the case of the Jabiru, as for some reason the manufacturer chooses not to include a desired lift off speed, it seems up to the pilot to decide for himself when to lift off. Quite tricky for a new student. In turn, that is quite imprecise compared to an aircraft like the Cessna 172 where the POH is quite clear when it states: Elevator Control - lift nose-wheel at 55 knots and climb at 70-80 knots.. In other words leave the nose-wheel on the ground until reaching 55 knots and then rotate for lift off (55 knots).
Maybe one is making a mountain out of a mole hill but as someone used to once operating jet transports where VR speeds are precise and safe, it puzzles me that LSA like the Jabiru have rather vague advice on speeds for take off. I can just imagine a student being puzzled.
The POH is correct, but it's not informative about technique.
We had a 160 for 6 years at our school, and recently sold it to buy another Aussie LSA.
At gross, the Vsf (take-off flap setting) is 47 with power off - but definitely sub 45 @ t/o power. Anyway, if you apply light elevator input going through 40, the nosewheel begins to lift off but acceleration ensures you are soon past 54 (45 x 1.2). It begins to unstick the mains at this stage - with only a small nose up attitude. Nothing that causes the student any alarm, and certainly only enough to not block out the view ahead.
Jabiru then adopts a very cautious approach and nominates 66 as the TOSS, and 70 as Vx. In real life, the aircraft will climb @ 55, but if allowed to reach 60 - it then climbs away quite well. For a student in a well under gross aircraft - the 160 accelerates up to 70 quite quickly and climb can be established.
The reasoning that I'm aware of is that the J160 tends to be easily diverted off track if the nosewheel has much weight on it, and is easier to steer with the weight coming off it earlier in the t/o run. (the corollary is in the landing where it's wise to keep the Jab nosewheel off until you're out of elevator command because it's a little squirrely if the nosewheel comes on fast and braking is applied - many Jab accidents due this). On any rougher surface strip - its prudent to lift off the nosewheel early on because it's not the strongest of the u/c structures. Mains will take a bit of bashing tho.
We used a Vy of 80 because ROC is better, it's good for cooling, and gives the student a clear definition between Vx,Vy.
Hope this is informative,
happy days,
We had a 160 for 6 years at our school, and recently sold it to buy another Aussie LSA.
At gross, the Vsf (take-off flap setting) is 47 with power off - but definitely sub 45 @ t/o power. Anyway, if you apply light elevator input going through 40, the nosewheel begins to lift off but acceleration ensures you are soon past 54 (45 x 1.2). It begins to unstick the mains at this stage - with only a small nose up attitude. Nothing that causes the student any alarm, and certainly only enough to not block out the view ahead.
Jabiru then adopts a very cautious approach and nominates 66 as the TOSS, and 70 as Vx. In real life, the aircraft will climb @ 55, but if allowed to reach 60 - it then climbs away quite well. For a student in a well under gross aircraft - the 160 accelerates up to 70 quite quickly and climb can be established.
The reasoning that I'm aware of is that the J160 tends to be easily diverted off track if the nosewheel has much weight on it, and is easier to steer with the weight coming off it earlier in the t/o run. (the corollary is in the landing where it's wise to keep the Jab nosewheel off until you're out of elevator command because it's a little squirrely if the nosewheel comes on fast and braking is applied - many Jab accidents due this). On any rougher surface strip - its prudent to lift off the nosewheel early on because it's not the strongest of the u/c structures. Mains will take a bit of bashing tho.
We used a Vy of 80 because ROC is better, it's good for cooling, and gives the student a clear definition between Vx,Vy.
Hope this is informative,
happy days,
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I don't know the answer to your question Centaurus but offer a practical observation which might be relevant. With a lot of the VLA/LSA class aircraft the power-to-weight ratio is often pretty impressive, so acceleration tends to be rapid. Once the weight starts to come off the nosewheel, many of them 'fly themselves' off the runway (although we all know there's a lot more to it than that).
One of things GA pilots flying LSAs often need to check is the tendency to hold the aircraft too long on the runway to gain flying speed. Even a little restraint of the nosewheel lifting can be bad news for these relatively lightly-built aircraft and I know of a couple that have come to grief on take-off at the hands of experienced GA pilots.
Having said all that, the VH-registered VLA I fly regularly has an entirely conventional POH, but sportier performance than the Jabs. I'm certainly not linking the flying tendencies to a particular POH format but am just noting the format difference may not be a large practical issue.
One of things GA pilots flying LSAs often need to check is the tendency to hold the aircraft too long on the runway to gain flying speed. Even a little restraint of the nosewheel lifting can be bad news for these relatively lightly-built aircraft and I know of a couple that have come to grief on take-off at the hands of experienced GA pilots.
Having said all that, the VH-registered VLA I fly regularly has an entirely conventional POH, but sportier performance than the Jabs. I'm certainly not linking the flying tendencies to a particular POH format but am just noting the format difference may not be a large practical issue.
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Personal practice - normally on long grass strip not too rough but gusts can be bad. This is not a C172 but a low inertia a/c very responsive to power but the J160 has effective controls
Start TO stick full back then forward until lift off at 50 kts with positive move. Hold in ground effect till 65 then climb till 70 and increase climb with flaps up at ~ 100ft
Landing - normal full flap 65 short final ~ 1700 rpm round out and chop to ~ when firmly down.
Can do it at 55-60 with 1900~2000 but not much margin - be prepared for a go round. Note that a stall in full flap/power can flick into a spin - play with this above 3000agl
Glide approach ~ 1300 is zero thrust @ 70 knts round out in nil wind and it will settle in about 70m - can do it at 65kts but if everything is not perfect you will hit hard OK for real but not practice.
Keep in practice with the feet my worst experience was taking control at 5 ft in a gusty crosswind at Bourke after the (qualified) wife's (small) foot slipped under the pedal.
Noticed this:
That was what I was trained for with the early 172 so dropped at MB to pick up a 172 on crosshire for a charter. Get keys, preflight and depart to BWK, essentially lose directional control at about 48kts - in the absence of better ideas pull back on stick and go into 1000fpm climb. Land at back at BWK and grab Bill Campbell-Hicks before loading pax -WTF - "that has a new leading edge knock at least 5 kts off the speeds - look at the book"
Start TO stick full back then forward until lift off at 50 kts with positive move. Hold in ground effect till 65 then climb till 70 and increase climb with flaps up at ~ 100ft
Landing - normal full flap 65 short final ~ 1700 rpm round out and chop to ~ when firmly down.
Can do it at 55-60 with 1900~2000 but not much margin - be prepared for a go round. Note that a stall in full flap/power can flick into a spin - play with this above 3000agl
Glide approach ~ 1300 is zero thrust @ 70 knts round out in nil wind and it will settle in about 70m - can do it at 65kts but if everything is not perfect you will hit hard OK for real but not practice.
Keep in practice with the feet my worst experience was taking control at 5 ft in a gusty crosswind at Bourke after the (qualified) wife's (small) foot slipped under the pedal.
Noticed this:
Cessna 172 where the POH is quite clear when it states: Elevator Control - lift nose-wheel at 55 knots
Last edited by Deaf; 26th Feb 2014 at 13:07. Reason: Noticed this
I don't know the answer to your question Centaurus but offer a practical observation which might be relevant. With a lot of the VLA/LSA class aircraft the power-to-weight ratio is often pretty impressive, so acceleration tends to be rapid. Once the weight starts to come off the nosewheel, many of them 'fly themselves' off the runway (although we all know there's a lot more to it than that).
Eyes outside, fly by attitude. If you look inside a Jab, while on the runway when I am instructing, expect a reprimand.
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The POH probably should have said something along the lines of "apply back stick to reduce weight on nose wheel" or similar. It certainly won't fly at 30-40 knots so there's not much of a chance of premature takeoff; reducing the weight on the wheel would solve the issue of controllability and may reduce the probability of a fast vibrating nose wheel on takeoff, plus the drag issue as Centaurus says.
The first question about raising the nose should be "by how much?"
The first question about raising the nose should be "by how much?"
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Experience shows me that Jabirus (and others) the whole process is a few seconds and often in around 250m strip.
Many will climb @ steep rates happily, with trim neutral they will easily really take off themselves.
Short operations calls for NOT lifting the nose as this does add drag and lengthen TODR
Historically (but not so much today) there was concern over nose wheel strength and getting it off the ground in take off and keeping it off in landing was taught as being important/wise. Side loads especially so higher speed steering not recommended.
Could be also to do with nose and rudder being hard connected so as soon as possible get rudder doing the work rather than sensitive nosewheel.
Many will climb @ steep rates happily, with trim neutral they will easily really take off themselves.
Short operations calls for NOT lifting the nose as this does add drag and lengthen TODR
Historically (but not so much today) there was concern over nose wheel strength and getting it off the ground in take off and keeping it off in landing was taught as being important/wise. Side loads especially so higher speed steering not recommended.
Could be also to do with nose and rudder being hard connected so as soon as possible get rudder doing the work rather than sensitive nosewheel.
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Then there is the issue that raising the nosewheel too early will mean that there is not enough airflow over the rudder for it to become effective, thus if you lift the nosehweel too early you can't steer effectively using rudder, particularly when the flaps are down. That's when you spear off to the left side of the runway because of the torque of the engine. All good fun. Particularly bad in the 4-seater version with the weight in the back making it even lighter on the nose.
