PDA

View Full Version : Jabiru Pilots/Owners


tobyethan
22nd Jan 2002, 06:53
Re: X-wind Landing Techniques

Any experienced Jabiru/3-axis ultralight pilots/FI's who can help with a question of technique, Thanks?

Whats the best x-wind technique for handling gusty crosswinds in 'low inertia' aircraft? Does it matter if it's a 'greaser'or more 'positive' touchdown?

As an inexperienced UL pilot, I've tried the slip approach and it seems to just add more drag; washing off speed even more! I've also tried to crab in and lower the into wind wing, but invariably gusts of wind at various speeds, means I have to dance on the rudder/aileron, hopefully touching down OK!

Thanks.

Genghis the Engineer
22nd Jan 2002, 13:59
The choice of crabbed or wing-down tends to depend upon the ratio of lateral to directional stability combined with rudder power. I believe the Jabiru is directionally a bit marginal, which indicates to me that a crabbed approach is "probably" the better option, although you'll have to switch to wing-down for the last 10 feet or so.

But, with a low inertia aircraft like that, the biggie is speed. If you are using the 1.3Vs approach speed recommended for most light aircraft, it's going to end in tears - or at least in a bit of a bone-cruncher of a landing. Aim to approach at about 1.7Vs, and start to roundout at about 10-15ft. In a really horrible crosswind or very gusty conditions, bring the approach speed up to 2Vs and hold your nerve - don't start the roundout too early.

Best bet of-all mind you, is to spend an hour or two with a microlight QFI.

G

ianhogg
24th Jan 2002, 21:08
Hi, I've just converted a chap on to his jab ul. .(he previously had a shadow and before that a Rans S6), I normally teach on Chevvrons so it was a bit of a learning curve for both of us.. .Two thoughts , I agree whole heartedly with Ghengis. .you want lashings of airspeed on the approach as this will both give you a bit of stored kinetic. .energy to cope with any unexpected gradient,(All microlights are like chucking a ball of paper across the room, they lose energy very fast in comparison to the heavy metal thats why they can land so short) so while you are getting the hang of it an absolute min of 60 over the hedge. Put a tippex mark on the asi so you just have to glance at it not think. . .The second big advantage of speed is it gives the piffling little rudder some authority (it needs all the help it can get on landing). We found setting the a/c up wing down at 60 with a couple of hundred feet to go let us settle the a/c and the pilots brain so as to avoid overcontrolling in the hold off as it needed a surprisingly delicate touch on the elevator in the final stages and lots of toe work . so we found approach fast, land slow and wing down and the a/c settled the last 200 ft.. .On the other hand I may be talking utter balls and we just got lucky. . .Pip Pip.

sistern
30th Jan 2002, 03:26
Hi PF

I'm building a Jabiru at the moment and I have found that the owners web site is a mine of useful information. Suggest you pose your question there. Try this link..http://www.btinternet.com/~jabiruowner/

Happy landings