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4 hours ago, facthunter said:

No I've never commented on prop direction only X-wind and visibility over the nose .. I have stated that, in my observations, it's rarely done well and is therefore less effective and sometimes dangerous.  Nev

Nev, although slipping always feels a bit scary, that’s the first mention I’ve seen of danger from slipping.
One experienced pilot told me not to slip with flaps deployed (makes sense) but I wonder if 1st stage (about 18 degrees) is unsafe. 
Can you outline how to keep safe while side slipping?

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Hi everyone, I recently had an opportunity to fly the Jabiru J230. I had the flaps fully extended, power off and speed about 70 knots on finals, with the trim set fully back. As a part of normal

@anjum_jabiru , 70 kts is a bit hot on finals with full flap isnt it ?  I would have thought more like 65, then 60 late late (nil wind, good condix)    BTW my J230 does not have a pronounced

On many aircraft with full flap down you really won't go  very well at all as far as climb performance is concerned. It's the excess power over drag that permits climb. When you don't have it you don'

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2 hours ago, anjum_jabiru said:

I think this makes a lot of sense. The reason you apply take-off flaps is not to increase the lift. It is actually to increase the drag, without affecting the lift too much. This gives you a steeper climb path (if there is such a thing), making it appear as though you have a better climb performance. What is actually happening in reality, is that you are able to climb to the desired height, within a lesser horizontal distance travelled (due to the drag created by the take-off flap). 

 

On applying take-off flap in a glide, once again the horizontal distance travelled will reduce (due to the increased drag), without much impact on the lift being generated. Hence your glide distance (horizontal distance travelled) from a given  height will reduce. Thus causing a deterioration in your glide performance!

This diagram shows the effects of flap on takeoff.  

images (1).png

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I never use any flap for takeoff except if the ground is soft or the grass is long or the field is very short. Cessna recommends no flap for TO in the 172 POH but many instructors advise 10 degrees anyway. I don't know what is in the Jabiru POH but all (3) Instructors have advised me 1/2 flap for the 160, 170 & 230. On a T&G for me it is full power, flaps retract (electric), stick forward to gain speed & then full climb, all in about 5 seconds.

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Hi kgwilson, when I did a few lessons on a Cessna 152, it was from the shortest licensed grass strip (490m), in Netherthorpe, UK. The instructor used to use 10' flaps and called it the "hedge" check. This was to ensure you clear the hedge at the end of the runway.

 

I think it's a good idea to use half flaps so that you can be airborne asap, and start climbing, in case you have an engine failure and need the runway ahead of you. Besides, one never knows,  but you might need the runway for a longer than usual run on a hot day or high altitude.

 

I  completely agree with regards to retracting half flaps and full power. The only issue is, that in the 3 to 5 seconds it takes to retract the flaps, and push the carb heat in, one can chew up to 100m of useful runway in a t&g, if you are travelling at 50knots. May not be very practical, while landing on a short runway, if you are already 200m into the runway during your landing flare.

 

The best option may still be to go around with full flaps, with nose forward, and retract flaps once you are established in a climb. 

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On many aircraft with full flap down you really won't go  very well at all as far as climb performance is concerned. It's the excess power over drag that permits climb. When you don't have it you don't climb. Larger flap angles have much more drag than extra lift. Some flaps don't provide a lot of extra lift at all. They mainly give you a steeper approach.

  OK from you  about 5 posts ago.. Control of airspeed is the biggest factor relating to safety . Since power is at idle it's about attitude. IF you are low the recovery becomes more critical. The smoother and more positively the process is achieved the better. Initially practice at a safe altitude. Get trained by someone who knows how to do it. Many don't.

     Sideslipping is more necessary in UNFLAPPED planes. IF you have adequate flaps why not just use them?

   The techniques are useful in executing good crosswind skills.. Regarding how the plane goes with flap I'd be guided by the handling notes for the type. Crude flat sided fuselages can FLAP around a bit and some control shielding may occur with flap use that may be a little off putting.. Nev

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1 hour ago, facthunter said:

...OK from you  about 5 posts ago.. Control of airspeed is the biggest factor relating to safety . Since power is at idle it's about attitude. IF you are low the recovery becomes more critical. The smoother and more positively the process is achieved the better. Initially practice at a safe altitude. Get trained by someone who knows how to do it. Many don't.

Thanks for the advice Nev. I got a basic introduction to sideslipping yonks ago in a Thruster. My little plane handles quite differently, but I guess the principle is the same. Can’t fit an instructor in mine, but might have a session in a Sportstar.

1 hour ago, facthunter said:

    Sideslipping is more necessary in UNFLAPPED planes. IF you have adequate flaps why not just use them?

Good point, but there will be situations where a sideslip is useful.

1 hour ago, facthunter said:

...Regarding how the plane goes with flap I'd be guided by the handling notes for the type.

Not available for my heavily modified version.

1 hour ago, facthunter said:

..Crude flat sided fuselages can FLAP around a bit and some control shielding may occur with flap use that may be a little off putting..

That might be very useful, Nev. My fuselage is slab-sided but even in the most extreme slip I’ve been game to do, I haven’t noticed any turbulence, but the flaps were shut.

 

I guess it might require more than wool-tufting to see where the wash from my flaps goes; perhaps some long streamers.

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