Jabiru 230 Go-around

[Old Koreelah]

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?

[Thruster88]

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.  

[kgwilson]

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.

Edited April 12, 2021 by kgwilson

[anjum_jabiru]

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. 

[facthunter]

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

[Old Koreelah]

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.

[facthunter]

Re the last bit you should feel it in the controls if it's happening.. Nev

[poteroo]

On 12/04/2021 at 2:15 PM, Old Koreelah said:

One experienced pilot told me not to slip with flaps deployed (makes sense) but I wonder if 1st stage (about 18 degrees) is unsafe. 

 

Slipping with full flaps never seems to 'work' for me, certainly where the aircraft has a large flap maximum of 40▫️ , eg SuperCub, heavier Cessnas. Bar talk about a severe nose pitch down as the crossed controls are uncrossed in the flare is something I've tried to reproduce - but no.  My RV9A has only 30▫️ max and even with idle power, & 60KIAS, wont sink faster than 600fpm. But, with nil flap, full crossed controls @70KIAS, it will exceed 1000fpm.  Reassuring that it never creates a risky configuration.  

 

My Brumby high wing has only 30▫️ full flap, and slipping isn t comfortable nor effective. Better to reduce the lift by slowing down from 60 to 50, which then creates more drag and less lift. (remember the v2 in the Lift equation?)  Anyway, full blooded slips down final don't really go over well with a load of tourists on a scenic, with a TIF if you're instructing,  or your wife/friend on a private jolly.

 

happy days,

[RFguy]

Hi Pot. Interesting what you say about the brumby and the low airspeed option.

 

I have done a fair amount of slipping in the Brumby high wing. I would agree- a flap slip in that aircraft are not that  useful, as all my simulated EPs often end up with a aggressive forward  slip or slipping turn (no flap)  maybe 65 in a pure forward, 70 in a slipping turn  to get into the nominated paddock.  I dont slip < 300 feet.  As usual, flaps go out when making the landing zone is assured.

 

.but. there is an interesting option here that should be brought up - 

There is one instance where the forward flapped slip in that machine might be used - when looking for maximum decent rate per distance covered. and its what you talked about, drag.

During a demo my instructor took over demonstrated it , essentially it added a whole load of drag is what it is, - it DID  NOT increase descent rate  per minute, (~1100-1300 I usually can get ) - but it slowed the airspeed a heap , thus  increasing  descent per distance ,  getting into a strip with no go around option , say plane on fire etc. 

 

 

[facthunter]

I Can't quite follow that. Even in a slip you control the airspeed with elevators. It's very essential to be able to do it well or you are someday going to get into strife..

 Slips should not be at high speed. A slip provides another way to the ground (other than hanging the nose up and mushing) which is inherently steeper.  It can  also be constantly varied  as to bank and turn  rate. smoothly and progressively. The ideal  way to slide over an obstacle and get on the ground near say a row of tall windbreak trees and use all of the paddock . Most practice ones are initially terminated at about 200 feet  till you really get the thing right. You can go right to  the flare but if you get it wrong  it won't be pretty. At least you aren't going at a great  rate of knots, but PLEASE make sure you know what you are doing. Nev

Edited April 26, 2021 by facthunter

[RFguy]

I understand slips came about in use for aircraft that had no flaps. 

 agree with your confusion with my explanation, Nev.  actually recalling it better now , the descent rate per minute did increase a little .

 

I have not used the flapped slip.    But my observations during the manouver were that it provided a higher descent rate at the lower airspeed (and lower margin for a F-Up) .  Mileage might vary aircraft to aircraft. (boxey types, smooth types..) 

 

With a forward flapless slip, if I hold the nose up (at 5000 AGL) , i'll get decreasing airspeed yes , and decreasing descent rate per minute .  of course, eventually controls go to mush, doesnt feel like a good place to be, drops a wing crossed   - hazardous ! 

 

 I AVOID  slips of any sort  at less than 65 kts (1.44 x Vs) .  I choose 70 minimum  in a slipping turn (1.65x Vs) . aileron first, then rudder. and the opposite coming out of the slip,  rudder centre, then unroll.- so I never have the plane configured with hard rudder with no opposite aileron applied..   I think I said elsewhere here I can spin a cessna flight-sim going rudder first then roll. 

 

I'd usually control the airspeed with elevators.

 

as for  " You can go right to  the flare but if you get it wrong  it won't be pretty."

 

golly that would take some getting right from my perspective , going from the high descent rate > 1000 fpm  and turning all that into energy for the flare...  golly gosh.
 

 

 

 

 

Edited April 26, 2021 by RFguy

[RFguy]

for others, as we are discussing potentially hazardous manouvers, I might point out, as usual, this is just bar talk, discussion here cannot substitute for professional tuition catering to your individual ability and experience . Critical  information, many things assumed,  may be left out  of this discussion.

 

Edited April 26, 2021 by RFguy

[turboplanner]

1 minute ago, RFguy said:

for others, as we are discussing potentially hazardous manouvers, I might point out, as usual, this is just bar talk, discussion here cannot substitute for professional tuition catering to your individual ability and experience . Critical  information, many things assumed,  may be left out  of this discussion.

 

Interesting comment; I know of many farm failures and accidents, and a few aircraft accidents where non-professional tutor, e.g. Dad to Dave have said "X" only to see a resulting accident unfold, and afterwards Dad saying "Why in hell didn't you put the hand brake on BEFORE you .....

 

One of the things I've noticed in pre-training briefings with professional instructors is they tell you the full scenario and the full reasons.

[facthunter]

It's not anything really. 1,000 fpm. That's about 10 miles/hr or 16 Kms/hr  You just ease out of the slip and into the flare where you may get the tail down a bit  Hopefully very close to the ground .Talk to your Instructor.  He seems with it. Nev

[facthunter]

  I hesitate to discuss techniques of even normal landings  here and don't usually. You need to get a good idea first what a sideslip IS. to even THINK of one. It's NOT an ungainly skid at speed "commonly  done when asked for" which is awful and does impose loads on the plane. NOR do much in the way of  of what a sideslip can do or is.. This matter has arisen quite a few times and there's plenty if inadequate talk around it. You won't get anywhere if your instructor doesn't do them and know how to  or even "Likes" doing them. . Nev

[RFguy]

wing down method I think people call it, for Xwind, is a form of less aggressive slip of course, flown to the flare and onto the ground. 

 

 for small amounts of X wind, I bring it in just with a bit of roll to coutner the drift  and straighten up just before the mains touch(crap). But for more severe   X wind, at aircraft limit, I wing down (roll) with opp rudder to maintain centreline all the way from the short final until the wing down wheel contacts the ground. 

Edited April 26, 2021 by RFguy

[facthunter]

That's your option but sometimes passengers may be a bit put off. Not that that really matters but crabbing  to track properly down the centreline is more common and the kick it straight and a bit of into wind wing down. On some planes flaps and engines location severely reduce the amount of wing down as you flare that is possible. Nev

[RossK]

3 minutes ago, facthunter said:

That's your option but sometimes passengers may be a bit put off. Not that that really matters but crabbing  to track properly down the centreline is more common and the kick it straight and a bit of into wind wing down. On some planes flaps and engines location severely reduce the amount of wing down as you flare that is possible. Nev

I was told to never wing down in a right hand x-wind, as it scares passengers, crabbing was/is the preferred method with passengers.

 

The Sportstar POH discourages slips, says the flaps are much more effective at losing height than a slip. 

[RFguy]

Well, your opinion is shared with my instructor - he says  try not to use a slipped condition with  passengers unless its an emergency. As the pilot, you wont feel the same awkward sensation.   

My high X wind landings are flapless, at least standard approach. Have not done alot of short field , crosswind at book  limit landings. The grass runway at cowra  is good for practicing those.  a reliable crosswind.

 

 

 

Edited April 26, 2021 by RFguy

[facthunter]

IF flaps are effective I suggested using them in preference way back. There's general agreement on most of this stuff and it makes sense.. There's no reason for everyone to work it out from scratch. Backed by the simple laws of Physics of the Newtonian kind. Of course your flaps may become unavailable if there's any assymmetry.  Not mentioned in RAAus circles as I recollect. Nev

Edited April 26, 2021 by facthunter

[RFguy]

I would conclude that I  only use slips in EPs  .  I have done some slips on final on  flapless approaches in training, but that's an exception.

 

A bit of rambling here.... for me . In good friendly conditions,  reducing power and holding the nose up  is the usual fix of a being too high on final . not a slip.  The flaps and reduced power does what you need. Once the flap go out, that's a one way trip and they stay on until the ground.

 

was thinking about this a bit more on why I use the slip more often on EPs than flaps- I dont want to put the flaps out  getting the plane lined up with altitude  onto the paddock only to pull them back up finding myself a bit low . (and usually use flaps only after when making the paddock is assured)

....the slip provides me  with a more quickly  variable fine tuned control of a rapid descent- - the slip feels like my manouver with the slip is more like just flying the plane, with something extra in my toolkit. ....rather than throwing our the anchors with the flap.  IE I feel like its just a useful tool.   . The club Brumby only has 1 flap setting (full) . so its all or nothing. 

 

messed up approach. hmmmm .   That can happen at an AD I dont know , where I turn base  a bit early, or if base leg  is not square  to the strip again somewhere not familiar with . ......Now,  if  I am way too high  , flaps out  , and it is a short or downhill strip, I'll  go around, safest solution and have another crack so my approach is stabilized  for a correct and orderly touchdown point. .... That can also happen if I have a big tailwind on base leg. A fast ground speed base leg .... There are various fixes for that.  I can S out the final turn a bit, reduce power a bit.  Reducing power, flaps out, nose up  descent rate can get pretty close to the slip.   slip is pretty much a last resort on being too high on a normal approach.   now, throw in a cross wind, well now its a different discussion.... 

 

golly there ARE horses for courses. How do ya teach all this stuff ?!!

Edited April 26, 2021 by RFguy

[facthunter]

I'd say many don't. After the initial licence nearly nothing formal or structured may happen. Some get input from the little elves at the end of the garden or worse get it on line or on forums.  If you get a career in aviation there are endorsements and upgrades that in some instances go right back to basics. Other times the bare minimum to get you the ticket.. How many bike riders or car drivers do any advanced courses? ' When you a re instructing you owe the show a professional approach and your students expect that you know what you are talking about and can handle the Plane to get it out of any situation you get it into..  With flying there's a lot of ego involved, especially with Blokes. Often it certainly doesn't help things. On the other hand you may fly with literally 1,000s of other pilots and learn something from most of them. Occasionally it might be that THEY can't be trusted. Nev

[Roundsounds]

2 hours ago, RossK said:

I was told to never wing down in a right hand x-wind, as it scares passengers, crabbing was/is the preferred method with passengers.

surely your instructor isn’t serious?

[aro]

1 hour ago, RFguy said:

In good friendly conditions,  reducing power and holding the nose up  is the usual fix of a being too high on final

I wouldn't really recommend this. You certainly get more drag as you slow down but you are also getting closer to stall. You should be keeping speed stable at the target airspeed on approach. If idle power and flaps are not enough to fix the approach, either a slip or go-around are the best options.

 

Depending on the aircraft, increasing speed might also be an option. A C152 at VFE with full flaps has an impressive angle of descent, and loses the speed again quickly. However the Jabiru I flew didn't have enough margin between VFE and approach speed to make this a useful technique.

[RFguy]

Maybe I didnt explain myself-  I dont hold the nose  it up so its about to buffet and fall out of the sky

 

- airspeed should be maintained that permits positive  aircraft control and authority.

 

I'd say on  a straight approach in little or nil wind, I dont think there is any issue with flying at 55 kts in  (45kts stall) instead of 65 kts.  Just keep your eagle eye on  the airspeed  and fly the aircraft.... On a short field approach  you  may do something like that anyway IE maybe to  reduce air speed over the fence. 

 

sure you can lose height by pointing the aircraft down but in aircraft I fly you very quickly run into VFE as you pointed out.  and then that's speed that has to be removed.

 

Edited April 26, 2021 by RFguy