TAKING OFF PROCEDURES !!

[GR8-DAD]

It sounds like one hell of a mission to get the aeries in the air.....

But can we perhaps move on to the part where we try and get these aeries back onto the ground....and I am pretty sure there would be more differences of opinions.

Fortunately my instructor still has this responsibility...

[Chaz]

Heya Morpheus

My traditional take-off is bar back in the neutral position Are you saying then with the bar forward i am going to have no rolling resistance, be off the ground a lot quicker and on lift off experience higher altitude at the end of the runway

Hmmm sooner Dave has that advanced microlighters session the sooner we can all attend.

Watch this "SPOT" for Chaz's scientific "REPORT BACK" :D :D :D

Your's in Flying
CHAZ

[Big-D]

Chaz wrote

sooner Dave has that advanced microlighters session the sooner we can all attend.

I agree. I need to get to Durban soon anyhow - Man, the curry down there is good!!! :D :D

[Junkie]

Im with Demon 100% on this when it comes to the Mainairs and some higher performance machines....

On the average trainer machine and especially those with cruddy steering! (incl some recent vintages!) the "Bar forward" technique does have some advantage for the beginner as:
> It keeps things a bit slower during initial few hours
... easier and less skill needed / think about
> It helps to avoid getting into a high speed wobble on the ground
> It avoids suddenly popping into the air when the bar is moved fwd
> It gives the student something positive to do early on
> It's maybe just a Cape thing (its how I was taught anyway)

I DONT advocate full bar fwd at all (for the reasons mentioned earlier) and it's not necessary - so if you teach Bar Fwd then start with bar fwd only about an inch or so from neutral...AND dont forget the WHY ,...

" ok John, now increase Angle of Attack by pushing fwd slightly on the bar to increase lift, ok thats fine, now apply full power progressivly as we discussed..."

Id prefer students are taught to use correct /normal flying technique for the type of machine as early on as possible

[Morph]

Let me just say, these techniques were taught to me and I fly 3-axis not trike. In the Challenger your short field take-off is exactly as I have mentioned it.

Chaz, maybe you should get an instructor in the plane with you, the last thing I need is something to go wrong

Heya Morpheus

My traditional take-off is bar back in the neutral position Are you saying then with the bar forward i am going to have no rolling resistance, [

No once in ground-effect you will have no rolling resistance

be off the ground a lot quicker and on lift off experience higher altitude at the end of the runway

yip works for me.

[Oddball]

Wow! Such fun...

I come from a PPL background (for what that's worth..) so here is my input. When flying a spamcan you wait for a rotate speed (normally between 60-70 knots indicated airpspeed in the Cessna/ Piper entry level aircraft) and then haul back on the stick a bit until you are up in the air, then you level out and build speed to best rate of climb speed, and then you initiate the climb and try to maintain that speed.

This is the 'classical' method and works well. However, one must bear a couple of things in mind. Ussually you are taking off from a prepared airfield where you have minimum rolling resistance and it may be wider so that you can afford to drift slightly.

In a trike we are normally taking off from some bit of half finished lawn and turf. In this case I think that the idea that you hold the bar full forward/ a little back from the profile tube is great; the transition from not flying to flying is very quick so there is no time mucking about half on and half off the ground, bouncing about and losing directional control. You're up and almost immediately your flight controls have authority.

The critical thing with this method is to pull the bar back in almost immediately after you have 'jumped' up into the air. Its the best of both worlds, viz.:

a) your wheels have good authority to control direction almost right up to the rotation
b) once you are in the air you are free of ground friction and bouncing
c) if you pull the bar in quickly in an ordered manner you will be well above stall speed almost immediately (the wing goes from a high angle of attack to a low one very quickly)
d) if you stuff it up you don't climb too far and mush slowly down

This transition from 'ground control' to 'flight control' is critical to all aircraft - look at the heavy metal on landing; as soon as thier weight settles onto the wheels they deploy spoilers on the wing to dump the lift off the wing and put it onto the undercarriage. Why? Because you do not want to be mucking about in that situation between the wind not quite flying and the wheels not yet having sufficient weight and thus friction to maintain directional control.

Thier take off is different because they make sure that the wing is flying before take off and then rotate sharply. Why? thier wings have super critical airfoils and cannot fly well below cruising speeds. They have to deploy high lift devices and use this technique for safe take offs.

We, on the other hand, have quite 'dirty' wings that create high drag but that also ensure that the airflow adheres to the top of the wing through most angles of attack. Thus, when we take off we have a large margin to play with, so if we very quickly, and smoothly, change the angle of attack from a high one to a low one we transition from ground to air quickly with the minimum of fuss.

I have also found that the bar forward technique gets me off the ground very quickly, and, I suspect, in a shorter distance.

If you look at it the bar forward technique is not much different from the Cessna/ GA technique; rotate as soon as possible, build up speed, climb.

Oddball

[Duck Rogers]

just a question- how far is your plane?

About 20 meters from yours and 42 Km's from home

Duck Rogers

[Cali]

I agree with Oddball.

Thats the way I have been taught to. I am 115 kg and my instructors are all in the 80-90 kg range.

Never felt like stalling on take-off. Bar in as soon as you leave the ground an voila, speed picks up like nothing.

I would like to try bar in neutral on a long runway to feel the diffs.

[Chaz]

Heya Big D, Cali :D :D

Just had a vision which was about you, me and cali in a three seater microlight I was wondering what the MAUW would be considering your 120kg + my 120kg + cali's 115kg = 355kg. Hmmm was wondering who is going to do the rotation, what would our ground speed be and air speed on lift. Wonder if a 912turbo would do the job :D :D :D .

Yeah i hope Dave was serious about that course as i would love to get some coastal flying in. Annette has already extended a invite to my daughter and i.

Your's in Flying
CHAZ

[Smiley]

Heya Big D, Cali :D :D

Just had a vision which was about you, me and cali in a three seater microlight I was wondering what the MAUW would be considering your 120kg + my 120kg + cali's 115kg = 355kg.

Your's in Flying
CHAZ

I hope you guys practiced your pitch & roll on landing!! Poor wheel axles!!

[Cali]

Heya Big D, Cali :D :D

Just had a vision which was about you, me and cali in a three seater microlight I was wondering what the MAUW would be considering your 120kg + my 120kg + cali's 115kg = 355kg. Hmmm was wondering who is going to do the rotation, what would our ground speed be and air speed on lift. Wonder if a 912turbo would do the job :D :D :D .

Yeah i hope Dave was serious about that course as i would love to get some coastal flying in. Annette has already extended a invite to my daughter and i.

Your's in Flying
CHAZ

:D WOW for once I am the skinny one :D

[Big-D]

Chaz wrote

Just had a vision which was about you, me and cali in a three seater microlight I was wondering what the MAUW would be considering your 120kg + my 120kg + cali's 115kg = 355kg.

Yip, sounds good to me. After our "flight" (more like a ride on the runway) we will all go out for a couple of Big Mac's and wash it down with a double thick milkshake

I am glad I am not the only big guy flying trikes. Andy Kasparson had to have my flight suit specially made.....It didn't fit. They are now making me a new one. Andy's words to me were "Hulle maak hom nie seun, hulle BOU hom"

[Chaz]

Heya Folk

Have organised a measuring wheel and Fred and i will be marking off the different lift points and speeds with bar in neutral and bar against profile tube. Personally i think bar forward on beach sand and no obstacles sounds okay. I still "DO" however disagree with a bar forward take off. A simple example would be next time in your car hold your hand out knife edge and then turn it slowly and see how resistance builds. Surely this would apply to a microlights wing as well. Also why do most or all aircraft have a 4 degree angle of incident built into the wing and not 10 or 15 degrees.

Anyway will post results here tomorrow.

Big-D you speak of a couple of big macs and a dobbel dik skommel like its a snack

Your's in Flying
CHAZ

[Big-D]

Chaz wrote

Big-D you speak of a couple of big macs and a dobbel dik skommel like its a snack

Indeed sir - Just enough to get our appetites going for the "braaivleis" to follow.

Look forward to the result of your experiment. Your measuring wheel will work better than me trying to pace off with half of Petit on short finals Saturday

[RudiGreyling]

Hi Guys,

I get into this a bit late but here is my 'take' on it.
You need to be taught both ways!

I understand the reasons for teaching the bar forward take off to newbies, but it is not the safest take off. You HAVE to come back on the bar forward, back to or close to neutral, otherwise you will fly close to the stall and the trike might/will stall depending on the horsepower on the back. Newbies don't have a feel for the airspeed, but they do know when the trike is airborne, which mean it is then time to come back on the bar immediately! If not they can get in deep trouble. This gets even worse if you get an engine failure immediately after take off with the bar full forward. You in effect hanging the trike on the prop thrust, with little speed margin and time before the trike stalls. Be sure to get that bar back quickly.

On the other side the neutral bar take off is a more traditional take off, safer, but you have to develop a feel for the speed, or watch your airspeed indicator. You should NOT push the bar forward since some trikes will just start to fly automatically when they are ready. Other trikes might need 1-2 inches of forward from neutral to get off the ground. On these trikes this pushing forward too soon too far might get the new pilot in trouble. Your take off roll will be longer though. Once you are flying, you are flying at a good speed not close to stall. If you get an engine out immediately after take-off it is easier to stay airborne, since you have surplus speed and time to pull the bar back from neutral before the stall for a good descent.

So it is Tit for Tat, depends on what you get taught after the wheels leave the ground! That is why you need to be taught both ways.

I personally feel the bar forward is a more advanced take off. I use it for short field take-offs or rough fields or soft fields where I want to spend minimum time on the ground. The increased angle of attack of the wing creates lift quicker earlier, means less drag on the ground. I use the Brake on, Bar forward, Full power, Brake off, As soon as the trike starts to fly i.e. leaves the ground, come back to neutral bar immediately and stay close to the ground effect until the airspeed build up before you fly away. I also understand the inherent risks with this type of take off.

Chaz if you do the test on smooth runway (like springs that is tarred) I doubt you are going to see much of a difference in take of distance, but do it on soft sand or a very rough runway and you will.

My 2c for the day

Kind Regards
Rudi