Take off technique

[Guest Crezzi]

I thought it was about time we had a new topic on this forum so how about take-off technique - do you start with the control bar in the neutral position oron the front strut (or somewhere else) ?

 

Cheers

 

John

 

 

[bushpilot]

My instructor teaches bar on the strut once rolling at about 20kts....onmy Airborne Redback - then, of course, pull in on lift off.

 

But lessons I took last yearin the USA - on a Cosmos trike - he taught neutral all the time.

 

I actually find the neutral position provides a bit more feel, particularly in roll response. i.e. ifyou are a bit off-centre you can feel it through the bar and adjust accordingly..

 

But, like John,I'm interested in other views.

 

Cheers

 

Chris

 

 

[AzharFly]

Hi,

 

I was taught this...on roll, keep bar in neutral until you can feel the wings wanting to lift off (control cables become taught) then rotate out fully and trim. Maintain climb speed.

 

Short field take off is different... roll and gain enough speed for ground effect to take effect then push bar forward and let aircraft lift off the ground. But you will be flying in ground effect as you don't have sufficient speed to maintain full take off so immediately after the wheels leave the ground, bring bar back to neutral to gain airspeed then rotate out fully and trim. This technique is used for boggy/wet ground conditions where you need to get off the ground fast.

 

Regards,

 

azhar

 

 

[Guest Andys@coffs]

I was taught bar out, however personally I always now take off bar neutral to slightly pulled back until Im ready to actually leave the ground.

 

My logic is as follows:-

 

In the event of an engine failure on take off if the bar is at the strut what airspeed do you have to trade for altitude... None as you cant push the bar anyfurther out. When its neutral to slightly back the wing has significantly more energy in it and if the engine fails you then have from neutral to the strut to use to trade Airspeed for altitude/ controlibility.

 

The other benefit is that when the wing is flying in a neutral position the airspeed is higher and the effort required to adjust for a wind gust or thermal is significantly less and significantly faster than when working with the bar at the strut. Take your beast up high and try you'll see what I mean. Of course if Runway length is limited, or ground profile dictates a very short take off then bar out is probably more appropriate.

 

Those that practise engine out failures on T/O will see what I mean. As someone who has had a 582 sieze on take off Im keen to give myself the best possible chance of recovery.

 

Regards

 

Andy

 

 

[Guest Crezzi]

An interesting answer Andy.

 

I posted the question because I noticed that most of the Aussi trike pilots I've seen used the bar fully out technique - presumably because that was the way they were trained. That wasn't what I was taught & got to thinking about the reasons.

 

It seemed to me that there were a number of advantages to not having the bar fully out. The logic of your EFATO scenario was one of those. Also with the bar at trim the pilot can make the decision about when to rotate so the plane isn't leaving the ground at the minimum flying airspeed. It seemed to me this would give better protection against gusts or x-winds in the first few seconds of flight. I think this is your second point expressed slightly differently.

 

The pilots operating handback for all the different trikes I've owned recommended 0deg angle of attack and some even advise against the bar out technique. As far as I know having the bar neutral isn't wrong for any trike wing but bar forward might be for some.

 

I'm not convinced about t/o with the bar fully out even for short field operations. I haven't proved this but I wonder if the increased drag from starting the roll with the bar fully out would lead to a longer distance than having the bar at trim and rotating at the minimum flying speed ?

 

Cheers

 

John

 

 

[Guest Andys@coffs]

John

 

I must admit to thinking of one benefit of the bar out approach. With bar at neutral and the pilot choosing when to leave the ground the time on the runway is going to be longer than with bar out. Where the runway is not grass then you have a greater risk of taking prop stone damage or wing stone damage. Having replaced my original brolga with a Bolly prop due to a severe stone strike I can assure that the cost was not incosequential.... That said I still dont T/O bar fully out.

 

probably worthy mentioning that the performance of the 3 blade Bolly prop is significantly better (in my subjective experience) than the original 4 blade brolga and while the cost hurt, the change didnt.

 

P.S if you over torque a brolga prop hub the internal fixtures and laminations of plastic and steel can easily be damaged and not visible from the outside. Overtorque in this case doesnt seem to result in a higher tension than the manual mandates just deformation and is therfore in my opinion easy to do. After seeing this 1st hand for myself Id suggest a full hub tear down from time to time to have a look. IN my case the plastic and steel insert had completely delaminated. This was not related to the stone strike, having occured earlier in my flying.

 

Regards

 

Andy

 

 

[Guest Crezzi]

Shouldn't there be less drag and therefore better acceleration with the bar neutral ? Hence less t/o distance (with the big if that the pilot can accurately rotate at min flying speed).

 

My first few years flying were in europe & prop damage was pretty rare but you are right that its definately a big issue here. There is a short sealed section on 1 of the rways where I fly which I try to use if conditions permit. Good practise using it for landing too

 

 

[Guest Andys@coffs]

The guy who taught me years ago has just emailed me to suggest that I may well have had my hand on the bar, but not the one that controls pitch!!

 

He tells me that he never teaches full bar out so sorry for those I missled. Must be an early sign of dementia setting in. In my defence, as you'll all know, Information overload is never far away when learning to fly and Ive simply forgotten.

 

Seeing as In having a BBQ with him tonight and was hopping to get him to buy me a beer I'd better get the fiction straight :<)

 

Andy

 

 

[Guest Crezzi]

Thanks for the clarification Andy - the least he can do is get you a beer in now !

 

Cheers

 

John

 

 

[Guest kylep]

In my school we teach both to show students both ways, and let them decide which way suits them, but our airfield also has two long (for a trike) tar runways.

 

Starting with the bar fully out takes away some of the guesswork of when the aircraft wants to fly, but also results intially in a very high angle of climb until the pilot returns the bar to the trim position. This method generally doesn't work well for pilots changing from 3 axis as they want to push out thinking this will lower the nose.

 

When starting in the 'trim' position, the pilot can feel what the wing is doing, but a lot of pilots do not 'let' the trike fly soon enough and end up rolling along the ground very fast, if the pilot then give the bar a big shove this can end in a very ugly rate of climb and then a tail slide (seen it happen :ah_oh: ). The advantages of this method when executed correctly is a 'gentler' take off and lower angle of climb.

 

Andy, your comments about engine failure on take off are interesting but lets analyse a little bit. If the engine fails as soon as the aircraft leaves the ground (ie: on or just after rotation), no matter what method you use, you are going to crash but most likely walk away. Until a trike has made it past at least 50ft, you have not got enough airspeed to recover from a nose high attitude (from take off) to nose down with airspeed and then flare out top touch down, the only thing to do in this situation is hold the bar out and hope the ground is soft today!!

 

Once a trike has made it to 150ft approx you then have the airspeed and altitude to lower the nose and flare.

 

A little food for thought, i think it is up to the pilot to decide which method is best for them.

 

Here is another question, how to you make your approach to land, powered or unpowered? Why?

 

Kyle

 

 

[Guest Perry]

If the engine fails as soon as the aircraft leaves the ground (ie: on or just after rotation), no matter what method you use, you are going to crash but most likely walk away.

I presume you are making reference to a lower powered (two stroke) machine here. With the 4 stroke machines we find that they lift without nose high attitude on takeoff and hence with EFATO shortly after roll, one can perform a straight in approach with nil impact. Bar returned to neutral and settle.

 

To demonstrate the finding, we recently experienced a throttle cable failure on take off with MTOW (2pax, full load) and gently settled the aircraft back down without incident.

 

Coming back to the original subject, with the 4 stroke machines we always roll on bar neutral and the aircraft takes off without any encouragement necessary. Most of the time throttle is set at 75% as climb rate is more than adequate.

 

Really quick climbing I have found leaving the ground, remaining in ground effect, winding up the machine gradually to 100% pulling bar in and then high angle climb leaving ground effect at 70kts gives me roughly 300ft before decayed back to 40kts and settling (with 2pax) - that is with a 100hp powerplant on the aircraft. This does give on quite a feeling, however one is placing quite a bit of strain on the wing (+-2g).

 

As an aside, we found the stone chips on props related more to the narrow track of the wheels as well as the position of the prop arc - more so the prop arc being close to the ground. Most serious damage was encountered either standing still or in the initial stages of roll, whereby the prop vortex sucks small stones up and through the outer leading edge. I found Arplast, Bolly and Brolga to suffer the same - heaps of superglue and bicarb whilst others enjoyed the skies! The ultimate remedy was to find a trike with a wide track and an elevated prop arc.

 

Regards

 

 

[Guest GA/Triker]

Hi Kyle,

 

 

I too would like to hear what people have to say about landings. I am just learning and about to get my licence.

 

 

Personally I conduct my circuits at 1000’ (as allowed) and on turning on to base I commence a descent and turn on to final at 500’. Initially I reduce engine speed only by about 1000 rpm and maintain a fairly neutral bar position. This result in a gentle descent path that obviously will send you a third down the strip if not corrected. I ensure I am lined up and when I know that I can make the runway if I had an engine out, I reduce power, bar in for positive speed and essentially conduct a glide approach.

 

 

This has been taught to me in order to ensure my making the runway if at anytime during the circuit I have an engine failure I can make the strip.

 

 

I know I have not mentioned all of the little control inputs that go on unconsciously but I suppose in a nutshell this is basically what I do. This was one of the most interesting differences I found between Trikes and the Cessna 172. As a GA pilot the fact is that we pretty much fly around taking little consideration if we had an engine out. Nice long ‘flattish’ approaches…. interesting and scary at the same time. I think in GA we sometimes take things for granted.

 

 

I hope I haven't missed anything out and I would love to hear how others do theirs???

 

 

[Guest Crezzi]

Here is another question, how to you make your approach to land, powered or unpowered? Why?

Kyle

Unless there is a reason to do otherwise, generally with throttle closed. I assume thats what you meant by unpowered rather than engine off (which I do periodically).

 

Simple reason is practice !

 

Cheers

 

John

 

 

[bushpilot]

As for landings - I do circuits at 500' and turn final with enough height to glide to threshold in the event of engine failure. Then approach on just enough throttle to stay a bit above idle - on the assumption that this reduces the likelihood of a stall with a cooling engine; my security blanket I guess!

 

 

[simonreeve]

My first contribution to this forum so here goes.

 

For short field or rough ground takeoffs I begin the takeoff roll with bar slighly pulled in (least drag situation I think ie wing horizontal) then after perhaps 20 yards I begin to push the bar out in order to take weight off the front wheel. By continuing to feed out the bar the machine will takeoff as soon as it is able. Providing there are no obstacles the bar is then pulled in to gain airspeed (preferably within ground effect) before climbing out.

 

When the runway surface is decent and length is no issue then by habit I tend to keep the bar in much longer, thence achieving a very positive climb out on rotation. Generally I wouldn't hold back on the power on takeoff.

 

For most flexies approaches can be kept quite high if you prefer glide approaches, since height can be lost quickly by pulling in the bar and you are unlikely to run out of runway. Powered off approaches to short strips obviously require more finesse/practice. I fly a P & M Quik and with its small wing surface area (only 10 sq. metres) I would avoid pulling the bar in on any approach (unless well out) because the airspeed will easily and rapidly reach 80 mph. Not a recommended speed to touch down at. Consequently I have to pay more attention to my height and airspeed. The technique is to approach with the bar pushed out (trimmed slow if you like). If power is off then some judgement is needed; aternatively the height is controlled by power changes while the bar position determines airspeed. I usually come in with some power applied.

 

 

[Guest Peggy2]

I've got 12 hours up doing a trike endorsement and after turning onto base from 1000' agl l'm told to return to idle and then after turning onto final my instructor insists that I pull the bar in to gain safety speed and I find that coming in to land at 45k I experience "speed weave" which makes it difficult to control and stay on the correct aproach before touch down with the bar pulled into my chest.

 

So far I've done 4 hours of practicing this method and my landings are still not the best.

 

Is this the norm when landing a trike?....I flew hang gliders for ten years and have a lot of hours GA and this method of landing seems a bit strange and not enjoyable at all.

 

I would have though that using the foot throttle would be a better way to control approach speed while keeping the engine warm and ready if needed for a go around.

 

During EFATO my glide in landings are greasers but I'm left scratching my head as to why I'm being instructed to land this way....I'm sure there's a reason but all I can think of would be landing in severe turbulance or cross winds :confused: .

 

 

[bushpilot]

Hey Bob (I guess..)

 

I was taught to pull in the bar to achieve about 38-40 kts; then to use a bit of throttle on final final; then round out at about 6' and hold off at 6" off the deck, then come off the throttle and let it settle. With this approach you get no PIO ('speed weave') and often you dont even feel the actual touch-down.

 

I practice this by flying 50% of the length of the runway at 6" off the deck; it's fun and teaches precision..

 

Cheers

 

Chris

 

 

[Guest Crezzi]

Its pretty much standard practice in trikes (& slower ultralights too) to teach glide approaches - you never know when you might have to do them for real. With a glide approach, you use the airspeed to control descent rather than maintaining a constant airspeed and adjusting power to control descent. You are right - its a very different technique & can take a bit of getting used to.

 

As trikes are pretty slow, the difference between trim speed and stall speed is relatively small and well within the range where a wind gust can have a serious effect. Hence the technique on approach of pulling the bar to increase the margin between your airspeed and stall speed to something safer. This also leads to a steep approach. As trikes are relatively draggy, the extra momentum is soon lost in round out and flare so there isn't a big problem with floating on.

 

Its worth mentioning that this does depend on the particular wing you are flying. I think Chris has the Wizard wing which doesn't actually accelerate that much even with the bar fully in (this isn't a criticism !). Hence thats the technique.

 

I've flown a few pilots used to the Wizard wing with my Streak3. All of them started by pulling the bar right in on approach. This leads to a speed of 70kts, a very windswept crew and the resulting float is likely to exceed the runway length ! The correct approach speed is 50kts which can actually mean pushing the bar out on finals.

 

The Q2 wing you probably have on the Quantum (?) is somewhere between these 2 examples.

 

Hope that helps

 

John

 

 

[simonreeve]

Hi,

 

I agree with John. Excepting the higher performance machines, microlights tend to come in quite steeply and rapidly lose momentum during the round out. Some bar in provides the safety margin over stall speed, gives more control to counteract any surprises and does no harm. Unless conditions are pretty rough or you need to lose height quickly then pulling the bar in to your chest shouldn't be necessary.

 

best wishes,

 

 

[eastmeg2]

Hi,

 

Am due to collect my XTS-912 next week and will be doing a few circuits or more to learn the differences compared to the Edge X Streaks I've been flying so far. From the check flight I did in an XTS-912 in December it seems that shallower powered approaches may be better suited due to the extra speed involved and I suspect I may need to get back into some low altitude training to fully appreciate the handling differences, climb angles and turning radius compared to the Edge X, just to make sure that I'll know what to expect if I have to do a go-around, and not get caught out by not getting the exact response I'm used to.

 

Rgds,

 

Glen

 

 

[Kev]

Hi,

 

A brief history. My ab initio training was with a Pomme instructor - since then, two Aussie instructors, but it is the initial training that has stuck. I currently have 280 ish hrs, all on trikes - Pegasus XL, Quantum 912 & Airborne edge 582. Also Rotax servicing qualified.

 

The following is as per my Pomme instruction.

 

Take off technique:

 

General - bar neutral - at stall speed, bar forward & lift off.

 

Short take off - bar neutral to nose down (reduces drag, accelerates faster) - at stall speed, bar forward & lift off.

 

Rough surface take off - bar fully forward (starts lifting, hence reducing weight on trike, particularly the nosegear, which is the weakest link) - and hold until take off.

 

Take off profile:

 

Bar in immediately on lift off.

 

0-100' Safe Low Level Climb Speed (1.5 times the stall speed min.) Max power. This is to maintain kinetic energy & low angle of climb to ensure safe recovery from EFATO.

 

100'-300' Best Climb Speed (or Best Angle of Climb if clearing terrain) Max power. Enough height to recover from EFATO, but not completely out of the woods.

 

300' onwards Cruise Climb (95% power & BCS). I know the Rotax book allows 5 mins at max power, but that doesn't mean that you have to use it, and minimum time at max reduces the stress on the engine.

 

Landing: Normal - power to idle, glide approach (from 500', 1.5 times the stall speed plus half the wind speed - kinetic energy again to see you through any wind gradient and/or gusting), flare and scrub off speed just above ground level.

 

Crosswind - As above or powered approach and landing, depending on level of crosswind component. Increasing your touchdown speed in a crosswind will reduce your drift angle and subsequently reduce the whiplash effect on the hangbolt and wing assembly. Also make sure that your nosewheel is pointing down the runway before touching down.

 

Gusting/rotor/thermic - Lower level constant power approach. Be ready for go-round (always).

 

The above works for me.

 

Safe flying

 

Kev

 

 

[Guest GawlerMicro]

Hooray ! Well done Kev,

 

I fully agree with your extensive explanation. It all makes sense with the high drag aircraft that we fly. We just arn't the same as the slippery 3 axis or GA stuff.

 

If I can add though, your rough field take off, also works the best for soft sand take-offs for the same reasons.

 

Also, be really carefull on having the bar back too much on take off, as we still want even a little positive stress on the cables, and definately not negative, as when the bar is moved out, sudden snatching of the bottom cables when the positive pressure comes on will take it's toll on the wing eventually. I know this is what you meant. Hope you don't mind the clarification.

 

regards, Rob........

 

 

[Kev]

Rob,

 

Thanks for the clarification, and I concur fully. Just because my explanation is clear to me, that doesn't mean that it is clear to anybody else.

 

Thanks also for the endorsement. I was beginning to think that I was the only one who thinks and flies the way that I do.

 

I look forward to hearing more on this subject.

 

Regards,

 

Kev.

 

 

[Guest Crezzi]

10 out of 10 - you are not alone !

 

The only difference with the instruction I received was that best climb rate/angle speed was adapted once it was no longer possible to land ahead. Although with the trike & airfield I learnt at this would probably have been about 300' anyway.

 

Hwere di you do your training in the UK ?

 

Cheers

 

John

 

 

[Kev]

John, Hi,

 

I actually did my initial training in Portugal with Gerry Breen (he's world famous in the UK), but it was to UK rules, before I knew that we were coming over to Aus.

 

Regards,

 

Kev