Streak 2B

[Guest MundooTriker]

I have acquired a EdgeX with 582 and Streak 2B.

 

Has anyone got suggestions on ideal cruise settings.

 

At present it is cruising about 46kts. (Middle hole)

 

It has been suggested to me it is easier to adjust cruise speed by sliding the hang point rather than simply going to the front hole on the hang block.

 

At present fuel consumption is approx 14lph.

 

Will adjusting the cruise impact this dramatically?

 

Feed back would be appreciated so that I don't simply burn fuel and time finding out what some of you clever chappies already know. :confused:

 

Thanks Andrew

 

 

[eastmeg2]

Hi Andrew,

 

I'd say its easier to go to the front hole on the hang block than to slide your hang block forward to the next set of holes on the wing keel. Then you're only moving 1 bolt instead of 2 and there's less technique involved.

 

I'm assuming your Streak-2B has round A-frame down tubes and not the aerofoil downtubes.

 

On the Streak-III wings the aerofoil shaped downtubes block access to the front hangpoint holes, hence why Streak-III (and Cruze) wings need to have the hang block moved forward on the keel to trim faster.

 

Cheers,

 

Glen

 

 

[Guest Crezzi]

I'd expect moving hang point 1 hole forward to add about 5kt to the cruise speed

 

Cheers

 

John

 

 

[Guest MundooTriker]

Thanks John & Glen.

 

I assume if airspeed increases, the motor/fan must be working harder.

 

Is it likely to have much of an impact on fuel consumption and more importantly, engine life.

 

A bit extra fuel consumption is not much of a concern as I don't do long distances, but I don't want to inadvertently and unecessarily shorten the engine life by increasing airspeed by 5kts.

 

Cheers Andrew

 

 

[Guest Crezzi]

I assume if airspeed increases, the motor/fan must be working harder.Is it likely to have much of an impact on fuel consumption and more importantly, engine life.

Yes, you will be using more rpm to cruise faster and therefore be burning more fuel. How much more depends on what the new cruise rpm is. The fuel consumption isn't linear with revs so going for example from 5400 to 5600 the increase in consumption will be much less than going from 6000 to 6200. There are some graphs of this in the Rotax documentation though IIRC they plot fuel consumption per hp which doesn't show the total burn rate.

 

Its to your credit that you are also thinking about reliability rather than just "great I can whizz about faster". That answer also depends on what the cruise rpm are - using the example figures above, cruising at 5600 rather than 5400 is very unlikely to have much of an impact. Cruising at 6200 .... thats probably a different story & I wouldn't do it.

 

Changing the hang point is very simple so give it a go - you can always put it back if necessary.

 

Cheers

 

John

 

 

[Guest MundooTriker]

Thanks for your input John.

 

I will give it a go.

 

I was worried about stressing the engine more than anything else.

 

Regards Andrew

 

 

[Terry Triker]

Hang point relocation.

 

Hi, Andrew.

 

I don't know if you have changed the hang point and had time to assess the result, but I can give you my take on it.

 

I own the same aircraft/wing combination as you, and performance characteristics of mine are similar to yours. I have a triker mate with an identical aircraft to mine, and we frequently go on cross country trips together. Due to my light weight (around 60kg), my mate slowly gets ahead on a leisurely cruise at trim. In order to catch up, I require to bar in slightly, but over extended distances, the mild pressure became somewhat of an annoyance.

 

I decided to try moving the hang point to the forward hole to avoid playing "catch-up".

 

I had a fair idea what the result would be, but undertook some enquiries just to confirm the pro's and cons, given my particular aircraft/weight configuration.

 

We live in northern Tasmania and were doing a x/c to the west coast and return, a trip of around 150nm, this being a good opportunity to assess this adjustment.

 

I have noted the following observations and the results are positive and pleasing.

 

The airspeed gain is around 5-7 knots, with an increase of several hundred rpm.

 

Fuel burn increases slightly, but the overall consumption for the distance covered is similar, given the earlier eta, due to speed gain. The handling is a tad more sensetive, but you soon tune in to that. I noticed this in particular when negotiating the rugged mountainous west coast on final in mild turbulence. Just be aware that the inputs/response will be slightly different in feel. As your general airspeed is increased slightly, likewise is the landing speed, and ground roll accordingly. Apart from slightly higher rpm, all instrumentation readings are pretty much the same. I don't think this will have an adverse affect on the engine, as many "heavy weight" trikers cruise two-up at mtow, therefore requiring the extra rpm to sustain cruise trim.

 

The sad part was that I inadvertently flew ahead and out of sight of my mate, but that was probably due to the fact that I climbed to 8000ft to take some panoramic photos of the snow covered central plateau. Yes, it was a bit breezy up there, and not as warm as when I last flew at Townsville. You guys get all the good weather up that way.

 

I only require to make this adjustment when flying solo on x/c, and am happy to leave it in the middle hole when going for a local squirt, or with passenger. I would envisage that possibly it may be a bit touchy trimmed for speed with a passenger, and may be as responsive as a "Red Bull" racer. I can't confirm that, but there may be someone out there that can comment on their findings.

 

Unless you intend becoming a speed demon, trying to cruise at 60knots, I don't believe it will be detrimental to to reliability/longevity of the engine. (mind you, I could handle a new XT912 tundra SST, along with the extra performance). Just for the record, my 582 has over 300hrs, and my mate had in excess of 750 hrs, both engines tested and untouched. My mate recently fitted a complete brand new 582, despite all inspection/testing indicating nothing amiss. I would suggest that properly maintained/inspected and operated, your engine will not be prematurely stressed by a few hundred extra rpm. Maybe this environment down here is a bonus for engines, as geographically it is a benefit. There is a whole heap of technical criteria that comes into play regarding flying/engine performance etc, depending on where you live. I will leave that one alone.

 

I will look forward to your call on the findings of the forward hole position, as there is a noticeable difference.My suggestion is to try the adjustment at the hang point block first, rather than moving the asssembly forward on the keel, until you are satisfied with the result. I have had the pleasure of flying in a 100hp DTA trike with electric in-flight adjustable trim, and the performance factor is awesome, but so is the cost.

 

Hope all goes well for you.

 

Regards, Terry. TAS.

 

 

[Guest Crezzi]

Thanks for taking the time to write such a comprehensive post Terry :thumb_up: Many useful observations which I'm sure will be interesting to anyone contemplating doing this.

 

My only comment is re the landing speed - just because the hands-off trim speed has changed doesn't necessarily require a different approach speed. The recommended approach speed in the POH is still the same, albeit that the input required to maintain this speed will be slightly different. If the trim speed is higher than the desired approach speed it becomes necessary to slow the trike down on approach. This might seem unnatural to pilots who learnt on lower performance trikes but would be very necessary if you get yourself an SST which, I believe, has the same recommended approach speed as the Streak 3

 

Cheers

 

John

 

 

[Terry Triker]

Landing speed.

 

Hi, John.

 

I do concede that your comment on the landing speed is basically correct.

 

I do apologise if I unintentionally conveyed misinformation, but it was my perception that a slightly higher approach speed was required at the time. I guess the ''new'' handling, coupled with the increased cruise speed, dictated a little more energy up my sleeve on final.

 

As mentioned before, we encountered a few lumps coming down the valley on approach.

 

I decided to err on the side of caution, given the modest change in input/response characteristics, I didn't want to compromise the situation due to low airspeed.

 

I shall take your advice onboard, as this is what it's all about.

 

The feedback is most appreciated.

 

Regards, Terry. :thumb_up:

 

 

[Guest MundooTriker]

Thanks for the very detailed response Terry.

 

Unfortunately I don't have the time to reply in kind at present!

 

I ended up shifting the hangpoint to the forward hole, and extra airspeed seemed to be between 5-7 knots. (The needle was bouncing a bit from getting so much closer to Mach1.)

 

I was solo, and my experience seemed very similar to yours, but I only flew for approx 30mins due to time constraints. I'm keen to test it out with a passenger.

 

The handling was probably a bit lighter, but no problems. I quite liked it. As long as the fuel is not excessive with a passenger, I'll probably keep it there.

 

I'll keep you posted.

 

:big_grin:

 

Andrew

 

 

[Terry Triker]

Trim and fuel burn

 

Hi Andrew.

 

It is pleasing that this adjustment is to your benefit.

 

I havn't tried it with pax yet, just solo with extra fuel onboard, around a 100kg payload all up. (plus a full tank)

 

Bear in mind that with extra weight, you will also have additional fuel burn in order to maintain increased cruise/trim speed, therefore fuel consumption will increase accordingly.

 

Hopefully the higher airspeed versus the distance covered will balance out, so basically for a set distance trip, the total fuel burn may be similar to the standard trim setting.

 

Obviously the rpm will be slightly higher again, and also hopefully still within safe limits, as long as you don't try to trim it to 60kts two-up.

 

All is good for you. Let us know how it goes.

 

Cheers.

 

Terry.:thumb_up:

 

 

[Outbackflyer]

Reading these posts about changing the hang point to achieve a changed (usually higher) cruse speed, I thought it pertinent to point out that these changes simply alter the “trim” or “hands free” position of the control bar / being the angle of attack of the wing.

 

So it won’t give your wing any more (or less) speed, but it will increase/ decrease the speed at the “trim” position.

 

If you are used to flying the initial approach at trim, and you have moved the trike forward on the keel tube then be prepared to enjoy a higher speed and more inertia near the ground or take over and move the bar forward slightly to return to the touchdown speeds you had before the position change.

 

Apologies for the explanation to the initiated, but I have had some exposure to some pilots who have not got there head around this one.

 

Cheers John

 

Breaking news, I have found a trike in Queensland and will soon be back in the air here in Alice Springs.

 

 

[skeptic36]

Apologies for the explanation to the initiated, but I have had some exposure to some pilots who have not got there head around this one.

Cheers John

 

Breaking news, I have found a trike in Queensland and will soon be back in the air here in Alice Springs.

Hi John,

 

No need to apologize, we like that sort of thing around here.

 

What sort of trike and wing have you found?

 

Regards Bill

 

 

[Outbackflyer]

Hi Bill,

 

I am driving over to Nth Qld tomorrow to inspect an Airborne Outback with a Streak 2b wing.

 

In Zambia I got used to flying the DTA and Aero Cobra with no pod, so I like the open aspect and simplicity of the Outback, I'v not flown a streak before, only a cruise, so thats the only un known factor.

 

I need something light and robust for out landings and other folleys in the desert.

 

Will hopefully have it back in Alice by the weekend.

 

Regards John.

 

 

[Terry Triker]

Hi, John.

 

A lot of information has been taken onboard regarding the outcome and effects of hangpoint relocation. Initially my perception was the requirement to have a slightly higher landing speed, in keeping with the additional gain in cruise/trim speed.

 

This has proven to be untrue. Yes, it does take some time to get one's head around this factor. The initial misconception stems from the inputs required in standard configuration, versus the slightly different control inputs necessary to land as per normal. Given my first landing with a slightly changed input/response feel, I initially deemed a higher approach speed was required. This is was not the case, as I eventually discovered, as communicated in an earlier post.

 

The hangpoint relocation is relative to the trim/cruise speed, and the landing process is as per normal, the only difference being inputs required to achieve this. It did take a little to realise that a slightly different bar ''feel'' and input was necessary to slow the aircraft to achieve the normal specified landing speed. Once coming to grips with all this, the penny dropped, so to speak. You have the same aircraft, same wing, and therefore the same landing process/speeds, albeit a slightly different input technique to achieve these elements of the final/landing phase.

 

I concede that initially it is hard for some to grasp this concept, and as I discovered, once aware of these factors, it became obvious that extra speed was not required.

 

It is pleasing to share these comments and responses in this forum, as it can only assist in expanding our awareness in such matters.

 

Regards,Terry.

 

 

[eastmeg2]

Hi John, Terry,

 

I moved the hangpoint forward along the keel of the Streak-3 wing on my XT-912 just before Xmas, as many others have done to get the trim speed up from 56knots IAS to 62knots.

 

What I've found is that when taking off and climbing out with a Passenger on board a glance at the ASI often reveales we're doing 65knots with a shallower climb than I'm used to. This was particularly obvious in one take off where we had to clear a ridge through sinking air and found ourselves much closer to the ridge than usual.

 

On the next time around we used a little bar forward to bring IAS back down to 55knots and the result was obvious, achieving the same steeper climb angle we were used to in the slower trim position.

 

It may seem obvious but I think a lot of trike pilots have it in their minds that they need to climb out at trim, or with some bar pulled in for more speed. But then it depends on each airstrip which has it's own unique quirks.

 

Cheers,

 

Glen