Wagga Wagga accident

[jamel]

And if I had any idea on how to go about registering it I would import the Northwing Maverick RT with the 40hp Kawasaki electric start and Pacer 13 XT wing with their version of a tundra kit tomorrow! It would suit my wants to a tee!

 

 

[allowera]

Has anyone performed a 360degree turn and run into their own wake? It is very surprising how much effect it has.

 

 

[dazza 38]

Has anyone performed a 360degree turn and run into their own wake? It is very surprising how much effect it has.

Yes

 

 

[campslive]

And if I had any idea on how to go about registering it I would import the Northwing Maverick RT with the 40hp Kawasaki electric start and Pacer 13 XT wing with their version of a tundra kit tomorrow! It would suit my wants to a tee!

jamel ,

i actually sent them an email and got a quote of around $3k to get one out here ,there also certified in the usa and could be registered here under lsa ,

 

they are also doing research on a slightly faster wing for the 582 i think the current one was 65 knot cruise , they are looking for a distrubutor or agent over here ,

 

i was happy to see some taking and researching more affordable trikes for normal wage earners ,

 

i wish there were more affordable models on the australian market ,, most seem to be around $60k t

 

 

[Phil Perry]

Has anyone performed a 360degree turn and run into their own wake? It is very surprising how much effect it has.

Instructors in the UK teach that in three axis types whilst showing a student how to carry out a nice balanced 360. . . . but not normally in trikes. . . .

 

Phil

 

 

[Stevie B]

Um pardon me but wouldn't there be greater wake turbulence coming from the prop on a trike as on as trike the prop is at the back! your 3 axis has the prop at the front and the passage of air over the aircraft must reduce the props vortices, but on a trike?????? maybe a trike could produce greater wake turbulence????

 

Anyway off topic, we already know that wake turbulence was not a factor in this incident..

 

 

[Phil Perry]

Um pardon me but wouldn't there be greater wake turbulence coming from the prop on a trike as on as trike the prop is at the back! your 3 axis has the prop at the front and the passage of air over the aircraft must reduce the props vortices, but on a trike?????? maybe a trike could produce greater wake turbulence????Anyway off topic, we already know that wake turbulence was not a factor in this incident..

Hiya Nafqr. . .

 

I dunno whether you were referring to the thread where I described an experience I had some years ago whilst carrying a cameraman to video someone's first flight in a flexwing ( sorry - Trike. . .) where I inadvertantly allowed my aircraft to drift into the wake of the trike ahead, as he turned unexpectedly in very still evening air. . . resulting in a really severe uncommanded roll by MY aeroplane, 90 degrees approx to the right at very low level, . . .I got lambasted for my comments about this from people with degrees in aerodynamics who explained ( obviously with a pained and sympathetic expression as they were typing ) that I was talking rubbish and that the sudden air disturbance MUST have been created by the WING of the preceding trike, as a result of it's aerodynamic lift and the fact that this MUST have been the reason. Sorry, but had this been the case ( and I've had that as well, on more than a number of occasions. . .) I feel that I would have been shaken around like a sack of spuds in a dustbin had it not been the rotational turbulence from the propwash which caused the incident. YES. . I agree,. . . It Could well have been a combination of both. . . .

 

Rotax two stroke engines rotate clockwise when viewed from the propeller end. . . and can cause terrific rotational wake turbulence, as someone I know found out last week when he departed immediately following a 912S powered trike, and ended up returning to the ground in an uncommanded turn and breaking the undercarriage, prop, and some of the ally tubes.

 

THIS is what created the rotational disturbance which caused my severe roll, . . . I understand ( without having a degree in the subject ) that there is quite a complex airflow situation over and under a trike wing, having amassed over a thousand hours experience flying on numerous types of trike, ( not enough to be anywhere near an expert, but having AT LEAST SOME knowledge of how they work. ) I really DON'T mind the " No Phil. . .You've got it wrong" comments so long as they come from a witness who actually SAW what happened, or else someone I like a lot. ( X ) !

 

Sorry about the thread drift.

 

Phil

 

 

[Keenaviator]

Sorry Phil but if you are suggesting the 'powerful rotational force' is caused by prop wash, you are wrong. I fly hang gliders and paragliders (no engine or prop) and these can produce very strong 'rotational wash', also known as wing tip vortices. These vortices are caused by spanwise flow of air along the wing from root to tip. When it leaves the wing tip it does so in a spiral a bit like water going down the plug hole of a bath tub. If you fly in these vortices you may experience a strong rolling force which may cause your aircraft to roll substantially. If conditions are very still these vortices can hang around for quite a while before they dissipate. This is why it is advisable not to land too close behind another aircraft.

 

 

[alf jessup]

I'm with Keenaviator on this,

 

I got a mate you can ask what it is like to catch a trike vortices in another trike he was straight and level one second then 9o degree roll to the left in the blink of an eye, I did warn him not to sit behind and slightly lower than I was but he was happy too until he got bitten.

 

Had plenty of height to recover but changed his view after that.

 

Alf

 

 

[Phil Perry]

Sorry Phil but if you are suggesting the 'powerful rotational force' is caused by prop wash, you are wrong. I fly hang gliders and paragliders (no engine or prop) and these can produce very strong 'rotational wash', also known as wing tip vortices. These vortices are caused by spanwise flow of air along the wing from root to tip. When it leaves the wing tip it does so in a spiral a bit like water going down the plug hole of a bath tub. If you fly in these vortices you may experience a strong rolling force which may cause your aircraft to roll substantially. If conditions are very still these vortices can hang around for quite a while before they dissipate. This is why it is advisable not to land too close behind another aircraft.

Thanks for that Keen. . . .

 

As I mentioned, " A combination of both " . . .having seen these things on numerous occasions in wind tunnel setups, the wing (+ prop) turbulence combinations displayed with visible smoke injection at different velocities and angles of attack can be really spectacular, and not to be treated lightly by ANY aircraft which may be following. . . .

 

Phil

 

 

[Stevie B]

Hiya Nafqr. . .I dunno whether you were referring to the thread where I described an experience I had some years ago whilst carrying a cameraman to video someone's first flight in a flexwing ( sorry - Trike. . .) where I inadvertantly allowed my aircraft to drift into the wake of the trike ahead, as he turned unexpectedly in very still evening air. . . resulting in a really severe uncommanded roll by MY aeroplane, 90 degrees approx to the right at very low level, . . .I got lambasted for my comments about this from people with degrees in aerodynamics who explained ( obviously with a pained and sympathetic expression as they were typing ) that I was talking rubbish and that the sudden air disturbance MUST have been created by the WING of the preceding trike, as a result of it's aerodynamic lift and the fact that this MUST have been the reason. Sorry, but had this been the case ( and I've had that as well, on more than a number of occasions. . .) I feel that I would have been shaken around like a sack of spuds in a dustbin had it not been the rotational turbulence from the propwash which caused the incident. YES. . I agree,. . . It Could well have been a combination of both. . . .

 

Rotax two stroke engines rotate clockwise when viewed from the propeller end. . . and can cause terrific rotational wake turbulence, as someone I know found out last week when he departed immediately following a 912S powered trike, and ended up returning to the ground in an uncommanded turn and breaking the undercarriage, prop, and some of the ally tubes.

 

THIS is what created the rotational disturbance which caused my severe roll, . . . I understand ( without having a degree in the subject ) that there is quite a complex airflow situation over and under a trike wing, having amassed over a thousand hours experience flying on numerous types of trike, ( not enough to be anywhere near an expert, but having AT LEAST SOME knowledge of how they work. ) I really DON'T mind the " No Phil. . .You've got it wrong" comments so long as they come from a witness who actually SAW what happened, or else someone I like a lot. ( X ) !

 

Sorry about the thread drift.

 

Phil

Hi PhilI'm of the opinion that a greater turbulence would come off a prop than a wing, and as a trikes prop is at the rear this turbulence could be greater or different than a 3 axis where the prop wash is perhaps lessened by some degree as it has to flow over the aircrafts fuselage. I'm happy to be told I've got it wrong and even more happy to be educated a bit on this subject.

 

 

[facthunter]

Looking at it you might think the prop would be the greater influence but I doubt it. The prop doesn't spin the air much,( depending on the slip which is much more when the craft is stationary). The rogallo ( sp?) wing may have strong tip vortices. You could test it because the tip vortices would still be there when gliding and especially when at a high angle of attack at higher speeds ( when more energy is involved) Nev

 

 

[allowera]

I thought I had seen a photo of a Trike surfing the 'morning glory' in the HGFA magazine some time ago. As I remember it showed the disturbance in the top of the cloud. I wonder if anyone has a copy?

 

 

[Tex]

Hi Phil as mentioned by others here: You get turbulence from the prop wash but not a massive rotational force... IF any rotation it is minor, VERY minor. The prop really doesn't wind up the air that much . It is best described as it is... WASH. The rotational disturbance is more defined and refined from the wing tip vortices. I have flown through hundreds of prop washes with in 90' of the proceeding aircraft (on tow). Messed with them while at altitude to feel it out (off tow). If you dig a wing into the prop wash AND a wing tip vortice at the same time you can and do get some dramatic effects but that is a function of how each wing happens to hit the turbulence.

 

Hang gliders fly behind trikes on tow all the time including through the wash. Sailplane pilots are taught to feel out the prop wash as part of their training (boxing the wash). They also go from low tow to high tow through the prop wash. You don't see them getting rotated around in uncontrollable rolls.

 

Fact is this is all just mechanical turbulence... some more violent than others because it is a factor of it its strength but also with respect to how your wing (or wings) hit it (including when in relation to each other) weather and conditions on the day as well.

 

 

[Phil Perry]

Hiya Tex,

 

Thanks for that. although, 90 feet away is one thing, . . . 30 odd feet is a little different ( ! ) we were flying in close formation when the "Happening" occurred, YES - - - I know that close formation flying takes a lot of practice, and we certainly DID have that over some years. . . BUT. . I just got TOO close after performing several identical "Camera ship" flights that day, and even though the lead pilot was "Hagar the Flexwing" ( around 14,000 hours instructing on trikes since flying a shopping trolley and a hang glider wing powered by a chainsaw motor in the 70's. . .) ) I failed to allow for the fact that he just MIGHT turn sharply on the climbout. This equals Pilot Error / stupidity / complacency on my part and I freely admit this.

 

If anyone ever tries to fly formation with me lately, ( some jokers do try this,. . ) I just have a good look around and then burger off in another direction !

 

Phil