Do vortex generators really work.

[Oscar]

That Auster was used for daily commuting plus tug work at the weekends - if the brakes ever got rusty, it'd have to have been landed on a beach, and it wasn't. Since I hand-propped it on occasions, I'm damn glad the brakes weren't U/S.. Great little beast - the only thing I've ever been in where you could tell the revs by what in the cockpit was shaking the crap out of itself. Could have been profitably sponsored by the Chiropractic Association and the Hearing Aid Manufacturer's Group - but hey, when your feet are frozen solid and you can get out and stamp them back into life after landing on a taxiway at Bankstown, who's complaining? (You did NOT hear that from me or indeed anybody, it's an urban myth - ok?).

 

 

[David Isaac]

Did any of you 'older' codgers fly the J1B KBY when she was based at Wagga Wagga Gliding club back in the 70s? She had an EFATO toing a glider in mid 70s from memory and was totaled. Finally rebuilt in 1998 some 20+ years later.

 

To Oscars point the Gipsy engine mounts go hard after a few years and need to be replaced this at least reduces the shake rattle and roll a relative amount.

 

 

[Oscar]

The Gypsy had MOUNTS? Get away, it had BOLTS. Mounts were an effete, latte-sippimg and chardonnay-swilling metro-sexual affectation of years later. Real men had their teeth fillings lock-wired and were proud of it.

 

 

[Dafydd Llewellyn]

Did any of you 'older' codgers fly the J1B KBY when she was based at Wagga Wagga Gliding club back in the 70s? She had an EFATO toing a glider in mid 70s from memory and was totaled. Finally rebuilt in 1998 some 20+ years later.To Oscars point the Gipsy engine mounts go hard after a few years and need to be replaced this at least reduces the shake rattle and roll a relative amount.

No, don't think I flew KBY; this is in an old log book and I'd have to excavate my archives to find it. The Bathurst club had two J1Bs, one of which was ex-Dubbo, VH-KCJ; they re-engined it with a Gipsy 10 Mk 1 and fitted an oil cooler, and I organised a propeller from Barrie Bishton - and it performed surprisingly well. However, I'm fairly deaf nowadays as a result of flying them.

 

 

[facthunter]

They bark alright especially the ones with stub exhausts. A crushed Marlboro packet used to stop the sliding window opening, if you were lucky. . We are slightly OFF vortex generators. Do they work? Yes. Austers fly too which was a bit of a surprise to me after what I had been told. Anyhow the hourly rate was the lowest for it at Kingsford Smiths at Bankstown so that made it attractive. Flying it after chippies and tigers was easy enough. Not the same but close enough to be similar. Nev

 

 

[David Isaac]

Mine is a bit quieter, I have the four pipes feeding into a single tail pipe, still noisy though. Decent headsets today would save your hearing quite a bit. Even the early C182s were bad enough to be placarded compulsory headset wearing.

 

 

[facthunter]

If I was going to fly one a lot these days I would consider putting the longer pipe and muffler on although it might be a little hard to suspend. If you do the lycoming conversion it is lighter, quieter and has enough hot air for a cabin heater. I'm a bit over noise. I even keep the motorbikes fairly muffled these days. ( and my wife's favourite lawnmower) Nev

 

 

[David Isaac]

Interestingly the military versions had a long pipe and muffler suspended under the cabin. I think that was to keep them as quiet as possible for their incursions into Europe during WWII. Dropping spies into the fields of France and sneaking out again.

 

 

[eightyknots]

...and my wife's favourite lawnmower

...powered by a Rotax, Jabiru or Lycoming?

 

 

[eightyknots]

I'm a bit over noise. I even keep the motorbikes fairly muffled these days.

But do they have Vortex Generators?

 

 

[Head in the clouds]

The whole business of using aircraft built to watered-down airworthiness standards, for what amounts to aerial work, via the loophole of private usage over your own land, is not something a manufacturer can countenance from a liability point of view; it can only be done by the relevant authorities "holding the telescope to a blind eye". How long that will continue to be tolerated is not something I'd gamble on.

I don't think so. If someone wants to take people on sightseeing tours, say from town to town, they will need a commercial driving licence and a vehicle that is registered and inspected according to the various State or Federal regulations for vehicles that are used for hire and reward. However, if someone wants to take people around their own property, never going on public roads, they can use a private vehicle, unregistered if they wish, and don't even require a driving licence. They might be taking a risk by doing so in event that something went wrong, but they wouldn't be breaking any laws.

 

I realise that example is not identical to the 'private aerial work' scenario but as far as regulatory authorities are concerned it's near enough. Granted the private aircraft conducting work on/over private land is accessing airspace used by other aircraft but the authorities have made it clear that their interest lies in where the operation originates from and terminates to, and whether the operation is 'commercial' in the sense of selling services for profit. Under commercial law a whole lot of different circumstances exist in regard of the regulator's responsibilities when hire and reward and/or paid services are in effect.

 

This matter has been determined on numerous occasions with consistent outcome. If the operation is conducted by the owner or controller of the land, whether or not he/she does the actual flying, and no-one is being paid to do the flying, though they may be being paid as a stockman or boreman or fencer, for example, then it is not deemed to be a commercial operation although the pilot must be suitably licenced and endorsed for the type of operation they are performing. Otherwise mustering endorsements, for example, would only be available to commercial pilots and not private pilots wouldn't they?

 

 

[Head in the clouds]

None of those designs get within a bull's roar of meeting FAR 23 certification criteria - and even those are minimal. David Isaac is correct, they need a larger weight limit in order to do so, and the large wing area necessary to get to the speeds SQUDI considers necessary*, limits the proportion of useful load to gross weight, so the MTOW has to increase disproportionately.

Bill Whitney has given me a full set of the plans for his latest aircraft called the Angel which hasn't yet been built. It's designed for FAR23 compliance for limited aerobatics and looks like a 7/8 Decathlon in some regards. With a Rotax 912 it fits comfortably in the 600kg MTOW limit for LSA, or could be VH registered of course.

 

Those who know Bill's work know that he doesn't underbuild things, hence his rather unkind nickname of RSJ ... The Lightwing is a good example of his earlier work. I think most owners of Lightwings would describe them as rugged aircraft, I know a few folks who call them Leadwings, not as a criticism of their flying characteristics but simply that they're heavily and strongly built. I have a number of hours in them and they perform well, I've used a couple for station work briefly and they get the job done quite as well or better than the Super Cub I spent a lot of time in.

 

I have a friend whose flying school Lightwing just turned 20yrs old and it's had a harder life from students than any station aircraft is likely to get and my friend is extremely mechanically savvy and keeps a very watchful eye for any fatigue issues that might develop, he's not come across anything yet. In fact as far as I know in all those years of training flights it's never had anything break at all except a fuel fitting on one wing tank which caused a minor leak.

 

So, whilst I'd agree that the majority of the 'sports car' LSAs "wouldn't get within a bull's roar", I think that the examples above show that a rugged FAR23 certificatable aircraft within the 600kg limit isn't at all impossible.

 

As far as SDQDI's mention of speed and your "limits the proportion of useful load to gross weight", I'd say you're still thinking there needs to be some significant useful load. There doesn't for present day operations, as I've pointed out, these days just a few tools and a couple of people is all that needs to be carried to 'fix things around the farm', it's not the amount of gear they carry but the transport aspect. Flying, even at only 65kts, to the boundary fence might take only 30 mins each way but on a couple of trailbikes it could take half the day. And the other main use for the aircraft is checking fences and the waters - making sure the troughs are full and the cattle aren't perishing - you don't need a fast aircraft for that, you need a slow one.

 

 

[eightyknots]

Is Bill's Angel likely to have vortex generators?

 

 

[facthunter]

Vortex generators might work in the inlet manifolds. The wife's favourite mower is a Victa two stroke last type made. I resurrected one for my daughter which was purchased new for my mother in 1956 and still going on the original everything. (except WHEELS). Nev

 

 

[Old Koreelah]

Back a bit closer to topic, how high should wing fences be? I have used 60mm as per Dafydd's suggestion, but Cessna 150 wing fences were much lower and the subject of an AD after a couple of crashes. http://www.ntsb.gov/doclib/recletters/1994/A94_177_180.pdf These fences were much lower but further out, between flap and aileron.

 

The height of the fence was to be reduced to about 19mm to prevent loss of control after stalling.

 

 

[Dafydd Llewellyn]

I don't think so. If someone wants to take people on sightseeing tours, say from town to town, they will need a commercial driving licence and a vehicle that is registered and inspected according to the various State or Federal regulations for vehicles that are used for hire and reward. However, if someone wants to take people around their own property, never going on public roads, they can use a private vehicle, unregistered if they wish, and don't even require a driving licence. They might be taking a risk by doing so in event that something went wrong, but they wouldn't be breaking any laws.I realise that example is not identical to the 'private aerial work' scenario but as far as regulatory authorities are concerned it's near enough. Granted the private aircraft conducting work on/over private land is accessing airspace used by other aircraft but the authorities have made it clear that their interest lies in where the operation originates from and terminates to, and whether the operation is 'commercial' in the sense of selling services for profit. Under commercial law a whole lot of different circumstances exist in regard of the regulator's responsibilities when hire and reward and/or paid services are in effect.

 

This matter has been determined on numerous occasions with consistent outcome. If the operation is conducted by the owner or controller of the land, whether or not he/she does the actual flying, and no-one is being paid to do the flying, though they may be being paid as a stockman or boreman or fencer, for example, then it is not deemed to be a commercial operation although the pilot must be suitably licenced and endorsed for the type of operation they are performing. Otherwise mustering endorsements, for example, would only be available to commercial pilots and not private pilots wouldn't they?

See CAR 206(a)(i):

206 Commercial purposes (Act, s 27(9))

 

(1)For the purposes of subsection 27(9) of the Act, the following commercial purposes are prescribed:

 

(a) aerial work purposes, being purposes of the following kinds (except when carried out by means of a UAV):

 

(i) aerial surveying;

 

(ii) aerial spotting;

 

(iii) agricultural operations;

 

(iv) aerial photography;

 

(v) advertising;

 

(vi) flying training, other than conversion training or training carried out under an experimental certificate issued under regulation 21.195A of CASR or under a permission to fly in force under subregulation 317(1);

 

(vii) ambulance functions;

 

(viii) carriage, for the purposes of trade, of goods being the property of the pilot, the owner or the hirer of the aircraft (not being a carriage of goods in accordance with fixed schedules to and from fixed terminals);

 

(ix) any other purpose that is substantially similar to any of those specified in subparagraphs (i) to (vii) (inclusive);

 

 

[Head in the clouds]

See CAR 206(a)(i):206 Commercial purposes (Act, s 27(9))

(1)For the purposes of subsection 27(9) of the Act, the following commercial purposes are prescribed:

 

(a) aerial work purposes, being purposes of the following kinds (except when carried out by means of a UAV):

 

(i) aerial surveying;

 

(ii) aerial spotting;

 

(iii) agricultural operations;

 

(iv) aerial photography;

 

(v) advertising;

 

(vi) flying training, other than conversion training or training carried out under an experimental certificate issued under regulation 21.195A of CASR or under a permission to fly in force under subregulation 317(1);

 

(vii) ambulance functions;

 

(viii) carriage, for the purposes of trade, of goods being the property of the pilot, the owner or the hirer of the aircraft (not being a carriage of goods in accordance with fixed schedules to and from fixed terminals);

 

(ix) any other purpose that is substantially similar to any of those specified in subparagraphs (i) to (vii) (inclusive);

This is getting to be a rather boring merry go round Dafydd. You've not been an AOC holder obviously. Those of us that have been, have discovered that the Regs aren't definitive as written and so requesting determinations became a regular pastime.

 

Anyway, use the literal 'translation' by all means. It's safer for you that way of course.