Vev

What are you trying to achieve? What is your context?

Expert opinions are good but a formal definition by an authority like CASA, ASA or ICOA is gold.

Cheers

Vev

Hi Dave,

Thanks for this ... Yes you are quite correct, AUW could exceed MTOW.

One would think simply relying on the words, as you say, would be enough, however it appears not to be the case in this issue.

I'll take a look at the book you suggested .. I did find another one today as well. Not withstanding published indipendent references are great, it's hard to beat something from an authority like CASA, FAA or ICOA, as it moves from opinion to law ... you know what I mean.

In any case, rest assured I will indeed quote you given half a chance.

Cheers

Vev

Source: http://www.airservicesaustralia.com/aip/current/aip/general.pdf

Hi Nev,

Many thanks .. You are very generous with your support.

Your right ... I can't possibly be he first person that would have ask the definition of AUW, when considering it is such commonly use term.

I'll keep digging and chance CASA .. if they use the term they surely must be able to define it.

Cheers

Vev

It's one area where you don't need a lawyer. The definitions should be specific.I have to say ( to complicate it slightly) that INDIVIDUAL aircraft manufacturers will sometimes make up terminology for their own aircraft that may "refine" the definition. but you shouldn't have to go there, unless you are flying their aircraft. Not talking U/L's here.. Nev

Can't see you are far off. AUW is the sum of everything (at a point in time or specified condition)The others relate to

(1)performance ( accelerate stop, Climb gradient(s)., obstacle clearance near, distant) and

 

(2) structural. Max taxi, MTOW. MAX landing ( Design criteria,. can be exceeded but conditions apply). There can be others like max zero fuel. ICAO is the ref you need. CASA or FAA would list those definitions. I'd go CASA first . nev

I've done my best so far but I've not actually found something from CASA... They recognise the term both as an acronym and as a phrase and reference it back to the AIS .. However I can't find a definition. The FAA don't seem to use the term but use Gross Weight, which doesn't work unless they link the two within a formal definition. I've searched through 90% of ICOA Annexes to no avail ... The best one so far is a reference in an aeronautical technical book of some credibility that Wiki use their quotes from. However I would really prefere to establish the definition in black and white from formal authority.

Cheers

Vev

Can someone point me to a credible reference (not wiki) to define AUW (All Up Weight)?

My understanding of AUW refers to the actual weight of an aircraft at a point in time (takeoff, landing, cruise etc) and will weight anywhere between its empty weight and it max structural weight i.e. MTOW or Max Taxi Weight.

I need a credible reference of this definition such as the AIS, ICOA or high profile published reference.

Can anyone help?

Cheers

Vev

Hi Major,

I dont think Valvoline ever bought Castrol.

I'm quite sure the chemistry between these products is very different and come from different sources ... Not much in common in terms of these formulations mate.... Sorry!

Nothing wrong with either product, but they are not the same .. I think the dye colour is even different too.

Cheers

Vev

In my view, there are three very simple things to do if you own a Jab, apart from following all of the proper maintenance procedures.

- Do a pull through before EVERY flight. If you find a soft pot do not fly, investigate why and fix it. Do not kid yourself it's ok to have a soft compression on a cylinder.

- Fly it hard. The extra fuel going through the engine keeps it cool and staves off detonation. Running your engine around at 2800 rpm will cook the engine... get the load up and pour in he fuel, it won't hurt it.

- Change your engine lubricant every 25 hours or 3 months, whichever is first, and check your filter for metals every 50 hours.

No engine is 100% reliable nor is there a 100% maintenance risk mitigation procedure.... however doing a few very simple things will help you manage potential problems before they occur as well as improve the durability and reliability.

Cheers

Vev

What could possibly go wrong with that ... only joking?

I've decided to go with the Trig radio and mode S transponder ... all of my enquiries say they are very robust and of excellent quality in a very compact matching package.

Cheers

Vev

I wonder how the new fibreglass prop will go over old the wooden one in terms of absorbing the loads and vibration?

Cheers

Vev

Engine heat dries out the hub, and it shrinks and loosens. More so with long trips. The previous posts bear out the need to investigate vibrations always . The 4 cyl motor is hard on props, and it is more likely to be a harmonic than engine pulses directly. There may be a RPM setting to avoid. ( most engine/prop combinations have them.) Nev

In the 2200, I believe the avoidable engine speed is 24-26k rpm ... I also understand that setting up the position of the blade relitive to TDC on number one cylinder is also important too. I picked up these peices of info when I did the engine school at Jab a few years ago, although I cannot substatiate this beyond what had been passed to me by Don at Jab.

Cheers

Vev

I Believe the 2200 engine is very hard on prop/hubs owing to engine pulsing every 180 deg, where the 3300 is every 120 deg and much easier on components. For what it is worth, I experienced a prop failure at take-off in 2010 in a J160. Take-off roll was normal and got to 300' up wind when I experienced a bad vibration, which I instantly recognised to be prop related failure owing to the frequency. I pulled the throttle power back to where there was less vibration and limped back around to land on the strip.

On inspection, I could see the back side of both blades had significant cracks at the blade/hub interface. It was clear the blades had coned forward and the tips may have moved as much as 1.5-2" ... I was lucky it didn't toss a blade/s at 300' as I was running out of clear land ahead, that is, if the engine hadn't departed the airframe altogether.

I also saw this repeated in a Mogan Cheetah with a 2200 when the prop suffered multiple fractures and lost bits off the blades. In this instance the vibration was so bad it lost the spinner and damaged the engine rubber mounts leaving the engine flopping around on the engine mounting bolts ... not sure how the pilot got it back home. I was following him and watching him loosing altitude, I ended up rushing ahead trying to get students out of the circuit to give him a good shot at a clear runway for a once only landing option.

The lesson for me .... I check my prop very carefully each day and don't hesitate to remove a spinner to take a good look if I suspect anything. I also check bolt torque every 25hrs, this may be an excessive regime but it gives me piece of mind.

Cheers

Vev

The Trig radio might be worth considering. They make an outstanding transponder and their radio has the same feature of seperate R/T unit and display head. This is great for panels that have very limited room.

Scott, interesting comment about transponder as I'm also looking into fitting a mode S in as well ... also keen to hear any comments about transponders too?

I do like the sound of these small round systems as Kyle as I could use the space in the panel and de-clutter things.

Cheers

Vev

Thanks guys .. I bought an icom 210 in 2005 and it has worked very well, albeit an was an early model and didn't have duel watch.

Is there any thoughts on the smaller type of radios .. Is there any out there worth considering or avoiding?

Cheers

Vev

Help .... I need to buy a new radio, who makes the best and why?

I haven't bought a new radio in some years and I'm in catch-up mode trying to get my head around what's out there today ... opinions welcome?

Cheers

Vev

Brings back memories "pinking" and "knocking" old friends from long ago before fadec and knock sensors.... I used to live on a steep hill and you would hear Morris's and Hilman's pinging their way up the hill with the old drivers tring to stay in third....

Cheers

Vev

Ahhh this is gonna sound dumb...probably because it is. Does higher octane fuel translate into more power in the same engine ? I can see how it will allow a higher compression ratio without detonation occuring but if the compression ratio doesn't change...is it burning more efficiently or something ?

Very simply no ... higher octane wont give you more power on its own ... it does allow you to optimise engine performance improvements ie higher compressions etc just as you mentioned.

I'm sure Nev can reply to this in detail with his hands on experience of performance engines.

Cheers

Vev

running a cocktail avgas / premium..........would that be good practice ???

Notwithstanding some engines (I believe Rotax) prefer >95 RON Mogas, cocktails usually don't cause a problem ... however you do need to observe the min octane requirement for your engine, being mindful of the different ways of measuring octane values. Apart from octane, you also need to take into account the higher propensity of vapour lock, carb ice and faster octane drops during storage as well as the potential for damage to synthetic and rubber materials if it's not designed for aromatics.

On the positive side ... the lead in avgas has a synergistic effect when it reacts with mogas in terms of octane, that is, the sum of the two parts are greater ... this is small but it is a positive outcome. Mogas additives do help keep the engine cleaner and in a cocktail will help reduce lead deposits and lead fouling as it acts as a diluent.

Personally, I am happy to have a 50/50 cocktails in my Jab but only use 100% Avgas in my Continental engine...

There's a lot to consider before you jump into using Mogas ... always best to consult with the engine manufacture and sick with their recommendations.

Cheers

Vev

VevIs that the case Australia wide or does it vary by state, or weather zones or.????.....in other words how can an aviator make an informed decision, or is it simply impossible because of the vagaries of supply chain and 3rd party/n parties involved?

 

Andy

Hard to answer this as it depends on the supply chain... the spec can be wide on allowable aromatic content which can move things around a bit, although the oil industry is very mindful of this and try to manage aromatics % carefully and not create big step changes... often engine components need to acclimate to the formulation and big changes can cause problems with seals etc.

Having said that, some brands have a lower caps on aromatics than others, BP 98 Ultimate is one of those.

Cheers

Vev

And they still need 1/2 g per litre lead to get it up to 100 I see from Google.

However there is a Max value of lead observed:

100LL = 0.56 gPb/L (blue fuel)

100 = 0.85 gpb/l (green)

Cheers

Vev

It's worth noting that the the 100 of avgas is not the same scale as the 98 of premium unleaded. On the same scale avgas is I thin about 112 or 114.

As a rough guide to align with Avgas octane nums

Mogas 98 RON (Aust) - 10 points ish = 88/89

Mogas 93 in the US is close enough to 98 in Aust ... about 88/89 MON or Avgas equivalent

Cheers

Vev

Could you give me a hint about the good stuff?Avgas is hard to get around hear , or a 2 hr return flight !

I do prefer avgas but usually end up with shandy in the tanks .

 

Cheers

Hawker SA right? BP Ultimate 98 is lower in aromatics in that region.

Cheers

Vev

I noticed that when I fueled up for the first time a couple of weeks ago , the next day the fuel lines had expanded and felt a lot softer ,Both the red silicon & the pirtec high press. rubber fuel lines , I had filled up with caltrx 98 vortex , I drained it out after a couple of days & replaced with avgas and a day or two later the lines felt normal again.

Cheers Mike

Cheers

Vev