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The Great Australian Air Rally 2011 - GAAR 2011


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Scratches head.....

Well, the numbers for GAAR83 *do* match the ones in the post above, whereas the listing for 'Mr D Williams of UK' don't. Unless Dai has his own entry on the sly (in which case he's beating both of us...)

Still, at the end of leg 4 I'm leading Team Mutley by 98.84 to 96.43, so your tyres are safe :pilotic:

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Still quite a long way down the leader board though -- there are people getting times consistently within low single digit seconds of their target, and a few exact times there too. I really can't imagine how they manage to do that, given varying wx conditions, circuits etc.

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I need help with the interpretation of this statement from the GAAR briefing...

 

"The individual Target Time includes a component based on a 12 nm circuit comprising a downwind, crosswind and final approach segments. See also the section on Airport Approaches under the “Visual Flight Rules” link."

 

I've read the referenced rules, but it's not detailed in that respect. I'm not sure what is meant by the "12 NM circuit". Is that a four-sided box 3 NM on a side, centered on the runway or is there some other interpretation?

 

I've scoped out the WX and airport details as well as the rules and I want to establish accurate user waypoints for the pattern entry point, the downwind-base turn and the base-final turn at the required distances. I'm just not sure how to apply the "12 nm circuit" business.

 

I'll be joining a left downwind. I presume I do that at mid-field. Is the remaining half of the downwind 1.5 NM?

 

Is the downwind track offset from the runway 3 NM, or is that 1.5 NM?

 

All this will affect my time if I don't do it the way they assumed, but I can't figure out the details of the expected pattern. A 1.5 mile error from what they assumed in the pattern at 110 knots is going to make almost a minute of difference.

 

I'm probalby over-analyzing this and what happens in the pattern at 110 knots may not have much overall effect on the time for a 220 NM leg, but want to do it as correctly as possible for obvious reasons.

 

Thanks for any help you can provide.

 

John

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John, the Hints, Tips and FAQs page, here says:

Question 11. How is my target time calculated?

Answer 11. The 'Target Time is based on the 'Test Flight Time'. It is applied to the distance for each respective Flight Leg with elements factored in for the various stages of flight, Climb, Cruise, Descent and Circuit. The Climb component factors in a reduced speed and distance covered, as does the Circuit component, which is based on a combined Downwind, Base and Final Leg of approximately 12 nm.

Does this help? Actually, I approached each airfield, worked out what would probably be the 'active', joined the circuit at the appropriate point - from my point of view - and landed. My traffic is non-existant and I don't bother with M.S. ATC either. And, as you said, with a Leg length of 220 nm, the odd 30 seconds ain't going to matter much! :whis:

Look forward to the PIREP... :thum:

Cheers - Dai. :cool:

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Does this help?

 

No, it doesn't. That's what I was looking at originally. That business of a "12 nm circuit" doesn't make any sense to me.

 

I've already worked out the WX and the runway and it will be a near-side approach, joining the downwind at mid-field. That's the best I can do with the sketchy information.

 

John

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I need help with the interpretation of this statement from the GAAR briefing...

"The individual Target Time includes a component based on a 12 nm circuit comprising a downwind, crosswind and final approach segments. See also the section on Airport Approaches under the “Visual Flight Rules” link."

I think 12nm is a little generous (at least for a light GA. heavier aircraft of course will fly wider circuits). Working backwards, a 3 mile final + a 3 mile base (quite a wide circuit...) leaves a 6 mile downwind, which would place you at about the point of the turn from crosswind for a typical 1 mile runway. Not unreasonable though.

Many places outside the U.S. a "downwind join" is flown from the beginning of the downwind leg, not from midfield, and typically you'd fly 'straight in' to that. If you're joining the circuit from the side, you'd typically make that a base leg join (or crosswind, from the other direction). Australia does actually allow a 45-degree midfield join (it's called a "midfield" or "45°" join), but Europe doesn't.

In practical terms, knowing your target time will greatly affect how you fly, particulatly as you approach, knowing how much time you have "in hand" can influence whether you fly a tight circuit or a lazy one, or whether you grit your teeth and fly straight in to a downwind landing. It's worth scoping out the airfield first too, since if it has a crosswind runway that's within limits, that can work in your favour. Joining downwind will add around 5 minutes to your time, over a straight in approach. That's offset by the fact that you will probably have had a tailwind for the cruise (the converse is also true: if the wind favours straight in, you've probably had headwinds for most of the flight).

This is also where flying the whole rally has its benefits, since you can refine your flying on successive legs and hopefully improve. I've discovered that cruise altitude has a bigger influence over the final time (at least for my aircraft): Higher is slower. I know that if I spend any length of time above 4500, I'm definitely losing time. However, just as in motor racing, where the race can be won or lost in the pits, in GAAR, a good time can be made or lost in the circuit.

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Here's the latest Team Mutley Roster:

GAAR Leg List, Pilots and PIREP's

1. Gold Coast YBCG to Chinchilla YCCA..........176 nm RWY 14/32 1073m x 18m asphalt......Dai.........Completed.....75.79 min

2. Chinchilla YCCA to Bundaberg YBUD...........234 nm RWY 14/32 1633 x 30m asphalt........Joe.........Completed.....97.33 min

3. Bundaberg YBUD to Lady Elliot Island LYT....187 nm RWY 09/27 575m x 12m coral...........Dai........Completed.....78.23 min

4. Lady Elliot I LYT to Hamilton Island YBHM....316 nm RWY 14/32 1767m x 90m asphalt......Joe........Completed....127.63 min

5. Hamilton I YBHM to Alpha YAPH.................237 nm RWY 18/36 1463m x 30m asphalt.......Rob.......Completed.....98.00 min

6. Alpha YAPH to Winton YWTN.....................220 nm RWY 14/32 1405m x 30m asphalt.......John......Completed.....92.30 min

7. Winton TWTN to Lavarack YLVK................. 334 nm RWY 09/27 579m x 18m grass...........Rob

8. Lavarack YLVK to Chillagoe YCGO..............236 nm RWY 17/35 981m x 18m asphalt.........E.J.......Completed.....83.29 min

9. Chillagoe YCGO to Lizard I. YLZI..................313 nm RWY 11/29 926m x 15m asphalt........Kieran...Completed...135.44 min

10 Lizard I YLZI to Cairns Intl YBCS.................134 nm RWY 12/30 927m x 18m asphalt........Kieran

Currently, the scores for our 3 participants are:

1. Tim..................99.00

2. Dai..................98.74

3. Team Mutley....96.53

Well done, Tim - great flying, mate! (Well, your tyres/tires are safe - for the present, at least! - Ed) :whis:

Cheers - Dai. :cool:

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Thanks Rob. Here's the latest Team Mutley Roster:

GAAR Leg List, Pilots and PIREP's

1. Gold Coast YBCG to Chinchilla YCCA..........176 nm RWY 14/32 1073m x 18m asphalt......Dai.........Completed.....75.79 min

2. Chinchilla YCCA to Bundaberg YBUD...........234 nm RWY 14/32 1633 x 30m asphalt........Joe.........Completed.....97.33 min

3. Bundaberg YBUD to Lady Elliot Island LYT....187 nm RWY 09/27 575m x 12m coral...........Dai........Completed.....78.23 min

4. Lady Elliot I LYT to Hamilton Island YBHM....316 nm RWY 14/32 1767m x 90m asphalt......Joe........Completed....127.63 min

5. Hamilton I YBHM to Alpha YAPH.................237 nm RWY 18/36 1463m x 30m asphalt.......Rob.......Completed.....98.00 min

6. Alpha YAPH to Winton YWTN.....................220 nm RWY 14/32 1405m x 30m asphalt.......John......Completed.....92.30 min

7. Winton TWTN to Lavarack YLVK................. 334 nm RWY 09/27 579m x 18m grass...........Rob.......Completes....147.36 min

8. Lavarack YLVK to Chillagoe YCGO..............236 nm RWY 17/35 981m x 18m asphalt.........E.J........Completed.....83.29 min

9. Chillagoe YCGO to Lizard I. YLZI..................313 nm RWY 11/29 926m x 15m asphalt........Kieran....Completed...135.44 min

10 Lizard I YLZI to Cairns Intl YBCS.................134 nm RWY 12/30 927m x 18m asphalt........Kieran

Just Kieran to go - Well Done Lads! :thum:

Cheers - Dai. :cool:

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Hey, Kieran - I'm sorry, I missed this post - apologies, mate! Good time, too - well done. :cheering:

The GAAR Results page has been updated for Leg 8 (see here) and the current standings are:

Tim - 98.98 points,

Dai - 98.57 points and

Team Mutley - 95.06 points.

Our Team is the highest placed team!! Excellent!! :icon_thumbup:

And, of course, we're the only team to have the guts to enter - Go Team Mutley... :pilotic:

So, well done, Tim - so far, that is, until we get to the end... :whis:

Cheers - Dai. :cool:

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I think that's a pretty credible showing. In a precision flying event, there's an obvious disadvantage for a team as it introduces another source of variability. In an individual entry, he's going to be flying the same AC on the same PC using the same controls hardware and, most importantly, with the same brain behind the yoke doing the flying according to his habits and preferences. Teams don't enjoy that advantage. Speaking for myself, I'm pretty well satisfied with our results so far.

 

John

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