Perhaps the explanation is the notoriously inaccurate algorithms in those %power gonkulators?

gonkulators
 

Creampuff - I've often wondered how those gonkulators work. Seeing as there is no torque gauges on little recips what do they base % power off. Is it a very general approximation combination of MP/RPM/FF? Explains the inaccuracy when operating LOP if the gonk factor was set for ROP operations

Thanks Trent - my standby altimeter stays on 1013 until the TL but given that 90% of the arrivals into Essendon start with "when ready, descend to 9000, QNH xxx" I'd rather not bust my clearance by being momentarily distracted when passing through 10,000 and having the cleared altitude warning go off as I pass through it (especially given the range of QNHs seen recently). So my practice is to set cleared ALT and QNH when clearance received so it's not lost or forgotten in the heat of the moment.

The gonkulators - yes - not really sure of the science and my bad that I just take what it says as gospel (and an irrelevance - power settings of 2200rpm/24.5" and fuel flow adjusted to control the TITs). I've been assured that the Auracle algorithim is pretty accurate but I don't know how it copes with LOP. Plus my fuel sensors are either no good or too sensitive as FF jumps around a bit during flight - 43.5 seemed about the average. Wouldn't need to be much higher to get the right % for 290HP (MCP) engines. The totaliser is usually pretty much right on the money.

I reckon that's what it is, the auracle gets screwy LOP. Must base the calculation from MP/RPM combination.

From the 602P performance data 193hp per side gives 220ktas at FL200 so 202ktas on 156hp seems to fit.

At ease everybody, I think we've solved this one.

sorry i got no pictured to post

There you go, our SOPs have it the other way round
Area on standby / EFIS
STD on PFD till approaching FL110

Lots of ways to skin a cat eh

lotsa good oil here for the bigger boys . .. . . not so much the paddock bashing wee J3 sort of aviator of course. . .. BUT . . only posting to
give Under Radar a mild serve for his use of a horrible Americanism
. . when he says " MY BAD "

That's the key point. :ok:

%power is simply a number gonkulated from other numbers. You already know the other numbers. The 'art' is to know their implications... ;)

(My apologies for the thread drift. Thread drift: Off.)

Actually, I have always been interested in the % power figure. How is it actually arrived at for any given engine, mine for instance. IO360.

Shadowoneau, Geelong Gliding Club's ASK 13 at Bacchus Marsh?

That sailplane must have just a few hours up on it, these days..

It's about the same age as you!

Ah, de Havilland!

Yes Gerry, it is Geelong's AS-K13 at YBSS. IIRC it has about 15000hrs on it over 40000 landings. And it is slightly (ahem) older than me!

OK Photos not in OZ But maybe you may like anyway
 

Takn at Farnborough on the 18th, I set off for the Yeovilton Air DAy tomorrow
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anyway you get the idea... click on the images and you can download these and other images in a larger size...enjoy

Great shots. But blue skies in England?

There have been some unnaturally warm, sunny and blue days recently in the UK! Won't last for long though! ;)

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Yesterday... departing NZAA for YSSY

Everyone knows if you own a black car it is hotter in summer and doesn't hide the dirt very well. Hate to see how many sponges and car wash Air New Zooland and going through. :eek:


Nice pics everyone.

That is a horrid paint scheme! Only a kiwi would like it!