About now Qantas CEO Alan Joyce and his CFO Colin Storrie will have moved from the pushover part of the announcement of the group’s financial result in the six months to December 31 at a general press conference this morning and onto the tricky part of the day, investor analyst briefings.

Their ambush introduction of underlying profit metrics, rather than traditional profit metrics, in their presentation and Q&A is likely to be a tougher sell to fund managers than it was to the media.

The headline traditional figures are that in the first half of fiscal ’09-10, Qantas made  what it now specifies as a “statutory” net profit before tax of $90 million, or earnings per share of 2.6 cents, and will, as was the case in the second half of ’08-’09, pay no dividend.

(In the half year to end of December ‘,08 Qantas made a “statutory” $288 million, or earnings per share of 10.9 cents and paid dividend of six  cents.)

Despite the sharp divide between the first halves of ’08-’09 and ’09-10, the results tell a generally good story about recovery, and cost cutting, timely capacity reductions, and the opposite trajectories  of Jetstar (rising strongly) and Qantas (falling, but less steeply than before.)

But the standard notions of profit guidance have been pushed aside, and the commentary based on underlying profit metrics looks like hitting some early turbulence.

Qantas declared the underlying net profit before tax at $267 million, and the underlying net PBT for the full year to June 30 guidance was given as between $300 million-$400 million. Joyce and Storrie declined to give any guidance in “statutory” terms, or the way, until this morning, that investors are accustomed to getting them.

Joyce defined the underlying profit metric as being what you get if certain changes in hedge derivatives — which have to be reported in a period when they didn’t actually have any effect — are removed from the figures.

Or as Joyce said more opaquely in a press release “Qantas removes the impact of non-recurring items to assess the underlying quality of returns.”

Joyce and Storrie gave a very reasoned explanation for their resorting to the underlying profit metric, but there are some obvious problems. No one else is doing it the same way, and there is some doubt as to precisely how it is arrived at in terms of fine details and consistency.

And, in terms of investors who will now miss two dividends in a row, how bad is a lower value of an underlying $300 million for the profit guidance for the whole year, if it was already precisely $267 million to December 31?

Storrie said Qantas itself lost $107 million on a PBT basis in the second half of last year and that the $60 million in underlying EBIT in the first half of this year was its worst ever first-half result.

This is the comparison of all the Qantas brands versus all the Jetstar brands (Asia excluded) offered in the newly dominant underlying profit before tax metric for the December 31 half year..

QF-JQ compared

While investors come to grips with the new maths at Qantas, passengers were told that changes in the size of premium and economy cabins will see the seat count in Boeing 747s eventually rise from 307 to 359 and reach 550 seats in some Airbus A380s compared to 450 seats now.