Thank you, Jamie. It's really great to be here. Yes, Jamie and I go way back, and so it's always nic

Stay on schedule here is, as any good airline event ought to. It's a pleasure to be able to turn things over to Southwest Airlines and to introduce my good friend actually, Tammy Romo, who was promoted last fall to CFO and Vice President of Finance. Having spent considerable time at Southwest in various planning capacities, also time as Treasurer. tour 18 And I see that you initially tour 18 joined the company in 1991, that would have been when I got my start as well. That's probably one of the reasons that you were the one of the very first people that I was more lucky to meet in the industry. So it's a particularly nice to be able to welcome you to the stage and turn the microphone over to you. Thanks.
Thank you, Jamie. It's really great to be here. Yes, Jamie and I go way back, and so it's always nice to see a friendly face. And my instructions on this clicker were to avoid this button, so it really makes me want to push it, so -- but I'll try to follow instructions. Anyway, thanks again. It's great to be here with you this morning. And before I begin, Marcy requires me to read this statement, but of course, tour 18 our presentation this morning includes references to historical non-GAAP financial tour 18 data, as well as forward-looking statements. Because these statements are based on Southwest's current intent, expectations and projections, they are not guarantees of future performance and a variety of factors could cause actual results to differ materially. For more information regarding forward-looking statements and reconciliations of non-GAAP to GAAP results, please refer to the Investor Relations site on southwest.com.
So now that we have all that out of the way, I thought I'd start by just updating you on the plan that we presented to you back in December. At the end of the year, we had a 7% pretax ROIC. And of course, as we went over with you in quite a bit of detail back in December, our plan is to grow that to 15% by year-end 2013.
And thus far, I'm happy to report to you that our first quarter is tracking in line with what we had laid out in our plan. We will be releasing our February traffic results later this week, and we expect low single-digits year-over-year PRASM growth in February. Both January and February, again, are in line with our expectations. Of course, we must keep a watchful eye on the broader economic conditions and are continuing to monitor demand closely for signs of weakening, resulting from the budget sequester situation and just higher tour 18 consumer income taxes, of course, which we -- which could hurt consumer spending. Albeit with this juncture, bookings for March are solid and we currently expect first quarter 2013 PRASM increase in the low single digits. So at least so far, trends tour 18 seem to be holding up.
Regarding fuel, energy prices, as you probably all know, have risen since the beginning of 2013 but fortunately have subsided here recently. And our current full year 2013 fuel price expectation based on the forward curve remains in line with our plan, which is in the $3.25 to $3.30 per gallon range.
tour 18 Just to give you a quick update on the first quarter, our fuel price estimate is also unchanged at $3.30 per gallon. And although Brent crude prices have increased, crack spreads have decreased, tour 18 so that gets us back in line with expectations.
Our unit costs, excluding fuel, profit-sharing and special items, guidance for the first quarter and full year, again, is also unchanged. We're still planning a year-over-year increase in the 5% to 6% range and an increase of approximately 1% for the full year. And finally, we also continue to aggressively manage our invested capital base.
Turning to our 2013 revenue plan. We have what we believe is a reasonable and achievable plan to grow our revenues, and our plan is to grow them by $1.1 billion in 2013 compared to 2012. Approximately $800 million of that planned growth is coming from our strategic initiatives, along with just the core business, of course. As I think you are all familiar, our strategic initiatives are the AirTran acquisition, the introduction of the 800 and our fleet modernization efforts, our revamped frequent flyer program tour 18 and the replacement of our reservation system.
Our strategic initiatives also remain on track with respect to AirTran and our $400 million net synergy target. We have taken a significant step to begin connecting our Southwest and AirTran networks. And as of -- you might have noticed, as of February 23, we are now selling coach air itineraries at 39 airports tour 18 for travel beginning March 10. As you might recall, we began testing in a handful of markets in January and that went really, really well. And we are now in the process tour 18 of rolling it out to our combined 97 destinations, including international. The rollout is running very smoothly, and we remain on pace to fully connect the networks in April.
Early results from connecting our networks are strong, with codeshare bookings of over $1 million a day and while very early, tour 18 these results are quite encouraging and provide us further confidence that our $400 million net synergy target tour 18 is achievable.
I am very excited with the progress we've made and couldn't be more proud of our Southwest team for achieving of this important milestone. As you all know, we've also been very aggressively optimizing our network. We are optimizing aircraft flows in the combined networks with each schedule, and we are currently published through September, but we will be releasing our schedule through the end of October later today.
We're also very -- well, let me just go over a couple of items on our schedule. We have really a lot of exciting schedule changes ahead for 2013. We're launching service to San Juan in April and Branson, and we'll be converting 7 of the AirTran markets to Southwest Branson in March; Charlotte, Flint, Portland, Rochester in April; Wichita in June; and Grand Rapids in August. So that would leave only 11 AirTran airports to be converted through 2014. And most of those 11 destinations would be international, of course.
As -- and our frequent flyer program, again, no significant update there except to tell you that it's also going very well, and we have a solid plan in place to produce $80 million in incremental revenues.
Our fleet modernization efforts are also going well. As you all know, we introduced the 800s in March of 2012, and we'll be at 54 by the end of the year. And we now have over 300 of our -700s converted to the new 143-seat Evolve configurations, and so all is on track with that as well.
The remaining $300 million tour 18 of our $1.1 billion revenue growth plan for 2013 is expected to come in 3 buckets. And number one, of course, we continue to aggressively optimize our network, and that's primarily through tighter turn and block times, and also just more seasonal variability. And we are implementing a new O D-based revenue management system this year. And of course, tour 18 we reported back to you that we had new ancillary revenues. And those are really coming from fee increases that took hold in February tour 18 and we began selling our A1 through tour 18 A15 premium boarding positions at the gate, and that began in January 21, that's also off to a good start. And we increased our EarlyBird fee by $2.50 each way, which was effective February 22.
So moving to just fuel for just a quick minute. As I've already mentioned, there's no change in our 2013 CASM ex fuel, profit sharing and special tour 18 items, which is an increase of about 5% to 6% year-over-year again and 1% for the full year 2013.
Just what's driving tour 18 our first quarter, tour 18 so how do we get to 5% to 6% to up 1% for the year? Again, we have the investment in the Evolve retrofit that I mentioned earlier. Though -- so we have some investment items that are driving higher year-over-year percentage increase tour 18 here in the first quarter. With all of our fleet modernization efforts ramping up through the year, we'll be trending to -- obviously, those unit cost pressures will ease substantially in the back half of the year.
With respect to the fleet, we still expect to maintain a roughly flat fleet count here in 2013. And our available seat miles are expected to be in line with last year for first quarter and up in the 2% range for the full year, again, primarily due to the additional seats per flight resulting from our fleet modernization efforts. tour 18 Again, we've got the 800s coming in. We've got more seats with the Evolve. tour 18 We are accelerating our Classic aircraft retirement, and we'll begin transitioning the 717s to Delta in August. So a lot underway in the fleet over the next couple of years.
And just a few notes on our capital efficiency. As I mentioned at the beginning, one of our goals is to really manage tour 18 our invested capital base and also maintain a strong liquidity. And our cash and short-term tour 18 investments were roughly $3.3 billion as of March 1. So very strong liquidity tour 18 and also based on our plan, we expect tour 18 very healthy cash flow, again, in 2013. Our 2013 capital spending is expected to be in the $1.2 billion range, and so far, this year in 2013, we've repurchased tour 18 9 million shares of LUV for $100 million, and that brings our program to date under the $1 billion authorization program tour 18 to 82 million shares repurchased for $725 million, and that gives you an average program price per share of about $8.85.
As we continue to aggressively manage our invested capital base, we've prepaid approximately $39 million of AirTran aircraft bad debt so far this year, which will bring our planned debt payments for 2013 to $220 million. Leverage currently is still in the low 40% range and of course, we maintain our investment-grade credit rating.
We'll continue to look for opportunities to aggressively manage invested capital and of course, enhance shareholder value. So in summary, evaluating our performance thus far in the first quarter and including our outlook for March bookings and current market fuel prices, we are still on track with our 2013 plan.
And just in closing,