Filed by Mesa Air Group, Inc. Pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant Rules 14a-12 and 14d-2 of the Securities Exchange Act of 1934 Subject Company: Atlantic Coast Airlines Holdings, Inc. Commission File No: 0-21976 The following slides will be used by Mesa Air Group, Inc., in connection with certain presentations to investors: [LOGO] Mesa Air Group and Atlantic Coast Airlines Creating the Leading Regional Airline October 7, 2003 [LOGO] Forward Looking Statement -------------------------------------------------------------------------------- This presentation contains various forward-looking statements that are based on management's beliefs, as well as assumptions made by and information currently available to management. Although Mesa Air Group (the company) believes that the expectations reflected in such forward-looking statements are reasonable, it can give no assurance that such expectations will prove to have been correct. Such statements are subject to certain risks, uncertainties and assumptions. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those anticipated, estimated, projected or expected. The company does not intend to update these forward-looking statements prior to its next required filing with the Securities and Exchange Commission. [LOGO] Why We Are Here Today -------------------------------------------------------------------------------- o ACA has an attractive franchise providing regional aircraft service to United and Delta o ACA intends to abandon its successful regional airline model in favor of recreating itself as a low fare carrier o Mesa, after completing the merger, aims to reaffirm ACA's commitment to long-term code share relationships with major airlines serving hub networks o Both sets of shareholders will benefit from consistent earnings growth derived through the continuation of Mesa and ACA's core businesses o New combined entity will become the leading regional airline Page 1 [LOGO] A Focus on Core Business Creates Value -------------------------------------------------------------------------------- Stock Price Performance Since March 1, 2003 7/2/03: ACA announces failure to reach agreement with United 7/28/03: ACA announces change of strategy MESA 10/03/03 +235% ACA 10/03/03 +43% [The following table was depicted as a line chart in the printed material.] Share Price Data Index ----------------- ------------------- Date Mesa ACAI ----------------- ------------------- 03-Oct-2003 335% 143% 02-Oct-2003 311% 141% 01-Oct-2003 299% 136% 30-Sep-2003 297% 135% 29-Sep-2003 297% 137% 26-Sep-2003 287% 131% 25-Sep-2003 303% 135% 24-Sep-2003 317% 145% 23-Sep-2003 340% 147% 22-Sep-2003 326% 141% 19-Sep-2003 312% 143% 18-Sep-2003 318% 147% 17-Sep-2003 319% 146% 16-Sep-2003 329% 146% 15-Sep-2003 323% 142% 12-Sep-2003 327% 144% 11-Sep-2003 319% 142% 10-Sep-2003 323% 132% 09-Sep-2003 338% 132% 08-Sep-2003 352% 133% 05-Sep-2003 322% 138% 04-Sep-2003 323% 137% 03-Sep-2003 329% 139% 02-Sep-2003 319% 131% 29-Aug-2003 317% 127% 28-Aug-2003 300% 126% 27-Aug-2003 289% 125% 26-Aug-2003 275% 127% 25-Aug-2003 268% 123% 22-Aug-2003 277% 128% 21-Aug-2003 284% 130% 20-Aug-2003 293% 131% 19-Aug-2003 304% 131% 18-Aug-2003 293% 128% 15-Aug-2003 290% 132% 14-Aug-2003 291% 129% 13-Aug-2003 270% 130% 12-Aug-2003 270% 132% 11-Aug-2003 262% 135% 08-Aug-2003 253% 129% 07-Aug-2003 248% 120% 06-Aug-2003 250% 119% 05-Aug-2003 259% 116% 04-Aug-2003 266% 117% 01-Aug-2003 280% 120% 31-Jul-2003 285% 120% 30-Jul-2003 282% 117% 29-Jul-2003 267% 111% 28-Jul-2003 272% 128% 25-Jul-2003 262% 169% 24-Jul-2003 260% 171% 23-Jul-2003 268% 159% 22-Jul-2003 253% 164% 21-Jul-2003 250% 159% 18-Jul-2003 265% 153% 17-Jul-2003 257% 151% 16-Jul-2003 271% 162% 15-Jul-2003 262% 166% 14-Jul-2003 267% 171% 11-Jul-2003 269% 165% 10-Jul-2003 264% 164% 09-Jul-2003 268% 173% 08-Jul-2003 271% 167% 07-Jul-2003 255% 164% 03-Jul-2003 241% 157% 02-Jul-2003 245% 153% 01-Jul-2003 225% 177% 30-Jun-2003 212% 212% 27-Jun-2003 209% 204% 26-Jun-2003 208% 206% 25-Jun-2003 204% 187% 24-Jun-2003 198% 185% 23-Jun-2003 192% 180% 20-Jun-2003 193% 185% 19-Jun-2003 191% 177% 18-Jun-2003 181% 177% 17-Jun-2003 173% 175% 16-Jun-2003 171% 172% 13-Jun-2003 172% 170% 12-Jun-2003 173% 176% 11-Jun-2003 169% 167% 10-Jun-2003 183% 166% 09-Jun-2003 180% 152% 06-Jun-2003 181% 160% 05-Jun-2003 171% 169% 04-Jun-2003 172% 165% 03-Jun-2003 162% 159% 02-Jun-2003 167% 154% 30-May-2003 165% 150% 29-May-2003 165% 145% 28-May-2003 161% 151% 27-May-2003 165% 154% 23-May-2003 161% 153% 22-May-2003 154% 156% 21-May-2003 149% 152% 20-May-2003 143% 155% 19-May-2003 143% 157% 16-May-2003 147% 159% 15-May-2003 166% 163% 14-May-2003 167% 153% 13-May-2003 174% 157% 12-May-2003 175% 156% 09-May-2003 165% 154% 08-May-2003 166% 143% 07-May-2003 167% 145% 06-May-2003 176% 155% 05-May-2003 169% 152% 02-May-2003 171% 156% 01-May-2003 158% 140% 30-Apr-2003 143% 133% 29-Apr-2003 134% 116% 28-Apr-2003 136% 116% 25-Apr-2003 131% 111% 24-Apr-2003 131% 113% 23-Apr-2003 133% 114% 22-Apr-2003 130% 114% 21-Apr-2003 127% 114% 17-Apr-2003 131% 120% 16-Apr-2003 121% 108% 15-Apr-2003 127% 104% 14-Apr-2003 127% 101% 11-Apr-2003 127% 103% 10-Apr-2003 126% 111% 09-Apr-2003 131% 115% 08-Apr-2003 120% 113% 07-Apr-2003 137% 116% 04-Apr-2003 135% 109% 03-Apr-2003 136% 108% 02-Apr-2003 141% 111% 01-Apr-2003 142% 106% 31-Mar-2003 133% 99% 28-Mar-2003 125% 100% 27-Mar-2003 125% 101% 26-Mar-2003 129% 108% 25-Mar-2003 122% 108% 24-Mar-2003 107% 105% 21-Mar-2003 116% 115% 20-Mar-2003 101% 102% 19-Mar-2003 103% 103% 18-Mar-2003 95% 102% 17-Mar-2003 94% 98% 14-Mar-2003 84% 93% 13-Mar-2003 80% 91% 12-Mar-2003 82% 88% 11-Mar-2003 83% 87% 10-Mar-2003 84% 90% 07-Mar-2003 82% 96% 06-Mar-2003 85% 95% 05-Mar-2003 89% 98% 04-Mar-2003 92% 95% 03-Mar-2003 97% 103% 28-Feb-2003 100% 100% ---------- Source: Factset as of October 3, 2003. Daily closing prices. Page 3 [LOGO] An Attractive Opportunity for ACA Shareholders -------------------------------------------------------------------------------- o 0.90 Mesa shares for each share of ACA. Represents $11.30 per share as of October 3, 2003 o All stock proposal to ACA and its shareholders o Tax free to ACA shareholders o Shareholders of each company will own roughly 50% of the combined company o 25% premium over October 3, 2003 closing stock price o 35% premium over the average closing price of ACA since July 28(1) o Receive shares in a fast-growing company committed to the regional carrier business o ACA shareholders will share in the upside of the combined companies' renewed focus on revenue guarantee relationships o Lower risk and diversification of partnerships for ACA shareholders ---------- (1) July 28, 2003, day of ACA change of strategy announcement; closing price $8.09; average price through October 3rd, 2003 $8.32. Page 4 [LOGO] Attractively Priced Transaction for Both Sets of Shareholders -------------------------------------------------------------------------------- (US Dollars in Millions) Mesa ACA -------------- -------------- Share Price (10/3/03) $12.55 $9.02 At 0.9x exchange ratio -- $11.30 Premium to Current Price -- 25% 2004E Revenue(1) $975 $900 2004E Operating Income(1) $68 - $88 $63 - $81 Margin 7% - 9% 7% - 9% 2004E EPS(1) $1.00 - $1.20 $0.95 - $1.05 2004E P/E Multiple 10.5x - 12.6x 10.8x - 11.9x -------------- -------------- Attractive All Stock Transaction ---------- (1) 2004 estimates based on Wall Street research. Mesa estimates adjusted for incremental US & UAL regional jets. ACA estimates based on Wall Street research preceding announcement of change in corporate strategy. Page 5 [LOGO] Creating the Leading Regional Airline Well Positioned for Continued Growth -------------------------------------------------------------------------------- o Reinforces the combined companies' position as a leading code share partner to United, US Airways, Delta and America West o Forms the number one independent regional carrier in the US - 300 aircraft serving 1,800 daily departures - Full geographic coverage of US, serving 250 destinations - A team of over 8,000 employees o Combination will form a more attractive partner committed to our core business model Page 6 [LOGO] Creating the Leading Regional Airline Well Positioned for Continued Growth -------------------------------------------------------------------------------- (US Dollars in Millions) Pro Forma Mesa ACA Combined ---- ---- --------- 2004E Revenue (1) $975 $900 $1,875 2004E Operating Income (2) $78 $72 $150 Regional Jets 97 118 215 Turboprops 54 28 82 ---- ---- --------- Total 151 146 297 FY '04 FY '03 % Revenue % Revenue % Revenue (3) ----------------- ----------- ----------------- Primary Customers America West 35% Delta 20% America West 18% United 15% United 80% Delta 10% US Airways 50% United 46% US Airways 26% ---------- (1) 2004E Revenue based on Wall Street research estimates and incremental US and UAL regional jets for Mesa. (2) Based on midpoint operating margin of 8%; based on Wall Street research, adjusted for incremental US and UAL regional jets for Mesa. (3)% Revenue on a Pro Forma combined basis is calculated as a weighted average using 2004E Revenue and 2003E Revenue for Mesa and ACA, respectively. Page 7 [LOGO] Meaningful Synergy Potential Mesa: The Lowest Cost Regional Operator -------------------------------------------------------------------------------- [The following table was depicted as a bar chart in the printed material.] 2003 2002 First 6 Months ------------ -------------- Cost per ASM (cents) Mesa 13.8 (cents) 12.4 (cents) ACA 15.5 (cents) 17.2 (cents) Potential Synergy $74mm(1) $215mm(2) Potential Synergy @15.5(cents) ------------------------------ $137mm(2) annualized ---------- (1) Based on ACA's 4.345 billion ASMs for fiscal 2002 as reported in their Form 10-K dated December 31, 2002. (2) Based on ACA's 2.236 billion ASMs for the first six months of fiscal 2003 as reported in their Form 10-Q dated June 30, 2003. Page 8 [LOGO] Meaningful Synergy Potential Substantial Incremental Accretion to Both Mesa and ACA Shareholders -------------------------------------------------------------------------------- o Increased operational efficiency, flexibility and rationalization o Ability to provide lower cost to strategic partners and garner additional business o Synergies lead to enhanced value for both shareholders: Illustrative Pretax 2004 EPS % of Combined % of Mesa Synergies (mm) Impact (1) 2004 Revenue 2004 EPS -------------- ---------- ------------- --------- $10 $0.07 0.5% 6% $20 $0.14 1.1% 13% $30 $0.21 1.6% 19% $40 $0.29 2.1% 26% ---------- (1) Assumes 84 million diluted pro forma shares outstanding and an illustrative 40% tax rate. Page 9 [LOGO] Combination is Well Capitalized for Future Growth June 2003 Pro Forma Balance Sheet (100% Stock at 0.90x) -------------------------------------------------------------------------------- (US Dollars in Millions) Pro Forma Mesa ACA Combined ---- ----- --------- Cash and Equivalents $154 $221 $375(1) Total Debt 211 118 329 Capitalized Operating Leases (2) 764 935 1,699 ---- ----- --------- Adj. Total Debt 975 1,053 2,028 Shareholders Equity 105 324 620(3) Market Value of Equity (4) 415 515 930 -------------------------------------------------------------------------------- Adj. Net Debt / LTM EBITDAR (5) 5.3x 3.3x 4.1x Adj. Net Debt / Adj. Total Cap. 76% 60% 62% Adj. Net Debt / Adj. Market Cap. (6) 59% 53% 56% -------------------------------------------------------------------------------- ---------- (1) Excludes transaction expenses. (2) Based on 7x 2002A rent expense. (3) Includes impact of purchase accounting for the acquisition. (4) As of October 3, 2003. (5) LTM EBITDAR is $154 million and $251 million for Mesa and ACA, respectively. (6) Represents market value of equity plus net book value of debt. Page 10 [LOGO] Mesa: A Rapidly Growing Regional Airline [The following table was depicted as a bar chart in the printed material.] Revenues 1998 1999 2000 2001 2002 2003 (est) 2004 (est) ---- ---- ---- ---- ---- ---------- ---------- ($MM) First Call consensus 495 405 471 523 496 600 910 US and UAL incremental RJs 70 Page 11 [LOGO] With Consistent Earnings Growth Record [The following table was depicted as a bar chart in the printed material.] Earnings 1998 1999 2000 2001 2002 2003 (est) 2004 (est) ---- ---- ---- ---- ---- ---------- ---------- ($MM) First Call consensus -16 10 17 15 17 20 32 US and UAL incremental RJs 3.4 Page 12 [LOGO] Committed to Future Regional Jet Growth [The following table was depicted as a chart in the printed material.] Year ASM'S (Millions) Regional Jets ----- ---------------- ------------- 2003 4,463 96 29% 2004* 7,246 144 61% 2005* 9,594 157 32% RJ Fleet 50 seat 75 99 99 70 seat 15 15 20 90 seat 6 30 38 -- --- --- Total 96 144 157 Note: excludes additional US CRJ-700s [The following table was depicted as a chart in the printed material.] Year ASM'S (Millions) Regional Jets ----- ---------------- ------------- 2003 4,463 96 29% 2004* 7,816 163 74% 2005* 11,260 182 44% RJ Fleet 50 seat 75 99 99 70 seat 15 34 45 90 seat 6 30 38 -- --- --- Total 96 163 182 Note: includes additional US CRJ-700s Page 13 [LOGO] Regional Carriers - Consistent, Stable Margins Through Revenue Guarantee Agreements [The following table was depicted as a line chart in the printed material.] Pretax Operating Margin 1998 1999 2000 2001 2002 2003 ------ ------ ------ ------ ------ ------ Atlantic Coast 17.8% 13.7% 11.4% 13.7% 11.7% 10.4% Mesa -5.0% 3.8% 5.9% 4.3% 5.6% 4.8% jetBlue -20.6% 7.2% 14.9% 12.0% AirTran -9.3% -18.5% 7.6% 3.1% 1.3% 5.6% ATA Holdings 7.3% 6.9% -1.5% -3.3% -8.2% -0.6% Frontier -12.1% 11.4% 13.2% 18.7% 3.8% -8.0% Note: 2003 is for the respective periods ending June 30, 2003 Page 2 [LOGO] Mesa Has a Proven Track Record -------------------------------------------------------------------------------- Current management took control of Mesa in late 1997 after the airline had lost its contract with United (approximately 50% of sales), had received contract termination notification from America West (approximately 20% of sales) and had less than six weeks of operating cash on hand. The new management team has successfully revitalized the company and in the process has: o Delivered consistent profitability - 19 out of 20 profitable quarters o Increased revenue diversity - partnerships with United, US Airways, America West, and Midwest Express o Established cost discipline - turning Mesa into the lowest cost producer in the industry o Restructured the company's fleet - added 95 regional jets and eliminated over 125 turboprops o Strengthened the balance sheet and improved liquidity - $170 million in cash; reduced debt by $125 million o Fostered excellent labor and customer relations - new 4.5 year pilot contract; extended flight attendant contract Mesa has the platform and experience to integrate ACA effectively and efficiently Page 14 [LOGO] Summary and Next Steps -------------------------------------------------------------------------------- o The merger represents a significant opportunity for both Mesa and ACA shareholders o Mesa welcomes a dialogue with ACA's management, board, shareholders and all other stakeholders to reach a friendly agreement o If ACA chooses not to enter into a dialogue, we are prepared to pursue this on an unsolicited basis and take our offer directly to ACA shareholders Page 15 Additional Information and Where to Find It More detailed information pertaining to the proposal by Mesa Air Group, Inc. ("Mesa") will be set forth in appropriate filings to be made with the SEC. Investors and security holders are urged to carefully read the relevant documents regarding the proposed transactions that will be filed with the SEC because they will contain important information. You will be able to obtain the documents when they become available free of charge at the website maintained by the SEC at www.sec.gov. In addition, you may obtain documents filed with the SEC by Mesa free of charge by requesting them in writing from Mesa Air Group, Inc., 410 North 44th Street, Suite 700, Phoenix, Arizona 85008, Attention: Office of the Corporate Secretary (602-685-4000). This communication shall not constitute an offer to sell or the solicitation of an offer to buy securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such jurisdiction. Participants in Solicitation Mesa and certain other persons named below may be deemed to be participants in the solicitation of proxies. The participants in this solicitation may include the directors and executive officers of Mesa. A detailed list of the names of Mesa's directors and officers is contained in Mesa's proxy statement for its 2003 annual meeting, which may be obtained without charge at the SEC's Internet site (http://www.sec.gov). As of the date of this communication, none of the foregoing participants, individually beneficially owns in excess of 5% of Atlantic Coast Airlines Holdings, Inc. ("ACA") common stock. Except as disclosed above and in Mesa's proxy statement for its 2003 annual meeting and other documents filed with the SEC, to the knowledge of Mesa, none of the directors or executive officers of Mesa have any material interest, direct or indirect, by security holdings or otherwise, in Mesa or ACA.