Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of income and expense during the reporting period.

On an ongoing basis, the Company evaluates its estimates using historical experience and other factors including the current economic and regulatory environment as well as management’s judgment. Items subject to such estimates and assumptions include: revenue recognition and related allowances, valuation allowance on deferred tax assets, certain accrued liabilities, useful lives and recoverability of long-lived assets, fair value of assets acquired and liabilities assumed in acquisitions, legal contingencies, assumptions underlying convertible notes and convertible securities carried at fair value and stock-based compensation. These estimates may change as new events occur and additional information is obtained and such changes are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates, and any such differences may be material to the Company’s consolidated financial statements.

Collateralized Borrowings

The Company has a revolving accounts receivable financing arrangement that allows the Company to borrow a designated percentage of eligible accounts receivable, as defined, up to a maximum unsettled amount of $5.0 million. The agreement is secured by a first security interest in all assets of Southern Airways Express (“SAE”), a subsidiary of Southern. The financing arrangement is uncommitted, and upon funding does not qualify for sale accounting as the Company does not relinquish control of the receivables based on, among other things, the nature and extent of the Company’s continuing involvement.

Accordingly, the accounts receivable remain on the Company’s Consolidated Balance Sheets until paid by the customer and cash proceeds from the financing arrangement are recorded as collateralized borrowing in Accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets, with attributable interest expense recognized over the life of the related transactions. Interest expense and contractual fees associated with the collateralized borrowings are included in interest expense and other expense, net, respectively, in the accompanying Consolidated Statements of Operations.

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Expenditures for major additions, equipment purchase deposits, renewals, and modifications are capitalized, while minor replacements, maintenance, and repairs, which do not extend the asset’s life, are expensed as incurred. The Company capitalizes expenditures for software developed or obtained for internal use. These costs include personnel and related employee benefits expenses for employees who are directly associated with and who devote time to software development projects, and external direct costs of consultants and materials for developing the software. Software development costs that do not qualify for capitalization as well as costs related to minor upgrades and enhancements are expensed as incurred and recorded in the Consolidated Statements of Operations.

Maintenance and repairs are expensed as incurred. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, or, in the case of leasehold improvements, over the term of the lease or economic life, whichever is shorter as follows:


Assets		Depreciable Life
Aircraft, equipment and rotable spares		3 to 20 years
Leasehold improvements		Shorter of the estimated lease term or 5 years
Office, vehicles and ground equipment		3 years and 5 years
Internal-use software		3 years

Depreciation of property and equipment is included within Depreciation and amortization on the Consolidated Statements of Operations. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the accounts and any gain or loss is included in the Consolidated Statements of Operations.

Impairment of Long-Lived Assets

Long-lived assets such as property and equipment, finite-lived intangible assets, and right of use assets are reviewed for impairment, whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable.

The carrying amount of a long-lived asset is not recoverable if it exceeds the sum of the undiscounted future cash flows expected to result from the use and eventual disposition of the asset. The Company performs impairment testing at the asset group level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. The amount of impairment loss, if any, is measured as the difference between the carrying value of the asset and its estimated fair value. Fair value is determined through various valuation techniques, including discounted cash flow models, quoted market values, and third-party independent appraisals, as appropriate. No impairment charges were recorded during the years ended December 31, 2025 and 2024.

Operating Leases

Operating lease right-of-use assets and liabilities are recognized at the lease commencement date, which is the date the Company takes possession of the asset. Operating lease liabilities represent the present value of lease payments not yet paid. Operating lease right-of-use assets represent our right to use an underlying asset and are based upon the operating lease liabilities adjusted for prepayments or accrued lease payments, initial direct costs, lease incentives, and impairment of operating lease assets. To determine the present value of lease payments not yet paid, the Company estimates incremental borrowing rates based on the appropriate term and information available at lease commencement in determining the present value of lease payments including reasonably certain renewal periods. The Company recognizes the lease cost for operating leases on a straight-line basis over the lease term. Aggregate lease cost is recorded in Cost of Revenue and General and Administrative expenses on the Consolidated Statements of Operations. Additionally, tenant incentives used to fund leasehold improvements or any rent abatements are recognized when earned and reduce the operating right-of-use asset related to the lease.

Finance Leases

The Company measures finance lease right-of-use assets and finance lease liabilities initially at an amount equal to the present value at the beginning of the lease term of minimum lease payments during the lease term, excluding that portion of the payments representing executory costs (such as insurance, maintenance, and taxes to be paid by the lessor) including any profit thereon, with the corresponding liability recorded within the liabilities section of the Company’s Consolidated Balance Sheet. During the lease term, each minimum lease payment is allocated by the lessee between a reduction of the liability and interest expense to produce a constant periodic rate of interest on the remaining balance of the liability (the interest method). Finance lease right-of-use assets are depreciated in accordance with the Company’s property and equipment policy and is included within Depreciation and amortization on the Consolidated Statements of Operations. The corresponding lease liabilities are reduced as lease payments are made.

Revenue Recognition

Scheduled Revenue

Scheduled revenue is derived from scheduled passenger flights under the EAS program and through passenger single seat sales.

The Company provides scheduled passenger flight service on certain routes which is subsidized by the U.S. DOT under the EAS program. The EAS program is enacted to ensure that small communities in the U.S. have the ability to maintain a minimum level of scheduled air services. The Company has contracts with the U.S. DOT that are typically in duration of 2-4 years and include commitments for the Company to provide passenger air service to certain locations for a specific number of times annually to each location. The Company generally bills the U.S. DOT on the first of the month following the prior month’s completed flights, and typically collects from the U.S. DOT within 12 to 14 days after billing. Revenue is recognized on a per-flight basis when the Company has fulfilled its commitment, generally as the flights are completed.

The Company earns revenue from the passenger for scheduled flight service through sales of tickets for single seats. These sales are generally paid by credit card. The Company also earns revenue generated by third-party travel booking sites or travel agencies. Tickets are refundable within 24 hours of purchase for flights scheduled to take place more than one week out, or when flights or services are changed, interrupted, or otherwise canceled by the Company. The Company recognizes revenue when it meets the applicable recognition criteria, which is at the point in time when a flight is completed or when tickets expire (generally within one year from the date of purchase).

On-demand Revenue

The Company earns revenue from the passenger for charter flight services, operated through a combination of its own aircraft and those of third party operators. These sales are generally paid for by credit card or wire transfer. The Company generally does not offer refunds after 24 hours of purchase. The Company recognizes revenue when it meets the applicable recognition criteria, which is at the point in time when a flight is completed or when tickets expire (generally within one year from the date of purchase).

Other Revenue

The Company also earns revenue from various ancillary services such as those relating to baggage fees, reservation change fees, package freight fees, and pet-travel (carry-on) fees. These fees are earned when the services are performed, generally at the time of travel.

Principal vs Agent

The Company evaluates whether it is a principal or an agent in contracts involving more than one party by assessing whether it controls the specified flight services before they are transferred to its customers. In transactions where the Company directs third-party air carriers to provide flights service to its customers, the Company determined it acts as the principal as it controls the services provided to the customers. In these instances, the Company is primarily responsible for fulfillment of the obligation in the contract, has pricing discretion, has the authority to direct the key components of the service on behalf of the member or customer regardless of which third-party is used. Therefore, the Company reports revenue and the associated costs on a gross basis in the Consolidated Statements of Operations.

When the Company is not primarily responsible for the fulfillment of the flight services, it acts as an agent and therefore recognized revenue in the Consolidated Statements of Operations is net of amounts paid to third-party air carriers and operators that provide the services.

In transactions where the Company operates aircraft on behalf of a third party, the Company determined it acts as the agent as it solely carries out the services based on the direction of the third party in exchange for a fixed service fee as determined by the related services agreement. In these instances, the Company reports the service fee as fee revenue net of any operating costs incurred by the Company to perform these services.

Operating Expenses

Cost of Revenue

Cost of revenue consists of costs that are directly related to delivering the Company’s services and certain facility costs. Delivery of the Company’s services primarily comprise of aircraft maintenance, fuel, airport-related expenses, and fees paid to third-party air carriers for operating aircraft in providing flight services and platform infrastructure costs. Cost of revenue also includes facility costs representing leases expenses and operating costs for stations throughout the service network and personnel related costs, primarily salary and bonus. Cost of revenue excludes depreciation on property and equipment and amortization of finite-lived intangible assets.

Sales and Marketing

Sales and marketing expense consists primarily of personnel related and other costs in connection with the Company’s sales and marketing efforts. Advertising costs are expensed as incurred and were $3.5 million and $2.2 million for the years ended December 31, 2025 and 2024, respectively. Sales and marketing excludes depreciation on property and equipment and amortization of finite-lived intangible assets.

Technology and Development

Technology and development expense consists of personnel and other costs related to technology development and management efforts including costs for third-party development resources, and allocations of overhead and facility costs. Technology cost also includes research and development cost associated with the Company’s hybrid electrification strategy. The Company’s technology and development efforts are focused on enhancing the ease of use and functionality of its Surf OS platform by adding new core functionality, services and other improvements, as well as the development of new products and services. Technology and development costs are expensed as incurred, except to the extent that such costs are associated with internal-use software development that qualify for capitalization, which are then recorded within Property and Equipment, net on the Company’s consolidated balance sheets. Technology and development excludes depreciation on property and equipment and amortization of finite-lived intangible assets.

General and Administrative

General and administrative expense consists of personnel related costs including salary, bonus, and share-based compensation for the Company’s executive, finance, facilities, and human resource teams and facility costs. General and administrative expenses also include professional fees and other corporate related expenses. General and administrative expenses exclude the depreciation on property and equipment and amortization of finite-lived intangible assets.

of these awards using the Black-Scholes option pricing model. The grant date fair value of share-based awards with service-only conditions is recognized as expense on a straight-line basis in the Consolidated Statement of Operations over the requisite service period, which is generally the vesting period ranging from 12 to 48 months. Forfeitures are recorded as they occur. For awards with performance conditions, the Company records compensation expense on a graded-vesting basis when it is deemed probable that the performance condition will be met. For awards with market conditions, the effect of the market conditions is reflected in the fair value measurement and expense, using an option pricing model, recognized on a graded-vesting basis, is not reversed to the extent that the market condition is not achieved. Additionally, awards granted to non-employees are accounted for using their grant date fair value, using Black Scholes option pricing model and are accounted for in the same manner as awards granted to employees.

Determining the fair value of share-based awards requires judgment. The Company’s use of option pricing models requires the input of subjective assumptions, including the fair value of shares of the Company’s common stock underlying the option award, the expected term of the option, the expected volatility of the Company’s common stock, risk-free interest rates, and the expected dividend yield of the Company’s common stock. The assumptions used in the Company’s option pricing model represent management’s best estimates. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used the Company’s share-based compensation expense could be materially different in the future.

Restricted Stock Unit Awards

The grant date fair value of restricted stock units (“RSUs”) is estimated based on the fair value of the Company’s common stock on the date of grant. RSUs vest upon the satisfaction of a service-based vesting condition and the compensation expense for these RSUs is recognized on a straight-line basis from the date of grant over the requisite service period.

Performance-Based Restricted Stock Units

During the year ended December 31, 2025, Company granted performance-based restricted stock unit (“PRSUs”) to employees, which will vest upon the achievement of an adjusted EBITDA metric for the year ending December 31, 2025 as well as a service period of four years from the date of grant. The grant date fair value of these PRSUs was determined based on the Company’s stock price the business day immediately preceding the grant date. Expense attribution for these awards is based on a probability assessment regarding the achievement of the financial metric. The Company will record compensation expense on a cumulative basis to reflect the grant date fair value of shares expected to vest over the service period of each award.

The Company granted founder PRSUs (“founder PRSUs”) that contain a market condition in the form of future stock price targets. The grant date fair value of the founder PRSUs was determined using a Monte Carlo simulation model and the Company estimates the derived service period of the founder PRSUs. The grant date fair value of founder PRSUs containing a market condition is recorded as stock-based compensation over the derived service period. Provided that each founder continues to be employed by the Company, either directly or as a non-employee consultant, stock-based compensation expense is recognized over the derived service period, regardless of whether the stock price goals are achieved. If the stock price goals are met sooner than the derived service period, any unrecognized compensation expenses related to the founder PRSUs will be expensed during the period in which the stock price targets are achieved.

Warrants

The Company assesses whether warrants issued to purchase the Company’s common stock are liability or equity-classified based on the terms of the warrants. If the warrants are determined to be liability-classified, then the warrants are remeasured to fair value each period with changes in fair value recorded within Changes in fair value of financial instruments carried at fair value, net on the Consolidated Statements of Operations. The Company recognizes the fair value of liability-classified warrants within Other liabilities in its Consolidated Balance Sheets. If the warrants are determined to be equity-classified, then the initial fair value is recorded in Additional paid-in capital and the warrants are not remeasured thereafter.

The Company estimates the fair value of warrants to purchase its common stock using the Black-Scholes option pricing model. Warrants are principally issued to lenders and non-employees, some of whom are related parties, in connection with debt and equity fundraising and debt restructuring activities.

that includes the enactment date. The likelihood of realizing the tax benefits related to a potential deferred tax asset is evaluated, and a valuation allowance is recognized to reduce that deferred tax asset if it is more likely than not that all or some portion of the deferred tax asset will not be realized.

The Company determines whether a tax position taken or expected to be taken in a tax return is to be recognized in the consolidated financial statements when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. The amount recognized is subject to estimation and management judgment with respect to the likely outcome of each uncertain tax position. The amount that is ultimately sustained for an individual uncertain tax position or for all uncertain tax positions in the aggregate could differ from the amount recognized. For tax positions meeting the more likely than not threshold, the tax amount recognized in the consolidated financial statements is reduced by the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement with the relevant tax authority. The Company recognizes interest and penalties accrued related to unrecognized tax benefits, if any, in its income tax provision in the accompanying Consolidated Statements of Operations.

Net Loss Per Share Applicable to Common Shareholders, Basic and Diluted

The Company calculates basic and diluted net loss per share applicable to common shareholders using the two-class method required for companies with participating securities. The Company considers preferred stock to be participating securities as the holders are entitled to receive dividends on a pari passu basis in the event that a dividend is paid on common shares.

Under the two-class method, basic net loss per share applicable to common shareholders was calculated by dividing the net loss available to common shareholders by the weighted-average number of shares of common shares outstanding during the period. For purposes of determining the number of weighted-average common shares outstanding, the Company has included issued and outstanding common shares, penny common share warrants, and vested RSPAs. Diluted net loss per share available to common shareholders was computed by giving effect to all potentially dilutive common share equivalents outstanding for the period. For purposes of this calculation, preferred stock, unvested RSUs, unvested RSPAs, stock options and warrants to purchase common shares were considered common share equivalents but had been excluded from the calculation of diluted net loss per share applicable to common shareholders as their effect was anti-dilutive. In periods in which the Company reports a net loss applicable to common shareholders, diluted net loss per share available to common shareholders is the same as basic net loss per share applicable to common shareholders, since dilutive common shares are not assumed to have been outstanding if their effect is anti-dilutive. The Company reported net loss applicable to common shareholders for the years ended December 31, 2025 and 2024.

Fair Value Measurements

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company elected the fair value option to account for its debt instruments because the Company’s debt instruments contain a number of complex features that would have otherwise required bifurcated derivative accounting. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Fair value measurements are based on a fair value hierarchy, based on three levels of inputs, of which the first two are considered observable and the last unobservable, which are the following:

Level 1 Inputs are unadjusted, quoted prices for identical assets or liabilities in active markets at the measurement date.

Level 2 Inputs other than quoted prices included in Level I, that are observable for the asset or liability, either directly or indirectly, such as quoted market prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability.

Level 3 Inputs are unobservable inputs that reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date.

Assets and liabilities are classified in the hierarchy based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of the assets and liabilities being measured and their placement within the fair value hierarchy.

The Company measures the fair value of certain long-lived assets including finite-lived intangible assets on a nonrecurring basis, when such assets are acquired in a business combination or are required to be written down to fair value if impaired. Such fair values are classified within the fair value hierarchy, as the valuations contain significant unobservable inputs, including assumptions of the present value of future cash flows, the use of these assets, as well as estimated disposition value.

There were no assets measured at fair value on a recurring basis as of December 31, 2025 and 2024.

The carrying amounts of certain financial assets and liabilities, including restricted cash, other current assets, accounts receivable, accounts payable, accrued expenses, and amounts due to related parties approximate fair value because of the short maturity and liquidity of those instruments.

SAFE and Convertible Notes at Fair Value

The Company’s Simple Agreement for Future Equity with Tokens (“SAFE-T”) are financial instruments whereby an investor provides an investment into the Company, and the note is subsequently converted into a preferred equity security at a discount to the price paid by other investors when and if a preferred equity is issued through a qualifying capital raise. Due to certain provisions included in the agreements for these instruments, they are classified as liabilities as of December 31, 2025 and 2024.

The Company elected the fair value option for the convertible notes and SAFE-T financial instruments, which requires them to be remeasured to fair value each reporting period with changes in fair value recorded in Changes in fair value of financial instruments carried at fair value, net on the Consolidated Statements of Operations, except for change in the fair value that results from a change in the instrument specific credit risk which is presented separately within other comprehensive income. The fair value estimate includes significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The decision to elect the fair value option is determined on an instrument-by-instrument basis on the date the instrument is initially recognized, is applied to the entire instrument, and is irrevocable once elected. For instruments measured at fair value, embedded conversion or other features are not required to be separated from the host instrument. Issuance costs related to convertible securities carried at fair value are not deferred and are recognized as incurred within their original expense categories on the Consolidated Statements of Operations.

Recent Accounting Pronouncements

Adopted

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for public business entities for annual periods beginning after December 15, 2024, with early adoption permitted. The Company adopted the guidance prospectively effective December 31, 2025.

Not Yet Adopted

In November 2024, the FASB issued ASU No. 2024-03, Disaggregation of Income Statement Expenses (Subtopic 220-40). The ASU requires public entities to disaggregate, in a tabular presentation, certain income statement expenses into different categories, such as purchases of inventory, employee compensation, depreciation, and intangible asset amortization. The guidance is effective for fiscal years beginning after December 15, 2026, with early adoption permitted, and may be applied retrospectively. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and related disclosures.

In September 2025, the FASB issued ASU No. 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. The ASU simplifies the capitalization guidance by removing all references to prescriptive and sequential software development stages (referred to as “project stages”) throughout ASC 350-40. The ASU is effective for annual periods beginning after December 15, 2027, and interim periods within those fiscal years. Adoption of this ASU can be applied prospectively for reporting periods after its effective date; or follow a modified transition approach that is based on the status of the respective projects and whether software costs were capitalized before the date of adoption; or retrospectively to any or all prior periods presented in the consolidated financial statements. Early adoption is permitted. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and related disclosures.