Aircraft Maintenance, Materials and Repairs. Aircraft maintenance, materials and repairs costs increased $3.6 million, or 26.1%, to $17.5 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021, primarily as a result of an increase in airframe and engine repairs of $0.6 million and $2.0 million, respectively, and an increase in materials used of $0.7 million. These increases were largely driven by higher maintenance rates and a greater reliance on third-party maintenance providers due to the ongoing labor shortage. For additional information, refer to Note 1, Summary of Significant Accounting Policies – Reclassification.
Other Rents. Other rents expense was relatively unchanged for the three months ended September 30, 2022, compared to the three months ended September 30, 2021.
Depreciation, Amortization and Obsolescence. Depreciation, amortization and obsolescence expense was relatively unchanged for the three months ended September 30, 2022, compared to the three months ended September 30, 2021.
Payroll Support Program. The contra-expense for the Payroll Support Program decreased $16.1 million, or 100%, for the three months ended September 30, 2022, compared to the three months ended September 30, 2021. There was no contra-expense recorded in the three months ended September 30, 2022 due to the cessation of the Payroll Support Program in 2021.
Purchased Services and Other. Purchased services and other expense decreased $0.4 million, or 10.2%, to $3.3 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021. The decrease was primarily due to a decrease in insurance expense and in corporate and fiscal expense. For additional information, refer to Note 1, Summary of Significant Accounting Policies – Reclassification.
Other (Expense) Income
Interest Income. Interest income increased $0.2 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021. The increase was primarily due to an increase in interest earned on the notes receivable due from United.
Interest Expense. Interest expense decreased $0.1 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021, due to debt payments made in 2021. For additional information, refer to the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations – Debt and Credit Facilities” within our 2021 Annual Report.
Loss on Marketable Securities. Loss on marketable securities increased $3.7 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021, due to a decrease in the market value of marketable securities.
Gain on Extinguishment of Debt. Gains on extinguishment of debt decreased $10.1 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021. The decrease is due to the forgiveness of the SBA Loan in August 2021 related to Air Wisconsin’s receipt of governmental assistance related to the COVID-19 pandemic.
Other, Net. Other income increased $0.3 million for the three months ended September 30, 2022, compared to the three months ended September 30, 2021, due to an increase in dividend income from investments in marketable securities.
Net Income
Net income for the three months ended September 30, 2022 was $8.0 million, or $0.17 per basic share and $0.13 per diluted share, compared to net income of $36.3 million, or $0.67 per basic share and $0.51 per diluted share, for the three months ended September 30, 2021. For additional information, refer to Note 10, Earnings Per Share and Equity.
The decrease in net income for the three months ended September 30, 2022, when compared to the three months ended September 30, 2021, primarily resulted from an increase in overall operating expenses and specifically no contra-expense related to the Payroll Support Program, under which we ceased receiving support in 2021. The decrease in net income can also be attributed to a decrease in operating revenues, a decrease in gain on extinguishment of debt, and increased losses on investments in marketable securities.
Income Taxes
In the three months ended September 30, 2022, our effective tax rate was 23.8%, compared to 18.1% for the three months ended September 30, 2021. Our tax rate can vary depending on changes in tax laws, adoption of accounting standards, the amount of income we earn in each state and the state tax rate applicable to such income, permanent differences between financial statement income and taxable income, as well as any valuation allowance required on our deferred tax assets.
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