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v3.25.2

Long-Term Debt, Finance Leases, and Other Borrowings - Schedule of Long-term Debt (Detail) - USD ($) $ in Thousands | Jun. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2023
--- | --- | --- | ---
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities | $ 113,744 | $ 315,210 | $ 538,300
Less unamortized debt issuance costs |  | (2,395) | (5,083)
Less notes payable warrants | (774) | (2,544) | (4,913)
Net long-term debt, including current maturities | 112,970 | 310,271 | 528,278
Less current portion, net of unamortized debt issuance costs | (84,725) | (50,455) | (163,550)
Net long-term debt | 28,245 | 259,816 | 364,728
Senior and Subordinated Notes Payable to Secured Parties, Due in Monthly Installments Collateralized by the Underlying Aircraft Through 2027 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  |  | 39,018
Notes Payable to Secured Parties, Due in Semi Annual Installments Collateralized by the Underlying Aircraft Through 2028 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 85,469 | 108,815
Notes Payable to Secured Parties, Due in Quarterly Installments Collateralized by the Underlying Aircraft Through 2028 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 73,884 | 90,401
United Bridge Loan Quaterly Collateralized By Underlying Equipment And Investments Through Two Thousand Twenty Four [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  |  | 10,500
Other Obligations Due to Financial Institutions, Monthly or Quarterly Collateralized by the Underlying Equipment, Due 2022 Through 2031 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 4,681 | 67,637
Notes Payable to Financial Institution, Due in Monthly Installments Collateralized by the Underlying Equipment, Through 2024 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  |  | 1,075
Notes Payable to Financial Institution Due in Monthly Installments Collateralized by the Underlying Equipment Through 2027 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 0 | 41,098
Notes Payable to the UST, Quarterly Through 2025 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 113,656 | 139,100
Gross LongTerm Debt Including Current Maturities [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 315,210 | 538,274
Notes Payable to the UST, Quarterly Through 2025 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities | 80,726 | 113,656 |
United revolving credit facility quaterly collateralized by underlying equipment and investments through two thousand twenty eight [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities |  | 37,520 | $ 40,630
Revolving Credit Facility, Quarterly Interest Through 2028 [Member] |  |  |
Debt Instrument [Line Items] |  |  |
Gross long-term debt, including current maturities | $ 33,018 | $ 37,520 |

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