This is Fukumoto, Director, Executive Officer, General Manager of Finance and Accounting of IHI Group. Before explaining the financial results, we would like to extend a deep apology for causing a great deal of concern and inconvenience to customers and stakeholders with regard to the misconduct in a test of snowblower equipped with rotary snowplows for roads, which were manufactured and sold by Niigata Transys, our consolidated subsidiary, as announced on July 31st, following the misconduct occurred at IHI Power Systems, as reported in April. The impact of these matters on the financial results is currently under scrutiny and will promptly be announced should there be any impact. Now, I will explain overview of IHI Group's financial results for the first quarter of fiscal year 2024. Page three shows the contents of today's presentation.
Please turn to page five for the group's financial results for the first quarter of fiscal year 2024. Orders received was JPY 328.7 billion, revenue was JPY 348.1 billion, operating profit was JPY 23.8 billion, and the operating profit margin was 6.8%, all of which increased year-on-year. We recognize that we are off to a good start against our record high operating profit target of JPY 110 billion for this fiscal year. Cash flows from operating activities, which will fund investment for transformation as set forth and promoted in Group Management Policies 2023, increased significantly year-on-year. Details will be explained using the following slides. Please turn to page six for highlights for the first quarter.
In the first quarter of fiscal year 2024, the IHI Group achieved increase in revenue and profits, driven by the civil aero engines business and steadily accumulated profits. Orders received increased significantly, both for new engines and spare parts for civil aero engines, along with solid recovery in aero passenger demand. Revenue increased due to the construction progress of large power plant projects in Asia-based EPC, of our subsidiary, mainly in Southeast Asia, and also due to increase in sales of civil aero engines. Operating profit increased substantially due to the timing difference of program-related costs, as well as increase in sales of spare parts in civil aero engines. On the other hand, profitability of vehicular turbochargers have deteriorated due to delay in progress of sales price negotiations.
Cash flows from operating activities improved significantly year-on-year and turned positive, as increase in working capital was restrained to a certain extent as a result of the steady progress in collection of construction payments, in addition to the steady growth of EBITDA. As for the impact of additional inspection program for PW 1100G engines recorded in the last fiscal year, there is no change in assumptions for the total dollar-based estimated amount. However, there is a negative impact of JPY 9.8 billion, as the yen equivalent amount has increased due to yen depreciation to the level surpassing JPY 160 to the dollar at the end of June. From the first quarter, we started to incur program-related expenditures such as compensation to airlines. Please refer to page seven for the overview of financial results, including orders received, revenue, and other major profit and loss items.
Please turn to page eight. This page shows factors of year-on-year change in operating profit in a waterfall chart. Please refer to page 19 for the factors of change in operating profit by segment. Changes in business environment pushed up operating profit by JPY 17.2 billion due to a major contribution from sales of spare parts in civil aero engines. In addition, as a result of reaping benefits from some of the initiatives aimed at reinforcing the cost structure, as well as the trend of the weaker yen, operating profit increased up to JPY 33.7 billion, excluding the FX impact of additional inspection program for PW1100G, or up to JPY 23.8 billion, including the impact. Please turn to page nine for the financial position.
Trade receivables decreased primarily due to steady progress in collecting payments for overseas projects, while inventories increased due to increased production in civil aero engines and progress in construction of defense systems. As for indicators for financial health, debt-to-equity ratio and the ratio of equity attributable to owners of parent improved to 1.36 times and 18.6% respectively, due to building up profits.
Please turn to page 10. There is a graph showing the cash flows. In addition to the steady increase in EBITDA, cash flows from operating activities improved significantly and returned to positive due to steady progress in the collection of construction payment. IHI Group will continuously accelerate the initiatives to further improve the working capital efficiency to generate JPY 75 billion cash flows from the operating activities on a full year basis. Please turn to page 12, Forecast of the consolidated results for fiscal year 2024. No changes in orders received, revenue, and each profit from the previous forecast. IHI Group is making a steady progress toward achieving record high operating profit of JPY 110 billion.
As for additional inspection program for PW1 100 G, IHI Group will continuously work with the program partners to enhance maintenance capacity and reduce the number of aircraft grounded. The expenditures in Q1 related to the program was no more than JPY 2.9 billion. The expenditures are expected to become gradually more significant from July onward. Full year impact is expected to be -JPY 50 billion or so, no change from the previous forecast. Please turn to page 13. Overviews of forecast. No change from the previous forecast, including the breakdown by segment. FX assumption for the guidance also remains the same, and is JPY 140 for $1 . FX sensitivity for the remaining nine months is JPY 1 move, will have JPY 1 billion impact on the operating profit, excluding the PW 1100 G additional inspection program impact.
Please turn to page 14. Above shows the factors of the change in operating profit and below shows the financial results by segment. No change from the previous forecast. Please turn to page 15. Dotted line shows the growth of spare parts handling amount in U.S. dollars basis. Q1 momentum was as strong as expected. The growth curve for the remaining nine months has not been revised from the previous forecast. Please turn to page 16, Status of Lifecycle Business in Core Businesses. Lifecycle businesses have been steadily expanding since 2019, and now the business scale has become 1.5x compared to 2019. Progress ratio in Q1 was approximately 20%, which was as planned and was the same level as ordinary years. In Q1, IHI Group could confirm the strength of civil aero engine business.
Although there are continuous uncertainties including FX trend, IHI Group will continuously work hard to achieve JPY 110 billion operating profit and more than JPY 75 billion cash flows from operating activities on a full year basis. The following slides are just for your reference. Please take a look at them later. This is the end of my presentation.