In response to criticism of the verdict by peers and MPs from all political parties, the MoD will cite a new computer simulation of the last moments of ZD576's flight by the aircraft's manufacturer Boeing. The simulation results, for the first time, include some detailed characteristics of the Chinook's software-controlled Full Authority Digital Engine Control (Fadec) system.
Problems with the Fadec, which regulated fuel to the Chinook's engines without direct commands from the pilots, caused the engines on other Chinooks to behave unpredictably at about the time of the crash of ZD576 on the Mull of Kintyre on 2 June 1994.
The results of Boeing's new simulation are expected to reach the same conclusions as its original mathematical model in 1994. Boeing had created diagrams which depicted the pilots of ZD576 flying at high speed directly into the Mull in full control of the aircraft.
In a detailed report dated 31 January 2002, a specially convened select committee of the House of Lords, under former senior appeal judge Lord Jauncey, examined the crash and its possible causes. It said the Boeing simulation "presupposed that the aircraft was at all times under control and flying a straight course although there was no evidence that this was necessarily the case".
The Lords' report added, "We conclude that it would be quite inappropriate to treat the results of the simulation as proven fact." The committee concluded unanimously that two RAF air marshals were "not justified in finding that negligence on the part of the pilots caused the aircraft to crash".
Next week the MoD will publish a statement in response to the Lords' report. It is expected to say there are no new grounds for reconvening the RAF Board of Inquiry or setting aside the verdict against the pilots.
Although the MoD will release the results of Boeing's new simulation, the assumptions on which the mathematical model was based are likely to be kept secret.
Next week's MoD statement - to be made nearly six months after the Lords' report was published - will come too late for a full debate before Parliament breaks for its summer recess.
In November 2000, the most powerful select committee in the House of Commons, the Public Accounts Committee, found that Fadec software on the Chinook Mk2 was flawed.
Doubts about Fadec led in part to the committee's rejection of the finding of negligence. It accused the MoD of "unwarrantable arrogance" in standing by the verdict.