Feature in this week's
Av Week on the MRA4's problems, adding to the insight provided by VC. Extracts:
Undesirable handling characteristics are forcing BAE Systems to augment the flight control system on its Nimrod MRA4 maritime reconnaissance and attack aircraft, with first flight of a modified version by year-end.
The U.K. MoD and BAE have yet to formally contract for the work package. According to a company official, discussions are ongoing. One issue is likely to be which organization pays for the cost of the so-called stability augmentation system (SAS).
There was a realization, even before the flight test program began, that there might be an issue with longitudinal stability, according to the company official, although there was "no definitive proof." The concern over longitudinal stability turned out to be valid, with the aircraft having a tendency to "porpoise," given the right conditions.
While the test crews are understood to be at ease dealing with "porpoising" effect, it was decided that the characteristic could not be disregarded.
The augmentation system will use a digital system to interface with the manual flight controls. The BAE official says integrating the package "is not a major issue."
There are indications the in-service date could slip until the end of 2010, or possibly further.
I/C