ORAC
11th Jun 2008, 06:13
Flight International 10-16 June: The Great Survivor (article on MRA4):
.....One well-publicised recent change to the aircraft was the introduction of a stability augmentation upgrade, achieved by computer modification and actuators, as an original speed trim system failed to work as well as expected. "We've added an inner loop [computer system] that works the elevator really hard, so the pilot thinks he's got a 'golden arm', says Harland. "It's making very rapid, very small corrections to the elevator, so the aircraft stays at the same place on the horizon without wavering around"
Also exposed during the flight test programme and the final stability element to be tackled, Harland says that the aircraft's stall "is not as pronounced as the certification agents would like it to be", a potential problem for an aircraft which could spend part of it's operational life hunting for submarines at an altitude of 200ft.
"Using the same angle of attack sensors and gyros we've added the capability to warn the pilot that he is approaching a stall, by shaking the stick. If he persists in pulling the nose back we also have a stick pusher". Software releases have been made during this year, and Harland says, "the pilots are pretty pleased with that, it's virtually carefree [handling] because it allows prompt recovery from the stall."
The aircraft's aileron rigging has been adjusted, so that the port and starboard ailerons do not move by the same amount, avoiding the onset of adverse yaw. BAE also has yet to prove some changes on roll authority, and is to investigate whether it needs to add more vortex generators/stall fences on the outer wing to provide additional lift in a slower speed regime..........
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Elsewhere in the issue:
Thales to offload Searchwaters: Thales is in discussion with possible users of surplus maritime search radars acquired for the UK's BAE Systems Nimrod MRA4 surveillance aircraft, with remanufactured Lockheed P-3 Orions having emerged as lead candidates for the system. The UK Ministry of Defence ordered 21 Searchwater 2000 MR radars for it's MRA4 fleet in 19996, but has so far signed for a production order of just 9 of the aircraft. It also has options to productionise its three development aircraft.
P-8A power-on set for this week: Boeing plans to reach the power-on milestone for the US Navy P-8A Poseidon this week...... Boeing is developing the 737-800ERX based P-8A to enter service in 2013 to replace the Lockheed P-3C Orion fleet, although the schedule could be accelerated by one year....
.....One well-publicised recent change to the aircraft was the introduction of a stability augmentation upgrade, achieved by computer modification and actuators, as an original speed trim system failed to work as well as expected. "We've added an inner loop [computer system] that works the elevator really hard, so the pilot thinks he's got a 'golden arm', says Harland. "It's making very rapid, very small corrections to the elevator, so the aircraft stays at the same place on the horizon without wavering around"
Also exposed during the flight test programme and the final stability element to be tackled, Harland says that the aircraft's stall "is not as pronounced as the certification agents would like it to be", a potential problem for an aircraft which could spend part of it's operational life hunting for submarines at an altitude of 200ft.
"Using the same angle of attack sensors and gyros we've added the capability to warn the pilot that he is approaching a stall, by shaking the stick. If he persists in pulling the nose back we also have a stick pusher". Software releases have been made during this year, and Harland says, "the pilots are pretty pleased with that, it's virtually carefree [handling] because it allows prompt recovery from the stall."
The aircraft's aileron rigging has been adjusted, so that the port and starboard ailerons do not move by the same amount, avoiding the onset of adverse yaw. BAE also has yet to prove some changes on roll authority, and is to investigate whether it needs to add more vortex generators/stall fences on the outer wing to provide additional lift in a slower speed regime..........
----------------------------------------------------
Elsewhere in the issue:
Thales to offload Searchwaters: Thales is in discussion with possible users of surplus maritime search radars acquired for the UK's BAE Systems Nimrod MRA4 surveillance aircraft, with remanufactured Lockheed P-3 Orions having emerged as lead candidates for the system. The UK Ministry of Defence ordered 21 Searchwater 2000 MR radars for it's MRA4 fleet in 19996, but has so far signed for a production order of just 9 of the aircraft. It also has options to productionise its three development aircraft.
P-8A power-on set for this week: Boeing plans to reach the power-on milestone for the US Navy P-8A Poseidon this week...... Boeing is developing the 737-800ERX based P-8A to enter service in 2013 to replace the Lockheed P-3C Orion fleet, although the schedule could be accelerated by one year....