I would have liked to link my statements but one have to make fifteen posts before being allowed to do so. But here's another tidbit you might like. As we're also discussing 'stealth', and all Swedish.
"Details of a formerly secret project to defend Swedish airspace against stealthy cruise missiles using a radical but inexpensive radar system were revealed at a conference in Oslo this week. The Associative Aperture Synthesis Radar (AASR) was approaching the hardware-test stage when it was cancelled in 2000 after eight years of work -- because there was no imminent cruise-missile threat any more. It has only recently been declassified and this was one of the first open, formal briefings on the project.
The AASR was designed to take advantage of the principle that a target's bistatic radar cross section -- where the radar receiver and transmitter are in different places -- may be affected minimally or not at all by stealth measures aimed at conventional radars. In particular, it exploits the "shadow" RCS behind the target, which depends entirely on the target's geometrical cross-section. The radar was also designed to operate in the UHF band where radar absorbent material (RAM) is less effective.
Developer Hans Hellsten of Saab Microwave Systems told the conference that the AASR used a number of novel techniques. Each transmitter would transmit on stepped frequencies so that receivers could tell where a signal came from. This made it possible to determine the length of the signal path, so that if a signal was picked up at several nodes it was possible to determine the target's location precisely.
One disadvantage: the transmitter and receiver had to be on opposite sides of the target, so it could not be detected until it had entered the defended airspace. To get around that problem and still intercept targets in a timely manner, Swedish planners expected to exploit the system's accuracy -- it could locate targets within 1.5 m -- and command-guide a high-speed missile on to the target.
But because the system used range rather than bearing to locate its targets, the antennas did not need to have accurate bearing resolution. Also, the system's use of UHF, its independence from target RCS and the fact that bistatic systems have long pulse times meant that the necessary power was modest.
The result was a price that caused sharp intakes of breath among the delegates. Each of the 900 nodes was expected to cost no more than 1 million Swedish kroner (about $156,000) and the entire system would be in the 1 billion kroner ($156 million) realm -- pretty much chickenfeed by defense standards.
Moreover, trying to destroy an air defense radar with 900 distributed apertures is an exercise in futility. The grid pattern does not have to be continuous, and the designers intended to emplace the modules using the same techniques that are used to locate cell phone base stations.
We've seen many anti-stealth ideas come and go over the years, such as the UK's cell-phone radar concept or the Russian Nagira high-powered radar. But AASR is the first advertised system-level attack on stealth to emerge from a full-up combat radar house -- and these are the people -- the former Ericsson Microwave, acquired by Saab in June 2006 -- who produced the world's first airborne AESA and notched up a number of other firsts over the years."
From Military.com
==
I saw someone stating that Gripen used 9 G
This one is from Robban.
"The Gripens max allowable AoA is 26 deg. The Gripen has flown controllably up to at least 110 deg AoA during tests. The Draken and Viggen could both do the so called cobra maneuver. Compared to these two the aerodynamics on the Gripen is more advanced, and its handling and maneuverability quite superior. AFAIK, the Gripen pilot cannot pull through the "stops" and achieve higher AoA's, but he/she can pull through the 9G stop and get 12G should he need it. Gripens G build up is 6G/sec, and in some cases even 12G/sec. I read this in a RSwAF news magazine called "Flygvapennytt" 10 years ago. I need to dig it up! I wonder how the JF-17 compare here?
I have seen the Gripen make such a rapid pull up that it could be mistaken for a cobra. The aircraft however continued flying straight up after the pull up, with little to no visible speed loss.
When I sat in 39.823 a couple of years back the technician told me to pull the stick to the stop. I did, and the stop was quite firm. He told me, there you have 9G. Then he told me to put some more back pressure on it. I did and all of a sudden the stick moved backwards a half an inch more. There you have 12G he said.
He pointed out another funny thing. Next to my right shoulder on the side panel there was a switch, locked by a very thin copper wire. The switch said "war" and "peace". It was locked in the peace setting. By simply breaking the wire and switch to war, he said the systems, the engine, everything in the airplane would be boosted. More thrust, longer radar detection range etc. The version D has an 8G limit, and a lower allowable AoA. Its lower level of instability makes it less snappy in pitch. Its ITR and its STR is lower than that of the C. It is slightly heavier, and the larger canopy might affect drag in a negative way. I guess roll rate is not affected as much."
When it comes to the plan crashing in Stockholm it was because of PIO (pilot induced oscillations), although created because the joystick wasn't responding as it should. They tried to blame it on the pilot first but after tests they had to call in a software specialist from the states to trim the software speaking with the plane. That as only the Americans used the system then if I remember right, and we needed their expertize in this. In February 1989 a JAS 39 Gripen prototype crashed when landing in Linköping, Sweden. Pilot-induced oscillation as a result of an over-sensitive, yet slow-response steering system was determined to be the cause. Subsequently, the steering system was redesigned.
Pilot-induced oscillation was blamed for the 1992 crash of the prototype F-22 Raptor, landing at Edwards Air Force Base in California. This crash was linked to actuator rate limiting, causing the pilot, Tom Morgenfeld, to over-compensate for pitch fluctuations.
The wiki Accidents_and_incidents_involving_the_JAS_39_Gripen doesn't mention that it seems? Don't know why? It's like all electronics that needs to communicate with humans, we need to find the right parameters, but Gripen has had very few crashes. In fact I think one of the lowest in the world, or the lowest?
==
This is the statistic I could find. there should be a better one, somewhere?
AIRCRAFT TYPE FIRST 90000 HOURS FIRST 213000 HOURS
AV-8A . . . . . . . . . . . . . . . . . 25. . . . . . . . . 50 (Includes RAF)
A-4 . . . . . . . . . .. . . . . . . . . .37. . . . . . . . . 64
A-7 . . . . . . . . . . . . . . . . . . . 37. . . . . . . . . 73
F-8 . . . . . . . . . . . . . . . . . . . 44. . . . . . . . . 79
A-6. . . . . . . . . . . . . . . . . . . .16. . . . . . . . . 33
F-4 . . . . . . . . . . . . . . . . . . . 17. . . . . . . . . 44
F-100 . . . . . . . . . . . . . . . . . .39. . . . . . . . . 78
F-102 . . . . . . . . . . . . . . . . . .27. . . . . . . . . 38
F-104 . . . . . . . . . . . . . . . . . .43. . . . . . . . . 88
F-105 . . . . . . . . . . . . . . . . . .31. . . . . . . . . 47
F-106 . . . . . . . . . . . . . . . . . .15. . . . . . . . . 26
A-10 . . . . . . . . . . . . . . . . . . .08. . . . . . . . . 17
F-15 . . . . . . . . . . . . . . . . . . .04. . . . . . . . . 15
F-16 . . . . . . . . . . . . . . . . . . .10. . . . . . . . . 30
So for the Gripen. . . . . . . . . . . . 3. . . . . . . . . est ?
Two crashed during the development and evaluation phase.
A further three aircraft have crashed in service with the SwAF: 1999, 2005 and 2007.
In january 2008 the aircraft type surpassed 100 000 flight hours.
2009 surpassed 130 000 flighthours.
So counting 3 crashes to that, yep. It's fairly correct.
One of the safest you can fly.
"Details of a formerly secret project to defend Swedish airspace against stealthy cruise missiles using a radical but inexpensive radar system were revealed at a conference in Oslo this week. The Associative Aperture Synthesis Radar (AASR) was approaching the hardware-test stage when it was cancelled in 2000 after eight years of work -- because there was no imminent cruise-missile threat any more. It has only recently been declassified and this was one of the first open, formal briefings on the project.
The AASR was designed to take advantage of the principle that a target's bistatic radar cross section -- where the radar receiver and transmitter are in different places -- may be affected minimally or not at all by stealth measures aimed at conventional radars. In particular, it exploits the "shadow" RCS behind the target, which depends entirely on the target's geometrical cross-section. The radar was also designed to operate in the UHF band where radar absorbent material (RAM) is less effective.
Developer Hans Hellsten of Saab Microwave Systems told the conference that the AASR used a number of novel techniques. Each transmitter would transmit on stepped frequencies so that receivers could tell where a signal came from. This made it possible to determine the length of the signal path, so that if a signal was picked up at several nodes it was possible to determine the target's location precisely.
One disadvantage: the transmitter and receiver had to be on opposite sides of the target, so it could not be detected until it had entered the defended airspace. To get around that problem and still intercept targets in a timely manner, Swedish planners expected to exploit the system's accuracy -- it could locate targets within 1.5 m -- and command-guide a high-speed missile on to the target.
But because the system used range rather than bearing to locate its targets, the antennas did not need to have accurate bearing resolution. Also, the system's use of UHF, its independence from target RCS and the fact that bistatic systems have long pulse times meant that the necessary power was modest.
The result was a price that caused sharp intakes of breath among the delegates. Each of the 900 nodes was expected to cost no more than 1 million Swedish kroner (about $156,000) and the entire system would be in the 1 billion kroner ($156 million) realm -- pretty much chickenfeed by defense standards.
Moreover, trying to destroy an air defense radar with 900 distributed apertures is an exercise in futility. The grid pattern does not have to be continuous, and the designers intended to emplace the modules using the same techniques that are used to locate cell phone base stations.
We've seen many anti-stealth ideas come and go over the years, such as the UK's cell-phone radar concept or the Russian Nagira high-powered radar. But AASR is the first advertised system-level attack on stealth to emerge from a full-up combat radar house -- and these are the people -- the former Ericsson Microwave, acquired by Saab in June 2006 -- who produced the world's first airborne AESA and notched up a number of other firsts over the years."
From Military.com
==
I saw someone stating that Gripen used 9 G
This one is from Robban.
"The Gripens max allowable AoA is 26 deg. The Gripen has flown controllably up to at least 110 deg AoA during tests. The Draken and Viggen could both do the so called cobra maneuver. Compared to these two the aerodynamics on the Gripen is more advanced, and its handling and maneuverability quite superior. AFAIK, the Gripen pilot cannot pull through the "stops" and achieve higher AoA's, but he/she can pull through the 9G stop and get 12G should he need it. Gripens G build up is 6G/sec, and in some cases even 12G/sec. I read this in a RSwAF news magazine called "Flygvapennytt" 10 years ago. I need to dig it up! I wonder how the JF-17 compare here?
I have seen the Gripen make such a rapid pull up that it could be mistaken for a cobra. The aircraft however continued flying straight up after the pull up, with little to no visible speed loss.
When I sat in 39.823 a couple of years back the technician told me to pull the stick to the stop. I did, and the stop was quite firm. He told me, there you have 9G. Then he told me to put some more back pressure on it. I did and all of a sudden the stick moved backwards a half an inch more. There you have 12G he said.
He pointed out another funny thing. Next to my right shoulder on the side panel there was a switch, locked by a very thin copper wire. The switch said "war" and "peace". It was locked in the peace setting. By simply breaking the wire and switch to war, he said the systems, the engine, everything in the airplane would be boosted. More thrust, longer radar detection range etc. The version D has an 8G limit, and a lower allowable AoA. Its lower level of instability makes it less snappy in pitch. Its ITR and its STR is lower than that of the C. It is slightly heavier, and the larger canopy might affect drag in a negative way. I guess roll rate is not affected as much."
When it comes to the plan crashing in Stockholm it was because of PIO (pilot induced oscillations), although created because the joystick wasn't responding as it should. They tried to blame it on the pilot first but after tests they had to call in a software specialist from the states to trim the software speaking with the plane. That as only the Americans used the system then if I remember right, and we needed their expertize in this. In February 1989 a JAS 39 Gripen prototype crashed when landing in Linköping, Sweden. Pilot-induced oscillation as a result of an over-sensitive, yet slow-response steering system was determined to be the cause. Subsequently, the steering system was redesigned.
Pilot-induced oscillation was blamed for the 1992 crash of the prototype F-22 Raptor, landing at Edwards Air Force Base in California. This crash was linked to actuator rate limiting, causing the pilot, Tom Morgenfeld, to over-compensate for pitch fluctuations.
The wiki Accidents_and_incidents_involving_the_JAS_39_Gripen doesn't mention that it seems? Don't know why? It's like all electronics that needs to communicate with humans, we need to find the right parameters, but Gripen has had very few crashes. In fact I think one of the lowest in the world, or the lowest?
==
This is the statistic I could find. there should be a better one, somewhere?
AIRCRAFT TYPE FIRST 90000 HOURS FIRST 213000 HOURS
AV-8A . . . . . . . . . . . . . . . . . 25. . . . . . . . . 50 (Includes RAF)
A-4 . . . . . . . . . .. . . . . . . . . .37. . . . . . . . . 64
A-7 . . . . . . . . . . . . . . . . . . . 37. . . . . . . . . 73
F-8 . . . . . . . . . . . . . . . . . . . 44. . . . . . . . . 79
A-6. . . . . . . . . . . . . . . . . . . .16. . . . . . . . . 33
F-4 . . . . . . . . . . . . . . . . . . . 17. . . . . . . . . 44
F-100 . . . . . . . . . . . . . . . . . .39. . . . . . . . . 78
F-102 . . . . . . . . . . . . . . . . . .27. . . . . . . . . 38
F-104 . . . . . . . . . . . . . . . . . .43. . . . . . . . . 88
F-105 . . . . . . . . . . . . . . . . . .31. . . . . . . . . 47
F-106 . . . . . . . . . . . . . . . . . .15. . . . . . . . . 26
A-10 . . . . . . . . . . . . . . . . . . .08. . . . . . . . . 17
F-15 . . . . . . . . . . . . . . . . . . .04. . . . . . . . . 15
F-16 . . . . . . . . . . . . . . . . . . .10. . . . . . . . . 30
So for the Gripen. . . . . . . . . . . . 3. . . . . . . . . est ?
Two crashed during the development and evaluation phase.
A further three aircraft have crashed in service with the SwAF: 1999, 2005 and 2007.
In january 2008 the aircraft type surpassed 100 000 flight hours.
2009 surpassed 130 000 flighthours.
So counting 3 crashes to that, yep. It's fairly correct.
One of the safest you can fly.
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