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Gamera, thanks for the update. In this article the miss wiring appears to have been done further up in the fuselage and was not a simple cross connection of the wiring looms to the flight control computers, as a result of this miss wiring the flight computers failed at takeoff. The Japanese authorities appear to be putting the fault as "professional negligence" onto the Nagoya factory employees and inspection procedures.

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I visited Gifu for a few days back in late '83 for their big product airshow. Fun place.

] Gifu for a few days back in late '83

Gifu in late '83, eh? You saw any flying Sabre or Starfighter? XD

] as a result of this miss wiring the flight computers failed at takeoff.

IMO, the avionics, flight control computer, flight control software, and pitch/roll rate sensors didn't fail. They worked as advertised and as designed, actually. They were just disinformed by the data they received.

To paraphrase the former US President Ronald Reagan: they only know what they are told.

Gamera, sorry about the vague wording.

What I intended to say was that it appears that none of the three primary computers could get a resolution of the inputs within acceptable limits and they took themselves off line, why the limited backup loop also failed has not, as far as I know, been publicly stated.

Based on published reports it appears that the production control system in the F2 is a triple redundant digital fly-by-wire(FBW) system based on the Block 40 F-16 flight control system with additional development features from the T-2 CCV FBW system concepts. It also has a a simplified analog backup circuit.

With this type of design the system functional logic would require two of the boxes to agree to maintain control.

WRT the human factors of the accident, as said before, suspected sabotages to multiple JASDF jet fighters at that Mitsubishi factory happened some years ago, and the company added security measures, such as CCTV cameras in the workplace, but they didn't or haven't enough evidence to publicly catch any saboteur.

Monday, 21 January 2008:
F-2.
3rd Koukuudan, JASDF, based at Misawa AB, Aomori Prefecture.
9:20, grip of control stick broke at its base, during air combat training, above Pacific Ocean, 100 km east of Misawa AB.
Electrical system cords still connected, and functions were controllable and normal, when pilot pushed in and fixated base part of grip.
After 30 minutes, emergency landed at Misawa AB.
Pilot not wounded.

Broken was metal part that fixated plastic grip part of control stick (length, 20 cm).
Accident aircraft entered service in 2001.
75 F-2 grounded for examination at fives bases, include Matsushima AB, Miyagi Prefecture, and Tsuiki AB, Fukuoka Prefecture.

http://headlines.yahoo.co.jp/hl?a=20080 ... 3-jij-soci
http://headlines.yahoo.co.jp/hl?a=20080 ... 0-mai-soci
http://headlines.yahoo.co.jp/hl?a=20080 ... 7-yom-soci

Gamera, Thanks for the update.

From the last article from the Yomiuri Online it appears that the sidestick controller broke off about 2.5 inches above the base and the pilot recovered by using this stub to fly back to base. I think the F-16 had similar problems years ago which were fixed.

Rough Translation of Japanese Text

The joy-stick of the Air Self-Defense Force close support fighter came off resulting in an emergency landing at Misawa on January 21st about 9:20 AM.

The Air Self Defense Force Misawa base 3rd Fighter wing is equipped with the F2 close support fighter.

During a training flight approximately 100 KM out over the eastern Pacific Ocean the side stick controller grip came off. The pilot declared an emergency, grasping the remaining several centimeters which remained, operated the jet for 30 minutes and landed safely at Misawa base.

Photo of F-2 control stick:
http://ja.wikipedia.org/wiki/%E7%94%BB% ... GAB001.jpg
http://upload.wikimedia.org/wikipedia/j ... GAB001.jpg

So, how is the F-2? If I recall, it's like an F-16 on steroids(a little larger, overall) with minor restriction to forward vision from canopy framing. How does it compare with our later model F-16s? Love their paint scheme though. Cool

A Jap article at
http://www.asahi.com/national/update/01 ... 10468.html
reports: instead of the control stick, the pilot uses a "force sensor" (5 cm length rod) to stabilise the aircraft.

What "force sensor" rod? (Luke Skywalker?)

Gamera wrote:

A Jap article at
http://www.asahi.com/national/update/01 ... 10468.html
reports: instead of the control stick, the pilot uses a "force sensor" (5 cm length rod) to stabilise the aircraft.

What "force sensor" rod? (Luke Skywalker?)

A sidestick controller uses force beam sensors with a little bit of tactile travel to send the control signals into the aircraft.

From this article it appears that the controller broke off at the base of the handle leaving a 5cm stub standing up. He was able to use this stub to provide sufficient control inputs to return to base. All the aircraft are being inspected for the same condition.

Last edited by Gamera on Jan 24, 2008 - 04:41 AM; edited 1 time in total

http://headlines.yahoo.co.jp/hl?a=20080 ... 8-mai-soci
http://headlines.yahoo.co.jp/hl?a=20080 ... 8-jij-soci

Wednesday, 23 January 2008:
JMOD accident investigation committee announced: Mitsubishi Heavy Industries has organisational problems, including MHI workers cannot distinguish between wirings of the two aircraft control devices (sensors), and operation procedure manual has unclear contents.

Between main computer and each sensor are three wires.
Wires have printings. Connectors are two types, L-shape and straight, and cannot misconnect into sockets. But worker reversed L-shape connectors, and misconnected into sockets.
Second aircraft maintained by worker, who claimed did not know importance of sensors, and did not remember misconnections.
Later, inspector and supervisor did not find mistake.

If the stick truly broke off, the pilot most likely used trim commands to fly the airplane back to the base and land. Pitch and roll trim are on the stick, with pitch, roll, and yaw trim available on the flight control panel.

http://www.asahi.com/national/update/01 ... 80010.html

28 January 2008:
JASDF aircraft test flights resume at Prefectural Nagoya AP, Aichi Prefecture, three months after F-2B crashed on 31 October 2007.
16:45, one helicopter took off for test flight.

asiatrails wrote:

Gamera, Thanks for the update.

From the last article from the Yomiuri Online it appears that the sidestick controller broke off about 2.5 inches above the base and the pilot recovered by using this stub to fly back to base.

Rough Translation of Japanese Text

The joy-stick of the Air Self-Defense Force close support fighter came off resulting in an emergency landing at Misawa on January 21st about 9:20 AM.

During a training flight approximately 100 KM out over the eastern Pacific Ocean the side stick controller grip came off. The pilot declared an emergency, grasping the remaining several centimeters which remained, operated the jet for 30 minutes and landed safely at Misawa base.

I'm sure that would entail a somewhat elevated pucker factor! Shocked

Glad the pilot was OK & he got the bird back! Very Happy

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