From today's edition of the RISKS digest: "Quirks" considered harmful.

(Syndication available on LJ as risks_digest)

I think "quirk" is even better than "glitch" for wrecking a $133 million aircraft and nearly killing the pilot. Next time my boss is mad because one of my infrastructure maintenance setups doesn't work I'll say I have a "quirk".

Date: Wed, 15 Jun 2005 11:10:34 +0200
From: "Peter B. Ladkin" <ladkin@rvs.uni-bielefeld.de>
Subject: Details of F/A-22 crash December 2004

On 20 Dec 2004, an F/A-22 Raptor, the USAF's new air-superiority fighter, crashed 11 seconds after takeoff from Nellis AFB, Nevada. It is the first production aircraft to be lost. They are said to cost $133 million each. The results of the investigation from the USAF Accident Investigation Board (AIB) are reported in this week's Flight International (14-10 June, 2005, p9).

The pilot ejected with the aircraft near-inverted. The aircraft struck the end of the runway going backwards.

There are three rate-sensor assemblies (RSA), manufactured by BAE Systems in the flight control system (FCS). There is a known "quirk" in the RSA, which is "programmed so that it could interpret a momentary power loss [to the FCS] as an instruction to enter test mode, which freezes or "latches" the unit, according to the AIB report."

The pilot shut down the engines during a maintenance check pre-take-off, thinking the FCS was continuously powered by the auxiliary power unit (APU). The FCS in fact loses power briefly during a shutdown, and that appeared to suffice to latch all three RSAs. "The AIB attributed the pilot's mistake to "ambiguous" language in the aircraft's technical orders."

The manufacturer, Lockheed Martin, has returned about 20 RSAs to BAE Systems for suspected latching events. Before this crash, such events only affected one or two of the RSAs, not all three together. There is a pilot warning for partial RSA latching, but no warning if all three latch.

The RSA has been redesigned and is being installed on the fleet.

Peter B. Ladkin, University of Bielefeld, Germany www.rvs.uni-bielefeld.de

Venezia at Dusk

Venezia at Dusk, originally uploaded by graye.

This picture makes me nostalgic for my two summers in Venice as a child. It also makes me wish we had better storms around here.

rumble

5.3 in Yucaipa

update

There was also a 2.0 basically under my house a few minutes before, and I thought it was a plane or a heavy truck:

Map of it, quake link.

VIctoria & Pomona was shaking, that must have annoyed the whores and the coke dealers.

Edit: Now that quake has disappeared from the site. Maybe it really was just a big truck or something. WTF? Probably the government was testing their new pain and fear broadcaster over in West Costa Mesa and it blew up and they're concealing it all.

scrobble scrobble

Are any of you other than cordiloquy on Audioscrobbler? I kinda like it. Then again I don't mind the entire Interweb knowing what I've been listening to on my computer.

food closures for may, orange county. mmmm!

I'm not surprised at the Minute King. I don't think that place has been mopped since before the airport allowed jets. It has that "funky liquor store smell". Also, I have no joke, I just like saying "awesome dog". Also wtf the Lodge? It's only been open for less than a year, right?

( click for attractively presented doom )

I guess now that everyone else has announced

What with everyone getting engaged and married lately, it's just been a dizzy whirl of wedding rings, Saturdays in June, giddy relatives, and Rule #6. It's as good a time as any to announce mine. As of two days ago, my right hand and I are affianced. We haven't set a date yet, but we're probably going to have an autumn wedding, probably in the mountains somewhere pretty or maybe just in the shower again.

We've had our good and bad times over the years. Once or twice it looked like I might abandon my own right hand for some so-called "woman", and there was that brief dalliance with the left hand during the tendinitis crisis. We've both agreed to leave the Jerking Strike of 1991 behind us.

The fact is, we're always going to be together, and we're always going to have each other. And we like it that way. Getting engaged is just our way of telling the world what we already know in my heart and my phalanges: this love is forever.

Details to follow, and I'll try to get a better shot of the ring.