Chris Sifford was slightly mentioned in this other article;
Jury orders $4M payment in Carnahan case
http://kansascity.bizjournals.com/kansascity/stories/2004/01/12/daily61.html
snip-
"Randy Carnahan was piloting the Cessna 335 that crashed on Oct. 16, 2000, in southeast Missouri, killing himself, his father and an aide, Chris Sifford."
more snip-
" Family members blamed the crash on a pair of Parker Hannifin vacuum pumps, which they said failed and killed power to several key navigational instruments. In radio transmissions with air traffic controllers in St. Louis, Randy Carnahan reported a malfunctioning primary altitude indicator, or artificial horizon, which is powered by the pumps."
Can any of our pilots help me pout on this one? I thought most planes have a back up indicator that isn't powered by pumps. Correct me if I'm wrong.
snippy about it-"
The company has argued that there was no evidence of its pumps failing in Carnahan's plane, relying on a report from the National Transportation Safety Board. The NTSB said in its investigation that the pumps probably were operating at the time of the crash.
Sounds like pilot error was not an option in this case.
I thought most planes have a back up indicator that isn't powered by pumps.Most planes only have one set of instruments, but larger ones have two sets with separate power sources. There is a bit of redundancy, though- most aircraft use a vacuum pump to drive the attitude and heading indicators and electric power for the turn co-ordinator. I don't know the FAA standards but in Canada even VFR pilots are required to train for instrument flight without the attitude indicator; it's exhausting but not impossible. My own take is that unless there was a compelling reason (such as low fuel) to make that approach he should have flown to some alternate airport where visibility was better.
Normally, the gyros in the Attitude Indicator ("artificial horizon") and DG or HSI (Heading Indicator or Horizontal Situation Indicator) are vacuum driven.
Vacuum pumps are notorious for failing at the worst possible times.
For that reason, the backup instruments are electrically powered or not powered at all. The (electrically-powered) Turn Coordinator, magnetic compass, and airspeed indicator give you enough information to keep the plane flying straight and level in an emergency. "Needle, ball, and airspeed"