Why can't we find Steve Fossett?

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"Millionaire Adventurer" Steve Fossett has now been missing for three days after his plane went down over Nevada. Search and Rescue seems to be having a lot of trouble finding him, which is a bit surprising. I had just assumed that he wasn't carrying a locator beacon for some reason (I don't think that PLBs are required, but I admit I'm not sure), but according to this he was:
"This is kind of strange because these aircrafts have transponders and emergency locators and you can usually readily find them anywhere in the world, including under the sea," said Ross Aimer, CEO of Aviation Experts, a San Clemente, California-based aviation consulting firm.

"This guy is totally lost.... So far, nobody's heard the electronic location beacon," said Aimer, who has flown the region several times. "That sounds to me very, very strange. There's all kinds of possibilities."


Officials say there's been no detection of the emergency locator beacon that would automatically go off in the event of a crash or could have been enabled by Fossett himself if he were capable. Fossett did not file a flight plan and didn't carry extra radio equipment because he was only planning to be gone for a short while, Ryan said.



My understanding from following Doug Ritter on equipped.org is that the beacons required on small planes that are automatically activated by a crash (ELTs-Electronically Locating Transmitters, I believe) aren't that reliable. He recommends carrying a PLB as a backup. Actually, he says the ELT should be a backup to the PLB.

So if Fosset crashed, the ELT might not have gone off, especially if it burned. If he didn't have a PLB or was too injured to use one, there'd be no way of knowing where he was.

The ELT requirement for small planes - certainly for the Citabria he was flying - is for an auto-activated emergency-transmitter that broadcasts on 121.5 MHz (of course a wealthy and prudent fellow like Fossett may have had better). A couple failure modes for the simple equipment are likely:

  • Transmitter never went off, Fossett incapacitated, unable to activate
  • Transmitter destroyed with aircraft
  • Transmitter went off, no one heard it, battery dead when people start looking.

Honestly that last one seems pretty likely to me. In principle even these 121.5 transmitters can be located from satellite monitors, but false alarms are frequent and the beacon could well have been lost before it was positively identified, much less pinpointed.

The newer the equipment he had, the better off he'd be. The 406 MHz ELTs are easier to detect and their signal is cross-referenced to a plane. Authorities can immediately confirm the plane's location with the owner. The PLB's are even better.

ELTs work until their batteries go dead. I don't know how long one will sound, but you have to replace the batteries after you've used them for a continuous hour, so I suspect that the sounding time is a few hours.

A significant number downed aircraft that are in compliance with regulations are not found for years.

A little more ELT info. It seems that the NTSB just issued an opinion that all general aviation aircraft should have the 406 MHz ELTs installed. Even better, the opinion describes some of the technical differences between the two kinds of transmitters on pages 5-6 and gives a couple case studies on how the transmitters are used. You can find a copy of the safety recommendation at http://www.ntsb.gov/recs/letters/2007/A07_51.pdf.

ELTs also need to be armed. Some self-arm, but part of the pre-flight take-off checklist is to arm or ensure the ELT is armed. Additionally, ELTs can be turned off (the switch has a guard though - so it is typically only possibly to do this on purpose). Finally, ELTs are notoriously unreliable in low-G 'off airport landings' and routinely need to be activated. If Fossett suffered an incapacitating event, it is possible that his aircraft returned to earth under relative control - depending on trim and other situations. The Citabria is not a high performance aircraft and trimmed for slow cruise would not produce a disasterous nose-down pitch once the fuel ran out and the aircraft substituted rate of decent and pitch to make the trim speed (absent power from the prop).

I just know that part of the PAX briefing is always to remind them that "in the event of an 'off-airport landing' and I am unable to do so, please move the ELT switch to the 'on' position."

The new type 406 MHz ELT's referenced do represent a quantant leap forward in reliability & functionality over the 1970's vintage technology of the 121.5 ELT's. Amazingly the American Aircraft Owners & Pilots Association (AOPA) has, todate, lobbed against the mandatory introduction of the 406 ELT in aircraft on the grounds of cost even though the price of an entry level 406 ELT is less than US$1000.00

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