Lynn Kelly, president of Kelly Aviation company of Grenola (KS), had something so new at Oshkosh that the website wasn't ready: the PCM-1000. He pulled our reporter over to show him...

What's a PCM-1000? It stands for "Personal Cabin Monitor," but it's more than that: it's a shirt-pocket-size timing device, hi-lo altitude bug, altimeter, density-altitude meter, hypoxia alert thingie, with an AGL feature in it, too. All this, and it's about the size of a couple beepers stacked atop one another.

Developed as a result of the Payne Stewart accident...

NASA developed this, and has made it available to the public through Kelly as a licensee, in part due to the type of accident that killed pro golfer Payne Stewart, whose chartered Learjet lost pressure and continued on its autopilot-guided path, after all aboard had lost consciousness in a depressurization accident nearly four years ago.

This 6.3 ounce (with two AA batteries) machine can alert a pilot when he's approaching a hypoxic condition, or keep him warned if he strays outside a pilot-preference altitude window. It's also an accurate altimeter, set to either standard or actual pressure.

If a pilot flies at 12,500 feet for half an hour, a vibrator, light, and warning tone all go off, to remind the pilot that it's time for auxilary oxygen. If 14,000 feet is reached, the same thing happens.

At lower altitudes, the PCM-1000 can help you not bust airspace. It can be set to keep you between two altitudes, programmable in 10-foot intervals. Try this: set the altimeter to the barometric pressure, and cross-check with your aircraft's altimeter, just to be sure. That will show where you are. Now, set the altitude below which you don't want to fly; then the altitude above which you do not want to fly. If you stray outside those limits, the PCM-1000 will vibrate; and light and beep intermittently, until you either reset it or get back into your altitude envelope.

It checks altitude 100 times a second; and it can be used as a backup altimeter, as well; or as an "AGL meter," for local flights, balloons, or gliders. It reads altitude in 3-foot increments, too; so "off-label" uses -- mountain and canyon climbers,  for instance -- find it useful. Race car and motorcycle tuners have used this device, as well, to map their engines to the track's density altitude.

If you fly in a pressurized cabin, it's a great monitor, to make sure your cabin altitude isn't climbing. for instance, if you have an 8000 foot cabin, and you set the altitude alert to go off at 9000 feet, you'll have plenty of time to react to a pressure drop. A slow drop in pressure, over a long flight, can be an insidious killer.

Since it's as portable as your shirt pocket (it also has a belt hook), the PCM-1000 could be used by the motorcycle racer who climbs mountains to reach the airport -- and it would be useful all along that trip. Since it's so accurate, it's a viable backup altimeter, too.

The small but readable face has a backlight; with "the worst AA betteries we could get," Mr. Kelly told us, "it will go 50 hours or so with the light on. Those AAs seem to last at least 3 months in normal use, too."

At Oshkosh, Kelly told us that the website price is introductory, and fifty bucks cheaper than the MSRP of $450.

FMI: www.kellyaviation.com