On Mon, Mar 24, 2003 at 07:28:41PM -0800, Bill Frantz wrote: > The simplest autopilots just keep the wings level. Almost equally common > are ones that can follow a radio location signal (VHF Onmi-Range (VOR) > usually). Altitude hold is less common, as are autopilots that can follow > an Instrument Landing System (ILS) in both azimuth and elevation.
Just got a private off-list note -- or at least that's what it seems to be, since the list wasn't copied and it hasn't shown up here. It made two points: * High end aircraft avionics can be programmed to fly an entire flight from GPS waypoint to GPS waypoint at arbitrary altitudes for each leg. * Fancy interfaces could allow someone to enter data into the autopilot via a radio link (possibly cell phone or wide area pager) for updates on the fly. The defenses against this would seem to be primarily radar and air traffic control. I can't see them being very effective if the target is a civilian government complex or non-governmental building in America's heartland, where general aviation is commonplace and airports would probably be in the close vicinity. As for something like Washington, DC? Well, security measures at College Park airport (inside the Beltway to the northeast) are strict. I couldn't quickly find a map on faa.gov, but I'd guess there are other general aviation airports within 20 miles of attractive targets in the heart of DC, much less if you count suburban ones like Langley or Fort George. If you assume that a plane can fly 200 mph, and the distance to travel is 20 miles, that's not much time for a military response. This is a different question from whether a 1,000 lb payload would be sufficiently dangerous as to cause a catastrophe, of course. Someone else pointed out that this has been discussed in a novel (wasn't aware). I hardly mean to say my prediction is unique. It's just one response to the question that the counterterrorism folks must ask themselves all the time: How to delivery a deadly payload of sufficient size to a target that's primarily defended against car bombs? Yet another reason to move out of DC. -Declan
