60,000 - 32,768 = 27,232
If one part of the system is so old that it can only handle 16-bit math and uses one sign bit, then it is limited to numbers between +32767 and -32768.
A reading of 60,000 would have overflowed its bits and registered as something in the range of 27,000 which is around where a typical jet might fly.
I wonder if this might be the cause.
Could be! Similar to the Y2K problem.
+1
If it was a standard Mode C reply to the ATC radar, it looks like they designed it to go to 126,700 ft. in 100 ft. increments.
Now if they had a problem with the D2 bit in the reply, that would happen at 62,800 ft.
http://www.airsport-corp.com/modecascii.txt
I wonder if this might be the cause.
*********************
absolutely not ,, 8 bit is FINE , 16 bit is fine , 64 bit is fine ,,, you can count to infinity with any of them ... this is (if the story is correct) an application issue , not a problem with the computer the program runs on.
Transcontinental and international commercial flights routinely fly above 30,000’. . .but below 40,000’. I’ve flown over that area in my F-15E at 50,000’. No problem.
U-2/TR-1 aircraft have been flying well above 60,000’ for better than half a century. . . one would think if that was a problem it would have manifested itself by now.
Perhaps the flight data system is maintained by the same people that wrote the software for the Big Zero’s healthcare website.
As I recall, there was one time that an EA-6B prowler switched on it's ECM systems off the East Coast, and shut pretty much shut down ATC radar all up and down the east coast.
Mark
Military air traffic out of Nellis AFB passes thu this air traffic control system every day and has done so for many many years. U-2’s, SR-71’s, RF-4C’s etc. if this were a real fault it would be happening all the time and have been corrected.
So either they had a component failure or this was human error.
I’ve been on passenger jets where the captain has announce that we will be cruising at 34,000. So a computer that couldn’t handle altitudes over 32,768 couldn’t handle routine flight operations.
Parts of the FAA system were still using x86 technology well into the ‘90s, when the company I worked for was called on to repair them. Parts were a nightmare and could take WEEKS to get, IF they could be found at all. I am sure they upgraded to at least ‘90s technology by the end of the first decade of the current century!