This happened about 15 years ago in South Africa. My wife, two children, and I were launching on a three and a half week flying tour of South Africa, Botswana and Zimbabwe arranged by Hanks Aero Adventures of Johannesburg. I had spent two days getting my South African pilot’s license and we were ensconced in a rented Cessna 206 with a cargo pod and STOL kit. For navigation, we had an extremely thorough trip package prepared by Hanks plus the latest Garmin GPS. In addition, we had the US Department of Defense paper charts which are about all you can get in some parts of the world.
Leaving Johannesburg, our first stop was a camp called Tuli Block, a private game reserve about 300 miles north across the Limpopo River in Botswana. It was a dirt strip bulldozed out of the bush and three to four miles away from the camp itself. The instructions were to find and buzz the camp and a Land Rover would be sent to pick us up.
I punched the identifier for Tuli Block into my GPS and it came up, instructing me to fly a heading of 273 degrees for 300 miles, which would put us well into the Kalahari Desert searching for a non-existent dirt strip in the bush. Not a good outcome. Thinking I had made an entry error, I reentered the identifier and got the same result. Third try? No change. I handed the GPS to my son who is also a pilot and he repeated the process and got the same error.
So we pulled out Hanks’ trip pack, entered the lat/long coordinates of Tuli Block, found the right course and were on our way. Even so, when we arrived at the destination, it took five minutes or so of looking to locate the dirt strip and camp. If the erroneous database had been off just a few degrees instead of 90 degrees, I would have failed to recognize the error and we could have searched the bush until our fuel ran out with no luck.
That night I sat down with the GPS and cross-checked each identifier of each camp we were to visit against its lat/long and verified the accuracy. When we got back to Johannesburg I checked my GPS against Hanks’ and found the same error for Tuli Block in his database.
A freak occurrence? Two years ago my son and I were flying his Bonanza to northern Saskatchewan for a fishing trip on a remote island. Our last fuel stop was a place called The Pas in Manitoba. Leaving Winnipeg, we entered the identifier for The Pas and it looked to be about the right heading and distance, so off we went. Seventeen miles before arriving at the GPS destination, we flew over a town and airport that looked suspiciously to be the right place (there aren’t a lot of towns and airports in this part of the world) but we continued on to the GPS destination with the predictable result – lots of trees and bush but no airport. We turned around and returned to The Pas where we refueled and continued to our destination.
Suppose we had been IFR? Suppose The Pas had been overcast and we didn’t see it? This was exactly what scared me in Africa – a small but potentially deadly error. Fortunately there was an alternate within reach of our fuel supply but once again a bad database could have produced disastrous results in a wilderness. We go to remote places – from the Arctic Ocean to the Amazon – there isn’t much room for error and twice is two times too many.
How do you protect against a database error? We’re all flying on Jeppesen data so I guess if you’re going to an unfamiliar, remote spot, all you can do is double check against the lat/long and hope that the data used for moving maps comes from a different source.