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Can GPS get you lost?

 

The answer is yes.

Many of us have become very dependent on these little gadgets. They provide a lot of information and are very accurate. They can however, fail. They can lose satellite coverage and batteries in portable units can die.

One B.C. pilot on a flight from Vancouver to Nelson, B.C. had to fly low through the valleys due to cloud cover. He was unable to use his GPS as satellite coverage was sporadic throughout the flight. He didn’t get lost but he had to rely on map reading, at which he had become very rusty.

We should always be in a position to navigate by means other than GPS - such as by map, VOR or ADF. This means that we must always know where we are on a map, VFR or IFR.

When the GPS stops giving us information, the natural tendency is to play with it to try to get some of the GPS information back. While we are doing this, we are not paying attention to where we are. When we revert to map reading, nothing looks familiar.

A PA 28-160 Warrior was flying in the Yukon when his GPS stopped giving him information. He became disoriented while trying to locate his position on a map and started to run low on fuel. His radio transmissions were heard by a PA 31 Navajo pilot who relayed the call for help through the nearest FSS.

The Navajo pilot also cancelled his IFR clearance and tried to locate the Warrior pilot. The warrior pilot eventually found a highway and landed on it.

In Canada’s far north, airports can be a long way apart. Time spent searching for a position fix can deplete the fuel supply to where the destination can no longer be made. Highways and roads that may be suitable for landing an aircraft are also few and far between.

A C-172 pilot in southern Ontario neglected to carry spare batteries with him and became disoriented as to his position after his GPS lost power. He was able to transmit his distress to an FSS where the specialist gave him a Toronto Area Control Centre frequency. The Toronto Area Controller provided radar vectors to an airport for a safe landing.

A PA 28-140 in northern Ontario lost satellite coverage for his GPS and became concerned as to his position. He was able to contact an FSS by radio and request a VHF DF steer to the airport. He was asked to give the FSS specialist a 10 count so the specialist could home in on his radio signals with direction finding equipment and give him a heading to the airport. Not all FSSs and Control Towers have this equipment.

There have been enough GPS failures in IFR flight that many IFR pilots keep their VORs and ADFs tuned to the nearest VOR and NDB frequencies so they can switch means of navigation quickly. It is a good practice for VFR pilots as well if VOR or ADF equipment is installed in their aircraft.

The VOR or ADF can be used to home or track directly to a VOR station or to an NDB. You can also use the VOR radial or NDB track from the station to help locate yourself on a map.

ADFs can be tuned into any AM radio station as well as NDBs. Local AM radio stations are often indicated on VNC maps.

If you need navigational assistance and you are unable to contact an FIC, FSS, Control Tower or Area Control Center, climb as high as the weather allows and keep trying. You can select 7700 on your transponder and monitor 121.5 and someone will contact you. Make some calls for assistance on 126.7 as well, aircraft flying in the vicinity may hear your transmission and relay your request for assistance.

If the worst happens and you become "uncertain of your position" (it would never do to admit you were lost), note the time you last knew exactly where you were. Estimate the distance you would have flown in the time since then and draw an arc on your map across your approximate track. You should be somewhere close to this arc.

Look on the map for readily identifiable features and then look outside to locate one (watch, map, ground). If you try to look at the ground first for a feature and then the map, you won’t know where to look on the map as you don’t know where you are and you will just confuse yourself further.

None of us want to admit to being disoriented or lost, but the sooner we ask for help, the more fuel we will have to get to a safe place to land. FIC specialists, FSS specialists, Tower Controllers and Area Control Centre Controllers are there to help. Use them if you need them.

You are never lost if you don’t care where you are. Most of us though, do care.

Dale Nielsen is an ex-Armed Forces pilot and aerial photography pilot. He lives in Abbotsford, B.C., and currently flies air charters. He still freelances as a flying instructor and seminar facilitator. Nielsen is also the author of seven flight training manuals published by Canuck West Holdings.

Got an aviation safety story to tell? Dale Nielsen would like to hear from pilots who have educational aviation experiences to relate. Excerpts from these stories will be used in upcoming safety articles. Dale can be contacted via e-mail: dale@flighttrainingmanuals.com.