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Should you use a handheld GPS or an iPhone as a navigation backup?

A pilot named Heather H recently asked a great question on Ask a Flight Instructor about whether she should use a handheld GPS or her iPhone as a navigation backup. Specifically, Heather will be transitioning from a G1000 aircraft into an older plane with only a single VOR for navigation and she wrote that:

Aside from the radio and looking out the window, I’d like to have a more solid backup plan for assuring I’m on the right path.
I have an iPhone but I honestly don’t know much about iPhone apps and aviation, are there any simple apps that don’t cost a fortune in subscription fees to just verify my position or should I buy a used, handheld GPS? (It wouldn’t need to even display a sectional, weather, etc…)

Heather added that the handheld GPS or iPhone would be for backup purposes and piece of mind. In addition, she would be flying VFR with paper charts and is just looking for a simple iPhone solution for backup purposes.

Bob Watson responded by writing that he has flown 20 years without a GPS and has always managed to find the airport. Bob also thought the iPhone should stay turned off in Heather’s pocket because he knows what its like to transition from a well-equipped aircraft to a more basic one. However, he added that once she gets used to the more basic aircraft, it will be “a lot more fun.” Otherwise, Bob wrote that a handheld GPS that’s an aviation model would be easier and safer to use than an iPhone or a non-aviation GPS model.

John D. Collins then wrote that he uses the ForeFlight APP ($75 per year) in lieu of carrying paper charts but he will still carry some – including his primary and alternate approach charts. John had also recently flew from Charlotte to Oshkosh and was forced to divert to Lexington Kentucky for fuel on the way back because of bad weather. Since he did not have a copy of the approach charts on board, he used the approach charts from ForeFlight.

Finally, Jim Post wrote that he has flown for 50 years without a GPS and he has always managed to get where he was going. Jim has even used road atlases and a pair of binoculars to read water towers but he has started to learn how to use a GPS and he likes what he sees. He also added that having a redundant navigation aid does not hurt from a safety standpoint.

Garmin GTN 650 and GTN 750 product reviews

John Ewing has posted a very thorough review of the Garmin GTN 650 (MSRP $11,495) and GTN 750 (MSRP $16,995) products (as gleaned from videos and announcements of their release) on has Aviation Mentor website that is well worth reading – especially if you (like many pilots) are unhappy with the shortcomings in Garmin’s 430/530/G1000 user interfaces. In fact, John began his post by noting that:

Not unlike Microsoft Word, many of us got used to the dance of cursor-mode-big-knob-little-knob-enter and tended to forget how bad the user interface (UI) really was. To their credit, Garmin has done the sensible thing: Confronted with a bad UI that suffers from the Tyranny of the Installed Base, they started over from scratch with a touch-screen interface. While I’ve yet to actually handle one of these units, a lot can be gleaned from the videos that have been released and the information at Garmin’s website.

John then pointed out that the GTN 750 and 650 are targeting the aging GNS 530W and 430W in terms of both size and features and he went into considerable detail about how manufacturers will attempt to use as few buttons or knobs as possible to save on manufacturing costs but then overload the buttons and knobs they do provide with too many functions.

However, the new GTN units are equipped with a touch-sensitive screen plus only two physical buttons, two knobs and an SD card slot. In addition, there are grip points on the sides and on the bottom of each unit so that pilots can steady their hands in turbulence. Furthermore, there are also suggestions that there might be voice control features at some point in the future but for now, the touch-screen will provide most of the user interface flexibility.

John also noted that one of the best things that Garmin did with the 430/530 was to make a PC-based simulator available to download at no extra charge as he contends that this was one of the driving forces driving forces behind the widespread acceptance by pilots and aircraft owners alike of the 430/530 series. However, John pointed out that there is (so far) no simulator available for the GTN series but he hopes that Garmin will see that its in their best interest and in the interest of pilots and aircraft owners to provide one.

At the end of his post, John wrote that he will leave it up to aircraft owners and aviation pundits to decide whether or not the GTN 650 and GTN 750 products are attractively priced at US$11,495 and US$16,995 respectively. Nevertheless, John also added that he would definitely like to try out any aircraft equipped with either GTN product.

What happens if GPS stops working?

The more dependent we become on GPS, the greater the risk that terrorists will use it to cause disruption and damage. It also puts aviation and large parts of the economy at risk from a single point of failure.

It may not be terrorists. Those morons who point laser pens at cockpits may have a new toy. New Scientist reports that a $30 GPS jammer can kill the signal.

Even accidents and mistakes can cause severe outages. New Scientist cites several examples. For example:

IT WAS just after midday in San Diego, California, when the disruption started. In the tower at the airport, air-traffic controllers peered at their monitors only to find that their system for tracking incoming planes was malfunctioning. At the Naval Medical Center, emergency pagers used for summoning doctors stopped working. Chaos threatened in the busy harbour, too, after the traffic-management system used for guiding boats failed. On the streets, people reaching for their cellphones found they had no signal and bank customers trying to withdraw cash from local ATMs were refused. Problems persisted for another 2 hours.
It took three days to find an explanation for this mysterious event in January 2007. Two navy ships in the San Diego harbour had been conducting a training exercise. To test procedures when communications were lost, technicians jammed radio signals. Unwittingly, they also blocked radio signals from GPS satellites across a swathe of the city.

The Royal Academy of Engineering has just released a detailed report (PDF), Global Navigation Space Systems: reliance and vulnerabilities that underlines the risks. While there is a risk of gross errors, the more insidious threat is “dangerously misleading results which may not seem obviously wrong.”

A significant failure of GPS could cause lots of services to fail at the same time, including many that are thought to be completely independent of each other. The use of non-GNSS back ups is important across all critical uses of GNSS.

Is it time to consider planning a non-GPS alternative as part of an IFR flight plan. For example, could you divert to an airport with a VOR or ILS approach? Could you fly a procedure or missed approach with just a VOR and no GPS guidance? As new GPS-driven glass cockpits take over – I just flew an Avidyne R9 Cirrus to Antwerp, for example – do we need to keep our old-fashioned NDB/DME/VOR/ILS flying skills current as a backup? It’s certainly something to think about.

Writing the sky with the GPS logger

Hat tip to Steven of the A mile of runway will take you anywhere blog for noting a recent post by Lynol Amero on EAA’s Oshkosh365 Forums. Lynol planned and flew a route in his Ercoupe in order to spell out "Merry Christmas" and he captured the result with his GPS logger. As you can see from the result, it took a considerable amount of planning and precision flying to achieve:

To see an interactive version of the GPS track, simply click here.

Garmin Aera 560 Portable GPS product review

For anyone thinking of buying a portable entry-level GPS device, Max Trescott has written a detailed review of the Garmin Aera 500. Priced at US$799, users get a product with a touch screen that can be easily switched between aviation and automotive functions by pushing a single key on the screen. And for pilots who want to receive XM Satellite weather, users can get this capability with the Aera 510 for US$1299 plus the cost of a XM subscription.

Max also noted that the Aera 500 comes loaded with accessories, including a yoke mount for the plane and a separate dash mount for the car. In addition, there is a XM Weather and Radio antenna along with cables for recharging the GPS from a cigarette lighter, AC wall socket or even a USB port. Moreover, Max noted that the device comes with a stack of user manuals that are “as tall as the unit is thick and considerably larger.” In other words, the manual has the answer to any possible question you may have.

Max then wrote about taking the device up for a test flight and for a test drive in the car. After discussing its finer points, he concluded that the more he uses the Aera, the more he liked it. In fact, he said his free evaluation could prove to be expensive as he is now seriously thinking of buying one for himself.

Saved by a GPS device and a satellite

In case you have not seen the February 2010 issue of AOPA Pilot magazine, there is a great article in it about the rescue of a pilot and a flight instructor who luckily for them, both had GPS devices capable of sending emergency signals. The incident involved a Cessna 206 that had crashed among tall pine trees shortly after take-off from a remote back country airstrip in Idaho – leaving the plane owner with minor injuries and the flight instructor with more serious ones.

And while the aircraft was equipped with a 121.5 MHz emergency locator transmitter (ELT), there was no longer any satellite monitoring of the transmitter’s frequencies while the downed aircraft’s location was in an area where few planes flew over. Hence, the transmitter would only be useful if rescue crews knew the plane was lost and had a general idea of where to start looking.

Luckily, both on board had SPOT 1 GPS devices and they immediately activated the emergency distress buttons which alerted a dispatch center. The dispatch center then contacted the pair’s designated emergency contacts and confirmed the location of the crash. All told, it only took about 20 minutes to dispatch a rescue team to the site – no doubt saving the lives of both crash victims.

In addition, the article mentioned another incident worth noting where a pilot had the same device but had attached it to the aircraft’s glareshield with Velcro. Unfortunately, the force of a crash caused the device to fly into a cluster of poison oak and it took an hour for the seriously injured pilot to retrieve it. Lesson learned: Ensure that emergency devices are secured to you and NOT your aircraft.