GTN screens
5 min read

The improvement in aviation safety is astonishing. No major US airline has suffered a fatal crash since 2001. Before this incredible 20-year period, the longest stint without a major airline fatal crash was barely more than two years.

Even regional airlines that previously did not come close to the safety record of the majors are now posting a near perfect record. In the past 20 years there have been only two regional airline fatal crashes, and the most recent was at Buffalo, in 2009. That’s more than 12 years ago.

We don’t have equally precise data on general aviation safety because we don’t know the exposure—the number of flights—as we do with the airlines, but all indicators show steady improvement in the GA record, too.

Though many factors contribute to the enormous advance in aviation safety—including some great flying and a solid dose of luck in the case of Sully and Skiles in the Hudson River—the single greatest factor is development of GPS.

GTN screens

GPS has fundamentally changed the aviation safety picture.

Think about it. Before GPS we never knew our exact position and track. Of course, the ILS aligned us with the runway centerline with near perfection, but that was only for a tiny portion of the flight. And our location along the localizer track was fixed by marker beacons. Two, or at most three markers, told us for an instant our position with decent precision. Even with an ILS DME available, we only see our progress in tenths of a mile, which is little better than Kentucky windage compared to GPS.

Many of we oldsters spent much of our careers trying to fix our position with a clock. We had to estimated groundspeed and then compute that into an along track position by timing from the last fix crossing. And that fix may have been something no more precise than the intersection of two VOR radials. That seems crazy today.

The real safety improvements are the technology that flowed from knowing exact position fixed by WAAS GPS.

For example, the first ground proximity warning system (GPWS) relied primarily on a radio altimeter that looked straight down to measure height above terrain. Much better than nothing, but when flying toward rapidly rising terrain the GPWS pull-up warning would come to late. It happened to an airline crew at Cali, Colombia.

With GPS position, track, height, and velocity data constantly available, today’s terrain warning systems look ahead. The system stores a terrain map, compares that map to your GPS fixed position, track, and altitude and computes terrain clearance ahead. These systems show us areas where terrain clearance is marginal, and then if we persist in flying too low, they yell at us to climb.

GPS has also made possible synthetic vision. Now we can see not only the runway ahead, but any terrain features or obstructions nearby. Syn viz is so good, and so realistic, it’s really easy to fly an “instrument” approach using only the syn viz display. Many of us have done it in Level D simulators. I was fortunate to fly such an approach for real—with a safety pilot in the right seat, of course—with the Gulfstream test pilots when they were developing the first syn viz to be certified.

The penultimate safety advantage made possible by GPS positioning is Garmin’s Autonomi emergency automatic landing system. Autonomi—now certified in several airplanes—can, with the push of a button, autonomously select the nearest suitable runway, fly the airplane to that runway, and safely land on it.

Automatic landing has been used in airline airplanes for decades, but those Category III systems only operate on specially approved runways. Autonomi can land at any runway that has a precision approach such as an LPV or ILS. Incredible.

iPad traffic

GPS means more than just present position; features like traffic alerts would be impossible without it.

GPS also makes possible traffic warning derived from ADS-B position reporting. The entire ADS-B system depends on GPS position fixing in each aircraft. Because ADS-B automatically reports each aircraft’s position it’s possible to compare those positions and altitudes and calculate a collision threat and issue a timely warning.

Another very important GPS-enabled safety feature is weather in the cockpit. The images of Nexrad radar come down from the satellite to our airborne receivers, but without the precise GPS position fix we couldn’t see our location relative to the radar returns. I know, there are latency issues between when the radar tracked the weather and when we see it, but still, Nexrad radar in the cockpit is a huge safety advantage we oldsters could never have imagined just a few years ago.

GPS has also contributed to safety in some smaller, but significant ways. For example, fuel planning. We always had the clock to keep track of fuel burned per hour, but with GPS we know with precision fuel burned per mile. And exactly how many miles to the destination. And precisely where any suitable diversion airport may be. There was little excuse for running out of fuel before, but with GPS, there is absolutely none left.

I still see student pilots lugging around sectional charts and E6B computers and plotters. Maybe that’s OK, kind of like new sailors learning to tie a bowline. And maybe it will teach new pilots what we oldsters already know—GPS is the best thing to happen to aviation safety ever.

Mac McClellan
28 replies
  1. pat c
    pat c says:

    Mac, from my perspective as a 67 year old pilot who started flying with his private pilot father at age 3, I would agree with you that GPS may be the single best advancement in improving aviation’s safety record. I still vividly remember the mild panic of not knowing exactly where I was on one leg of my long solo cross country, when I was 17 years old, as unforecast raindrops from the clouds above started hitting the windscreen of my little Cherokee 140 trainer. There was a lot of chart and VOR fumbling until I finally figured out approximately where I was and was just dumb lucky enough to land at Santa Maria (the correct airport) and not Lompoc (the wrong one) along with somehow avoiding the Vandenberg AFB airspace. My old school instructor felt that VOR navigation was a crutch and that pure pilotage needed to be mastered first. I also fondly remember being a passenger in a commercial 737 headed to Anchorage from Seattle in 1996 after I purchased my first handheld Garmin GPS90. I had the suction cup antenna stuck to the passenger window and the flight attendant asked me what it was. I shared with her that it was a GPS and told her exactly how far we were from Anchorage and exactly what our ground speed was. She came back 5 minutes later and said that the captain wanted to see what magic I was using that was so accurate. I was ushered to the front of the jet and the captain came out of the cockpit to see this new device which was not then part of his fancy panel. Fast forward to today, I fly behind a Collins Pro Line 21 which provides amazing situational awareness along with my iPad mini which is velcroed to the center of the yoke utilizing Foreflight for charts and a plethora of other things. It is still quite amazing to me that the $2000 combination of the iPad connected to the Stratus with the built in AHARS and Foreflight synthetic vision is arguably more capable than the multiple hundred thousand dollar Collins Pro Line, all courtesy of the GPS technology. It certainly is nice to have as a stand alone back up system if needed. And that is just the tip of the ice berg when it comes to what GPS has enabled. ADS-B traffic, weather, fuel planning, descent planning both normal and on RNAV arrivals, and much more. Flying today may require a little more technical learning but it is oh so much easier/safer than it was when I was 17 years old.

    • Stephen Phoenix
      Stephen Phoenix says:

      When I stuck the antenna of my new Trimble GPS to the passenger window, they told me to turn it off: “It might be dangerous”.

  2. Kim Hunter
    Kim Hunter says:


    I agree with every word of your article.

    I think this safety comes at a price for student, and newly minted pilots though. For us older pilots, the first exposure we had to real adversity in flight was getting lost. We had to calm ourselves, take stock of our tools (ADF, VOR, paper chart …), formulate some kind of plan and have the discipline to execute. I have (not fond) memories of getting well and truly lost on a couple of occasions.

    Getting lost is not an emergency. But for generations of fledgling pilots it helped solidify the emotional equanimity and mental focus needed to deal with the real emergency that would invariably come.

    • Ed Ruebling
      Ed Ruebling says:

      I remember on one of my X countries in the late 80’s I overcorrected for the wind and got off course. Ended up flying over an airport with it’s name printed on the tarmat to determine where I was. Watertowers work good too.

  3. Jim Kilpatrick
    Jim Kilpatrick says:


    Another great article that only years of experience can provide this prospective. I agree and still amazed with the technology available to the average pilot. In my little RV I have Dynon Glass panel, color weather, traffic, WAAS GPS and a coupled auto pilot. Much advanced from the the B-777 I flew before retirement. I agree this GPS the foundation but for me, just as important is the in flight weather. I am now comfortable knowing what is ahead and I can avoid it or land with total confidence knowing I have the knowledge to make the correct decision.

      Mac MCCLELLAN says:

      Hi Jim,
      I agree that having near real time weather in the cockpit has changed the way you and I fly GA airplanes. And all for the better.
      The key to the weather is two satellite technologies. The extremely powerful Sirius/XM satellites send down the weather data, including the radar image. Then our onboard equipment uses our GPS fixed location to position our own ship display in the correct position relative to the radar image so we can make accurate avoidance decisions.
      That we can receive so much data with such a tiny antenna is truly a miracle of technology.
      Mac Mc

      • Patrick Bailey
        Patrick Bailey says:

        Great article Mac! I too grew up on the E6B, Sectionals, and the dreaded NDB approach. As an aviation trial lawyer I still handle tragic crashes that could have easily been prevented modern with now, ancient technology. Thanks again.

  4. Greg Johnson
    Greg Johnson says:

    I completely agree with you, and the others comments. As a professional land surveyor and civil engineer I was an early adapter of GPS technology around 1989, and it significantly changed the surveying and geographical information business in tremendous ways. When I restarted flying in 2005, bought my first airplane, and installed a GPS navigator I then earned my instrument rating in it. My instructor would see my huge smile while I was under the hood on approaches as I explained how fascinated I was that this box was computing the pseudo glide scope and localizer every second what took us two hours to complete each vector solution on a 486 laptop! GPS certainly has become one of life’s pleasures.

  5. Cary Alburn
    Cary Alburn says:

    I think all of us older pilots (older both in age and experience) have to agree that the technology of today, including GPS, is absolutely amazing compared to what it was when we learned to fly. For me, that was in late 1972, with my private check ride in February 1973, in Anchorage. Although my little Cessna is 59 years old this month, and it’s by no means as well equipped as some, I have in-cabin weather, certified GPS WAAS, and the capability of knowing my exact position both horizontally and vertically at almost any time—so much more capable than the so-called “fully Kinged” 182 that I took my instrument training in back in 1975, and much better than virtually any airliner of that era. I can look on a screen and see not only the weather around me, but the traffic around me, much more clearly than by looking out the window (although I do that, too!)—and if the traffic or terrain gets too close, I have a disembodied voice telling me so in my headset. Oh, and with my headset on and turned on, my otherwise noisy little airplane is as quiet as most cars. All that’s pretty remarkable. Now if I can just keep my body updated and functioning as well as my airplane does, so that I can be sure of joining the UFO Club in a couple more years, that would be close to magic! [UFO=United Flying Octegenarians]

  6. Mike
    Mike says:

    “…sectional charts and E6B computers and plotters. Maybe that’s OK, kind of like new sailors learning to tie a bowline. And maybe it will teach new pilots what we oldsters already know—GPS is the best thing to happen to aviation safety ever.”

    What happens when the electronics fails? GPS is obviously great, but new pilots should always be taught what we oldsters know – chart navigation, and practice it! That also means learning the math and using a watch.

    • Kurt Kleiner
      Kurt Kleiner says:

      Your point is exactly spot on. Thank you for that contribution to this discussion. Another reason why we still see students “lugging around a sectional and E6-B” is because pilotage and dead reckoning are still tested on the Private Pilot knowledge test and practical test (check-rides). It sounded a bit demeaning the way it was written. In addition to what you wrote, I believe DPEs still need to evaluate a private pilot applicant’s knowledge of how ground speeds, wind correction angles, and magnetic headings are derived after applying the winds aloft (speed and direction) to one’s flight planning. I know this is true, since I send students to check-rides as an active (but older) CFI. I advise my students that, once they have their private pilot certificate, they can push a “Direct To” button and follow a magenta line as much as they want to, but that they still need to know their exact position by looking outside and down, and find/know their position on a chart. They also need to know the location and approximate heading and distance to the nearest airport or suitable landing field in the event of an emergency, with or without relying on a GPS to tell them. This way, they are well prepared for the day when the I-pad overheats or the GPS system is shut down by the military. I explain that, when we say pilots should always have a “Plan B” or a “way out” of any adverse situation that arises, this goes way beyond escaping a box canyon in the mountains or escaping bad weather or icing by making a U-turn. The same goes for using VORs if one is installed in an aircraft. Why not be proficient in its basic functions as a back-up navigation tool. One principle of Single-pilot Resource Management (SRM) is to be proficient in the use of all available resources to help us fly safely and successfully out of a potential problematic situation. Although I fly with an I-pad and Foreflight, I will continue to carry a paper Sectional as my backup as long as they are still published, and I never stop looking outside and below for the best available emergency landing spots.

  7. Bruce
    Bruce says:

    I totally agree with the article and comments above regarding GPS and it’s derivatives being the most single factor in achieving impeccable aviation safety. Ranking below GPS, but also contributing the flying safely, would be procedural management. When I first learned to fly, too many moons ago to count, SOP’s were never heard of in Part 91. Maybe it’s because of GPS and advanced avionics, and better auto-pilots, that we now have the time and ability to practice and execute SOP’s and flying by the numbers, rather than being overly focused on determining where we are. A great article!

  8. Loren Jones
    Loren Jones says:

    I can’t argue with your major point, but still teach E6B and paper charts to newbies as foundational information to understand what their gee-whiz iPad is doing behind the scenes. I addition to GPS, I’d rank the iPad as next in line for safety, helping pilots economically realize the benefits of the GPS technology while making CURRENT charts available easily and all the time. Together they comprise a quantum leap forward in GA safety.

  9. Phil Hertel
    Phil Hertel says:

    Good article EXCEPT “—including some great flying and a solid dose of luck in the case of Sully and Skiles in the Hudson River—” had nothing to do with GPS and everything to do with professionalism, knowledge, experience, and skill.
    Cheers, Phil

  10. Brian Lloyd
    Brian Lloyd says:

    GPS is the best thing to happen to aviation safety ever … until it isn’t there. I have had GPS go away on numerous occasions, including several times on long over-water flights. Why? No clue. I have had times where, for whatever reason, the ephemeris in the GPS hadn’t updated. Sometimes it is NOTAM’ed ahead of time and one can plan for it. Sometimes it is just … WTF? And it isn’t the receivers as it happens to all of them at the same time. If one has a lot of glass from different vendors, i.e., Aspen, Avidyne, L3, plus an iPad running Foreflight, it becomes clear that the failure is external, not internal. In one over-water case the answer was ADF/NDB.

    So what’s a girl to do? The ability to maintain spatial situational awareness is a crucial skill. The ability to transition to VOR, ADF, vectors, or even ded rekoning, as I had to do a couple years ago when IFR over the SW and encountered both a GPS and VOR failure. (“Hey Center, looks like GUP is off the air. I need a vector to PGE.”) We become so wedded to and dependent on GPS that when it goes away, and it goes away a LOT more often than we are led to believe, we are unable to cope.

    Don’t get me wrong, I love GPS. I love the terrain and obstacle database. But I also know how fragile GPS is and how easily it can be made to go away. Slavish dependence on GPS is going to cause someone a problem some day but that person is not going to be me.

  11. Joe Brown
    Joe Brown says:

    I agree with article, but at times we can become too dependent. Even children of the magenta line need some backup if form of use of charts, pilotage.
    Attended a seminar last month and the scenario was a IFR flight in SD with some mild ifr weather. pilot lost his IPAD due to a bad charging cable. The 4 possible solutions involved continue flight., climb to 25,00 to get above only had o2 by nose clip , drop to, 2000 to try to be below and land to recharge ipad.

    Suggested solution was continue flight. Out of some 40 pilots only two of us said continue. Other pilot was 92 and I am 80.

    We should use everything we have available, but we should not become too dependent as anything can fail at a bad time.

  12. Stephen Phoenix
    Stephen Phoenix says:

    As an instructor, I too have wondered about the value of time spent on E6Bs and pilotage. I doubt that anyone could whip out an E6B and plotter after a GPS failure and save the day. Other backups like a cellphone and aircraft electrical system seem more plausible. Time would probably be better spent learning modern backup systems.

    But while we’re using GPS, what about that deep seated need for magnetic compasses and courses? The GPS has to back calculate it and the rest of us just care about the ground track. Seems like if the GPS is reliable enough to go without a chart and plotter, we could also go without a compass.

  13. Michael Leeds
    Michael Leeds says:

    Thanks for the great article Mac. This one and all of you’re leadership over so many decades.

    You mentioned that Garmin’s Autonomi is the penultimate safety advance. What’s the ‘ultimate?’ Full autopilot from startup or at lining up on the runway?

      Mac MCCLELLAN says:

      Hi Michael,
      I think you’re probably right. We’re not there yet, but reducing the direct human involvement with actually flying the airplane–manipulating the controls–is I believe the ultimate in risk reduction.
      About 15 years ago I was in Israel to fly the new Gulfstream G150 that was built by Israeli Aircraft Industries (IAI). We had some time so IAI offered a plant tour, including a visit to the company’s drone design and manufacturing facility. Israel and IAI are acknowledged leaders in development and deployment of drones for military missions.
      The person in charge of the drone program told me they learned early on that they had to keep real pilots from “flying” the drones during a mission. He said human pilots made quick decisions and too often screwed things up.
      Instead he said IAI programmed the entire drone mission into the aircraft before launch. The program could be changed in flight, but only with a new program, not by direct control inputs by a pilot on the ground. He said they had vastly increased success using this technique.
      So, at least in one pilot’s view, humans degraded the success of a mission. And this fellow, like many at IAI, was an air force fighter pilots and had flown real combat in more than one of the country’s wars.
      Mac Mc

  14. Tom
    Tom says:

    It is hard to dispute the value of precisely knowing your location and the ability to predicted where you will be next. We should not forget the underlying computer and information technology that makes these improvements in flying safety possible. This same technology also provides and helps manage information about airplane systems and weather. It suffuses nearly all aspects of our lives including driving, health care, work, and leisure. We can now have a pretty good flight in just about any airplane with little or not cost right in front of our computer without leaving the ground. This trend is only going to continue.

  15. Ray Nord
    Ray Nord says:

    Mac, Thanks for yet another great column. GPS (and derivative technologies) have indeed changed flying and aircraft safety and we are all so much better off as a result. But I continue to hear comments from seasoned pilots, instructors and FBO folks that there is a new breed of GA pilots who are quite cavalier about what might happen and what they will do in the event of equipment failure or other unforeseen problem If true, it seems that there will need to be changes in the flight review syllabi more focussed on “whatif” scenarios and perhaps not so much on all the maneuvers that we were all expected to demonstrate. You did not mention it but another beneficial effect of GPS is in locating people who did not get to their destination for whatever reason and to help in the analysis of aircraft accidents. Keep the good stuff coming and cheers to you and Stancie.

      Mac MCCLELLAN says:

      Hi Ray,
      Thanks for the kind words. Of course you’re correct about the need to practice and prepare for failures of all types in flight.
      At the upper end of GA, and the airlines, that’s exactly what happens. Very little of your time in simulator training is spent with everything working. Engine failures are dramatic to practice, but equipment and system problems are also teachable moments and remind us of what we may have forgotten about how our airplanes function and how to deal with the unexpected.
      Light GA pilots can also benefit from regular equipment and system failure review and practice.
      Mac Mc

  16. Danny
    Danny says:

    Yep…way back when we received our first handheld Apollo model, on a ferrying helicopter flight on a multi state cross country (of course backed up with charts), make sure both crew members are trained and proficient on the instrument. Climbing out of Little Rock, departure asked for on course heading VFR…just swapped PIC, I was flying the hand computed course, and asked crew for the exact GPS (going pretty straight) destination heading….he says “Just a moment”….I tell controller same….asked crew again, same response….controller asks again…..crew leans over to show me the Apollo and says, “How do you turn this on?!” There’s your sign!!!

  17. Sebastian Massimini
    Sebastian Massimini says:


    Penultimate means “next to last” according to Merriam-Webster. How does that apply to Garmin’s system? Sorry to nag, but look it up. ;-)

    But I do agree that GPS is the biggest thing for aviation in the past 20 years–but it does not explain the accident reduction.



      Mac MCCLELLAN says:

      Hi Vince,
      It is next to last, with the last being full autonomous flight.
      Another meaning of penultimate is the latest in a series of events or developments, with more expected to come. That is closer to what Garmin’s achievement represents–more to come.
      Mac Mc

  18. Gursel Ozal
    Gursel Ozal says:

    GPS is definitely a great safety improvement providing convenient and accurate situational awareness during flight. ILS is also very accurate and reliable precision approach instrument, at the final approach phase. Localizer and glideslope signal to noise ratio improves greatly as aircraft approaches the transmitters during final approach and this ensures reliable and accurate approach to the runway. GPS signal has to travel long distances and and therefore much weaker signal. It may not have the same reliability at the critical final phase of the approach in very low visual range.


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