Look Out! Avoiding Terrain and Obstructions

looking out my window and I see a looming dark mass I thinking you know there's something out there so we we just climb as best we can because we know there's mountains right in front of us and we can't see anything because we're in the clouds something does not feel right you know I'm looking at my airspeed and I'm doing my normal 60 the GPS was showing a ground speed of 120 see fit if you're not familiar with the term it stands for controlled flight into terrain what it means is flying a perfectly good aircraft into the ground for one reason or another for a lot of us these accidents fall into the can't happen to me category we were we were way too high too close in and way too high but we felt like you know yeah we can't do anything right but although see fit is fairly rare there are scenarios where it's easy to get taken by surprise some of which we'll highlight here fortunately you can avoid virtually all of them just by being aware of the issue and stopping to think about potential trouble spots prior to flight let's start with the big picture then zoom in maps whether they're printed on paper or displayed on a screen are literally the big picture and the information they contain is the best tool you have for obstacle avoidance as maps have transitioned into the digital world they've also gotten smarter modern flight planners for example display your route of flight directly atop the chart and some offer a profile view showing in detail any potential conflicts with terrain of course most pilots already fly with GPS and most units are able to display terrain in relation to the altitude of the aircraft the same capability exists with tablet computers and even phones usually for a lot less money than aviation specific devices and often as part of the same app that handles flight planning whatever your particular setup and many are low cost or even free the terrain awareness these tools can provide is invaluable so display options aside what should we be looking for first and most obvious is the graphical depiction of terrain mountain ranges and other large-scale features are visible at a glance and along with the terrain color coding lets you know generally what to expect second is the NEF or maximum elevation figure this is the highest obstruction within each grid sector plus a little slack it's useful for altitude planning purposes and it's a good thing to be aware of should you ever need to know at a glance whether you're high enough to clear terrain man-made obstructions like communication towers can cause issues as well there are monsters lurking out there as high as 2,000 feet AGL that's well within VFR weather minimums so you don't have to be Scud running to hit one keep an eye out for the bigger the two tower symbols and remember that even huge structures like these can be difficult to see under certain lighting and visibility conditions oh and remember that missing the tower isn't enough you also have to miss the much larger array of guy wires which can be virtually invisible the wind farm is a more recent phenomenon new ones pop up all the time covering thousands of acres with massive turbines blades slicing 400 feet into the sky that may not sound very tall but when you consider that turbines are often situated on ridge lines another high ground well you get the picture you have an app that has terrain awareness that's an excellent tool to use in preflight planning and in route awareness situational awareness understand where things are going to be even a handheld GPS with some additional terrain information would have been you know much better than just trying to figure it out via a sectional and a airport facility directory entry now let's zoom into the most critical spots for obstacle avoidance the arrival and departure areas there are two important questions here one are there any tall structures or terrain in the immediate Airport area and - are there any reasons why you'll need to either descend earlier than normal before landing or delay your normal climb after takeoff the first question is answered with a combination of sectional and or terminal charts Airport diagrams and the chart supplement formerly known as the AFD we're looking for terrain features tower symbols and altitudes and notes about either what about the second question is there any reason to descend early or delay climbing for VFR pilots invisible obstacles like Class B airspace shelves can easily lead to terrain or obstruction conflicts so can weather a low cloud deck for example that's where you need to pay attention to that smallish Ridge line or tower you might otherwise have skimmed past chart notations can also provide important clues for example if you see RP or write pattern in the airport information block pay a little more attention one of the reasons airports use right-hand patterns is high terrain now I think I would get on Google Earth or another satellite map company and and you know if I can put myself on the ground there and then do a 360 degree spin just to see what might be out there maybe even getting on a flight sim and just taking a short flight into that Airport just to see what's there and that would be very helpful IFR flyers still want to look closely for obstructions but in most situations where there are special issues they have the benefit of defined procedures obstacle departure procedures or ODP s to be exact these provide specific routes altitudes and climb requirements even in visual conditions following the ODP ensures adequate obstruction clearance which is always good to know especially if you're unfamiliar with the area and of course VFR pilots can use them too for IFR arrivals the best strategy is a thorough approach briefing familiarizing yourself with critical altitudes and being fully aware of the arrival and missed approach procedures one quick reminder absent specific instructions from ATC you're required to be established on the approach before descending to a published altitude on the procedure that means being on one of the heavy dark lines on the approach plate flying at night has numerous disadvantages from an obstruction avoidance standpoint some less obvious than others for example some nights e-fit accidents happen because the airplane hits the ground short of the intended runway this typically happens at isolated airports where the runway lights are the only lights the so-called black hole approach there are two main items to look for here first when flight planning take note of the airport surroundings and runway equipment the type of runway lights whether their pilot controlled and whether there's vertical guidance if it's out in the middle of nowhere be on guard be even more on guard if there's no vertical guidance like Vasi or pappy if there isn't and your instrument-rated it's worth looking to see whether the runway has an approach with vertical guidance you can use as a backup if there's nothing it may be better to wait for daylight another nighttime concern is the relative width of the runway be on the lookout for runways that are unusually narrow for their length for example you might see one that's over 7,000 feet long but only 75 feet wide at night absent other visual cues your brain will tend to interpret that skinny shape as an indication that you're high on the approach to make the sight picture match what you're used to you'll tend to fly a lower glide slope sometimes right into unlit terrain even more than normal if something doesn't feel right about an approach at night be ready to throttle up and go around sometimes pilots run into terrain not because they didn't see it but because they couldn't avoid it particularly in mountainous areas high-density altitude means anemic aircraft performance the severity of the hit often takes pilots by surprise and leaves them little or no ability to cope with additional factors like icing and down drafts in that thin air you perform at your craft is so diminished you better have an out because you're not gonna have power this was not one of your options if you fly any amount of time in the mountains and even relatively bigger equipment 185's are curved and it still happens so you've got to be an aviator such that you have a way to get out of that descending air issue time spent with the poh helps but you'll find that seeing a 50% longer takeoff distance on paper and experiencing a 50% longer takeoff role in the cockpit are two very different things high-density altitude does more than just increase your takeoff role and reduce your climb rate because true airspeed increases relative to indicated airspeed at higher altitudes it also flattens your climb gradient the altitude gained for every mile over the ground that means long climbs big wide turns and a temptation to climb at dangerously slow air speeds because it feels like you're going faster add it all up and it's easier to see how pilots end up crashing into mountain sides in broad daylight to be able to do a box turning in a canyon it is it is frightening for most people until they actually see how close you have to come to the rocks to make that work so I recommend and really recommend there are some really great trainers various flight instructors out there get the experience from somebody that's been there and done that see fit accidents are really not very difficult to avoid but staying safe does mean thinking ahead and actively considering the possibility of a mishap we've been holding and we were tired and all those factors together get into that judgment decision the hindsight we wouldn't have done are you flying to an unfamiliar Airport at night shooting an approach to an airport in hilly terrain flying VFR under a low cloud deck scenarios like these are when your internal terrain awareness alarm should be going off take your time consider a few what-if scenarios and use the resources available to you you'll get there safely and spare yourself any uncertainty along the way

Channel: Air Safety Institute

Views: 106,951

Keywords: airplane, airport, pilot, safety, risk management, decision making, flight plan, vfr, ifr, air traffic control, flight safety, safety tips, flight training, aviation safety, general aviation, cfit, collision, terrain, mountain

Id: 3GIubG1cgQA

Length: 11min 40sec (700 seconds)

Published: Thu Jun 23 2016