The survey of pilot opinions about the perceived effectiveness of the "see and avoid" approach to midair collision avoidance is timely and important. But there's a problem with taking pilot opinions about such a matter as evidence about anything other than their perceptions of a situation whose reality may be, and I submit is, very different. You see, I've concluded that "see and avoid" is a misnomer for an approach that could be more accurately called "big sky dumb luck," or perhaps "dumb luck" for short. It's not hard to show with elementary geometry that "see and avoid" is outright impossible in many common situations, both in the pattern at approach speeds and out of the pattern at cruise speeds. The problem is especially acute when planes are coming head on, where for either aircraft, the visual angle subtended by the other oncoming plane remains very small until about 5 seconds before impact, and when planes are climbing or descending at differential approach speeds in the pattern, where the other plane cannot be seen by either pilot before impact. How many pilots have never seen the planes that ATC called for them, thankfully glad to finally hear ATC call "no factor"? Any pilot with moderate cross country flight time has had this experience as well as the experience of unexpected "close encounters," shall we say. It's time to move into the 21st century with reliable "see and avoid" sensing and alerting technology in the xxxxpit, rather than mere "dumb luck."
All Comments
95% of the time I can find the traffic. There are usually extentuating cirxxxstances when I can't, like it just IS NOT where they said it is(in a static world it might be), or that there are terrain factors that make it very hard to spot traffic. I had to pick out a cessna today when I was at about 8,500 and this cessna was below 6000ft where the terrain is flat and 5000...it was silver and most of the distance was due to altitude, it really looked like a car, and when transposed on a road, impossible to tell otherwise.
I think there is a lot lof "luck" or "odds" going on that are pretty high that conflicting traffic will eventually "see and avoid", but my point is that these odds are no where near good enough, and I think that "big dumb luck" is unfortunatly part of the equation, "see and avoid" seems unrealistic at times.
Speaking of oncomming traffic, we have parallel runways and sometimes when you roll out on base you roll out EXACTLY at the same altitude and distance as an opposing aircraft going for the parallel runway. I'll tell you what, it is a pretty "interesting" picture that makes you pretty apprehensive and edgy. Especially when it's a nice big twin with all of it's lights on, you surely don't miss it, but every single time you hope to god he doesn't overshoot and makes his turn at the right time.
I don't see midairs as anywhere near the greatest risk in GA. Nope, there are many higher risks, such as flying when there is rapidly changing convective activity, flying when ill, tired, upset, rushed, and so on. But I think we've reached a point where there is NO single factor that accounts for much of the total risk, whereas the total risk remains admittedly high and worthy of analysis. The problem from a statistical probability point of view is simply this: there's an astronomical number of risk factors, each associated with a small but finite amount of risk. The sum of this large number of small risks is substantial, and the only way to reduce the overall risk now is to tackle the individual small risks one by one. Sorry about this lengthy post about what's probably obvious. Back to midairs: based on my own recent review of NTSB data, I think the current annual average number of GA midairs is 12-16 per year, involving 24 to 32 aircraft per year, depending on how the annual average is computed. A surprising number of these aircraft involve no fatalities, perhaps half or so. But of all the risks we face, this is one of the easiest to virtually eliminate - as the airline industry has done - through dirt cheap technology beginning to become standardized, reliable, and acceptable.
yes, but one of the first things that anyone studying saftey learns is that the numbers don't mean a whole lot. It doesn't mean that you can't extrapolate meaningfull information, but due to the rarity of aircraft accidents and the chaos factor, the numbers don't mean a whole lot. Take airline A for example, just because airline A has had only 3 accidents in the last 10 years, doesn't mean it's any safer than airline B that had 20 accidents. The rareness and randomness of aircraft accidents allows the "luck" or "chance" factor to get in there.
How many near misses are there each year? I've had my share, no doubt. Ones that I saw, and ones that I never saw, and while I may be able to mitagate the risks to some extent, the differences between some "near misses" and midair collisions is very VERY slight.
Yes, VFR pilots flying into IFR conditions are still one of the biggest threats with GA, but traffic avoidance and conflict is also a huge one. I'd say that it's a whole lot easier to mitagate the risks of convective activity, because you can simply stay out of it. Check your composite moisture stability chart, your radar summary, your low level significant weather prognostic charts, if you do that (as you should) you'll have a pretty darn good idea if convenctive activity is forecast.
Avoiding and spotting traffic on the other hand is different, you are not in control of that situation and you are not gaurenteed to know about it like you do with some sort of weather activity. It's a skill that most pilots develop (spotting traffic) but every once and a while a situation gets in there where you don't see it, perhaps you take evasive or precautionary action to mitigate the risks, but I think there is a far greater real risk from middair collisions, because when you've done everything in your power to mitagate the risk, it's still going to be there to some extent, unlike choosing NOT to fly VFR into IFR.
"Dirt cheap" $4000 dollar mode S transponders and TIS will help, and it will definitly do a lot to lessen the risks, but it will also create complacentcy and with any technology the limits of the technology have to be realized and in the end you are going to have to use your eyes.
I agree that there are probably no overwhelming risks, but that it is a mixture of several smaller ones, and it's somewhat of the dutch dike senario, we patch up one area, but another starts to leak. This is because it's a continous processes and we must keep training and practicing all of it to be as safe as possible, but there's still a few out there making it hard on the rest of us, highlights of this week;
tower "cessna xxxx, say altitude?"
cessna "6000"
tower "ok, i've told you numerous times your altitude restriction is 6500, turn right, traffic is a cessna on downwind to final"
cessna (condescinding tone) "lets just COOL IT ok??"
tower "you were told numerous times what your altitude restriction was, you blew through two traffic patterns at their altitude, creating a danger to the aircraft in the pattern and airspace, you need to call us after you land"
I was sceptical about TCAS when it was first installed in transport aircraft. I expected the same experience as GPWS, so many false warnings that it would become almost useless. There were quite a lot of false warnings at first, but the programmers quickly corrected that. Now I can't imagine not having it. Not only can it save you when see and avoid or ATC fails, it gives you great situational awareness of the traffic situation.
I've got the Monroy el cheapo product and it is not working as well as I had hoped it would as a portable unit, often not even warning me of heavy traffic I can see within 1 mile horizonal and 1000 feet vertical. I agree that $4,000 is a lot of money, but considering it as a sort of family life insurance policy might increase the perceived value relative to the actual cost. I admit that since some pilots continue to operate knowingly or not without encoding transponders, or even radios, the ultimate solution is not quite at hand. But silicon and electronics, outside of airplanes that is, are truly "dirt cheap" and maybe the industry and, more importantly, the FAA, will eventually realize that giving us such equipment to dramatically enhance safety will increase the poxxxxrity and demand for all general aviation equipment in the long run.
"See and avoid" is often just a nice name for "dumb luck." In Section 4.3 of my article published 1997 in Risk Analysis: An International Journal (http://web.wt.net/~b1rd/JournalManuscript.htm), I provided the equation needed to calculate the probability of detecting particular collision path scenarios. My article proved that random altitude pilots live longer than those who accurately obey any discrete altitude cruising rules, such as the hemispherical cruising altitude rules of FARs 91.159 and 91.179. This fact was corroborated by a NASA ATC programmer at Ames Research Facility in a 2000 article for Air Traffic Control Quarterly (http://web.wt.net/~b1rd/RussPaielliFinalPaperFall2000AirTrafficControlQu...).
If you'd like to crash virtual aircraft in your own computer to prove me wrong, try my Java applet at http://web.wt.net/~b1rd/MidairApplet/JAppletMidairCollisionTestingDriver....
The goal of the game is to adjust altitude limits, airspeed limits, aircraft size and pilot accuracy obeying the law to see if FAR 91.179 can be justified as a safety rule. (Hint: It's impossible. You have to make the piloting accuracy +/- 500 feet to get comparable collision counts.)
The fix for this problem is the Altimeter-Compass Cruising Altitude Rule (ACCAR), promoted by my request for a Notice of Proposed Rulemaking at http://dms.dot.gov/search/doxxxent.cfm?doxxxentid=268833&docketid=17079. This 70-year-old technique was proposed in 1968 by Leighton Collins (Richard's father) in four Air Facts articles, one of which is available at http://web.wt.net/~b1rd/Historical.pdf. Imagine there is a compass rose sticker on your altimeter. To use ACCAR fly so that the 100-ft altimeter needle points at the altimeter compass rose direction that matches your own magnetic heading. Everybody doing this flys parallel same-direction paths at all altitudes. See example altimeter pictures at http://web.wt.net/~b1rd/10AltitudeHeadingCombosACCAR.gif. By design, head-ons are automatically 500 ft apart. Right angle path crossings are automatically 250 feet apart. Only overtaking collisions are allowed after a long chase up the turbulent wake of the slow plane up front. Under FARs 91.159/179, BY DESIGN, near polar heading aircraft are at the same altitudes in head-on collisions. For example, aircraft heading 359 and 181 degrees are required by law to be as common altitudes.
Since 1997, over 100 deaths in two collisions were encouraged by the current regulations, and 147 deaths in 11 midair collisions were permitted that could have been avoided with an ACCAR environment. See table at http://www.geocities.com/rpatlovany/PreventableMidairs.html. The ACCAR idea is so neat because it cost the pilot and aircraft owner virtually nothing, and it takes about five minutes to learn with that much practice. Unfortunately, it cost the FAA the admission that they and their international counterparts made a technical error over 30 years ago in enacting safety regulations that are guaranteed by laws of physics to maximize midair collisions. See the mean free path formula discussed in Section 4.2 of my Risk Analysis article.
If you have any questions, write me by deleting the underscores and tildes out of r_p~a_t~l_o~v_a~n_y@r~o_c~k_e~t_m~a_i~l.com (confuses the spam generating bots).
Robert Patlovany
is the mid-air collision threat really head-on? The accidents that I have studied usually involved aircraft that were turning or changing altitude, either with a large area blocked or doing the classic "low wing over a high wing". It doesn't sound like a bad idea but does it really have much to do with the mid-air threats that are mostly base-to final or on final.
Most collisions happen in the traffic pattern, and any conformity to the pattern eliminates head-on collisions there. However, head-on orientation collisions to occur and they obliterate see-and-avoid effectiveness because the visible time to impact is shorter than the scan time. Your eyeballs and brain simply cannot absorb enough visual stimulus fast enough to detect a threat that is visible for only five seconds if it takes 20-30 seconds to scan from right to left, and check the panel. The bad thing about FARs 91.159 and 91.179 is that they are designed to permit (even encourage) head-on collision that would be far less frequent in a purely random altitude cruising altitude scenario. In other words, the more you follow the rule, the more danger you are in. That hardly qualifies as a valid safety rule. That is why I proposed to the FAA that they abandon the bad rule and try something that is proven to be better--the Altimeter-Compass Cruising Altitude Rule. See
http://dms.dot.gov/search/doxxxent.cfm?doxxxentid=268833&docketid=17079
Robert Patlovany
r_p~a_t~l_o~v_a~n_y@r~o_c~k_et_m~a_i~l.c_om (remove underscores and tildes)
Even though mid-airs are a comparatively small statistical risk, they are likely to become more common if the number of airplanes in the system increases, controller resources become more strained, or pilot proficiency decreases. There are many potential influences including sport pilot, GPS-Direct routing, VLJ's etc.
When flying under IFR in visual conditions, I see about 50% of the traffic that is called. I also occassionally see trafic that is pretty close that is NOT called.
I agree that, in this day and age, it should be relatively easy to make a sub-$1000 gizmo that would give accurate range and azimith to nearby aircraft. This would help a lot.
I know this is controversial, but I really don't think there is much excuse for not at least having a transponder in any aircraft.
Although I love gizmos and other toys, I'll toss this out:
"Historically accurate, museum quality reproduction or restoration of a J3 Cub."
The question is, do we ground such animals? Place a gazillion restrictions on them? I dunno, but I don't think that's the right thing to do. What I think is reasonable is that those who fly such aircraft use a handheld radio and ATC flight following. And for those pilots that say that something like that would spoil the spirit of flying such an aircraft, my reply is that I've been involved in museum quality restoration of steam locomotives. Although mounting a modern Motorola 50 channel railroad frequency radio permanently in the cab would be completely inaccurate, it is much safer to operate such equipment using handheld radios, and not depending on line-of-sight hand signals. And the visiting public is none the wiser, anyway. Similarly, the use of a hand-held aviation radio in a restoration doesn't take away a thing from flying it and makes everything safer (not to mention less frustrating for the instructor in the 172 who's trying to figure out why the Stearman's stopped in the middle of the grass runway - been there, done that).
A simple and technically inexpensive method would be to combine a 12-channel GPS, transceiver, and microprocessor into a hand-held or panel-mount device to (1) report the unit's 3-D coordinates and either arbitrary ID or N number on a dedicated frequency, (2) receive similar reports from other units in range, and (3) process and announce conflicts as well as "optimal" conflict resolution strategies consistent with the data (and database), where "optimal" has a sensible default definition that can be adjusted to some extent for user preferences. This method circumvents the dubious role that pilots already play in announcing their "position" (we get it wrong a lot, and we don't do it enough even in situations where we know we should), in inferring the location of conflicting aircraft, and in quickly choosing an effective avoidance strategy. The key problem would be to compress the information and minimize the transmission time, and "listen" first before initiating transmission - neither of which is something real pilots are very good at, but which machines can do flawlessly. If the equipment allowed users to fully utilize all components, e.g., with the usual GPS display and database, and it was priced right, then the market would probably grow steadily after it became available - even without an FAA incentive.
Question;
I'm not trying to be an a-hole or jerk, but do you believe the cost to design this system and certify it would be cheaper than just buying mode S transponders with garmin 430 units?
The system you are describing is not a bad idea, but it requires software be written, hardware be designed, all of it be certified, and that you buy something that may not be very usefull outside of this one use.
Mode S transponders are not *that* expensive, and GNS 430s are standard on many planes, and can be retrofitted if needed. These aren't cheap, but I'd bet that the cost would be comparable, if not cheaper, because this technology already exists in this role.
My school got screwed (ERAU) because they signed into a contract to buy the ADS-B recievers/transmitters and MFDs to display all of it. They ALREADY had GNS430s and to upgrade to a Mode S transponder would have been relatively cheap, and the Mode S will interface with the GNS430 and provide traffic information. It is a really neat system and it recieves radar from center so you can see all of the contacts that they see. I saw something moving up on my 6 one time real fast, faster than I'd ever seen anything move before. I thought someone had fired missles because that is truly what it looked like on the display. It was a pair of fighters though about 1000 feet above me. It probably really would have screwed with their head if I had taken evasive. I could see that I did not need to of course because of the altitude it showed them at, but even still it was real wierd and a situation where I'd have been taken by suprise if I did not have any prior warning. We recieve TIS on it, but mode S also recieves TIS and is way cheaper than buying a bunch of recievers/transmitters and MFDs when all you need is a new transponder.
What you are describing sounds very similer to what many modern Army armor and artillery units have now. All the vehicles talk to each other and display the other's by information recieved from their GPS units. Not cheap unfortunatly.
So the FAA could require mode S transponders instead of the current mode C. Perhaps having the interface with the GNS would not be mandetory, but at least anyone who wanted to improve their situational awareness could get a unit that does Nav, Com, and traffic all in one.
Anyway just some ideas and differing viewpoints.
I think the major problem is with certification and standardization. The FAA has to grapple with two distinct aviation components: the intense commercial passenger and freight transport activity and the broad spectrum of GA activity, ranging from purely recreational to commercial. It's absurd and impossible to impose the same requirements and costs on both. How can we realistically justify the $10,000+ cost of installing the mode-S and GPS in a typical GA aircraft? Since the intentional random error component was eliminated (or at least reduced) from GPS, even a $100 handheld unit available now can provide astounding accuracy - certainly enough for the job we're talking about. Likewise with transceivers. Why spend $10,000 to solve a problem that can be solved for under $500 (for a basic "see-and-avoid" device) by simply consolidating what most pilots are already using anyway? The problem is to acknowledge the long list of small risks that cumulatively yield a significant risk, and provide inexpensive technologies that cumulatively reduce those risks. Weather access in the cockpit comes to mind, but I digress.
The reason why hand-held devices, including telephones, are not certified in aircraft as airworthy is due to electromagentic properties of the materials, and the EM and RF emissions of the devices that could, inadvertently, interfere with other navigational, or even non-navigation, but just as critical instrumentation in the aircraft. Panel mounted devices that are accepted for use are accepted on the basis that their EM signature while powered off, and on, and in-use, have been mapped out and measures taken to negate effects on neighboring equipment.
Anyone that has ever held a speaker, or magnet, to their PC's monitor can get a very graphic illustration of just how magnetic field distortions can be visualized... and from a further distance than what one may realize. While you try that experiment, realize too that the electron gun painting the scan lines in your conventional PC monitor (the tube kind, not the flat panel LCD's), has a fair amount of power behind it, and it takes a fairly strong field to manifest a distortion.
Now.... with a handheld device mounted on your yoke that's one thing... but think about the travel path of it when making turns, climbs, descents, etc. and it's position relative to the panel instrumentation behind it. What are you affecting? Also, what about when you don't have it mounted in the yoke bracket? Do you know if the unit has caused an adjustment problem with an instrument that didn't rectify itself?
Think about this... it's possible to put one's headset up on the dashboard panel of a plane, near the mag compass. Headsets have magnets in the earcups. They can cause the mag compass to deflect in it's adjustment over time, requiring re-calibration (with a non-magnetic plastic or brass screwdriver).
While most handheld units may not cause an issue, one needs to be careful about what one uses, and how it may affect the aircraft cockpit environment. All that testing is part of what contributes to the price of the equipment.
Having said that... not wanting mode S, or GPS (WAAS) capable, may be understandable from a cost perspective, yet how many of us now think that mode C is detrimental to safety versus a benefit? The same will eventually be true of all the whiz-bang gizmos with things like glass cockpits with TCAS, etc., coming to general aviation aircraft. I'm still a believer though that one needs to engage computer #1 (human brain), with the Mark I visual target acquisition unit (human eyeball), and be able to fly the plane even when every fancy gadget fails.
See and avoid is a matter of maintaining vigilance, practicing good scan technique, and understanding the airplane you are in and what it's visibility parameters are (struts, fueselage, angle of view, glass distortion, wings, etc., that act as limits). Every airplane has it's quirks, like the way on a C-172, distortion along the cockpit glass near the corner bends at the top, affect ones ability to see with complete accuity at times. This is all part of learning the aircraft, and dealing with those quirks. No amount of gadgetry is foolproof, so one needs to make certain that every tool, including that of the pilots eyes and brain, are engaged in the process. See and avoid works... but one must also follow the rules, and know that there are some out there that don't follow the rules, and expect the unexpected.
Things like TCAS are wonderful, but don't let it lull you into complacency either. If it says a plane is 1500 feet below and at 11:00... LOOK THERE!! Don't depend on the display alone unless time is so critical that you have to make an emergency manuever immediately.
GPS, by the way, is not foolproof. It's wonderful, but it has errors inherent in the system. Currently there are 32 known factors that can, and do, affect GPS Satellites. I know this because I know the people that build them, design them, and launch them. Those 32 known factors are being worked on to improve accuracy and reliability, and are part of the improvments with WAAS coming into play. It is, however, just yet another reminder that nothing is perfect.
I think the latest news on cell phones is that they don't really cause significant interference with aircraft systems at all, though there is some issue about cluttering the cell systems. So I wonder if that's the way it really is with most handheld devices meeting FCC limits. I don't know of any accidents attributable to such interference, and I've never observed any when using them myself and continuosly cross-checking every instrument with the others and what I see. It would be more critical during IMC flights, especially low approaches, but there's little evidence interference plays a role there - though I know it might be possible that someone could fly into the ground or past a MAP into rising terrain due to such a problem. More likely, however, the latter cases involve purely human failures that could perhaps have been mitigated with such technology.
My question is, has anyone ever actually seen interference in flight attributable to use of any portable electronic equipment, whether gps, hand-held radio, cell phone, laptop computer, pocket PC, ANR headset, games, TVs, CD players, tape recorders, or whatever. And, if so, what was the nature of the interference? I have never seen it in spite of experience with nearly all the above, or heard from anyone who has, so I respectfully submit that this issue may be overblown and detrimental to the evolution and use of inexpensive electronic technologies to solve problems causing real GA crashes and fatalities every year.
Interference is of two kinds;
1) Electromagnetic
2) Radio Frequency (though RF waves are part of the electromagnetic spectrum, hence could be considered part of item 1, however I'm using this colloqually, not in the strict scientific definition as this is relative to the part of the EMS that is specific).
The FAA had concerns, and still does, about certain kinds of devices, including cell phones and other devices. While on commercial airliners this may be less of an issue than once thought (due to the range of the fields involved and the larger physical spaces on an airliner), no such evaluation has been conducted that I'm aware of for the small confines of GA aircraft. The FCC regulation, Part 15, that govern device interference, are there for a reason. Older devices, and devices that may have been dropped or otherwise altered and gone slightly out of phase (especially ones that are old enough not to have PLL tuning in transcievers), can generate RF and EM fields out of spec that certain other devices may be influenced by.
As for cell phones, they "broadcast" to local towers, which is not a problem on the ground, but in the air that means they blanket many towers at once. Depending on atmospherics, you could be blanketing quite a wide area. Cell towers are designed for "x" amount of capacity, so the more towers you are simultaneously occupying, the less load capacity for other individual callers (not to mention being a violation of FCC part 15). There are advances in technology that will allow a NEWER cell phone to operate eventually on an airliner, but this technology is not yet approved. It entails having a mode on the phone that drives the calls with much lower power to a local tranciever box located within the aircraft. That box then uses a digital transmission on a different frequency band to special antennae that put the call into the various carriers normal system loop. This is not yet implemented, but is one alternative being looked at.
At any rate, there are too many "ifs" involved with the plethora of old and new devices out there, and hence too many permutations to iterate here, that could be potential causes for concerns. Indeed, even older radios (aircraft and otherwise), can have drift, or bleed, that can affect other systems that may be older, and less well insulated from signal interference.
I'm not saying that it's an absolute. I'm saying the potential is there. If you are in IMC it's even more critical, but if you have a situation that lets your navigational information go awry, then you are opening yourself up for a navigational conundrum that could have been avoided by simply sticking to approved devices.
I have seen some instances, though rare, where a device caused some difficulty. The devices in question were older, as was the avionics package in the plane. The potential is there. As for accidents attributable, I'd have to check with the NTSB reports just as you would. The problem there is whether or not they would provide a breakdown of that sort of causality. I'm certain that if there was such a situation with approved devices, an AD would be put out. But on non-approved devices, they would not need to AD because the devices weren't approved to begin with.
The question begs... is one ready to be a test pilot? Can insurance tollerate the risk? Are we, as pilots, willing to bet our lives (and those of your passengers) on such a scenario, because that is what one would be doing. My own common sense says not to do it. Once it's been approved for use in aircraft on a given device, fine... but even then, know under what set of parameters that a given device is approved for use.
As I recall, the current "turn off your hand-held electronic devices (below 10,000 feet)" rule on airliners is attributable to the uncommanded roll of a DC-10 during a coupled approach. It was traced back to a Playstation being used in the cabin.
Anyway, the FAR in the GA world leaves it up to the pilot to determine whether the device will cause interference. If someone wants to videotape a flight with me, I spend some time on the ground with the equipment and a VOT signal to ensure nothing odd happens. And the rule is "If I say turn it off, that means, NOW!".
I had forgotten about that playstation incident! Thank you!
And now that you mention it, Richard Collins makes a special point about noting he uses a special handheld video camera for his shoots in the cockpit with a device tested as compliant because he too has run into a few problems with interference.
Thanks again for the memory jog :)
I didn't hear about the playstation incident so would like to find it, presumably in NTSB files. About when/where did it happen?
It's hard to believe that's all we know of. But I do agree that it's a big leap from cavernous transport aircraft to GA aircraft. So, surely, there is someone who can say, "yes, I saw my ____ go wild upon turning on my ____, which was then corrected by turning it off." I'm talking about with current technology, too, not 40 year old tube equipment.
Thus, I still submit that we have a known number of avoidable crashes every year, due to avoidable midairs alone (about 12-15 aircraft destroyed, with fatalities, every year), whereas we have not one known crash ever related to putative electronic interference. Over several years, the cost adds up quickly.
I agree that shooting a coupled IMC approach with superfluous entertainment equipment on is foolhardy, but if we're talking about key sensing and processing equipment designed to avoid encounters with other aircrart, terrain, thunderstorms, icing, or whatever, and if we're watching the gauges with hands on controls during a low approach in the soup, then that's quite another matter.
And I think it's just as foolhardy to stubbornly resist change that could immediately cut fatal accident rates in half, as long as we did the appropriate, FAR-required, pretesting with such equipment in our aircraft before undertaking the practical transportation flying where it is needed most. My family and I have already served as "test pilots" of the see-and-avoid concept and found it failed miserably - I reported a near-midair to the FAA as a result (see earlier post). My wife - a nonpilot - was completely disillusioned by the experience, and so was I. Something's got to change.
I'm certainly not against having certified anti-collision/traffic detection devices installed on an aircraft to enhance the situational awareness of a pilot. At the same time, bringing non-certified equipment that you "think" may not interfere based on ground tests is something that I certainly wouldn't want to encourage. For one, you can't be sure that you have tested all modes and permutations of the adjunct device, therefore you can't be sure that some mode it enters won't cause some harmful, and unintended, side effects.
Does something need to change? Sure! Skies are getting more and more crowded, both from commercial and a general aviation flights, and we're all plying around in the same sky. Midairs and close-calls are always tragic, and almost always fatal. Fortunately the number of incidents is small compared to the number of flight undertaken daily.
By "test pilot" I mean using non-approved/non-certified equipment as an enhancement aid until such a device is thoroughly tested by people with the processes, and equipment, to say with a high degree of certainty that safety is not compromised. Even when an engineer thoroughly tests a device, it still may have a hidden danger. After all, that's why AD's are issued, are they not? Something comes up that was not anticipated, or encountered, on a part or design at the outset, then an "oops" occurs and an AD becomes necessary. To presume that you can test something as thoroughly, or more thoroughly, than a team of engineers with specialized equipment is ... unwise.
Just my two cents (okay... by now I think I'm up to a full dollar's worth).
Date: 2/19/2004 9:53:45 PM
Author:C. Craig Morris
... It's time to move into the 21st century with reliable ''see and avoid'sensing and alerting technology in the cockpit, rather than mere ''dumb luck.''
I agree. My wife and I recently did a quick little sight-seeing flight (most of what I do; I just don't have the money to fly much cross-country) from Calgary Springbank (CYYC) to the picturesque foothills community of Bragg Creek. There were at least two other VFR flights from YYC to Bragg Creek at roughly the same time.
Even though Bragg Creek is outside of the control zone, and at the altitudes in question we were below Calgary's class C, the Springbank controller was suggesting altitudes to fly and offering radar service for these flights. I gladly stayed on tower frequency and took him up on it. On the return to Springbank there were people above and below me, the one above me on a reciprocal heading to mine. The controller called that traffic probably a whole minute before my wife and I saw it. When we did finally see it, if it had been at our altitude, I don't think I would have had much time to react.
There must be a better way other than relying on controllers to provide voluntary traffic advisory services.
I'm all for some cheaper more widespread technology here.
Here's another fact relevant to the whole issue. Much of the certified older VOR, DME, RNAV, equipment flying today is much LESS accurate, and more prone to random fluctuations, than the uncertified handheld GPS units available for a few hundred dollars. That goes for the localizer, too; I can't say about the glideslope as I've not tried a careful evaluation. I speak from repeated experiences operating both simultaneously and individually at a variety of locations around the country. When the two conflicted, I knew which to trust, based on MY experience - and it wasn't the certified equipment. Did I have shops check the equipment? Of course, but they never found anything wrong with it; the problem wasn't the equipment, it is the technology itself.
Another fact is that the certified equipment itself can easily experience craziness, without any outside interference source, which may not be immediately detectable without some independent source of information. I had an autopilot once that would occasionally go crazy when I flipped another switch powering other certified equipment in the aircraft. This autopilot would then produce an uncommanded roll, climb, or descent. I don't think the shops ever really fixed this problem either, though they probably thought they did.
One solution is to purchase a new aircraft with state of the art, functioning equipment. That has appeal, but lacks realism.
Date: 3/24/2005 8:25:53 AM
Author: C. Craig Morris
Here's another fact relevant to the whole issue. Much of the certified older VOR, DME, RNAV, equipment flying today is much LESS accurate, and more prone to random fluctuations, than the uncertified handheld GPS units available for a few hundred dollars. That goes for the localizer, too; I can't say about the glideslope as I've not tried a careful evaluation. I speak from repeated experiences operating both simultaneously and individually at a variety of locations around the country. When the two conflicted, I knew which to trust, based on MY experience - and it wasn't the certified equipment. Did I have shops check the equipment? Of course, but they never found anything wrong with it; the problem wasn't the equipment, it is the technology itself.
Another fact is that the certified equipment itself can easily experience craziness, without any outside interference source, which may not be immediately detectable without some independent source of information. I had an autopilot once that would occasionally go crazy when I flipped another switch powering other certified equipment in the aircraft. This autopilot would then produce an uncommanded roll, climb, or descent. I don't think the shops ever really fixed this problem either, though they probably thought they did.
One solution is to purchase a new aircraft with state of the art, functioning equipment. That has appeal, but lacks realism.
How do you know for a fact that it wasn't the uncertified handheld unit that you were using simultaneously that caused the fluctuations you experienced?
Did you know that there is up to a 100 foot error in position inherent in GPS units under certain conditions? That's why WAAS is needed.
Since there was nothing found wrong with your conventional equipment, you may want to have your handheld GPS unit checked for signal leakage. Same thing can be said of the autopilot and other equipment you were dealing with where the uncommanded roll happened.
Your post illustrates my point quite well... thank you.
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