Collision Avoidance [Archive]

ShyTorque

18th Feb 2008, 21:57

There's a lot of mythology touted by the "never in my lifetime" brigade, all of whom have probably never seen TCAS in operation.

Myth: Pilots with TCAS fly with their eyes inside the cockpit all the time and TCAS is therefore a dangerous, counterproductive piece of equipment.

Rubbish! Used properly, as a part of a lookout scan, TCAS makes the pilot keep his eyes looking OUTside. He is made aware of aircraft coming his way WELL before he has any chance of seeing them and can plan or take early avoiding action if required, to the mutual benefit of both pilots.

I've been lucky enough to have flown aircraft fitted with TCAS (or TAS) for ten years now (and thankfully only a few without). It has proved to me many times, almost on a daily basis, that the human eye is very limited in it's effectiveness at detecting other, possibly conflicting aircraft. (Before the doubters cast aspersions on the limitations on my personal eyesight, it's 6/5 on a class 1 medical).

For example, on Sunday I flew from a landing site "up north" to LHR and back. As it was a fine day (but hazy), there were many aircraft airborne, the length of the country. Heathrow Radar and Northolt Approach stopped giving me individual information on other traffic because there were simply too many to call. I saw most of the ones called by ATC and many others in addition, as well as many others further north. I'm sure I also missed seeing some, we're all human.

At least three aircraft crossed S & L ahead with me firmly on their right side, at the same altitude, passing close ahead without even so much as waggling a wing. Obviously, they should all have given way in that instance but didn't, so I was eventually obliged to avoid them. I presume that these other pilots were aware of the rules of the air and their obligation to give way to an aircraft on the right so I can only conclude that they didn't see me at all, even though I put two pairs of landing lights on to help them!

It's not such a "Big Sky" in Class G airspace these days; it's getting much busier out there, with the performance of aircraft using it increasing, too (the one I currently fly cruises at 155-160 kts).

Another thing to bear in mind is that the ones who are adamant that TCAS and transponders are totally unnecessary are possibly some of those who actually don't see many other aircraft passing by and believe it's less busy than it really is...... :8

wigglyamp

18th Feb 2008, 22:05

Just a small correction.
The Garmin GNS430 and 530 won't display traffic from ANY type of traffic device on the map page unless the 430/530 is receiving heading information. In most cases, this means having the 430/530 interfaced to a Sandel EHSI or a Shadin Fuel/airdata computer, top get serial heading data, or the traffic device is a Skywatch or KTA870 receiving synchro heading from an H.S.I.
Traffic will always be available on a dedicated track-up page, but not overlaid with any nav information.

Personally, I'd sooner have a traffic system (in my case TCAD) and have some warnings of something I might not have seen, that nothing at all. It's a shame so many people with transponders don't always use them, or else leave Mode C off.

davidd

18th Feb 2008, 22:38

tigerbatics

With the hazy mucky layer over the south coast today, tcas and transponders would have beaten my eyes every-time today.
I had mode C switched on and I hope it helped other's 'see me'
I think it should be mandatory to carry both.
Old Aircraft included, lithium polymer batteries do the job.
Surely its a safety plus without any question?

Tony Hirst

18th Feb 2008, 22:42

I've got the Zaon MRX. It isn't snake oil. It works well. It provides minimal information (relative height and distance) so does not encourage an eyes in mentality. It is tiny and the batteries last a fair time.

They are passive receivers only - they eaves drop on transponder conversations between aircraft and ground stations. The distance is calculated based on power output assumptions. These assumptions are used to identify the host aircraft transponder and separate from others. Occasionally the host's transponder may be confused with another aircraft's and generate spurious same height 0.1nm warnings as I had in IMC on approach to Exeter after being warned about near by corp jet. Was not happy with that, possibly bad placement by me. Despite that I think this unit is useful for IMC. If you are like me and reasonably diligent, there is less value in VMC and I rarely use it as such.

I recall I paid < £300 for mine.

englishal

19th Feb 2008, 00:16

I fly with TIS in California, and now I wouldn't be without it. In busy area's like that it is literally a lifesaver. It does not encourage you to keep eyes in, but helps you NOT to fixate on traffic becasue you know it's relative altitude and course. It also helps you to pick up traffic with the Mk1 eyeball....It may also stop some people making irrational decisions....

LowNSlow

19th Feb 2008, 07:09

Thanks for the opions and experiences peeps.

Tony, thanks for the perspective of an actual user of the Zoan. Sounds like it might be useful in the busy and often hazy area where I normally poodle about. I might get the unit that tells you which quadrant the traffic is in.

millard64

19th Feb 2008, 14:08

I have a Zaon MRX and would not fly without it now it does not make you look out less in fact it makes you look out more than you already do. It warns you with several beeps through your headset of any transponder signals it considers a threat. It does not mean that there aren’t aircraft in the vicinity that do not have transponders so you still have to look out. I think it is an aid to prudent flying just like GPS, it does not replace a map but can be used in conjunction with one. I say grasp the technology, get one you can never have enough help when your aviating especially with look out!

scooter boy

19th Feb 2008, 21:40

"There's a lot of mythology touted by the "never in my lifetime" brigade, all of whom have probably never seen TCAS in operation.":D:D:D

How true ShyTorque.

My experience is similar - I have avoided at least 2 near misses with fixed wing aircraft and one with a helicopter since commencing flying with TCAS, those who have never experienced it usually have the strongest anti-TCAS opinions.

Midairs happen.

TCAS is a great way of helping the eyes to pick out traffic.

SB

vee-tail-1

20th Feb 2008, 09:07

Just a thought..
If like me your flying budget is limited, and you fly a small two seater, VMC only. What would give the most safety?
Fit a mode C transponder (used) plus the zaon unit. Cost £1500-£2000
Or fit the brightest strobes/leds with sequential flashing, and visible in all attitudes. Cost < £1000
:confused:

Tony Hirst

20th Feb 2008, 09:50

VT1,

Depends if you feel the safety is gap is best filled with you being aware or others being aware of you. With a PCAS setup you don't need a transponder so you deal with significant amount of the first former. By fitting a transponder you deal with a minority of the latter.

If anything, without a transponder you don't suffer the nuisance alerts that I mentioned earlier.

Lights are questionable. In bright daylight strobes don't seem to be that visible. Not sure about the new LED ones.

IO540

20th Feb 2008, 10:12

Depends if you feel the safety is gap is best filled with you being aware or others being aware of you. With a PCAS setup you don't need a transponder so you deal with significant amount of the first former. By fitting a transponder you deal with a minority of the latter.

If anything, without a transponder you don't suffer the nuisance alerts that I mentioned earlier.

I strongly disagree with the above. Carrying a Mode C/S transponder means that radar equipped ATC can see you and see your altitude. This enables them to deliver a meaningful radar information service (RIS) to all participating traffic! Anybody flying under an RIS (which is great many pilots; an RIS is worth having at any time) will know how hopelessly useless the service is when other traffic is non transponding. You just get loads of reports of "level unknown" traffic which most of the time will be somebody crawling down ~ 1000ft but you cannot bet on it. In turn, the large traffic reporting workload this creates for the ATCO means that traffic which might actually affect the recipient of the RIS may not be reported.

Carrying a Mode C/S transponder also makes you visible to commercial traffic's TCAS systems which (should you make a navigation error and end up busting CAS) can then take avoiding action. Of course, none of the people who don't carry transponders ever make a navigation error so they can ignore this paragraph :)

Carrying a Mode C/S transponder also makes it easier to get CAS transits in many areas, especially abroad.

And finally carrying a Mode C/S transponder makes you visible to GA traffic carrying some kind of traffic warning device, either one of the cheapo transponder receivers, or the full £20k system.

It is obvious from the pattern of UK GA that pilots who fly without a transponder are statistically much more likely to be flying low down, and it is low down where they are much more likely to get hit. So the "only bimbling" anti-transponder argument is the wrong way round. These are the very people who have the biggest benefit from carrying one.

Tony Hirst

20th Feb 2008, 10:42

IO, I'm answering within the context of the specific question posed, not the philosophy of transpondering in general :)

Rod1

20th Feb 2008, 10:51

IO540 makes some good points but thay are minority cases.

Most of the recreational flying community fly at weekends when VFR traffic, certainly in my area, are most unlikely to get granted a RIS outside controlled airspace. Result, this is of very little value in the real world.

“Carrying a Mode C/S transponder also makes you visible to commercial traffic's” true, but how many commercial movements are there a less than 1000 ft in class g airspace? For that mater how many at less than 2000 ft. Again, this is a very small advantage in the real world.

“Carrying a Mode C/S transponder also makes it easier to get CAS transits in many areas, especially abroad.”

Completely true, and the reason I have mode c, but most recreational flying stay in the uk and fly most of the time if not exclusively in class g. Again this is a minority advantage.

“And finally carrying a Mode C/S transponder makes you visible to GA traffic carrying some kind of traffic warning device, either one of the cheapo transponder receivers, or the full £20k system.”

Again completely true, but most flying machines do not have such a device. I did an estimate of the traffic in my local area following the recent collision (which was at 1400ft agl by the way) and came to the conclusion that 80 – 90% of the local flying machines did not have transponders. With this in mind I have modified my operating procedures and increased my lookout as much as possible.

“It is obvious from the pattern of UK GA that pilots who fly without a transponder are statistically much more likely to be flying low down, and it is low down where they are much more likely to get hit. So the "only bimbling" anti-transponder argument is”

I have nothing against transponders, I have a fully serviceable mode c unit and I use it. However we must face the fact that most uk flying machines cannot fit one, and unless the LASP finally arrives (which is very unlikely) they never will.

Please feel free to use traffic alert systems, but still work on the lookout. I recently had a ride in a top end IFR single doing 140kn with all the kit, and the owner made no attempt to keep a good lookout, he just engaged the autopilot and monitored the systems. When I asked him he was of the opinion that his equipment would warn him if there was an issue. This is a very bad idea, please do not do this.

The only option in town for spotting most of the traffic which is flying around at the weekend is lookout. We all need to give it more effort.

Rod1

IO540

20th Feb 2008, 11:12

Most of the recreational flying community fly at weekends when VFR traffic, certainly in my area, are most unlikely to get granted a RIS outside controlled airspace. Result, this is of very little value in the real world.

Why not get RIS?

There are two issues here. If they fly low, they are much more likely to get hit, and presumably they accept that by flying low. Not having RIS is not really relevant - one needs to think of the other aircraft's safety too.

If they fly in a high density area and are non-transponding, ATC can't see them properly either and cannot provide a service to traffic flying higher up, where the traffic can get a service.

Maybe I am missing something but this sounds like a "I don't benefit, why should I help other GA pilots?".

“Carrying a Mode C/S transponder also makes you visible to commercial traffic's” true, but how many commercial movements are there a less than 1000 ft in class g airspace? For that mater how many at less than 2000 ft. Again, this is a very small advantage in the real world.

That's true, until one busts CAS. There are a few hundred serious busts every year, and probably many more on top of that which did not get near enough CAT.

“Carrying a Mode C/S transponder also makes it easier to get CAS transits in many areas, especially abroad.”

Completely true, and the reason I have mode c, but most recreational flying stay in the uk and fly most of the time if not exclusively in class g. Again this is a minority advantage.

Unfortunately you will need to fit Mode S fairly soon.

“And finally carrying a Mode C/S transponder makes you visible to GA traffic carrying some kind of traffic warning device, either one of the cheapo transponder receivers, or the full £20k system.”

Again completely true, but most flying machines do not have such a device.

That's a catch-22. Most people won't get one because most other traffic is non transponding. If most traffic was transponding, the value of a "traffic receiver" would go up massively. The argument would then be just down to money.

I did an estimate of the traffic in my local area following the recent collision (which was at 1400ft agl by the way) and came to the conclusion that 80 – 90% of the local flying machines did not have transponders. With this in mind I have modified my operating procedures and increased my lookout as much as possible.

Lookout can make one feel better, and I do plenty of it, but it doesn't actually work, because a target on a genuine collision course will be a totally stationary point in the sky. Those which you do spot would not have hit you anyway.

However we must face the fact that most uk flying machines cannot fit one

Come on, that is hardly true!!! The vast majority of powered machines can fit one, but don't want to until forced, which I can sort of understand; this is GA after all....

, and unless the LASP finally arrives (which is very unlikely) they never will.

This affects only the cost situation. An existing Mode S can be easily battery powered if necessary, already.

Please feel free to use traffic alert systems, but still work on the lookout. I recently had a ride in a top end IFR single doing 140kn with all the kit, and the owner made no attempt to keep a good lookout, he just engaged the autopilot and monitored the systems. When I asked him he was of the opinion that his equipment would warn him if there was an issue. This is a very bad idea, please do not do this.

Which merely proves one can be a pilot and be an idiot at the same time. One can find loads of idiots in every walk of life. I don't know any pilot who has that attitude, and I know many pilots, face to face, not online. In fact owners of IFR planes tend to be very serious, compared to owners of "sports/ultralight" machines who on the whole tend to take life in a much more lighthearted manner :)

The only option in town for spotting most of the traffic which is flying around at the weekend is lookout. We all need to give it more effort.

This will make you feel better, but I don't think it affects the statistics, for the reason given above.

The best way to avoid a mid-air in the present Class G non-mandatory-transponder environment, is to fly well above 1000ft and in IMC (or better still above clouds). Being above clouds is the very best place - great view, sunshine, and virtually no traffic.

Flying Binghi

20th Feb 2008, 11:23

NTSB Identification: LAX04FA095A
14 CFR Part 91: General Aviation
Accident occurred Friday, January 16, 2004 in Tehachapi, CA
Probable Cause Approval Date: 5/30/2006
Aircraft: Cessna 180K, registration: N61691
Injuries: 1 Fatal, 1 Minor.

A Cessna 180K and a Beech 95-B55 collided head-on during cruise flight over a valley, between 1,500 and 2,000 feet above ground level. The Cessna's right wing separated, and the airplane descended to ground impact. The Beech, which had been in a cruise climb, experienced a punctured windscreen and fuselage. The pilot made a precautionary landing without further mishap. The collision occurred on a clear day about 6 miles west of the Tehachapi Airport, from where the Beech pilot had departed. Neither pilot was receiving services from the Federal Aviation Administration. Radar track data indicated that the Cessna had flown in a southeasterly direction after departing the Bakersfield area. Minutes prior to the collision, the pilot changed to a northerly course. Seconds prior to the collision the pilot initiated a northeasterly turn. The Beech pilot had just configured his airplane for a cruise climb, and was flying in a westerly direction toward Bakersfield. The Cessna was flying about 135 knots, and the Beech was flying about 140 knots. The closing speed was about 275 knots, or just over 4 miles per minute. The Cessna was equipped with a Mode S transponder, and its signal was detected by Traffic Collision Alerting Device (TCAD) installed in the Beech. Seconds prior to the collision, the Beech pilot heard the audible "traffic" alert warning in his headset, and he observed an illuminated target in close proximity on the annunicator. The target was within 200 feet of his airplane's altitude, and in his 1 to 2 o'clock position. The Beech pilot reported that although he looked for the target, none was seen. The collision angle between the airplanes was documented. The impact was ascertained by fitting the Cessna's right main landing gear wheel in the punctured right side front windscreen of the Beech. As the Cessna's landing gear passed through the upper portion of the Beech's fuselage, the right wing's lift strut was lacerated upon impacting the leading edge of the Beech's vertical stabilizer. Thereafter, the Cessna's right wing separated. An evaluation of the pilots' visual angles revealed the airplanes were within each pilot's field of vision.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's inadequate visual lookout during cruise, and the pilot of the other airplane's inadequate visual lookout during climb.

Rod1

20th Feb 2008, 12:38

“Why not get RIS?”

There are almost no LARS units working at weekends. Trying to get a RIS from local regional airports (when VMC) gets “service not available due to controller workload” 99% prob.

"I don't benefit, why should I help other GA pilots?".

Not at all!

“Unfortunately you will need to fit Mode S fairly soon.”

They have been saying that for many years. At this moment in time there is no regulation which is defiantly coming in which will stop me touring. This may change, but remember I do have mode C, without which the above would be untrue. I will be attending the LAA / CAA meting in March and am involved in the LAA response to the second consultation.

“That's a catch-22. Most people won't get one because most other traffic is non transponding. If most traffic was transponding, the value of a "traffic receiver" would go up massively. The argument would then be just down to money.”

If the traffic in my local area was mostly transponder equipped then I would very seriously look at a device, but I do not think this will ever happen.

“Lookout can make one feel better, and I do plenty of it, but it doesn't actually work, because a target on a genuine collision course will be a totally stationary point in the sky.”

Spoken like a true IFR man who flies in straight lines. My most likely collision risk is with a Glider, and Gliders spend most of the time going round in circles and are not transponder equipped. You constant angle point is therefore of little real world value unless you are flying along at FL XX above cloud.

“An existing Mode S can be easily battery powered if necessary, already.”

Most flying machines cannot fit a current tec transponder under existing rules. I would be happy to debate this with you for hours as I have spent many many hours on this but I will give you one example. There are 4000 uk Microlights. Micros have a max empty weight beyond which you cannot fly the aircraft. A Eurostar (very popular micro selling in volume) is so close to this limit that it cannot be painted. There is no way you could fit a transponder, wiring and an aerial without making the aircraft illegal. I could give you many more examples, both micro, unregulated, gliders, LAA fleet etc etc, and if you want to contact me off line I am very happy to have the debate.

“The best way to avoid a mid-air in the present Class G non-mandatory-transponder environment, is to fly well above 1000ft and in IMC (or better still above clouds). Being above clouds is the very best place - great view, sunshine, and virtually no traffic.”

No argument from me, I spend lots of time up there. My problem is getting out of an unmarked grass strip in a busy bit of class g. Max risk is the first 70 sec from takeoff, after that I am above 2000 ft AGL and less likely to bump into anything. I would however be a pop up to anybody receiving a RIS at say 1400 ft, and unless ATC were really quick there would be no time to make a radio warning.

Rod1

IO540

20th Feb 2008, 12:57

Micros have a max empty weight beyond which you cannot fly the aircraft. A Eurostar (very popular micro selling in volume) is so close to this limit that it cannot be painted. There is no way you could fit a transponder, wiring and an aerial without making the aircraft illegal.

This argument, if true, affects absolutely anything one might want to fit into the said aircraft. One could not even fit a better quality seat belt buckle.

A GTX330 with the antenna and wiring is probably about 3kg.

It would be an utterly bizzare regulation. Why doesn't somebody press the (obviously stupid) manufacturer to increase the empty weight? Or replace a few bits with lighter ones - should be easy to fit titanium/magnesium parts on a homebuilt. Then, the issue will become a MTOW limit and be entirely in the hands of the pilots and how many £100 burgers they consume :)

More basically, why do people buy these machines when they are so obviously a regulatory trap / dead-end? Are the buyers unaware of these issues? Even if Mode S remains for ever non mandatory for certain bits of airspace, not being able to fit it makes the machine hugely restricted. Does the UK dealer for these spell out that in the near future, large chunks of European airspace will be closed to them? If he doesn't, he is likely to get sued. I know I could not sell a plane which on the basis of empty weight will be illegal to fly in a lot of perfectly OK VFR airspace, unless I spelt this out in the sale contract.

Whatever one thinks of Mode S, the writing has been on the wall for years and nobody can pretend they didn't know. The European Mode S war has been lost; all that remains is some haggling over which bits of low level airspace will remain open in which countries.

Presumably if somebody wants to fit a GPS, it has to be a handheld, on a clip-on bracket, so they can pretend it is portable and does not add to the empty weight.

vee-tail-1

20th Feb 2008, 13:41

Thanks for sort of answering my question.
It seems:- when I fly at weekends no RIS is available. Below 2000 ft a non transponder a/c may hit me, or a transponder equipped a/c not looking out may hit me. A microlight may hit me anywhere, and a glider could hit me at high altitude, even above the cloud. And even if I look out all the time I will miss an a/c on a direct collision course. Unless I disorientate myself by flying in circles.
If I fit a mode C/S transponder the risk to myself & others is reduced, but a Zaon unit could only give warning of the relatively small number of transponder equipped a/c in my vicinity.
Back to strobes and the new LEDs.. are they useless, or could they give just enough extra visibility to make a life or death difference? :confused:

Rod1

20th Feb 2008, 13:48

The argument is true, trust me. The CAA have said it will see if the extra weight can be “allowed” by a change in the rules, but no plan for doing this has been put forward. If you want the full tec regs have a look at the section s rules on the LAA site.

The Eurostar is only one of a large number of machines which have this problem. I completely agree the rules are mad, that is why I spend time trying to improve them! The empty weight limit only applies to installed kit, so a GPS and an Icom can be clipped in and then removed. I avoided the problem by going VLA which does not have the silly rule.

Gliders are often operated at close to MAUW. My old MC100 was 2lb under its extended MTOW with me in it in standard gliding gear. There was no panel space and no weight to fit any extra kit at all.

I notice you did not comment on the constant angle issue.:E

Rod1

Edited to add, the French have no planes to mandate Mode S for VFR flight in any airspace. You may use Mode C as per the old rules and no date has been set to change this. Again just one example, the Mode S “war” is going to drag on for many many years. Eventually the tec will be replaced by phase three, ADSB, and a new war will start. Some people will avoid Mode s altogether, some will end up fitting it for a quiet life. I may eventually fall into the second group, but not this side of 2012 unless the Europeans change their minds.

Just to be clear, the French example above is taken from a formal question asked by the CAA a few weeks ago and the responce receved by the DGLC.

IO540

20th Feb 2008, 13:56

Rod1

Like most pilots going somewhere, I do fly straight tracks between waypoints - unless taking photos etc, and I agree that gliders are the remaining issue which is probably un-solvable but they should be visible because they are usually flying random tracks.

Well, one can solve it by flying in or above the clouds; preferably above since gliders sometimes go into cloud.

BGA is the best organised lobby in GA, with solid support among the partly ex air force staffed regulatory bodies around Europe. They may get away from Mode S for a long time.

vee-tail-1

I think lights are a good idea but they need to be really bright. The U.S.-made gas discharge lights are great (very bright, lower power usage, almost indefinite life) but appear to be difficult or impossible to fit to a G-reg other than a homebuilt.

Rod1

20th Feb 2008, 14:04

VT1

I sometimes have the honour to fly with an ex member of the ROC. He spent many years training to spot other aircraft and he is vastly better at it than me. I have always seen this as a challenge. If he is so good, then I can get better. See and avoid can and does work but you have to work at it and it is not perfect. The biggest problem with it is that most old spam cans have so many blind spots that it is hard to keep a good lookout.

Rod1

funfly

20th Feb 2008, 16:52

Quote: Never owned a machine with a transponder and don't intend to if I can help it.

Irresponsible

bet he won't agree with GPS iether.

Rod1

20th Feb 2008, 17:17

Irresponsible???

The CAA has made it clear they have no planes to make Transponders compulsory in all UK airspace. If a qualified pilot chooses to fly a non-electric aircraft the length of the UK with no radio and no transponder he is allowed to do so. I know several people who flew from the south coast to Wick is such aircraft least summer. This is not irresponsible at all. There are far more flying machines with no transponders in the UK then with.

The CAA position is that if a VFR pilot chooses to fit mode s they will have more straightforward access to some airspace. Do not try to demonise the majority of pilots, a Transponder is not ever going to be fitted to an unregulated 115kg machine, but sales of such are likely to be an order of magnitude more than traditional GA. The traditional single engine C of A fleet is about 7000 strong. 12000 paramotors were sold in the UK in 2006. In total there are about 4000 micros, 1000 LAA machines (without transponders) 4000 gliders, etc etc etc.

Rod1

IO540

20th Feb 2008, 17:41

12000 paramotors were sold in the UK in 2006.

and they are used to travel.... how far on average from the launch point???

You will be quoting lawn mower sales next. I am sure they are even higher. And they probably cover more distance (seriously) :)

I have no problem with people flying without transponders in so far as they are legal doing so (ok, it renders an RIS useless much of the time, causing the £millions spent on LARS to go to waste) but they have exactly zero moral high ground to stand on if something goes wrong.

We all share the same airspace, and each of us ought to be chucking something into the common pot.

Fortunately, the statistics are firmly on the side of the pilot who gets airborne, puts the autopilot on, and never looks outside the window. All he has to do is keep above 1000ft AGL and enter IMC as soon as possible.

gpn01

20th Feb 2008, 17:53

<quote>
and they are used to travel.... how far on average from the launch point???
</quote>

Doesn't matter how far they travel. You can still hit them even if they're over their launch point.

<quote>
each of us ought to be chucking something into the common pot
</quote>

Agree....it's called LOOKING OUT. It's not a guarantee but it is the one thing that paramotors, LAA's, microlights, gliders and powered aircraft are ALL equipped to do. If the power jockeys want to carry additional whiz-bang electric boxes that help them from hitting similarly equipped aircraft, or allows them to fly in controlled airspace, then that's fine by me BUT it shouldn't be done at the expense of reducing look out.

soay

20th Feb 2008, 18:46

Agree....it's called LOOKING OUT. It's not a guarantee but it is the one thing that paramotors, LAA's, microlights, gliders and powered aircraft are ALL equipped to do. If the power jockeys want to carry additional whiz-bang electric boxes that help them from hitting similarly equipped aircraft, or allows them to fly in controlled airspace, then that's fine by me BUT it shouldn't be done at the expense of reducing look out.
I often wonder how useful looking out really is in the conditions we've had recently: murk below the temperature inversion; and low winter sun. I'm inclined to support compulsory mode C or S in everything with an engine, for all the reasons IO540 has cited. I'd certainly get some form of ACAS if that was the case, and enjoy more relaxing flights when I can get a RIS.

Perhaps a compromise could be transponders not required below 1000ft AGL, where the microlights could fight it out with the RAF. :eek:

Cobalt

20th Feb 2008, 21:15

I have no problem with people flying without transponders in so far as they are legal doing so (ok, it renders an RIS useless much of the time, causing the £millions spent on LARS to go to waste)

LARS tends to be primary radar, AFAIK, with some units (for example Southend, IIRC) not even having the capabiliy to interrogate/receive transponders. While they will probably not show paramotors, they show non-squawking aircraft, microlights and probably gliders - can anyone from the ATC front tell us if they see gliders?

Rod1

20th Feb 2008, 21:36

“I'm inclined to support compulsory mode C or S in everything with an engine”

Support it all you want it will never come to pass. It would ground 1000’s of aircraft and the CAA have realised it cannot do this.

“and they are used to travel.... how far on average from the launch point???”

As has been said, they only have to get airborne to be a threat

“We all share the same airspace, and each of us ought to be chucking something into the common pot..”

I have no problem with this. I have mode c, which is entirely adequate, in fact overkill for my long distance VFR touring. What I object to are people who know nothing about the light end of aviation making sweeping statements when they have no idea of the impact.

I am sure almost all high-end micros would fit transponders tomorrow, if the rules on empty weight were changed. I have no expectation that the rules will change this side of EASA taking over completely, which is a long way off.

I am sure the gilders would fit them if it was technically possible, but in most cases it is not.

I am sure the Lutons and Turbulents will not fit them as the technical challenge is too great on an aircraft worth £3000 all in.

Do we really want to ground all this because some rich guys with all the toys cannot be bothered to work on lookout. If you all feel that without a transponder you are in too much danger to carry on flying then give up and let the rest of us have a bit more room to play with. I have always believed in the brotherhood of aviation, but perhaps I am just incredibly stupid. :(:(:(:(:(:(

Rod1

robin

20th Feb 2008, 22:19

>>>Perhaps a compromise could be transponders not required below 1000ft AGL, where the microlights could fight it out with the RAF. <<<

Forgive my ignorance, but doesn't that fall foul of Rule 5....

Rod has been a lone voice of common sense here. Reliance on technical solutions, as I have also seen flying with well-equipped a/c, is scary.

Fly in the Class G area around Popham on an event day using your 'glass cockpit' instrumentation. In the event of a collision, who would be at fault - the non-tx microlight or the totally-equipped pilot who sets up his autopilot and TCAS?

I've watched my (very experience) pilt friend, and he is spending so much time looking at the screens and fine-tuning his flight profile, he almost never looks out.

Unless and until a technical solution appears at a cost that is proportionate (£3-4k for an Evans VP1 is not that), then the CAA have guaranteed (grin, grin) that Mode S will not be mandated, so TCAS will never find all the potential targets.

Effectively those who fly on instruments/autopilot will prefer to fly high, and that will bring in a degree of separation. My issue is with those pilots who plan to fly lower and mix it with us 'indians' then blame us for getting in their way - quoting safety as a rationale.

ShyTorque

20th Feb 2008, 22:37

Effectively those who fly on instruments/autopilot will prefer to fly high, and that will bring in a degree of separation. My issue is with those pilots who plan to fly lower and mix it with us 'indians' then blame us for getting in their way - quoting safety as a rationale.

Sometimes it's not possible to fly higher, either to avoid icing, or regulated airspace above.

I don't think anyone is blaming "us indians"- who is that group, anyway? As far as avoidance and "getting in the way" is concerned, the rules of the air apply to everyone, irrespective of nationality. :=

scooter boy

21st Feb 2008, 07:55

"I've watched my (very experience) pilt friend, and he is spending so much time looking at the screens and fine-tuning his flight profile, he almost never looks out."

JAYSUS!
Here is further perpetuation of the groundless myth that those who have TCAS do not keep a look out.

Why don't we all go back to the days of non-radio biplanes, flying helmets and no electrics in the cockpit. We could munch carrots to keep our vision sharp (like blackadders glorious 20 minuters) and exchange steely-eyed tales of derring do in front of bowled-over maidens in the flying club bar.:rolleyes:

what bollocks!
Get real, the future is here, get a GPS, get a transponder, and for God's sake activate mode-C, (if you can) get a TCAS and use a combination of avionics and eyeballs to keep you as safe as possible.

Anyone with experience counted in thousands of hours will have had enough close calls to confirm that use of the eyeball as a sole means of collision avoidance is a flawed concept.

SB

Flying Binghi

21st Feb 2008, 08:50

Scooter Boy, it would be interesting to get your thoughts on the NTSB report - about post 26 in this thread.
My thoughts are that the TCAD may have been the cause of the acceident.

dublinpilot

21st Feb 2008, 09:19

Scooter Boy, it would be interesting to get your thoughts on the NTSB report - about post 26 in this thread.

My thoughts are that the TCAD may have been the cause of the acceident.

I read your posting when you made it, and wondered what the relevance was, and what point you were trying to make. Now I know, but I can't say I agree! I can't see where you draw that conclusion! After all the the NTSB says it was inadequate look out.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's inadequate visual lookout during cruise, and the pilot of the other airplane's inadequate visual lookout during climb.

The TCAD seems to have given some warning..obviously not enough, but I can't say that there is anything in the report to say that it actually contributed to the accident!

dp

scooter boy

21st Feb 2008, 09:58

"interesting to get your thoughts on the NTSB report - about post 26 in this thread"

My opinion as requested:

the TCAS worked for the pilot who had it. He got an audible warning and this might have saved the day had he then been able to visually locate the traffic and maneuver accordingly. Seems it was the subsequent use of the eyeballs in locating the conflicting traffic that proved "inadequate".

I would have this one down as a near-TCAS-save.

At 275 kt closing speed the eyeball is woefully inadequate.

IMHO TCAS is useless without lookout but the corollary is also true, lookout is vastly better when augmented with TCAS.

SB

Islander2

21st Feb 2008, 10:15

IMHO TCAS is useless without lookout but the corollary is also true, lookout is vastly better when augmented with TCAS.As someone who has spent the first 25 years of his GA flying without TCAS, and the latter 5 years with it (Skywatch 497), I unequivocally agree with scooter boy's opinion.

Rod1

21st Feb 2008, 11:07

“Get real, the future is here, get a GPS, get a transponder,”

I agree with you, provided you add, if practical. I have just wasted lots of time trying to explain why most flying machines CANNOT fit a current tec transponder under current rules. The CAA fully agree with this which is why “GA” won the argument over mode s for all which has been abandoned.

Rod1

soay

21st Feb 2008, 11:14

Do we really want to ground all this because some rich guys with all the toys cannot be bothered to work on lookout. If you all feel that without a transponder you are in too much danger to carry on flying then give up and let the rest of us have a bit more room to play with. I have always believed in the brotherhood of aviation, but perhaps I am just incredibly stupid.
I note you didn't take me up on my point about how useful looking out actually is. Aside from the aforementioned visibility issues, when flying under an inversion layer, or into a low sun, just how visible is a high wing aircraft climbing into the path of a low wing aircraft, from behind?

In 6k visibility, two aircraft approaching each other in a head on collision course, at a closing speed of 240kts, will have 50 seconds to take avoiding action. A full scan should take at least 20 seconds, so if the target was spotted at the end, rather than the beginning of the next scan, and you had a look at your map between scans, your reactions had better be sharp!

A "toy" could help in all those situations, but only if the "brotherhood of aviation" installs transponders.

Rod1

21st Feb 2008, 12:14

“A "toy" could help in all those situations, but only if the "brotherhood of aviation" installs transponders.”

Back in the real world we understand that the "brotherhood of aviation" cannot fit the d*** things. So we work on our lookout and do not over rely on a toy which can only “see” a small percentage of threats. If the CAA come up with a mobile phone size unit with a 10 hour battery life from a built in battery then things change. With current tec TCAS will miss almost all the people who could kill you on a Saturday PM over Derbyshire at 2000 ft. You can either except that and work on your lookout, or decide lookout does not work, that flying is too risky for you and give up.

Rod1

IO540

21st Feb 2008, 13:11

Rod, with the amount of time you have spent on here in the past telling everybody how easily you can do pilot maintenance on your permit machines, why not re-make some parts out of lighter materials, shave a few kg off the empty weight, and then you could fit a transponder.

I don't think the powered planes that truly have no electric power available for accessories represent a significant hazard to other traffic. They tend to fly at very low levels.

Your requirement for a mobile phone sized unit with an integral battery is a bit silly. Why not have it fit into a wristwatch - would be even smaller then :)

soay

21st Feb 2008, 13:44

You can either except that and work on your lookout, or decide lookout does not work, that flying is too risky for you and give up.
So, please help me by explaining how I can improve my lookout in the situations I listed, while flying at 120 kts.

Rod1

21st Feb 2008, 13:45

“I don't think the powered planes that truly have no electric power available for accessories represent a significant hazard to other traffic. They tend to fly at very low levels.”

You really are out of your depth on this. Lots of home built aerobatic types have no electrics and fly just as high as you. I suppose I will now get told that home built aircraft are not allowed to do aerobatics…

Rod1

PS the mobile phone device was put forward by our very own CAA as a solution to this very problem. Unfortunately, nobody has been able to build one which was rather "inconvenient" for the CAA.

IO540

21st Feb 2008, 14:02

MadamBreakneck

21st Feb 2008, 14:24

... and how long is it before I and my colleagues are going to be banned from flying at 45kt without a TAS and ModeS transponder because we can't get out of the way of you fast boys quick enough.

The faster you fly, the more chance I have of being run over from behind. I already get a stiff neck trying to maintain a 360degree lookout scan!

:ouch:

MB

shortstripper

21st Feb 2008, 19:32

Islander2

21st Feb 2008, 20:12

I've not said anything up until now as those who think TCAS, GPS ect ect are the answer to everything simply do not listen to anything they don't want to hear. I'd happily fit a transponder if 1) I had the panel space, 2) It wasn't likely to fry my balls!My a/c is happy low down, but I do fly high when the mood takes me. It's not irresponsible, it's simply my right.

My a/c cost me £2500 to make, and it's the only thing I can afford to fly right now. The fact that those with more money would prefer me and my kind to keep out of "their" sky is a sad reflection on modern society. My answer is simply STUFF YOU! If you can't see beyond your nose, you are not fit to SHARE my (and your) airspace. If you truly think you can buy your safety, and would happily force out those that cannot, then you really can say that you know the cost of everything and the value of nothing!
Shortstripper, full marks for a really terrific rant. But since you talk of not listening ......... if you unplug your ears for long enough you'll find that significantly more than a few of us who are keen advocates of modern technology are also huge fans of (and participants in) your kind of flying and will defend to the hilt our (and your) right to do it. I'm sure I'm not alone in finding your comments markedly offensive.

soay

21st Feb 2008, 20:15

The fact that those with more money would prefer me and my kind to keep out of "their" sky is a sad reflection on modern society. My answer is simply STUFF YOU! If you can't see beyond your nose, you are not fit to SHARE my (and your) airspace.

If you all feel that without a transponder you are in too much danger to carry on flying then give up and let the rest of us have a bit more room to play with.
Hmmm!

It's undeniable that transponders would help everyone. The problem is making them practical and affordable, so it would be better to try to see how that could be achieved, rather than sinking to these depths of intolerance.

ShyTorque

21st Feb 2008, 21:07

SS, A disappointing and largely uncalled for response; where on earth did you find all that pent-up vitriol?

I am lucky enough to fly a TAS equipped aircraft for the owner - they come with the equipment as standard. I don't fly for pleasure, only as my job, but I am obliged to use the same airspace as "sport" pilots like yourself. In these times of increasing useage of airspace we should all be trying to do what we can to keep us all safe. "Stuff you" is hardly conducive to flight safety of anyone.

TAS, or TCAS certainly does not comprise the whole answer to flight safety; used properly it can only enhance it. I know no-one who thinks it is the full answer and a replacement for a proper, effective lookout. Again, I think these so-called pilots who think it IS the full answer are the product of more crewroom mythology. Everyone who uses it is fully aware of the limitations of this equipment.

I know one pilot who has miraculously survived TWO mid-air collisions, both in pre-TCAS days. One faster aircraft hit him from above and behind, as it descended in Class D airspace, the other from below, in Class G. Not surprisingly, his lookout is now rather intense. He is a big fan of TCAS because he knows how limited lookout can be..... :8

IO540

21st Feb 2008, 21:30

shortstripper

The "IFR crowd" (or whatever one wants to call them) is not in any way trying to push VFR pilots out. For starters, there are far more VFR-only pilots flying than ones with IFR privileges.

Speaking for myself, what I don't agree with is some people saying this and that cannot be done when there are technical solutions right now.

Unfortunately "anti Mode S" and "anti transponders" generally have become a sort of religion, often without any rational justification. One could argue that Mode S is pointless but the general concept of a Mode C (altitude reporting) transponder is pretty solid, except where genuinely technically impossible or just plain silly (like on a parachutist).

ChampChump

21st Feb 2008, 22:08

Well, how about everyone calms down and fits a nice big high visibility jacket to their aircraft? Yes the cloak of invincibility....:E

shortstripper

22nd Feb 2008, 03:10

:\

LOL! Sorry folks, I was about two glasses of a rather nice wine over my usual quota last night when I added my little rant :uhoh: Mind you, it's quite nice to vent the spleen now and then :E Hopefully this post won't turn into a rant also (I'm time limited so it can't really :})

My rant was born of the frustration of seeing threads like this come up with monotonous regularity. The same old arguments over and over and what's worse, is that if I'm honest, it's an argument I seem to be loosing, and nobody likes to loose do they? The CAA would happily have seen everything unable to carry a transponder grounded. They lost a battle because of the PFA, BGA, BMAA ect, but I fear the war is far from over. I'm hopeful that sense has been seen, but so many pilots now seem to be blinkered into thinking that their experience of aviation is the basis for all. We could keep replacing bits from our light aircraft with "other" bits that make us more visible ... but where do we draw the line? Remove the heaviest bit (the pilot)? ............ It's OK, I am joking :p

I have nothing against modern technology, but until it's practical for all ... it's not really practical at all! It would be rather ironic for someone to go out and buy all the kit, only to fly smack bang into a sailplane in cloud because they assumed that all the non transponder stuff would be low down and of little risk :{ I'm sure I heard the glider boys in Euroland had come up with a gps based avoidance system of some merit? Perhaps we're just looking at the wrong technology? Surely there must be a system that doesn't involve powerful radio transmitters, high power consumption, size and weight? I'm seriously looking at building a Thatcher CX4 as my next project. It has a much larger cockpit than my T31 and a lot more performance. I'd be quite keen to add some electrickery, but I'd prefer to use the space and weight limitations to add stuff that actually makes sense, rather than just false hope! I've had a couple of "gezzzus"! encounters before, so I'm no die hard "eye ball saves all" type, but what use is TAS, TCAS in a busy circuit where the risk is highest?

More to say, but coffee break is over :(

SS

IO540

22nd Feb 2008, 06:44

There is no technological solution to the circuit problem, at a busy airfield. You just have to look out and hope others do the same. It's a risky place to be... Fortunately one can expect traffic to be in certain places so one can watch those. This is why I think the overhead join is stupid - several planes all head for the same spot at the same time - how clever is that?

Rod1

22nd Feb 2008, 07:46

IO540,

Tolerance mode on//

“Rod, with the amount of time you have spent on here in the past telling everybody how easily you can do pilot maintenance on your permit machines, why not re-make some parts out of lighter materials, shave a few kg off the empty weight, and then you could fit a transponder.”

I have a transponder thank you! I choose to spend some of my time fighting the corner of the people who cannot fit one and trying to explain this to the CAA who listens and you lot who seem to find the concept inconvenient.

Yes I advocate regulatory systems which allow aircraft to be maintained by builder pilots. I spent 1800 hours building mine so I have a reasonable knowledge of how it fits together. There is a world of difference between building and maintaining an aircraft and designing one. My aircraft was designed by two of the best light aircraft designers in Europe. I would not even consider trying to mod it to save weight. In the whole build I registered one mod, a high intensity strobe in the tail.

soay

“So, please help me by explaining how I can improve my lookout in the situations I listed, while flying at 120 kts.”

If you really want to improve your lookout go fly gliders for a few years or get an ex member of the ROC to help you. Both would help more than trying to force 1000’s of people to fit kit which cannot be fitted to their aircraft so you can rely on electronics. You may be going at 120kn in the conditions you specify, my problem is I will be going at 138kn in the opposite direction…

Islander2

I do not think SS or I are anti tec. I have a state of the art carbon composite aircraft which is very close to my ideal flying machine. You are seeing frustration because SS could not fit a mode s transponder to his machine; it is just not technically possible to do it given current tec. I have spent 100’s of hours on the Mode s campaign along with many others. The CAA started out with “everyone must fit mode s” and finished up agreeing this was not technically possible. I realize that is inconvenient, as mandatory transponders and TCAS would be very convenient for you, but it is not going to happen. I say this not from the point of view of being anti tec, but from the point of view that the majority of flying machines cannot fit the devices.

I am genuinely astounded at the lack of knowledge of the lighter end of GA exhibited by some of the postings on this thread. It is a shame we cannot all get together at some suitable airfield. A good look round SS excellent machine would soon convince you we are not making the technical issues up, as would a look at the w&b of a Eurostar or CT.

Tolerance mode off//

Rod1
:ugh::ugh::ugh::ugh:

soay

22nd Feb 2008, 08:05

[Tolerance of condescension mode on]
If you really want to improve your lookout go fly gliders for a few years or get an ex member of the ROC to help you.
That would not help much with the issues of blind spots and relative speeds that I'm concerned about.

The CAA started out with “everyone must fit mode s” and finished up agreeing this was not technically possible. I realize that is inconvenient, as mandatory transponders and TCAS would be very convenient for you, but it is not going to happen. I say this not from the point of view of being anti tec, but from the point of view that the majority of flying machines cannot fit the devices.
Could a remote mount transponder be a technological solution to the problem in the lightest powered aircraft? There should be space for an on/off switch on any panel, which would suffice if the unit only squawked a fixed code. That code should be reserved for such devices, so that ATC would know their limitations. The market for such a transponder must be larger than that for the GTX330, so it shouldn't be too hard to persuade a manufacturer to make them, and the extra simplicity should reduce cost and weight.

[Tolerance of condescension mode off]

ShyTorque

22nd Feb 2008, 08:44

I certainly don't agree with anyone being grounded because their aircraft is incapable of carrying certain new equipment; I don't personally think the CAA would succeed in making that happen, nor should they try.

On the other hand, as a flyer, I have a moral and legal responsibility to keep safe both my passengers and do my utmost to minimise the risk to those flying in the same airspace as myself. I use an ATC service wherever possible, I also use my TAS as effectively as I can to enhance my lookout scan. Those folk with a transponder fitted get a much better chance of me being aware of their presence in advance (often 10 miles or more) and my avoiding them by a good margin. Those without a transponder don't get that extra protection factor; both myself and the other pilot have to rely on the Mk1 eyeball, with all it's limitations, it's as simple as that.

My eyesight is good enough to see a light aircraft about 4 or five miles away in good average conditions, unfortunately that is about the limit of human visual acuity, Beyond that the "target" is simply too small - our eyes weren't designed to do any more than that. Possibly when we evolved as "hunter gatherers" an animal further away than that was too far away to chase - we'd be cream crackered by the time we got to it.

It's not too uncommon for my TAS and/or ATC tells me an aircraft is very close by but try as hard as I can, I just can't see the damned thing, often because it's a very small aircraft with insufficient colour or brightness contrast to the background. In these cases, I put on all four landing lights and hope the other pilot sees me :eek: . This possibly irritates some pilots, but at least he's seen me if he's irritated ;) .

Since I began flying TCAS/TAS equipped aircraft nine years ago (28 years prior to that without the benefit), I have become aware just how busy our lower airspace is becoming; far more busy than when I began flying gliders some years ago. Just like our roads are so much busier and more dangerous these days. Back in the early 1970s I also protested against the mandatory wearing of a helmet whilst riding a motorcycle (even though I already chose to wear one myself and knew it made good sense).

I do think that transponders and TCAS / TAS are very good bits of kit to have, much better than seat belts in cars or crash hats on motorcycles because they can, in many cases, help to prevent an accident, rather than try to minimise the after-effects to the individuals involved!

SS, I can't really agree with your example of the unseen sailplane in cloud as an argument against the fitting conspicuity equipment, surely it is an argument FOR fitting it to all aircraft that operate in IMC? Actually, this was the basis of another discussion here some time ago (which went on for ages)! At least one glider pilot voiced the opinion that everyone should fly around on "his" glider frequency whilst in IMC, even to the detriment of obtaining an ATC service elsewhere, just in case he might be gliding in cloud, which he rarely did, on his day off. :rolleyes:

vee-tail-1

22nd Feb 2008, 08:53

Dear oh dear! been away for a bit and this thread has become vitriolic.
Everyone agrees lookout is vital but not 100% (or even 50%) effective.
Surely strobes, lights, LEDs, could make a significant difference in the most dangerous situations.... weekends, haze, low level, lots of non transponding a/c etc?
I have been looking at the lights available, and there seems no way of comparing them. Aircraft Spruce sometimes quote "candles", or say "gives high intensity flash". Other manufacturers quote "very bright" or "best on the market". Some suggest that "alternating dual flashing white strobes" are the way to be seen.
Back to basics, and a simple a/c with an alternator giving say 2 to 3 amps of 12 volt DC power... What system could be fitted to give the maximum visibility and enhanced safety? :sad:

BackPacker

22nd Feb 2008, 08:54

Could a remote mount transponder be a technological solution to the problem in the lightest powered aircraft? There should be space for an on/off switch on any panel, which would suffice if the unit only squawked a fixed code. That code should be reserved for such devices, so that ATC would know their limitations. The market for such a transponder must be larger than that for the GTX330, so it shouldn't be too hard to persuade a manufacturer to make them, and the extra simplicity should reduce cost and weight.

My guesstimate is that the problem is not in the physical size of the unit, but in the power consumption and hence the size of the battery in a non-electric aircraft.

Is there anybody who has more knowledge of electronics than me, who can do a few calculations based on power output, transmission losses etc. and come up with the size of a battery that can support a mode S transponder for a reasonable flight time (say eight hours - I understand that for a Silver C in gliding you have to do a five-hour flight)

Whirlygig

22nd Feb 2008, 09:02

I'd have thought the solution was simple; make it mandatory for all aircraft to wear a hi-vis vest! :}

Cheers

Whirls

shortstripper

22nd Feb 2008, 09:07

SS, I can't really agree with your example of the unseen sailplane in cloud as an argument against the fitting conspicuity equipment, surely it is an argument FOR fitting it to all aircraft that operate in IMC? Actually, this was the basis of another discussion here some time ago (which went on for ages)! At least one glider pilot voiced the opinion that everyone should fly around on "his" glider frequency whilst in IMC, even to the detriment of obtaining an ATC service elsewhere, just in case he might be gliding in cloud, which he rarely did, on his day off.

ST

I wasn't using that example as an argument against anything. It was to illustrate the danger of assuming that non transponding aircraft are likely to be low and slow and in VMC.

I'm still amazed that nothing small and lightweight can't be thought of. What BackPacker suggests would be fine ... BUT NOBODY HAS INVENTED ONE! When they do, or they develope a better system, I'll sign up straight away. I'm not so stupid as to gamble with my own life just to make a point. I'd love a foolproof avoidance system that I could fit. As it stands, no such system exists :rolleyes:

SS

Rod1

22nd Feb 2008, 09:18

VT1

Your best bet is to visit a few busy airfields and look at the strobes in use. I fitted a high intensity strobe to the tail of my machine. This was on the basis that I stood a chance of seeing stuff coming at me from the front but people overtaking me from the rear was the big problem. The strobe uses solid state tec and consumes a max of 2a. It is very bright on the ground, but has proved to be of very little use in the air.

The number of mid air collisions in the UK is very small. This thread has, to some extent, made it seem that we all bump into each other every day. I have had a number of close encounters, but most have been in the circuit.

Rod1

mm_flynn

22nd Feb 2008, 10:32

My guesstimate is that the problem is not in the physical size of the unit, but in the power consumption and hence the size of the battery in a non-electric aircraft.

Is there anybody who has more knowledge of electronics than me, who can do a few calculations based on power output, transmission losses etc. and come up with the size of a battery that can support a mode S transponder for a reasonable flight time (say eight hours - I understand that for a Silver C in gliding you have to do a five-hour flight)
The Trig mode-S seems to draw 6w (about .5 amp in a 14v aircraft), so if you wanted to have a 10 hour capacity you would need 60Whr of battery, A Lithium Ion battery would need to be about 0.4kg of battery (or about 10 digital camera batteries).

I am sure IO has also measured power consumption on his 330 and come up with a number not dissimilar.

BackPacker

22nd Feb 2008, 11:24

The Trig mode-S seems to draw 6w (about .5 amp in a 14v aircraft), so if you wanted to have a 10 hour capacity you would need 60Whr of battery, A Lithium Ion battery would need to be about 0.4kg of battery (or about 10 digital camera batteries).

That is actually much better than I suspected. For reference, the car battery in my VW diesel is 70 Ah. Theoretically that would supply enough juice for 140 hours of operation.

Although I am a bit suspicious: The Trig brochure claims 240 watt nominal power output at the antenna connector. That power has to come from somewhere and with losses and everything suggests a power draw of 300-400W. Obviously that's burst power in response to an interrogation but it does mean that the busier the area is, radar-wise, the more responses are required (selective interrogation helps a lot here, obviously) and the more the power draw goes up. And I believe TCAS does active interrogation as well, don't they? Instead of relying on scatter from transponders in a radar environment?

It would be nice to hear what the impact of being in a busy radar environment is on power consumption. Nevertheless, I'm impressed with the numbers and I've got the feeling that power consumption therefore should not be an issue in creating a portable/rechargeable transponder of a size not much larger than, let's say, a milk carton, batteries and everything included. Make it robust enough and you could even argue that parachutists should be taking one with them.

mm_flynn

22nd Feb 2008, 12:22

Re - Parachutists and plastic planes - you still have the problem of a ground plane for the antenna and the fried nadgers issue.

I think you will find that the 250W reply transmitter is on for about 1.6% of time the transponder is actually being interrogated. Assuming the SSR beam width is 3-4 degrees, a given ground station will illuminate a transponder for about 1% of the time. Therefore the 250W output is only needed for about 0.016% of the time, and is therefore a vanishingly small amount of the power requirement.

BackPacker

22nd Feb 2008, 12:27

Re - Parachutists and plastic planes - you still have the problem of a ground plane for the antenna and the fried nadgers issue.

I thought parachutists were required to have balls of steel?:rolleyes:

shortstripper

22nd Feb 2008, 12:46

I thought parachutists were required to have balls of steel?

Great for pulling power! Balls of steel and induced magnetism thrown in for free! :cool:

SS

IO540

22nd Feb 2008, 13:51

It would be easy enough to run say a GTX328/330 from a laptop-style LIPO battery.

As mm_flynn explains, the transmission duty cycle is miniscule and this also deals with the much advertised health hazard; this isn't a mobile phone which - in a poor signal area - can be radiating as much as 0.4W 100% of the time, and be doing it right up against the side of your head.

Rod1 - how is the empty weight of your homebuilt made up? % due to engine, airframe, avionics, etc. It should be trivial to save 5-10kg by replacing certain non-structural items. I realise you carry a transponder but you gave this example as representing huge numbers of pilots.

On the topic of not understanding homebuilt capabilities, I do know full well that just about anything with an IC engine can reach at least 10,000ft. The question is: how often is this used? The issue in all "mid-air" debates is the statistical likelihood of an encounter, and my experience (~ 900hrs) firmly confirms that large chunks of GA do fly very low. To a large degree, the 0-1000ft AGL band is a fair game (full of various flying lawn-mowers, helicopters, towers, etc, and with ineffective radar service due to terrain) and if you fly there you should accept the greatly reduced safety (albeit still a very low mid-air probability). It is above that which I am not happy with.

scooter boy

22nd Feb 2008, 14:20

"the overhead join is stupid - several planes all head for the same spot at the same time - how clever is that?"

How right you are!
Ban the overhead join I say.

SB:D

BackPacker

22nd Feb 2008, 15:06

It would be easy enough to run say a GTX328/330 from a laptop-style LIPO battery.

The other issue is certification of course. Does the CAA/JAA/ICAO allow a solution where, say, you have a plumbed-in antenna but possibly a removable transponder and definitely a removable, rechargeable battery? Because that would seem like the obvious solution in a glider or other non-electric airplane.

I can see a few things where this might be a problem:
- Source of static pressure needs to be calibrated and you need to extend your current static pressure plumbing to fit a quick-connect to which to connect the transponder. Simply taking cabin air as static pressure won't always work. Although I don't know the required accuracy of the FL encoding in the transponder signal. It might be so that the variation between cabin pressure and static pressure is less than the accuracy required for the transponder signal.
- Quick connectors in various places may corrode, particularly to the plumbed-in antenna, leading to degradation of the signal. And what I understand is that devices like Zaon makes, derive part of their solution from the power output from the transponder so even a minor signal loss might lead to solutions that are way off.
- It would make sense to have an indication of battery charge somewhere, and a warning when battery voltage drops below a certain critical threshold. The current breed of transponders, intended for aircraft with an electric circuit, don't incorporate these.
- The transponder itself might end up in the wrong airplane - think a gliding school with dozens of planes and dozens of transponders to recharge every day. Something is bound to go wrong, leading to wrong flight IDs and ICAO IDs to be transmitted.

Fuji Abound

22nd Feb 2008, 15:24

I have a few comments having caught up on this thread.

See and avoid.

It is a nice idea. However, there have been a number of studies that suggest at best it works poorly. I have posted before the times we typically have to spot another - they are quite sobering, particularly if you factor in our reaction time (which we usually forget about).

The truth is the majority of the time collision avoidance is down to "good luck".

I am sure we can all recall on a busy days when we have been receiving traffic how little of the reported traffic we actually see.

Avoidance.

There are a number of good strategies to reduce the risk of collision. The usual suspects are to fly as high as possible (there is far less traffic), to think about choke points caused by CAS, navigation or terrain, and, best of all, leave the landing light on in conditions of poor visibility.

PCAS.

I am pretty much convinced the system works well most of the time. The more basic of the units is still very useful even though it does not give you the direction of the traffic. The key here is that it will warn you if traffic enters a "protected bubble" around your aircraft. It displays the vertical separation. If traffic enters this bubble you climb or descend to ensure a vertical separation is maintained.

The systems provides an audible warning so there is no need alter your head out of the cockpit time.

All in all, keeping a good look out can do no harm, with luck you might avoid an aircraft by doing so, PCAS adds, for a very small cost, an additional (and in my opinion significant) margin of safety which combined with defensive flying and receiving a RIS whenever possible all help to reduce the risk of a collision significantly.

Should all aircraft carry a transponders?

I was for many years opposed. It is important to protect our rights and to recognise the problems fitting a transponder to some aircraft and gliders. As the cost of these units has fallen I find it more difficult to justify exempting some aircraft, whilst appreciating that in some cases cost is not the only factor.

I would guess that if there was a market a portable transponder that only squawks 7000 would be cheap to produce and could be made so it was both portable and could be powered by a self contained NiCad. If the purpose of a transponder in the more "basic" aircraft is only to enable the transponder to be interrogated for collision avoidance and the pilot has no intention of operating within CAS this would seem a very simple solution.

ChampChump

22nd Feb 2008, 15:36

Well, how about everyone calms down and fits a nice big high visibility jacket to their aircraft? Yes the cloak of invincibility....

I'd have thought the solution was simple; make it mandatory for all aircraft to wear a hi-vis vest!

I guess great minds think alike...

Rod1

22nd Feb 2008, 16:23

IO

”Rod1 - how is the empty weight of your homebuilt made up? % due to engine, airframe, avionics, etc. It should be trivial to save 5-10kg by replacing certain non-structural items. I realise you carry a transponder but you gave this example as representing huge numbers of pilots. “

A VLA does not have the problem of a max empty weight. It is the micros, which have the problem. The CT and Eurostar aircraft are within 0.5kg of max empty weight factory built and that is with min allowable kit, no radio and no transponder. My glass panel and standard kit is quite light (the HSI is 300g all in including the solid state gyro). If I had to save weight the navcom is 3.88 lbs and the transponder is about 2 kg excluding wiring and aerial so they would be the obvious choice. I could exchange the CS prop for a fixed pitch, but this is only going to save a few kg as the prop is a state of the art carbon bladed electrical unit. Non of the above will help the CT/Eurostar as they would not have any of it to start with. The empty weight of mine is 253kg, mtow 490kg so she nearly lifts her own weight.

I agree that large chunks of GA are below 2000ft, including most spam cans. It was your assumption of a connection between no electrics and flying low that I was disagreeing with. The aerobatic boys do not fly low and a lot of home built and some factory stuff comes with no electrics to save weight and improve performance. I make no comment on this being a good thing, it just is.

Ironically, the number of flying machines, which cannot carry transponders, is set to increase massively over the next few years. Literally 100’s of unregulated 115kg max empty weight machines are on order and new designs are coning in to this new CAA approved category. Do not assume these will not fly above 2000ft

WR

There is a guy at Old Sarum who works in engineering and owns a vintage piper who has exactly the setup you describe. In practice he gets about 1.5 hours out of the battery with the wind generator operating, but that is with the radio and transponder on. It is sufficient to get him into L2K and out again but he only uses the transponder to get into cas. Sorry I cannot remember his name; it has been a long week.

Rod1

Rod1

22nd Feb 2008, 18:13

If Richard can only get about 1.5 hours with a wind generator backing up the battery then you would need a very big battery to get 8 hours. I therefore assume that the transponders get interrogated a lot more than the above examples assume. The guy who did the “science” part of the LAA submission to the CAA certainly thought it was a non starter to power an existing transponder with a battery, but I do not have a copy of this assumptions and calculations. Unless you could build an entirely portable box it would be of little use in most aircraft anyway.

Rod1

shortstripper

22nd Feb 2008, 18:56

I still think we're approaching the problem with the wrong technology. What's wrong with the gps based FLARM system? see ... http://http://lbs.gpsworld.com/gpslbs/article/articleDetail.jsp?id=308235 (http://lbs.gpsworld.com/gpslbs/article/articleDetail.jsp?id=308235)
It appears very practical, cheap in comparison and light. Power consumption is low and it is self contained. I'm guessing that because the system works aircraft to aircraft and not aircraft to ground, that the CAA ect have nothing to gain. It's the sort of system that could actually work if we all supported it but just like TCAS, will fail if only a few aircraft use it. It does though seem more likely to be practical than transponder based systems, or am I missing something obvious?

SS

IO540

22nd Feb 2008, 20:26

A straight calculation based on modern LIPO batteries seems to defy the above logic.

The CT and Eurostar aircraft are within 0.5kg of max empty weight factory built and that is with min allowable kit, no radio and no transponder

I know I keep coming back to this, but do the dealers who sell these clearly state that

- you cannot fly to NORDO airfields (loads of them)
- you cannot fly in transponder airspace (plenty of that too esp. abroad)

Looking at 253kg, saving 5-10kg on that should be easy. There are loads of parts which are not significantly stressed and these could be made of magnesium instead of ally. I machine Mg routinely at home; it's perfectly safe.

Finally, I agree aerobatic planes fly potentially anywhere vertically but they are not a statistically significant bit of the big picture. If they were, they would be introducing a new hazard, but aerobatic pilots generally choose places to do it where there isn't much traffic.

BackPacker

22nd Feb 2008, 20:56

Finally, I agree aerobatic planes fly potentially anywhere vertically but they are not a statistically significant bit of the big picture. If they were, they would be introducing a new hazard, but aerobatic pilots generally choose places to do it where there isn't much traffic.

Well, a vertical block altitude of 2500" should generally be enough for a full sequence. The height of a loop is approximately 500" and a one-turn spin should cost less than 1000" so to say that we "fly anywhere vertically" is a bit of an exaggeration - unless you aerobat in a jet of some sort.

We do indeed tend to fly in places that see little through traffic though, try to get the best ATC service available (well, at least I do) and squawk either the assigned discrete code or 7004. There is an implicit expectation that ATC, where possible, will issue traffic warnings about aerobatics pilots when they know about them, regardless of "limited service due to controller workload" or the exact service that someone obtained, as keeping a lookout while doing an aerobatics sequence is a tad harder.

Fortunately we do change direction, altitude and speed a lot, making us a little more conspicuously than traffic that flies straight and level. Remember it's the traffic that doesn't move with respect to your windscreen that kills you.

Rod1

22nd Feb 2008, 21:18

“I know I keep coming back to this, but do the dealers who sell these clearly state that”

I have no idea and it is not really relevant to the debate. If you allowed us to junk the current rules and start from scratch we could knock up a better regulatory set of rules in a few days. When we started all this the CAA said that there would be a mobile phone size transponder, when it did not materialise we pointed out some basic ideas. Number one was allow micros with a transponder to increase the max empty weight by 5kg. The CAA group who were peddling the “transponders for all” went away and asked their opposite number in a different department, who said no way. This was one of the nails in the transponders for all coffin. It would still be good if we could win the concession, but I am unaware of any progress on this in the last 9 months. You now start to see what we are up against…

If you think it is possible to save 10kg on my aircraft basic structure give Cristoph Robin a call at Dyn Aero, he will probably reward you greatly. Just remember it is mostly carbon fibre and is much lighter than any of the opposition, which is why it performs so well.

“FLARM system”

This was pushed hard by the BGA. The formal CAA response to the 1st consultation spends some time dismissing it as unsuitable. I think you will find the document on the LAA site, but it must be on the CAA site too.

Can I suggest that if some of you would like to get involved at the sharp end of all this I know of several organizations who are desperate for help. Be prepared for a big shock, as any allusions you had that there is a big plan and somebody has thought it all through will rapidly disappear. The considerable number of people who worked on this on your behalf may not have won every battle, but we did iron out a huge number of kinks in the plan.

There is a meeting on the 15th March at LAA headquarters open to all. The CAA will be presenting the case for the second consultation and will be available to answer questions. I will be there and it would be nice to think you would all come along...

Rod1

vee-tail-1

23rd Feb 2008, 11:59

Thanks Rod..will try to make it.:ok:

Rod1

23rd Feb 2008, 18:16

There is a mode a/c on afors

Rod1

wigglyamp

25th Feb 2008, 17:24

I've installed battery-only powered transponders in non-electric aircraft.
A couple of light-weight/low power examples:

Filser TRT800. Weight 570g. Consumption typical 200A.
Becker ATC6401. Weight 800g. Consumption 370mA.

A typical battery used in Tigermoths and many gliders is the Yuasa 6.5A/Hr sealed lead-acid. When operating both a VHF (Becker AR4201) and a transponder, battery life is normally around 5 hours. A new aviation approved Lithium battery is about to be available which doubles the capacity to 13A/hr in the same size case - it's being targeted directly at the glider community.

If you needed to swap the transponders between different aircraft, both of the above units store the aircraft data in non-volatile memory, either in the aircraft mating connector (TRT800), or in a 'dongle' (ATC6401) which plugs into the transponders (same method as many 406 ELT's use), so you don't need to re-programme or risk sending the incorrect Mode S address when you swap units around.

BackPacker

25th Feb 2008, 17:41

And all this is approved, as far as approvals are necessary? Sounds very interesting.

Is this mode A, C or S? If C or S, do you get static pressure from the cockpit or does it tie in with existing static plumbing?

Are the units accessible in-flight to change a squawk?

How about the antenna. Is it permanently wired into the aircraft or portable in some way?

Oh, and I assume the Filser uses 200mA instead of 200A...?:}

wigglyamp

25th Feb 2008, 18:29

Whoops! Yes, 200mA.

Both units have EASA ETSO approval, so installation is good in any European state. These units are approved for aircraft below 175kts/15000 feet, but both manufacturers make similar units for higher speed/altitude.

The Filser unit has a built-in altitude encoder - you connect the aircraft static directly to the back of the unit. The Becker needs an external encoder (they were promising an encoder module to plug on the back, but I haven't seen one yet).

An external antenna is required (Comant CI01 for about $90), and this needs a ground plane - this can be foil or copper mesh on a plastic aircraft - it needs to be about 15cm diameter. You can even mount the antenna internally on fibreglass or fabric aircraft (not with carbon-fibre, as it shields the signal)

If you want to do the installation in an EASA certified aircraft, you will need some form of design approval, either from an EASA Part 21J design organisation, or via a direct minor modification application to EASA. If it's an annex 2 aircraft, you apply directly to the National Authority for the minor change (In the UK, most Part 21J companies also have a UK national design approval as well for annex 2 aircraft).

Hope this helps.

soay

25th Feb 2008, 19:00

Is this the Filser unit?

http://www.lxavionics.co.uk/images/trt800-nm.jpg

More information here (http://www.lxavionics.co.uk/transponders.htm).

shortstripper

25th Feb 2008, 20:53

So what about FLARM? Anyone have any experience of know anything about the system first hand?

SS

IO540

25th Feb 2008, 21:17

These units are approved for aircraft below 175kts/15000 feet, but both manufacturers make similar units for higher speed/altitude.Don't you just love the totally blatent cynicism of aviation marketing ;) It's the same damned product.

I would like to know what is the real meaning of an "aviation approved" lithium battery. It's a bit like a barbeque approved for use inside a petrol refinery.

Wigglyamp - should there be a problem with a transponder which is fixed to the (non-electric) aircraft's panel, and the battery being on a flying lead with a connector? That makes the battery portable, and portable stuff does not need approval (except for transmitting equipment where the CAA has the responsibility for approving e.g. Icom handheld transceivers).

It also means that if the battery starts smoking, you can unplug it and chuck it out of the window (if you have a window at all).

wigglyamp

25th Feb 2008, 22:37

You can't have an approved transponder installation with a PORTABLE battery - it's not certifyable. To certify the installation means showing that all component parts will remain in place to specified G loads - bits in the cockpit which can injure the occupants in an accident must be secure to 18G forwards. Hidden bits need to meet 9G (all details are in EASA CS23.561)

The Lithium battery problems with catching fire have long been recognised - hence they've not seen widespread use so far, other than memory back-ups in GPS systems and deployment batteries for ADELTS (helicopter deployable ELT's used on North Sea).
The new development in Li batteries is meant to address these issues and provide the opportunity for smaller, higher capacity batteries so you can run essential equipment e.g. transponders in non-electric aircraft. I've heard it mentioned from a battery manufacturer that the EU will ban production of Lead-Acid batteries from 2012 - will we go to Ni-Cad, with similar overheat problems, or to the new high-capacity Li. I think it'll be the latter, as we'll end up with more glass cockpits needing more power for continued operation when the generator fails.

On the different transponder units for height/speed ranges, certainly the Filser unit required a different altitude sensor to get the required 35000 feet, and it's got to maintain it's accuracy, so it's got to be pretty good, considering it's tiny space in the existing transponder case. Also, for both Filser and Becker, the output power is higher for the greater range requirements. As aviation product runs are much smaller that commercial electronics, I guess the manufacturers see this as a way to claw back some of the additional development and certification costs.

robin

25th Feb 2008, 22:55

ChrisN has lots of experience of FLARM, but the CAA are quite clear that currently it is illegal to use it in the UK - apparently it upsets people who have radio-controlled garage doors, or something!!!

robin

25th Feb 2008, 23:04

>>>>>>>>>>Can I suggest that if some of you would like to get involved at the sharp end of all this I know of several organizations who are desperate for help. Be prepared for a big shock, as any allusions you had that there is a big plan and somebody has thought it all through will rapidly disappear. The considerable number of people who worked on this on your behalf may not have won every battle, but we did iron out a huge number of kinks in the plan.

There is a meeting on the 15th March at LAA headquarters open to all. The CAA will be presenting the case for the second consultation and will be available to answer questions. I will be there and it would be nice to think you would all come along...

Rod1<<<<<

Rod

Well said. The whole issue is one that needs constant monitoring in our 'copious spare time'.

I have been to many such meetings and have spoken to the CAA staffers. I have usually come away somewhat mollified, then, weeks later, found that others in the department have reneged on everything that was said previously.

Whilst I have great respect for one or two in the Mode S CAA team, I can see that they have decided to use 'salami tactics'. That is to come to the original conclusion slice by slice.

Where in this new consultation is the commitment to the 'mobile phone sized, sub 700 euro LAST/LPST? They do state that in Phase 2 gliders will lose exemption, but, again, make no comment as to how this can happen.

The radiological study is lacking the 'Ladybird Guide' for scientific innocents like me, despite a strongly worded request from the LAA.

No, as many of us as possible need to highlight the outstanding stupidies and impracticalities in the CAA document and a good start is to attend one of the roadshows.

I'll be at Turweston, as well, if only to scrag a CAA rep

chrisN

25th Feb 2008, 23:49

robin wrote:
"ChrisN has lots of experience of FLARM, but the CAA are quite clear that currently it is illegal to use it in the UK - apparently it upsets people who have radio-controlled garage doors, or something!!!"
------------------------
Sorry, not quite accurate. I have a Flarm, but have not yet used it in the air – a job for this season, assuming CAA approves it. I have, however, read lots about it, including results of trials in 2007 at Portmoak and elsewhere. My impression is still that it does more good than harm, but only of course between Flarm-equipped aerial conveyances, which is likely in the UK only to be some gliders, some tugs, and maybe some of various other categories at the light GA end.

Nothing would prevent other GA from getting them too, especially those who complain that they hate gliders/can’t see us/it’s our fault we can’t fit transponders (even for those gliders where it is not our fault, of which there are many) etc. – but I’m not holding my breath.

Although Flarm uses radio-controlled garage door frequency, I have been told it is too low powered to cause a problem. No doubt that is part of what CAA were/are looking at.

CAA were saying it had no approval YET for UK use, but the BGA told me, in effect, watch this space; it was likely to get either approval or at least not actively disapproved early this year.
- - - -
I shall be interested to see if the Li battery mentioned by somebody comes about with aviation “approval”. I’d like the extra juice, but don’t think I would dare use them unless the “approval”/formal certification is real. (Would chancing it without such approval endanger insurance cover in the event of a fire or other incident/accident? Don’t bother answering here – the only answer I would believe would be from my insurer and only then if in writing.)

Chris N

bookworm

26th Feb 2008, 07:39

Nothing would prevent other GA from getting them too, especially those who complain that they hate gliders/can’t see us/it’s our fault we can’t fit transponders (even for those gliders where it is not our fault, of which there are many) etc. – but I’m not holding my breath.

So I have to carry a completely separate bit of kit, displaying on a separate screen, to detect gliders... And then next year, the microlight community will decide they want to use a different technology with different standards and I have to go and buy/fit another piece of kit...

There's a perfectly good standard out there for this which is an ICAO standard. It's ADS-B over 1090ES which most large aircraft and an increasing number of light aircraft already have the equipment to use. The issue is surely only about the power required vs the range of the equipment -- I can't see anything about FLARM that improves the range to power over 1090ES. All the cost is in the certification and it's as easy to certify a light and low-power 1090ES transponder (or at least, ADS-B-out box) as it is to certify FLARM.

IO540

26th Feb 2008, 08:13

I've heard it mentioned from a battery manufacturer that the EU will ban production of Lead-Acid batteries from 2012 - will we go to Ni-Cad, with similar overheat problems, or to the new high-capacity Li

Highly unlikely lead acid will be banned, since lead acid is the only battery technology that can be charged satisfactorily from a simple constant voltage source (an alternator with a voltage regulator). One would need a major change in car and plane electrics to use a NICD/NIMH or LI battery.

I've designed countless charging circuits for battery powered appliances over the years.

NICD or NIMH needs a constant current charger with a voltage and/or temperature-rise based cutoff. I wonder how they charge the ones used in jets?

Rod1

26th Feb 2008, 08:21

bookworm

I think the point about FLARM is that it is very popular in parts of Europe so it has an installed base. However the CAA have rejected it and given a full explanation as to why. I have never seen this refuted, and as far as I know FLARM is off the table.

wigglyamp

I do not think CS23.561 would apply to most of the aircraft with no electrics. Most would come under CS-VLA or Section S which I think uses lighter loads. In LAA land you could certainly get approval for a mounting box which would allow a battery to be clipped in and removed. Approval might involve full stress calculations etc though and this only overcomes one of the many problems such as weight, space etc.

Rod1

IO540

26th Feb 2008, 09:57

The clever bit, if it worked, Rod1, is that a removable battery might not feature in the empty weight ;)

Mind you, even a "huge" laptop LIPO battery weighs only a fraction of 1kg.

Rod1

26th Feb 2008, 11:12

IO540,

It would defiantly not count in the empty weight if it was powering “optional equipment”. If the aircraft had to carry a serviceable transponder and it needed the batt to work then it would count.

Rod1

chrisN

27th Feb 2008, 11:02

Bookworm on 26.2.08 quoted me: “Quote: Nothing would prevent other GA from getting them [Flarm] too . . . “ and wrote “ . . . So I have to carry a completely separate bit of kit, displaying on a separate screen, to detect gliders... And then next year, the microlight community will decide they want to use a different technology with different standards and I have to go and buy/fit another piece of kit...”

BW, there is a great difference between “ nothing would prevent” and “ have to”, as I’m sure you must be aware.

I have better things to do than spend time on a fruitless dialogue. If, however, anyone seriously wishes to discuss the issues based on facts as far as they can be determined, logic rather than emotion, and realistic possibilities of outcomes, I might be prepared to spend some further time on the subject.

For what it’s worth, the present position that I have reached is that mode S. has its place, but mandating it across all aircraft in the UK is not on. FLARM and ADS-B also have their place at present in some parts of the world, and I believe that could include the UK today as far as FLARM is concerned. It may be that at some future point FLARM could be replaced by ADS-B, but that would require further development of ADS-B, taking on board the utility that FLARM already has, and a price, package, and weight combination that makes it feasible. I suspect that even then, there would be issues that it simply is not practical to fitted into certain aerial conveyances. Mandating any universal requirement for additional instruments would either result in grounding some aircraft, or there would have to be exemptions if they were able to continue flying. That is a matter of hard, practical fact. I am not totally opposed to mode S; I have already taken some steps to be able to fit one into my glider, and if there is a reasonable technical solution I might well obtain one because of the particular areas in which I fly, and the particular things which I wish to do myself. I do not regard the technical and price package available at the moment as acceptable or justifiable, but if and when that changes, I would probably go for it.

I don’t mind explaining the reasons for my present position, if anybody is interested and wants to have a sensible dialogue.

Chris N.

bookworm

27th Feb 2008, 16:42

BW, there is a great difference between “ nothing would prevent” and “ have to”, as I’m sure you must be aware.

What I meant was "In order to detect gliders I have to carry a completely separate bit of kit...", not that such a thing would be mandated. The point was that there would be a proliferation of incompatible standards.

I have better things to do than spend time on a fruitless dialogue.

I've obviously wound you up which was not my intention, sorry: it's evident from your past contributions that you take a balanced and logical approach. Nevertheless, I would maintain that

a) in collision avoidance systems, interoperability is crucial, hence common standards are paramount

b) there is no technical reason why a 1090ES certified system would be more expensive or more power hungry than a certified FLARM system of equivalent range -- the reason FLARM is cheap and light is that it is uncertified and shorter range.

c) 1090ES is the established ICAO standard

Therefore the sensible way forward for all airspace users is to rally around a light and affordable 1090ES-based system that is proportionate in its cost and power consumption to the class of aircraft in which it is to be used.

chrisN

27th Feb 2008, 19:23

BW wrote 27.2.08: “
a) in collision avoidance systems, interoperability is crucial, hence common standards are paramount

b) there is no technical reason why a 1090ES certified system would be more expensive or more power hungry than a certified FLARM system of equivalent range -- the reason FLARM is cheap and light is that it is uncertified and shorter range.

c) 1090ES is the established ICAO standard

Therefore the sensible way forward for all airspace users is to rally around a light and affordable 1090ES-based system that is proportionate in its cost and power consumption to the class of aircraft in which it is to be used.
-----------------------------------
My reactions:

a) in collision avoidance systems, interoperability is crucial, hence common standards are paramount

In an ideal world, and other things being equal, I would agree. But other things are far from equal today, and I see no sign that they will be in the foreseeable future.

b) there is no technical reason why a 1090ES certified system would be more expensive or more power hungry than a certified FLARM system of equivalent range -- the reason FLARM is cheap and light is that it is uncertified and shorter range.

Even the difference between certified and uncertified is likely to add so much cost that it will preclude wide use, except where it is virtually or actually mandatory, such as glider flying in the Alps. EASA replacing the hitherto BGA airworthiness and modification system in the UK at the very least adds cost, and in practice may make widespread or universal adoption virtually unattainable.

I suspect that, for many gliders, even uncertified FLARM, in a portable rather than installed form, is at the very least difficult to put into universal operation. Anything bigger, certified, requiring more battery, and if developed for other users and not delivering the algorithm-based outputs for which glider pilots designed it, it’s going to be less welcome and/or less practical.

c) 1090ES is the established ICAO standard

Fine, but new developments based on it will have incremental development costs which have to be recovered, and will take time which means it is not an immediately available solution.

“Therefore the sensible way forward for all airspace users is to rally around a light and affordable 1090ES-based system that is proportionate in its cost and power consumption to the class of aircraft in which it is to be used.”

AFAIK, it is not accepted by any of the major players, stakeholder organisations, or the majority of their constituencies, that it is the sensible way forward. For such a plan to get off the ground, I think it would need selling to them. They would need to see how it addresses their concerns, and how it is going to benefit them. Everyone with a financial turn of mind would want to see that their personal costs and the overall investment in any such scheme are a sensible and proportionate use of money, in relation to the risks and/or costs of not adopting universal and interoperable systems. I am certainly not so persuaded myself, at present.

Again, AFAIK, mode S, ADS-B, and Flarm were all developed in different “communities” and even different countries, to address different needs. They each obtained sufficient support and take up among their respective communities to justify their respective development. Their continued expansion by those who want them shows that this process is continuing. The strength of objection to spreading any of the three, potentially to take over some part or all of one or both of the other two functions, is indicative of the difficulty in convincing people that there is a widely acceptable universal solution to collision avoidance.

I realise that these arguments are largely glider oriented, but that of course is where I come from, although I do take a wider view too.

Chris N.

wigglyamp

27th Feb 2008, 21:53

IO-540
Many aircraft, particularly gas-turbine heliciopers and small turbo-props, have Ni-Cad batteries charged directly from the constant voltage bus - Bell 206 JetRanger amongst others. They do have overtemp warning fitted.

The new generation Ni-MH batteries currently under development have a patented charging system to allow use in environments such as aircraft, and the designer is confident we'll have them in certified aircraft in the not to distant future, and certainly in gliders in the UK very shortly. They are already in service with the UK and foreign military forces for specific roles (not yet primary aircraft power as far as I'm aware)

Rod 1.
I mentioned CS23.561 with my Part 21J hat on - in EASA land, I'm required to show compliance in design with the latest standard (21A.101) unless I can show good reason for staying with an older cert basis. I accept that many LAA type aircraft don't come under this rule, but if I was to certify a design in an Annex 2 aircraft (Tigermoth etc) under my BCAR design approval, I'd still have to meet the same design criteria, as the BCAR approval is piggy-backed on the EASA Part 21J approval and has to use the same design rules and procedures.