Very Light Jets with no TCAS in commercial airspace

[rosie11]

Pilot ACAS Survey

Hi,

I am a university student currently studying Air Transport with commercial pilot training and I currently hold a CPL.

For my dissertation I am studying the Pilot's opinion of ACAS and have developed a survey for pilots who have flown a ACAS equipped aircraft.

The survey will take less than 5 minutes and is completely anonymous and optional.

I would greatly appreciate your cooperation

Thanks


Click Here to take survey">Click Here to take survey

[Nugget90]

Does being a Professional Pilot/Air Traffic Controller affect the Outcome?

This thread contains posts that have queried the value of TCAS/ACAS II when the pilots might be termed 'professional' (whatever that means). IMHO this doesn't mean very much, and it matters less if the 'professional' being discussed is a pilot or an air traffic controller. ACAS II is there to provide the pilot with advice that can 'save the day' in the event that something has happened to allow two aircraft to approach one another closer than either the pilot, or the controller if one is involved, would wish. So, for example:

The pilot of the intruder aircraft has continued climbing through his cleared flight level because he made an incorrect selection or because he misheard the numbers or because the 'altitude acquire' function failed to operate as expected and wasn't detected in time. Or because the controller cleared the aircraft to a wrong flight level or gave a heading that induced a conflict. or the pilot of an aircraft that could only post TAs attempted a last minute manoeuvre in IMC that induced rather than reduced the risk of a conflict.

There are many other scenarios: see the excellent series of ACAS Bulletins posted by EUROCONTROL to see what I mean! It really doesn't matter how 'professional' the pilots of one aircraft or the controller on the ground are when the 'other guy' does something unexpected: that is what TCAS/ACAS II is for - to post advice that, if followed, should save the day.

Just a comment also on the merits of TCAS I. This has not been mandated for any class of aircraft in the JAA Member States area because there can be no assurance or expectation that VMC will prevail. In the UK, many police and air ambulance helicopters have TCAS I to help their pilots identify any potential traffic operating in their vicinity: since they operate VMC for the most part this makes good sense. Yet for aeroplanes that will frequently be operating in IMC, TCAS I makes no sense: it's not dissimilar from a non-altitude reporting intruder being shown on the TCAS display. You can see the threat, but you don't know plus or minus a few thousand feet how his altitude differs from yours - and he could be co-altitude with no possibility of co-ordinated RAs if those algorithms are infringed! TCAS I is - arguably in IMC conditions - worse than no TCAS at all (but only if the non-TCAS aircraft has a serviceable, operating altitude-reporting transponder, of course).

In the busy air environment that is shared by many passenger and freight/cargo aircraft, TCAS/ACAS II is highly valuable safety equipment and should, I would argue strongly, be carried by all aeroplanes that by virtue of their size, weight, speed or complexity of operation render the 'see and avoid' principle of little value.

[IO540]

There are some people here who think the VLJs will be flying the same tracks and levels as CAT.

A bit more understanding of "IFR GA" in European airspace is needed here.

The VLJs won't be on the same tracks - they are much slower and the lower end VLJs from the GA piston makers have a low ceiling (e.g. the Diamond D-Jet, FL250 max).

So a large % of so-called VLJs will in fact be flying Eurocontrol routings not very different from what a piston IFR tourer will be flying - in that great void between the airway MEAs and about FL200/250. That's where I fly around Europe and there is quite obviously virtually no traffic there. Only rarely does one get visual with a big jet - even on a 700nm flight right across Europe's businest airspaces at say FL170. It's obvious from the ATC interaction there is not an issue flying "slower" in this huge unused airspace void.

And the Eurocontrol routings will take a flight plan filed for say FL150-250 way away from the busy terminal areas in which there is CAT at those levels, so that isn't an issue either.

And if a VLJ has a ceiling of say FL400 and you file the Eurocontrol flight plan for that and get it accepted (which you will) then given your TAS will be maybe 2/3 of a 777, ATC are not going to actually give you anywhere near the same level on the day.

So.... the "problems" are solved even before they appear. It's a non-issue.

Some VLJ owners are going to get a few suprises on the last front, relative to what they paid for, thinking their new jet will be so much more capable than the turboprop which would have carried them a little bit slower but much further, much cheaper and with more load, but that is not a safety issue

Finally, the marketing case for "thousands of VLJs" (phrase taken from a NATS presentation I went to) falls flat on its face as soon as one starts looking at Europe. Most of it hangs on air taxi operations anyway. It's easy to look at turboprop sales and activity over the past 10-20 years and they are only a little slower. There isn't any reason to believe the manufacturers' wild projections.

Incidentally, are there even any certified TCAS systems capable of generating an RA, for light GA? I am not aware of any.

[Denti]

Thanks for posting that link Mike, according to those mission profiles the Eclipse uses pretty much the same altitude profiles as say a 737 or most probably any other shorthaul jet.

[threemiles]

It's obvious from the ATC interaction there is not an issue flying "slower" in this huge unused airspace void.

This is a dangerous conclusion. Even this huge unused airspace would be used by commercial jet aircraft climbing and descending to higher altitude somewhere.

[IO540]

Even this huge unused airspace would be used by commercial jet aircraft climbing and descending to higher altitude somewhere.

It isn't because the route accepted by the Eurocontrol computer will take you away from those areas.

Mike Jenvey - you are right IMHO and some VLJ operators may get suprises. However, there won't be suprises on routings granted by Eurocontrol because you know the filed route before you fly. It may be 700nm for a GC distance of 600nm...

[PPRuNe Radar]

Apart from military airspace, where is this great void over Europe where there is no traffic ?

[Jetscream 32]

reply for mike jenvey.....

Mike - you seem to endorse a vigilanti style approach to things you do not like or see fit to investigate further or indeed have knowledge in?? Regulators make the decisions, we have to abide by them.

Im all for lobbying for things in the interest of flight safety but you have to have a a clear structured approach to what you want to achieve and the reasons you want to achieve it, based on facts not on personal opinion.

Just because YOU want every other aircraft operating in YOUR atmosphere to know where you are is not reason enough to call all the media into hysteria about this new breed of aircraft- when you have no facts to prove your ASSUMPTIONS...

Lots of pilots have had near misses with military traffic some very close, not fitted with TCAs, not under radar control - there will be mid-air's it is a statistic that is inevitable - however your approach is pretty rubbish in how you wish to enforce your views.

You seem to care little about your actions and how they affect jobs both directly and indirectly

If you have a problem - then get round the table and do things properly, talk constructively to the people that understand your concerns and can make a difference......

[ZFT]

Remember 31/08/86? All the lessons should have been well and truly learnt that day!

[FlexibleResponse]

It won't be too long before the introduction of the "Free Flight" system will make these systems mandatory for all aircraft operating in the Free Flight designated airspace. When confidence is gained, designated free flight airspace will be expanded enormously and then all aircraft will be required to carry appropriate avoidance equipment. Even sky-divers will carry a transponder. Non-free flight airspace will then be the exception for certain types of flying activities.

My gut feeling is that will occur sooner rather than later. In the meantime...

If any aircraft wants to mix it with public transport aircraft on airways and in civil airspace, then that aircraft must be equipped with TCAS regardless of its size.

[threemiles]

It isn't because the route accepted by the Eurocontrol computer will take you away from those areas.

There is nothing such as Eurocontrol routes in Europe nor are there Eurocontrol computers taking you away from an airspace. Have you ever flown level in Central Europe at FL250? Amsterdam, Brussels, Frankfurt, London, Paris, Praha, Zurich? There will be traffic climbing and descending through your level every minute.

I assume you fly over the norther North Sea..., that may be the only place where your assumption is true.

[IO540]

Not flown (nor filed flight plans for) at FL250. Below that there doesn't seem to be a problem - the routings take one away from the SIDs and STARs.

One can fly overhead Frankfurt at FL130+ and I have done so a number of times. The traffic to/from the airport is a long way below.

[1985]

We have been briefed recently about these VLJ's and it is worrying if they can fly around Europe in the Upper airways and TMA's without TCAS. The performance figures we were shown put them in them in with commercial pax carrying traffic. They have high performance figures in the climb and descent and this is where having no TCAS will cause problems.

If they want to fly in the ATS route structure they should be subject to the same rules and regs as everyone else. I don't want to be worrying wether one aircraft has TCAS or not.

[Graybeard]

Ye of great faith in TCAS know should know that the VLJ will have Mode S transponders, so TCAS equipped a/c will escape and evade them quite handily. The VLJ will just have no TCAS protection from each other, thereby removing themselves in pairs from the aluminum gene pool..

As they mix it up with the heavies, a greater risk to VLJ will be wake turbulence.

GB

[threemiles]

One can fly overhead Frankfurt at FL130+ and I have done so a number of times. The traffic to/from the airport is a long way below.

Inbounds/outbounds EDFH, EDFM, military traffic Ramstein, EDDN and so on...
It can be silent on the one freq your on, but if you had a TCAS you'd seen what's going on around you...

Ye of great faith in TCAS know should know that the VLJ will have Mode S transponders, so TCAS equipped a/c will escape and evade them quite handily. The VLJ will just have no TCAS protection from each other, thereby removing themselves in pairs from the aluminum gene pool..

TCAS does not rely on Mode-S and Mode-S does not make it better than Mode A/C. TCAS on one aircraft only is 50% safety only as the TCAS one would get a RA and try to escape, but the VLJ stays level. 100% is definitely better.

[ESSP Flyer]

Vdl Mode 4

Maybe it's finally time for VDL MODE 4 to be implemented?

This enable all ac's to see each other, plus ac-ground vehicles when taxiing, all sort of things. Not very costly.

The system is invented by mr Håkan Lans, which was stolen from him and is now called ADS-B.....

http://www.eurocontrol.int/vdl4/publ.../homepage.html

[Graybeard]

"TCAS does not rely on Mode-S and Mode-S does not make it better than Mode A/C. TCAS on one aircraft only is 50% safety only as the TCAS one would get a RA and try to escape, but the VLJ stays level. 100% is definitely better."

Try to escape? TCAS does better than that; it provides full escape from any correctly reporting target.

Mode S is better than Mode C for a long list of reasons, as it was the first real improvement in IFF since WWII. The VLJ will have full air data computer for altitude, reporting in tens of feet, rather than hundreds.

Mode C has only Gillham Code input of 11 distinct, unmonitored wires. Break one connection, and reported altitude is wrong, by hundreds of feet. In spite of FAA requirement to use the most accurate altitude source in the airplane for TCAS retrofits, some operators or TCAS vendors chose Gillham when an ADC was available. A KAL 747 with the early Honeywell TCAS nearly collided with another jumbo, as it was reporting 10,000 feet, while really at 7,000, or v-v.

Replying wrong altitude is highly unlikely with Mode S wired to a well monitored air data computer like the VLJ will have.

Remember, TCAS is the backup collision avoidance. Mode S provides much more info to ATC than Mode A/C.
And then, there's the latest, enhanced Mode S, which the VLJ will have.

GB

[funfly]

It's not only in airspace, fly at less than 1000' in the area I know well (N Wales) and experience the thrill of military jets screaming under you at god knows what speed or, as I have had, three Herculese a couple of hundred feet above!

[CDN_ATC]

It's still quite amusing to listen to the amount of confidence people have in TCAS of any version.

It's a last ditch save, which hopefully works correctly. I've seen TCAS cause more incidents than it's ever saved.

[greywings]

Confidence in TCAS

As someone who has had his bacon saved more than once by TCAS, yes, I do have a lot of confidence in it. I think we should all remember what led to the push to have TCAS developed - an awful accident involving a public transport aircraft and a light trainer, in, I think, the Los Angeles TCA (or at least very close to it).

Most of the many midairs that have occured in recent times have been in 'controlled' airspace, where normal ATC procedures should have prevented them. One, unbelievably, happened in the middle of thousands of square miles of empty airspace, over the Indian Ocean. To the best of my knowledge, in none of the accidents were both aircraft TCAS-equipped. Had they been, it is almost certain - in my humble opinion - that the accidents would not have happened.

TCAS not only provides accurate and timely avoidance guidance to prevent a collision but also enhances situational awareness in a way that no other single piece of equipment can do so.

Whilst it is impossible to put all VLJ's neatly into one performance category (some are faster, higher than others), all will be mixing in with other traffic in already congested airspace. It makes no sense to permit them do so without TCAS, regardless of what a certain CEO (who should be ashamed of himself for making such a fatuous comment), has said.

I have found (most of) the preceding posts on this subject to be sensible and constructive, and the common thread seems to be that TCAS should be required.

Some of you may be interested to know that the Royal Aeronautical Society will be holding a two-day conference on the introduction of VLJ's into Europe, on the 26th and 27th March. There is an impressive line-up of speakers, representing, manufacturers, users, regulators, ATC, and, of course, pilots.

There should be some interesting discussions.

GW