IFR and collision avoidance

[Sarik]

Hi,

I'm a 'low time' pilot at the minute (40 hrs so far, still learning), and tend to spend most of my time either thinking about Helo's or reading about them.

Of the 40 hours flying I've done, I've spent a few of those with other helo's in visual range...I'm wondering if you IFR pilots can answer what is probably a very simply question..

How do you 'apply' collision avoidance if your IFR..??...

(Or do you just hope no one else is stupid enough to be flying around in that particular thunderstorm..??? :D )

Sarik.

[ClearBlueWater]

Look up Quadrant Rule, Semi Circle Rule and Radar Advisory Service for complete answers.

[Nick Lappos]

Under IFR the collision avoidance job is legally assumed by ATC for all aircraft filed and flying under IFR. If an IFR aircraft is in visual conditions, it must clear itself from other aircraft flying under VFR, but any aircraft filed under IFR is separated from any other IFR aircraft by ATC. Of course, in cloud in controlled airspace, this means that you are fully protected, but might only be threatened by some wacko who has not filed IFR.

[widgeon]

Lots of threads on fixed wing forums about TCAS and the midair over Germany . Goodrich Market a TCAD as do Ryan and I think Honeywell ( king). Is the main difference between TCAS and TCAD that TCAD only alerts but does not give resolution advice ( assuming that the approaching target probably does not have an active tcad ) ?.

[SASless]

Nick,

The mini-gun smoke is getting into your eyes again! Should I recount an experience that happened on the North Sea....wherein I passed a BAH S-61 going the opposite direction in cloud.....close enuff to still recall the clothing the BAH pilots were wearing....down to the length of sleeves...and which one was driving? Or, the time at Hilton Head Island over the US Army NDB there, where not two....but three UH-1's found ourselves holding at the same altitude.....momentarily! Also the time while riding Jump seat in an Iranair 727, we crossed the Shiraz VOR at the same altitude and time as an Iranian AF 747 (in cloud)...Or.....the latest crash in Germany........if you will add "in theory" to the statement then I will accept that.

[Arm out the window]

Depends where in the world you are, too; in Australia depending on what flavour airspace you're flying in you can either have

(a) full separation,

(b) be told where other IFR are based on their estimates at reporting points (or on radar info if there is any where you are), and sort out your own vertical or time-based separation for yourself, or

(c) broadcast on a frequency that other IFR listen out on (no air traffic control or information service) and figure out where they are and whether they're going to affect you.

I think in the UK it's pretty much full separation for all IFR, isn't it? Please correct me if I'm wrong!

[Hezbollah]

In UK it depends what service you are getting.

Radar Control service (always if IFR in CAS) - ATC provides mandatory separation.

Radar Advisory Service - ATC gives you advisory heights and headings to maintain separation - you dont have to obey, but if not you have to tell ATC

Radar Info Service - ATC tells you about positions of conflicting traffic, and you sort out your own separation

Flight Info service - ATC might tell you about traffic he knows about ( he may not have a radar) - you fly quadrantals, and use the big sky/small aircraft theory for seperation.

Thinking back to my PPL days, this is not a subject well taught to beginner pilots - I didnt have a clue what ATC services were available as I wandered around the fringes of Gatwick airspace. I suspect there are many more in that situation now.

[Nick Lappos]

SASless,

Please note that I wrote "legally assumed" that ATC is responsible for separation. That means that if you had a midair with that opposite bound traffic, you would not be legally dead, I think.

Just guessing.