tcas on departure/final approach

[almost professional]

scenario:-public transport aircraft lined up to depart,VFR helicopter, transponder on, manouvering NW of airfield below 1500ft within two miles-VMC, traffic info passed and helicopter in sight of departure and vice versa.
A:would you refuse to depart on the grounds a TCAS RA would be generated?
B:when airborne would you comply with a TCAS RA generated by the helicopter?

Also is there a lower limit level wise below which TCAS should be inhibited?

thanks in advance (yes this is something that has happened more than once and the only way round so far has been to get the helicopter to squawk standby, hardly a satisfactory procedure)

[goatgruff]

An interesting point, because at our place it happens virtually every day.
We're outside controlled airspace, but have tightly regulated agreements with an adjecent airfield as to whose traffic can do what depending on the runway in use at our and their bases.
This probably gives us (and perhaps the piolts?) a greater degree of flexibility than most airports inside CAS.

We give the traffic information to the Tcas equipped aeroplane on the known traffic and keep them updated, and I've yet to see any of them take any tcas originated action.

This is with both UK, European and non European operators of aircraft of all shapes and size.

It would be interesting to know from the pilots perspective though.

[Little One]

This seems like a normal scenario that we have in here. We have 2 VFR Chopper routres that run east/west 2NM north and South of the runways OM position. Traffic on these routes are deemed seperated from the dep/arr tfc but ussually a TCAS warning will be received by the acft. Traffic info is not ussually given to dep/arr flights unless the flinging deviates from the published route as flight crews are expected to know that choppers could pass below them on these routes as it is published in our AIP. I ussually pass tfc info anyway just to avoid the paperwork if an acft reports a TCAS warning, although our SOP's state that TCAS should be turned off in the TMA and CTR. (Our Company requires us to file a report for all TCAS warnings if the pilot reports such warning on Freq even if std seperation was maintained.) Most Airlines who operate here keep there TCAS on at all times in flight.
As PIC I feel that you may refuse dep if you wish with the chopper in the climb out path as you have final responsibilty for the flight (this will usually envolve some choice words from the ATC before they key the mike again- Take notes on how to **** an ATC off in 1 easy step.) In most cases here unless the helicopter if medical or police the helicopter will be instructed to move for your dep if you refuse to depart however we seldom get a refusal to depart.:cool:

[ETOPS]

Almost Professional

Just select TA Only on the transponder for departure and when clear of the traffic set it back to TA/RA .........

[SLT]

On the Airbus series, the TCAS RA's are inhibited at certain stages of flight as a function of aircraft altitude. The following cases are inhibited on the A320:

"all intruders flying below 380 ft AGL when own aircraft altitude is below 1700 ft AGL. all TA aural messages and all RAs below 1100 ft in climb and 900 ft in descent. In this case, the RAs are converted to TAs. 'Descend' type advisories below 1220 ft AGL at takeoff or 1000 ft in approach. 'Increase Descent' RA below 1450 ft"

The above is an extract from A320 FCOM 1.34.80 p6. The logic is the same on A330, but some of the height bands are higher, and there are no aural TAs at all below 500 ft AGL.

Hope this helps :)