TCAS RA
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From: flying by night
Follow the RA, trade speed/inertia for height (and avoid stalling), you're trying to avoid a collision, not to cruise. Generally TCAS are not aware of aircraft performance, though many inhibit climb RA above a certain altitude (check with your outfit). Where that is the case, when 2 level a/c are on collision course, TCAS will generate a descend RA for one and keep the other level.
Last edited by deptrai; 15th September 2015 at 18:32.
Joined: Nov 2009
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From: flying by night
TCAS takes performance into consideration- it will give you a climb at max altitude, but one your residual performance can handle.
Afaik TCAS is NOT aware of actual performance limits, e.g. degraded performance due to loss of an engine, but some limits have been taken into consideration during certification.
http://www.faa.gov/documentLibrary/m...-55C_CHG_1.pdf :
and (courtesy of airbus)
( AC 20-131A here: https://www.faa.gov/regulations_poli...cumentID/22190 )
Afaik TCAS is NOT aware of actual performance limits, e.g. degraded performance due to loss of an engine, but some limits have been taken into consideration during certification.
http://www.faa.gov/documentLibrary/m...-55C_CHG_1.pdf :
(1) Aircraft not inhibited to climb when at maximum certified altitude should climb in response to TCAS climb RAs.
(2) Aircraft that are climb-inhibited from TCAS climbs at maximum certified altitude will be issued a “DO NOT DESCEND” RA.
(2) Aircraft that are climb-inhibited from TCAS climbs at maximum certified altitude will be issued a “DO NOT DESCEND” RA.
AC 20-131A defines the maneuvers that the aircraft must be able to perform.
• In particular, the aircraft must prove that it can respond to a TCAS RA CLIMB order, even when it is at its maximum altitude.
• In particular, the aircraft must prove that it can respond to a TCAS RA CLIMB order, even when it is at its maximum altitude.
Joined: Jun 2001
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From: Boldly going where no split infinitive has gone before..
Correct depral- so you CAN comply with an RA even if it is "CLIMB" while at max altitude.
Also right about single engine- which is why S/E checklists (on Boeing anyway) include putting TCAS into TA only.
Also right about single engine- which is why S/E checklists (on Boeing anyway) include putting TCAS into TA only.
Joined: Nov 2007
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From: Bangkok
Hopefully the answer you want.
No it is part of the certified engineering package, based on the certified Ceiling from the OIM. I believe in later installs it can be changed visa the MCDU but I am not sure on that.
TP
TP
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From: flying by night
Generally aircraft have been tested that they can comply with RAs in most scenarios. During installation, various inhibit parameters can be set, most obviously AGL, but also configuration; this will depend on manufacturer/type, and your outfit.
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Read a circular once from the European safety agency before EAsA and ITBASICALLY implied instigate some sort of a climb (even the slightest) at max altitude as it will relay and coordinate with the other a/c and force him into a descent.
Pin
Pin
Joined: Aug 2013
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From: Washington.
"( AC 20-131A here: https://www.faa.gov/regulations_poli...cumentID/22190 )"
There is a more current AC now - AC 20-151B and here's a brief excerpt:
There is a more current AC now - AC 20-151B and here's a brief excerpt:
2-16. Aircraft Performance Considerations. Use paragraphs 2-16 through 2-17 and Table 1 of this AC to help you evaluate the need to inhibit TCAS II CLIMB and/or INCREASE CLIMB RAs resulting from inadequate aircraft climb performance. The collision avoidance maneuvers posted as RAs by TCAS II assume an aircraft’s ability to safely achieve them. If it’s likely the required response to CLIMB and INCREASE CLIMB RAs are beyond the performance capability of the aircraft, then TCAS II must know beforehand so it can change strategy and issue an alternative RA.
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From: Oztrailia
From the A330 FCTM, it says you MUST follow the RA even if above Max Alt
If a RA is generated:
• The flight crew must always follow the TCAS RA orders in the correct direction, even:
‐ If the TCAS RA orders are in contradiction with the ATC instructions
‐ At the maximum ceiling altitude with CLIMB, CLIMB or INCREASE CLIMB, INCREASE CLIMB TCAS RA orders
‐ If it results in crossing the altitude of the intruder.
If a RA is generated:
• The flight crew must always follow the TCAS RA orders in the correct direction, even:
‐ If the TCAS RA orders are in contradiction with the ATC instructions
‐ At the maximum ceiling altitude with CLIMB, CLIMB or INCREASE CLIMB, INCREASE CLIMB TCAS RA orders
‐ If it results in crossing the altitude of the intruder.