It is usually detailed in the MEL OPS proc for Main gear inop( Airbus) . It indicates that specific Perf has to be done
A most important point. MEL applies to INTENTIONAL operation with a U/S.
The Design Standards still must be observed, hence most MELs include additional restrictions to address whatever the U/S might compromise in the way of the Standards.
In this case, performance still requires OEI segment capability .. hence the usual significant weight delta.
Doesn't seem to be any reference for the test pilots to just leave them hanging because they cooked the brakes
A specific FT consideration when playing with accel stop activities. Not relevant to routine line operations.
The point was that the rest of the world pretty much adopted the US certification specifications
.. but with significant differences in philosophy as becomes clear should you read and compare.
Our take off calculations are taking into account engine out
Precisely .. and that ALWAYS includes OEI segmented obstacle clearance considerations.
For a normal take off (with gear down as the example of the original poster), segment compliance is absolutely not an issue, nor a requirement.
Absolutely not so.
Should you INTEND to leave the gear down - doesn't matter what the reason might be - then the operation falls into the realm of MEL considerations. One MUST incorporate a weight penalty, and whatever else may be relevant to the Type, to address the normal OEI segmented takeoff exercise .. this time around, with the gear down.
The AFM defines what a normal takeoff might be, not the pilot on the day.
there are no segments in a normal takeoff
Again, not so. The AFM defines how you should be conducting the actual takeoff for whichever of AEO and OEI applies on the day .. recalling that any given takeoff will involve one or both ... Both are considered as an each time exercise and one or the other will dictate the limiting case for the RTOW calculation.
The overall inference, of course, is that the AEO procedure keeps the aircraft flight path above the OEI gross path.
they set the standards for what they considered to be a safe clearance of obstacles for design of instrument procedures.
.. and of no relevance to takeoff ..
An aircraft that does 15-20% climb gradient all engines operating, will have no problems making a 3.3% gradient with the gear extended.
Providing that the handling procedure is appropriate .. but of no relevance for OEI considerations.
Takeoff calculations only deal with engine failures at ONE specific point in time: V1
.. for the AFM calculation. The inferred responsibility on the operator/pilot is that the aircraft, AEO, will be operated in a manner which doesn't compromise a post-V1 failure. This can get a bit complicated if the takeoff requires turn(s).
The operator/pilot is responsible for making sure that the takeoff can get to an appropriate terrain clear point for a failure at any point during the process ..
YOU takeoff in a twinjet and both an engine failure happens and you happened to forget to remove the gear pins and YOU CANNOT retract the gear.
Fortunately, I haven't been in that situation ... although a mate was years ago on the F27 .. didn't seem to hurt his career as he ended up a successful and, by all accounts, a good checkie.
Seriously, though ..
(a) the Design Standards don't have regard to incompetence
(b) .. nor multiple significant failures
In the situation you posit .. the pilot could be in really serious strife, depending on the nature of the aerodrome on the day.
Or do you figure something out right away?
I suggest that most competent commanders will have armchaired that sort of scenario (gear retract failure) and have at least a generic plan. For difficult terrain runways in a commercially rational world .. there are some situations which are best handled by not getting out of bed that morning ...