TOGA time limit (JAR vs FAR)

[alatriste]

According JAR, TOGA is certified for use for a maximum of 10 minutes in case of an engine failure at take off. On the other hand ,and as far as I know, FAR only allows 5 minutes in the same scenario.
So, for the same enviromental conditions and aircraft/engine type, the [U]Obstacle Limited TO Mass might be different (higher)for the company operating according JAR than for the one complying with FAR.
I donīt believe this could really happens, it might be a great disadvantage for americans.
Can anybody out there explain me that?

Thank you in advance.

[barit1]

It IS a disadvantage for American operators when there are remote obstacles to clear OEI, thus RTOW limited. However on modern engines there is really no basis in technical fact for the 5-min. limit.

I used to do test cell runs in which we repeatedly held rated TO power longer than 10 minutes, and while I can't say it was good for long-term retention of EGT margin or SFC, there was NEVER any reliability issue.

Thus - the beancounters are not delighted by the prospect of early removal of a performance-limited donk for seal refurbishment, but flight crews of a modern engine should not hesitate to use TOGA as required.

[john_tullamarine]

Basically dollars .. you buy the AFM supplement from the OEM and away you go with 10 minutes.

[Old Smokey]

Yup, that's the regulations. If you really need the extra 5 minutes, USE IT without fear of failure, just don't PLAN to do so!

Regards,

Old Smokey

[manuel ortiz]

N registered aircraft operating in Europe under JAR's... Do they have to buy the "10 min" also?

Any US airline that you know of using the 10 min limit?

Any idea how much $ switching over to the 10min limit can cost?

Tks.

[john_tullamarine]

cost ?

Can be significant .. put it this way, some years ago we were looking at the problem with a twin jet. In the end we convinced the local regulator that we could do a local flight manual amendment to "permit" the use of 10 minutes without taking any credit for the extra performance ... got us around our particular problems at next to no cost. I can't remember the OEM cost but it was in the many thousands ...

[mutt]

According JAR, TOGA is certified for use for a maximum of 10 minutes in case of an engine failure at take off. On the other hand ,and as far as I know, FAR only allows 5 minutes in the same scenario.

Not totally correct, FAA permits 10 minutes in the same scenario. Manufacturers offer it either as standard (Embraer) or at a cost (Boeing/Douglas), although if its new aircraft purchase, this additional cost usually doesnt apply. We operate 5 aircraft types under FAR121 with 10 minutes.


Mutt