PPRuNe Forums - View Single Post - V1 = Vr, Balanced field???
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Old 16th Aug 2005, 01:10
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Old Smokey
 
Join Date: Jun 2004
Location: Australia
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Alpine Pilot,

Clearways are sometimes available, Stopways are sometimes available, often they are unequal, or one exists and the other doesn't. If they're available, why not optimise performance and use them?

There's nothing sacred about using the 'Balanced Field' technique, in fact adherance to such a policy can be restrictive. Personally, I'd prefer to work with an unbalanced field to optimise both the Stop and Go cases.

Most commonly, V1=Vr when the aircraft is NOT Accelerate-Stop limited, i.e. when V1 could have been above Vr, but as this is not allowed, V1 is reduced to Vr.

Considering the runways that you're operating from, it's strange that your company has opted for a lower V1 speed schedule. I sincerely hope that this was an AFM / Manufacturer's option, and not just something that some bright person in the company thought of.

Because of the permitted credit for Reverse Thrust for the Accelerate-Stop, and a reduced screen height for Wet Runways / Contaminated Runways, it IS possible in some circumstances to have a Wet / Contaminated Runway RTOW in excess of that for a Dry runway. Common sense, safety, and in some cases the regulatory authority, dictate that if this is so, the lesser of the Wet / Contaminated and the Dry Runway limit weights be used.

Regards,

Old Smokey
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