Balanced Field Length, V-speeds

[Basil]

...NEVER reduce your V1 because of Ice, ..!

What's your rationale behind NEVER reducing V1 on an ice covered runway? Seems to me that an icey runway is the BEST time to reduce V1.

 

[con-pilot]

Hmm...Falcon..Airbus...

Add the Boeing 727 to that list, V-1/V-R is the same on nearly all takeoffs.

PNF call is, "V-one, rotate."

 

[hobbsmeter]

What's your rationale behind NEVER reducing V1 on an ice covered runway? Seems to me that an icey runway is the BEST time to reduce V1.

Agreed!
A snowy/slushy/icy runway is when you WANT to reduce V1, as to make the "GO" decision earlier in the takeoff roll.
You might not be able to stop on the remaining slippery runway if you abort with no adjustment to V1.

 

[semperfido]

Agreed!
A snowy/slushy/icy runway is when you WANT to reduce V1, as to make the "GO" decision earlier in the takeoff roll.
You might not be able to stop on the remaining slippery runway if you abort with no adjustment to V1.

I agree. I too, would reduce to V1min on critical runway situations.

 

[Hugh Johnson]

This a great general review, with lots of pictures and big type! Doesn't really answer the thread questions but is on topic.

selair.selkirk.ca/Training/systems/power-point/AVIA%20240/04V-speeds.ppt

 

[Hugh Johnson]

This is a great article! Actually approved data!

 

[Thedude]

NEVER reduce your V1 because of Ice, short runways, etc... I have seen guys do that too many times!

No, you want to reduce your V1 on a contaminated runway. Takes more distance to speed up to V1 and may take more to slow down.
IF I had a short runway, that is excalty when I would want to reduce V1.

 

[NGT]

Wow your rotation and single engine climb speed are the same? I have never heard of that.

3-1=2. Single Engine failure in 50/900 is an Abnormal not an Emergency. Falcon list VR = V2 in performance data and recommends holding whatever speed is reached with normal rotation speed. If failure occurs at speed higher that V2(VR+rotation) maintain that speed.

 

[SDCFI]

No, you want to reduce your V1 on a contaminated runway. Takes more distance to speed up to V1 and may take more to slow down.
IF I had a short runway, that is excalty when I would want to reduce V1.

Yes, but only if the Flight Manual has data that accounts for the reduced V1. If you tank an engine at the lower V1 you may not have enough thrust to accelerate to VR on a contaminated surface. It sounds like some people are saying they arbitrarily adjust V1/VR depending on the conditions of the day, that is no different then aborting past V1, either way you're now a test pilot.

 

[GCAP]

Performance calculations for the Boeings produce a recuced v1 for long runways. I remember many times trying to explain this to other pilots when departing 31L at JFK (14,572') The long runway allows more time (runway) to accelerate to VR and clear obstacles.