wet V1

[Capt. Picard]

Anyone out there, please help:

1. Do all 737-200 operators always use a wet V1 (dry V1 minus 9)
and If so, why?

2. What are the Vmca and Vmcg figures for 737-200

:confused:

[john_tullamarine]

(1) pass

(2) the easiest way to check, if the figures aren't quoted explicitly is to look at the QRH min speed takeoff speed schedules, noting that the figures may well vary according to the specific engine thrust rating.

(a) as the weight reduces, if the V1 becomes fixed, then that indicates a Vmcg-limited V1

(b) ditto .. if the V2 becomes fixed, then that indicates a Vmca-limited V2 (ignoring PEC considerations, this will indicate 1.1Vmca)

[Smokie]

On our aircraft, the wet V1 is taken from the take performance manual. It is based on the temperature used in our TMS for either a rated or flex (reduced thrust) take off.
Then the flap setting is taken into consideration as is the length of the runway.

So for a 36,000 kg aircraft:-

32 degrees,flex take off, flap 18, would give something like a V1 of 116kts
Flap18 on a runway less than 2000 meters would give a correction of -9 kts.
Wet V1 is then 107kts

same temp,flap 24, would be some thing like a V1 of 111kts.
Flap 24 on a runway less than 2000 meters would give a correction of -7 kts.
Wet V1 is then 104kts.

I hope this helps.

[Capt. Picard]

Thanks fellows,

however, typo on no.1 question. should've read (Vr minus 9)

[john_tullamarine]

Then you should also indicate that your company uses (probably) min speed schedules ... otherwise this would be an interesting sort of way to go about determining V1s in the overspeed scheduling case ..... ?

[mutt]

VR - 9kts? Where on earth did you get this procedure from?

V1 i can understand, VR has me confused.....

Mutt.

[BlueEagle]

I remember that we used to use the dry V1 - 9kts to establish the wet V1, an old B737-200 practise, (1977 and up).