When to use F.O.S (RTOW) speeds and NOT QRH speeds

[tenela]

May someone in the know how pse enlighten me on when to use FOS(RTOW Charts) speeds instead of QRH speeds and pse explain why.

[SOPS]

If I had the slightest idea about what it is you are talking about, would love to help:confused:

[mutt]

The easy answer is ALWAYS.......... if the RTOW charts are providing speeds then they are runway specific, the QRH speeds arent....


Mutt

[galahad]

RTOW which computed from FOS must be checked before every takeoff.
If the weight corresponding to wind and OAT is greater than Maximum
Structor Weight, QRH speed will be used, if not use RTOW's speed no
matter what the actual weight.
kind regards,

[mutt]

If the weight corresponding to wind and OAT is greater than Maximum Structor Weight, QRH speed will be used

Why?

Mutt

[galahad]

mutt,

My statement is taken from ATR's FOS user manual and FCOM.
There're 2 speeds sets can be used for ATR, RTOW chart speed
and QRH speed. Takeoff speed used must be from RTOW chart
with exception that if the computation weight is greater than
the maximum structure weight, use QRH's speed corresponding
to the actual takeoff weight.

kind regards,

[mutt]

The QRH speeds are based on BALANCED FIELD, it is possible that the RTOW speeds are based on optimum speeds or unbalanced, therefore how do you know that you can clear the takeoff obstacles using balanced speeds at maximum structural weight?

Mutt

[galahad]

mutt/snam
RTOW's chart speeds always used for takeoff at obstacle airport, also hot and high.
The QRH speeds are useful at airport which pressure altitude not more than 1000'
which we'll be limited by FL, or 2nd segment when OAT is greater than 40 DEG C.

[emirmorocan]

ATR has the QRT(Quick reference tables) , if you dont have FOS you can use it, they are not optimized .

[revolucionpilot]

jo say...amigo...basta masturbaciones mentales.... have a life!!!

[SOPS]

I now see we are talking about an ATR..no wonder I was confused......:}

[ClimbSequence]

QRH speeds are for Non-limiting runways only.
FOS speeds are optimum for a specific runway with specific atmospheric conditions

[oz in dxb]

You are using the the wrong forum to discuss this tenela. Try tech log and put some more details into your question!!!

Pls close this thread!!

Oz