TAKEOFF REF — V-speeds

Step-by-step: TAKEOFF REF — V-speeds

1. Open the TAKEOFF REF page so you can enter the OFP performance numbers.

   All the values on this page come from a takeoff performance calculation — an EFB app, printed tables, or the airline's performance software. The calculation uses your actual takeoff weight, runway length, temperature, wind, and airport elevation to produce safe speeds. Boeing's page differs from Airbus: FLAPS lives on the left, V-speeds on the right.

2. Enter takeoff flaps. Type 5 and press 1L.

   Madrid LEMD has long runways (up to 4350 m), which allows lower flap settings. Flaps 5 is the 737-800's typical takeoff setting — a balance between lift, drag, and resulting V-speeds. Flaps 1 gives the best climb performance after takeoff but needs more runway. Flaps 15 or 25 are reserved for short or contaminated runways.

3. Enter V1 (decision speed) of 140. Type 140 and press 1R.

   V1 is the speed above which you must continue the takeoff even if an engine fails. Below V1 you can still stop on the remaining runway; above V1 there isn't enough runway left to stop, so you commit to flying. For the 737-800 at typical Madrid takeoff weight, V1 is around 140 KIAS — fresh calculation per flight.

4. Enter Vr (rotation speed) of 143. Type 143 and press 2R.

   Vr is the speed at which you smoothly pull back to rotate the nose for liftoff. Vr is always at or above V1; the small gap gives a buffer after committing to the takeoff. Below Vr the wings aren't yet generating enough lift to leave the runway.

5. Enter V2 (takeoff safety speed) of 148. Type 148 and press 3R.

   V2 is the safe climb-out speed assuming one engine has failed. The aircraft must reach V2 by 35 ft above the runway. FAA certification requires V2 ≥ 1.13 × the stall speed in takeoff configuration; if you changed the flap setting, V2 changes too.

6. Performance data complete. Return to the RTE page.

   On a real flight the next stop after TAKEOFF REF is the briefing — captain runs through the V-speeds with the first officer, calls "V1, Vr, V2" out loud, and both pilots cross-check the numbers against the OFP. The CDU values are then frozen until something material changes (weight, runway, wind).