TAKEOFF REF — V-speeds
PremiumintermediateTakeoff flap and V-speeds on the TAKEOFF REF page — the three numbers that turn a runway analysis into a takeoff you can fly.
What this scenario covers
V1, VR and V2 are entered on TAKEOFF REF along with the takeoff flap setting. They come from the airline's performance software, computed for today's weight, runway, wind, temperature and configuration — not from the FMC.
Once entered, the speeds are displayed on the airspeed tape and used by the flight director and the takeoff protections, which is why they have to be right rather than approximately right.
How it applies in flight ops
V1 is the go/stop decision speed; VR is where the aircraft is rotated; V2 is the speed to fly if an engine fails after V1. The whole runway analysis is compressed into those three numbers because the decision they support has to be made in about a second.
Both pilots verify them against the same source. Takeoff performance errors — wrong weight, wrong flap, transposed speeds — are a well-documented accident category, and the defence is boring, repeated cross-checking.
Fly this one with Premium
Everything about this scenario is on this page, steps included — reading it costs nothing and always will. What Premium adds is doing it: the CDU validates every entry as you make it, tells you when an entry was accepted but wrong, and saves your progress across devices.
Step-by-step: TAKEOFF REF — V-speeds
- 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.
- 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.
- 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.
- 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.
- 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.
- 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).
What to take away
- The FMC does not compute your V-speeds; performance software does.
- Flap setting belongs to the same data set as the speeds.
- The entered speeds drive the tape, the flight director and the protections.
- Cross-check both pilots, against one source document.
The rest of Performance & Fuel
Pre-Flight Fuel Planning (PERF INIT)
PremiumintermediateAt the gate with the OFP for a Geneva sector: weights and fuel on PERF INIT, on one page where the Airbus uses two.
📍 EGLL → LSGG — pre-flight planning⏱ ~5 min📊 7 stepsAssumed Temperature — Reduced Thrust Takeoff
PremiumbeginnerReduced-thrust takeoff, Boeing's way: the assumed temperature method. Tell the engines it is hotter than it is and they produce less thrust.
📍 LOWW → EDDM⏱ ~3 min📊 5 stepsCost Index — What Does It Do?
PremiumbeginnerThree cost index values on PERF INIT — 0, 30 and 80 — and the speed schedule changes under you.
📍 LIRF → LEMD⏱ ~3 min📊 5 stepsMid-Cruise Fuel Check (PROGRESS)
PremiumintermediateThirty minutes into the sector: read the predicted destination fuel on PROGRESS, then reconcile PERF INIT against what the gauges actually say.
📍 EGLL → LSGG — cruise FL360⏱ ~5 min📊 5 steps
Background reading
- GuidePMDG 777-300ER Cold and Dark Startup: Complete Step-by-Step Guide
Battery to takeoff in the PMDG 777-300ER with interactive checklist. FMC setup, GE90 engine start, and the stabiliser trim that prevents tail strikes.
- GuidePMDG 737 FMC Tutorial: Program Your First Flight Plan Step by Step
Program the PMDG 737 FMC from scratch: IDENT, POS INIT, ROUTE, PERF INIT, takeoff speeds, and VNAV setup. Every CDU page explained with the exact inputs.
- GuideThe Boeing 737 CDU / FMC Explained: Every Page
What is the 737 CDU and FMC? A plain-English guide to every Boeing 737 CDU page plus the EXEC/MOD workflow. Practice free in our CDU trainer.