Before Takeoff Checks

A sequence of flows verified by checklists, run at planned pauses so nothing competes with taxiing. AC 120-74's placement guidance: complete predeparture checklist items at the gate when possible — including setting takeoff flaps — or while stopped or taxiing straight ahead without complex intersections or hot spots ahead. The skill element adds the word that gets applicants: complete the checklists in a timely manner — meaning done before the runway, never finishing a checklist while taking the runway. During the checks you must be able to explain, on request, any system's operating characteristics, limitations, and the corrective action for a malfunction (AA.II.E.S3) — in a type-rated airplane, the run-up of your commercial days is replaced by systems verification against the AFM's acceptable ranges.

Takeoff data — V1/VR and V2, takeoff power settings, and required field length — is computed prior to each takeoff from: airplane weight, runway length available, runway gradient, field temperature, field barometric pressure, wind, icing conditions, and runway condition (AFH ch. 16). The crew procedure:

• Without an FMS, record it on a takeoff data card
• Both pilots review the data entered in the FMS, or separately compute and cross-check against the data card
• If takeoff plans change while taxiing — recalculate (AFH ch. 16)

That last line is the risk element about a runway change (AA.II.E.R2) in one sentence: new runway, new data, new brief. No exceptions for "it's longer anyway."

Working definition: takeoff decision speed — the speed by which the continue/stop decision must be made; below V1 it's considered safer to stop within the accelerate-stop distance (AFH ch. 16). The FAA's expanded definition (from the Takeoff Safety Training Aid, AC 120-62, via AFH ch. 16) — V1 is the speed selected for each takeoff, based on approved performance data and specified conditions, which represents:

1. The maximum speed by which a rejected takeoff assures a safe stop within the remaining runway (or runway and stopway)
2. The minimum speed which assures the takeoff can be safely completed within the remaining runway (or runway and clearway) after failure of the most critical engine at the designated speed
3. The single speed permitting both, when operating at the minimum allowable field length for a particular weight

In certification, V1 hangs on VEF — the speed at which the critical engine is assumed to fail, itself not less than VMCG — plus the speed gained during recognition before the pilot's first stopping action (25.107(a)).

• VR — rotation speed: rotation to the takeoff attitude begins. It may not be less than V1, nor less than 105 percent of VMC, nor less than the speed that allows reaching V2 before 35 feet above the takeoff surface (25.107(e); AFH ch. 16)
• VLOF — lift-off speed: the calibrated airspeed at which the airplane first becomes airborne (25.107(f))
• V2 — takeoff safety speed: the speed at which the required one-engine-inoperative climb performance can be achieved after lift-off (AFH ch. 16). Its floor, V2MIN: not less than 1.13 VSR for two- and three-engine turboprops and jets without provision for reducing the OEI stall speed, 1.08 VSR for turboprops with more than three engines and jets with that provision — and in all cases at least 1.10 times VMC (25.107(b))

The numbers for your airplane on today's runway are AFM output — the concept you must own is that V1/VR/V2 encode the entire engine-failure plan before brake release.

Most manufacturers recommend identifying a low-speed regime (80 knots and below) and a high-speed regime (100 knots and above) of the takeoff run (AFH ch. 16):

• Low speed: abort for any malfunction or abnormality, actual or suspected
• High speed: reject only for catastrophic malfunctions or life-threatening situations — weighing the threat against the risk of an overrun

The statistics behind the split: although only 2 percent of rejected takeoffs are high-speed aborts above 120 knots, they account for the vast majority of RTO overrun accidents (AFH ch. 16). SOPs add a speed callout at the regime transition — a last crosscheck of airspeed and thrust, and an incapacitation check by challenge-and-response. The briefing states this split out loud so that at 130 knots nobody is inventing criteria. The maneuver itself is Task III.I; the plan is this task.

Because V1 is where deceleration must begin, not where deciding starts. The go/no-go decision should be made before V1 so that deceleration can begin no later than V1 — if braking has not begun by V1, the decision to continue has been made by default. Delaying the RTO just one second beyond V1 adds 4 to 6 knots on average, and crews require 3 to 7 seconds to identify an impending RTO and execute it (AFH ch. 16).

Execution order matters too — the instinctive "normal landing" sequence delays the primary deceleration force when every second counts:

1. Apply maximum braking immediately while simultaneously retarding the throttles
2. Extend spoilers
3. Deploy reversers

A rejected takeoff should be perceived as an emergency (AFH ch. 16).

FAA-approved takeoff data is demonstrated in ideal conditions: a clean, dry runway and maximum braking — reverse thrust is not used to compute stopping distance (AFH ch. 16). The AFH lists these degraders:

• Reduced runway friction
• Mechanical contaminants (rubber, oily residue)
• Natural contaminants (standing water, snow, slush, ice)
• Wind
• Low air density
• Flap and bleed configuration
• Underinflated or failing tires
• Penalizing MEL or CDL items
• Deficient brakes or RTO autobrakes
• Inoperative anti-skid
• Pilot technique

One mitigation to know by name: a reduced V1 — less than normal or maximum V1 but above minimum V1 — properly adjusts the RTO stopping distance for the degraded stopping capability of wet or contaminated runways, while adding roughly 2 seconds of recognition time for the crew (AFH ch. 16).

The captain's briefing is an essential part of CRM, accomplished prior to takeoff (AFH ch. 16). Built from the ACS skill element, AC 120-74, and the AFH's sample captain's briefing (AFH Figure 16-12), a complete brief covers:

• Runway and intersection, verified against the clearance — plus airport NOTAMs and closed taxiways/runways
• Takeoff performance: the computed V-speeds and thrust setting, obstacle clearance and minimum climb gradients, and any MEL/CDL special considerations
• Departure: SID or IFR departure, initial heading, altitude, and fix
• Terrain and weather: significant terrain or obstacles relative to the departure routing, significant weather — windshear gets its planned response stated (AA.II.E.S5)
• The abnormal plan: reject criteria by regime before V1, and for powerplant failure after V1 — continue, fly the engine-out profile (the maneuver is Task VII.B; the commitment happens here)
• Who does what: the PM's callouts and monitoring duties during the roll are set "as directed in the captain's briefing" (AFH ch. 16)

The test of a good brief: if the engine fails at 200 feet tonight, was every first action already spoken aloud on the ground?

Holdover time is the estimated time deicing/anti-icing fluid will prevent the formation of frost or ice and the accumulation of snow on the protected surfaces. It begins when the final application of fluid commences and expires when the fluid loses its effectiveness (121.629(c)(3)). The carrier's program must provide procedures to increase or decrease the determined time in changing conditions. After any maximum holdover time is exceeded, takeoff is permitted only when at least one of these is true:

1. A pretakeoff contamination check determines the wings, control surfaces, and other critical surfaces are free of frost, ice, or snow
2. An alternate procedure approved by the Administrator in the carrier's program makes that determination
3. The aircraft is redeiced and a new holdover time determined (121.629(c)(3))

• A pretakeoff check is a check of the wings or representative aircraft surfaces for frost, ice, or snow, conducted within the holdover time — the routine confirmation that the fluid is still doing its job
• A pretakeoff contamination check verifies the wings, control surfaces, and other critical surfaces are free of frost, ice, and snow after the holdover time has been exceeded. It must be conducted within five minutes prior to beginning takeoff, and from outside the aircraft unless the carrier's program specifies otherwise (121.629(c)(4))

A carrier operating without an approved deicing program lives under 121.629(d): whenever contamination could reasonably adhere, no takeoff unless the aircraft is checked free of it within five minutes prior to takeoff, from outside the aircraft. And behind all of it stands the clean aircraft concept — no takeoff with frost, ice, or snow adhering to critical surfaces (121.629(b)), with dispatch into expected icing itself conditioned on the opinion of the PIC or aircraft dispatcher that safety won't be adversely affected (121.629(a)).

• Bugs and instruments: V-speeds set from the cross-checked data; flight instruments set and checked for the departure (the AFH ch. 2 discipline — heading indicators verified against the compass, bug to runway heading or as assigned — scales directly into the glass flight deck)
• Avionics: frequencies, initial navigation sources and courses, autopilot preselects, and transponder configured to the clearance (AFH ch. 2)
• Flight director: set to the modes your operator's profile calls for on this departure — and stated in the brief, so both pilots expect the same commands at rotation
• The verification gate: before entering the runway, verbally coordinate flap setting, runway identification, compass heading, FMC entry, and receipt of the proper ATC clearance for that runway (AC 120-74)

The autopilot/flight-director risk element (AA.II.E.R5) is really a mode-awareness question: be ready to state what the FD will command at liftoff and what happens if you engage the autopilot with the wrong lateral mode armed — in your airplane's terms, from your AFM.

Everything downstream of the runway assumption gets redone:

• New performance: recalculate the takeoff data — weight didn't change, but runway length, intersection distance, gradient, and wind component did (AFH ch. 16: if takeoff plans change while taxiing, recalculate)
• New setup: FMC runway and departure, bugs if the speeds changed, nav/comm as required — heads-down work done stopped, not rolling (AC 120-74)
• New brief: the abnormal plan was runway-specific — reject margins, engine-out routing, terrain
• New taxi picture: route to the new runway, hold lines, hot spots — expectation bias is exactly the trap AC 120-74 warns about: fly the clearance received, not the one you briefed (AA.II.E.R2)

If the frequency pressure doesn't allow all of that before the runway, the professional answer is "unable" — a transport airplane is never obligated to accept a takeoff clearance faster than the crew can rebuild the plan.

• Read back takeoff and landing clearances including the runway designator, and state "intersection departure" when applicable (AC 120-74)
• Use the complete call sign — clipped call signs are how another aircraft's clearance becomes yours, and the AC flags similar call signs on frequency as a specific hazard
• LUAW is not a takeoff clearance: expect ATC communication within 90 seconds or query, keep TCAS on, and monitor for traffic on your runway (AC 120-74, developed in Task II.C)
• Confirm the runway physically: the verbal coordination gate — runway identification and compass heading against the clearance — happens as you take the runway (AC 120-74), the last defense against a wrong-surface departure
• Landing lights on when takeoff clearance is received — the lighting signal that tells everyone else you're rolling (AC 120-74)

The chain, assembled from 121.629:

1. Dispatch into icing at all rides on the judgment of the PIC or aircraft dispatcher that expected icing won't adversely affect safety (121.629(a))
2. Conditions that could produce adherence trigger the carrier's approved ground deicing/anti-icing program — which defines who decides procedures are in effect, each group's duties, and the fluid types and procedures in use (121.629(c)(1))
3. Fluid application starts the holdover clock at the final application's commencement (121.629(c)(3))
4. Inside the holdover time, a pretakeoff check of the wings or representative surfaces confirms the fluid is holding; beyond it, the three options apply — contamination check, approved alternate procedure, or redeice with a new holdover time (121.629(c)(3)–(4))
5. The takeoff itself must satisfy the clean aircraft concept — nothing adhering to wings, control surfaces, propellers, engine inlets, or other critical surfaces (121.629(b))

Crew training on all of this — holdover use, fluid characteristics, contamination recognition, communications — is a required element of the program itself (121.629(c)(2)), which is why the examiner can expect fluent answers rather than a shrug toward the ground crew.

• Contaminated or slick runway: shifts the accelerate-stop problem — the reduced-V1 logic and the degraded-stopping-factor list (AFH ch. 16) become today's numbers, not trivia
• Gusting crosswinds: in strong, gusty wind it is advisable to carry an extra margin of speed before the airplane is allowed to leave the ground (AFH ch. 6) — in transport practice, applied per your AFM/operator gust-additive policy, and briefed with the crosswind technique for the roll
• Windshear: the ACS names it in the briefing element (AA.II.E.S5) — the planned response is stated before takeoff, and the escape maneuver belongs to your operator's procedures
• Low visibility: ties the takeoff clearance to the taxi problem — SMGCS routes and the verification gate against a wrong-surface line-up (Task II.C)

The common thread: every one of these changes either the data, the brief, or both. Weather that changes nothing you compute or say out loud hasn't been assessed yet.