Original source: Mentour Now!
With: Ben and Petter · Petter · Ben
This article is an editorial summary and interpretation of that content. The ideas belong to the original authors; the selection and writing are by Streamed.News.
This video from Mentour Now! covered a lot of ground. 13 segments stood out as worth your time. Everything below links directly to the timestamp in the original video.
This is one of the most misunderstood VNAV behaviours in the 737 FMC — get it wrong and the aircraft simply stops climbing where you least expect it.
Alt Intervene Clears Only What Lies Between You and Your Cleared Level
When ATC clears an aircraft above a restriction already programmed in the FMC, VNAV will still honour that restriction and refuse to climb through it — even if a higher altitude is set on the MCP. Pressing Alt Intervene removes only the restrictions between the aircraft's current position and the ATC-cleared level. Any restriction programmed above that cleared level remains locked in, no matter how many times the button is pressed.
"You only clean what's between you and your cleared level with alt intervene."
737 Takeoff Sequence: From 40% Thrust Spool-Up to VNAV Engagement
A complete 737 departure runs in tight sequence:
- Spool-up: Advance to 40% thrust first, letting engines stabilise symmetrically before selecting TOGA.
- Rotation: Call VR at 138 knots, pitch to 15 degrees then follow flight director.
- LNAV: Engage lateral navigation at 400 ft radio altitude.
- Autopilot: Engage Command A at 1,000 ft AGL.
- Flap retraction: Bug up, verify speed above each white bug, call flap 1 then flap up.
- VNAV: Engage at 3,000 ft once flaps are up and standard pressure is set.
Each step is triggered by a specific speed or altitude cue, not a timer.
Descent Planning and CAT III Setup: Two Rules That Prevent Costly Errors
A quick mental arithmetic check governs descent planning: multiply the first two digits of current altitude by three to get the miles needed to lose that height. At flight level 150, that means 45 miles to the runway. For a CAT III autoland, arming approach mode is the critical enabler — without it, only one autopilot can be engaged. Below 1,500 ft, both pilots must independently verify that "flare" appears on the mode annunciator, with a cross-check callout at 500 ft radio altitude from each seat.
"At 500 ft on the radio altimeter, the captain will say 500 radio and I check it flare armed — and then the first officer will also check they've got flare armed."
Before Takeoff Checklist: Specific Values and a Low-Vis ILS Alignment Trick
The pre-takeoff checklist centres on three verifiable figures: flap 5 selected with a green light, stabiliser trim at 6.37 units, and V-speeds of 138/138/143 knots with the V2 of 143 confirmed in the FMC. In low visibility, the crew also monitors the ILS localiser diamond on the primary display while lining up — a magenta diamond centred on the display confirms correct runway alignment and guards against lining up on a runway edge line or an adjacent strip.
FMC Direct-To Entry: Preview Before You Execute
Entering a direct routing to VABKA in the FMC follows a specific safety sequence:
- Line-select: Pull the target waypoint into the scratchpad from the Legs page.
- Position: Place it at the top of the Legs page, above the current active waypoint.
- Preview: Verify a white dashed line appears on the navigation display — this shows the intended track before any commitment.
- Confirm: The pilot not flying verbally agrees the route looks correct.
- Execute: Press Execute; the line turns magenta and the aircraft begins turning.
- Verify: Confirm LNAV is engaged; select it manually if it has dropped out.
The preview-then-confirm step is the safeguard most commonly skipped.
CAT III Autoland at East Midlands: Full Execution from Localiser Capture to Runway Stop
With RVRs of 400 m at touchdown, 350 m at midpoint, and 400 m at the stop end — all within CAT III limits — the crew executed a fully automated landing. The landing checklist ran with auto-brake set to 3, flap 40, and approach speed at VREF plus 5 knots. After glide slope capture, the missed approach altitude was set immediately. The "landing gate" — a white bar on the display marking 1,000 ft above the actual runway threshold, distinct from the radio altimeter reading — confirmed the aircraft was fully configured before crossing it. Flare armed, both pilots called at 500 ft radio, and the aircraft landed itself.
"500 radio, flare armed. Passing 400 radio, flare armed."
▶ Watch this segment — 1:02:11
Below-the-Line Checklist: Taxi Light as a Takeoff Clearance Reminder
Once cleared to line up and wait, the below-the-line checklist arms the autothrottle, sets LNAV, activates the transponder to TA/RA mode, and verifies three MCP lights — master, autothrottle arm, and LNAV. The taxi light is deliberately left off until takeoff clearance is received, serving as a physical visual reminder that the crew is not yet cleared to roll. Before entering the runway, the pilot not flying independently repeats the ATC readback to eliminate confirmation bias, followed by visual checks both left and right.
FEDRA MILP: A Personal Top-of-Climb Flow Borrowed from Light Aviation
Adapted from light aircraft practice, the FEDRA MILP acronym provides a structured cruise-entry check covering Fuel, Engines, Drift-down altitude, Radios, Altimeter, Minimum safe altitude (grid MORA), Ice, Lights, and Pressurisation. The drift-down check is the least obvious step: navigating to VNAV > Engine Out > Any Engine reveals the maximum single-engine cruise altitude and the speed at which to fly it — in this case, 23,000 ft at 226 knots. The grid MORA check addresses the scenario of a rapid depressurisation, establishing the lowest safe altitude over terrain below.
FRISK Acronym Structures the Pre-Approach Verification Flow
Before commencing the CAT III approach into East Midlands, the crew ran the FRISK check: Frequencies (ILS tuned), Rings (fix page distance markers set at 5 nm for gear down/flap 15, and 10 nm for flap 1), Ident (ILS identifier IEME confirmed audible), Standby instruments (set to approach mode), Kourses (268° set on both sides). Approach mode was then armed, enabling simultaneous engagement of both autopilots — Command A and B — which is the prerequisite for any autoland.
Ten Checks Flow Prepares the 737 for High-Altitude Cruise
Passing flight level 100, the ten checks flow transitions the aircraft to high-altitude configuration using the FLAPS acronym: Fuel (balanced, landing weight checked on the progress page), Lights (turned off above 10,000 ft), APU (off), Pressurisation (bleeds and packs verified), Seatbelts (released if no turbulence), then a Recall check — pressing the button illuminates all warning lights momentarily; any that remain lit indicate a hidden system fault. The flow concludes by setting 121.5 MHz on a secondary radio box to monitor the international distress frequency throughout the cruise.
PIOSE Model Drives Diversion Decision to East Midlands Over Luton
Faced with Stansted's closure, the crew applied the PIOSE framework — Problem, Information, Options, Select, Execute, Evaluate — to work through the diversion. Luton, the closest alternate, was ruled out because its weather sat at borderline CAT III minimums and capacity would be exhausted by the wave of simultaneous diversions. Birmingham offered only a non-precision approach from the south. East Midlands offered a CAT III approach above minimums, a long runway, large apron capacity, and held status as the airline's designated commercial alternate — making it the clear choice despite requiring an immediate descent.
Config Check During Taxi: Triggering Takeoff Warnings Before the Runway
During taxi, the crew briefly advances the thrust levers fully forward then back — a config check that replicates the takeoff thrust signal without actually accelerating the aircraft. If flaps, stabiliser trim, or the parking brake are misconfigured, the system issues an audible warning horn at this stage rather than at the runway threshold. The crew also stopped at the Cat 3 holding point, which sits further from the runway than the Cat 1 position to prevent interference with ILS signals during low-visibility operations.
FMC Holding Fuel Calculation Shown to Be Wrong — Mental Maths Is the Safety Net
When the FMC displayed 1 hour 48 minutes of holding fuel against an available extra of roughly 700 kg, the figure was immediately recognisable as wrong. The mental arithmetic check: the 737NG burns approximately 40–50 kg per minute, meaning 1 tonne of extra fuel equals roughly 20 minutes of holding. The more economical MAX yields slightly longer, but the ratio holds. When the FMC returned a figure six times higher than expectation, that gap confirmed a computer error — not a fuel windfall.
"If you go in and you say I'm expecting to see 25 minutes of holding and it says 1 hour 48, you know that the computer is wrong."
Also mentioned in this video
- The pilots set the scene for the flight, detailing the low visibility weather… (2:32)
- Petter performs the 'after takeoff checklist,' which is a read-and-do sequence,… (15:19)
- The difference in automation between a 737 and an Airbus for this task, while… (22:00)
- The pilots update the FMC for their new cruise altitude, perform triple checks… (23:43)
- While Ben sets up the FMC for the diversion to East Midlands, which involves… (45:12)
- The pilots discuss the importance of briefing the cabin crew and passengers… (49:03)
- ATC for further altitude clearance, engage engine anti-ice due to temperature,… (55:56)
Summarised from Mentour Now! · 1:08:39. All credit belongs to the original creators. Streamed.News summarises publicly available video content.
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