Missing Runway & Extended Centerline on ND During Takeoff (B747-400) #921
Description
On the MS-Sparky 747-400, the Navigation Display (ND) does not depict the departure runway centerline or extended centerline during takeoff and initial climb.
On real Boeing 747-400 aircraft, the ND does display the runway centerline ahead of the aircraft during takeoff, including an extended centerline beyond the runway end. This is visible during the ground roll and early climb phase and is not dependent on LNAV capture.
Currently in Sparky, no runway geometry is shown on the ND in this phase.
Real-World Reference (Boeing Behavior)
On a real B747-400 ND during takeoff:
The aircraft symbol is positioned on the runway
A solid runway centerline is drawn forward of the aircraft
An extended runway centerline is shown beyond the runway end
The display appears in MAP mode
The centerline:
Is aligned with runway heading
Scales with ND range
Uses standard Boeing symbology (thin line, no runway box)
Display is active during:
Takeoff roll
Initial climb
The runway depiction is independent of LNAV engagement
This behavior can be observed in real-world cockpit videos and training material.
Current Behavior in MS-Sparky 747-400
No runway centerline is drawn on the ND during takeoff
No extended centerline is shown
ND only shows route legs once airborne
Departure runway geometry is not rendered at any phase
This results in a noticeable realism gap, especially during manual departures.
Expected Behavior
When a departure runway is active:
The ND should draw:
Runway centerline ahead of the aircraft
Extended centerline beyond runway end
The runway depiction should:
Be visible during ground roll and early climb
Scale correctly with ND range
Respect MAP / TRK UP / HDG UP orientation
The depiction should be removed or faded once:
The aircraft is well clear of the runway environment
Or a defined distance / phase threshold is passed
Technical Notes / Possible Implementation Direction
Detect active departure runway via:
FMS runway selection
Or inferred from first route leg
Extract runway geometry from:
X-Plane navdata (apt.dat / CIFP)
Render using:
Custom ND drawing logic
Not X-Plane default map APIs
Treat runway centerline as a special ND overlay, not a flight-plan leg
Why This Matters
This is standard Boeing 747 ND behavior
Improves:
Situational awareness during takeoff
Manual departure realism
Summary
Missing feature:
Runway centerline + extended centerline depiction on ND during takeoff
Aircraft:
MS-Sparky 747-400 (X-Plane 12)
Phase affected:
Takeoff roll and initial climb