feat(flight_model): Add drag from landing lights

[crocket63]

Fixes #[issue_no]

Summary of Changes

We already have gear door drag that is added through changing MSFS gear position behind the scene.

Now we also add landing light position to add more drag when they are extended as well as RAT.

Screenshots (if necessary)

References

FCOM states up to 1% more fuel consumption when lights are extended

Additional context

Discord username (if different from GitHub):

Testing instructions

This can impact gear mechanisms and ground collision, so quite some non regression tests to do when landing, and also trying to land with no gear / only left gear (using gear actuator failure) / only nose etc....

1. Check drag from landing lights:
   -Steady speed autothrust on.
   -Extend landing lights.
   -Check increased engine power from auto thrust

2. Check drag from RAT:
   -Steady speed autothrust on.
   -Extend RAT.
   -Check increased engine power from auto thrust

3. Check gear door drag still works :
   -Steady speed autothrust on.
   -2 turns on gravity gear handle
   -Check increased engine power from auto thrust

4. Check gear drag:
   -Steady speed autothrust on.
   -3rd turn of gravity gear handle
   -Check increased engine power from autothrust

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[alepouna]

QA Report

Discord: alepouna
Object of testing: #8554
Tier of Testing: 1
Date : 6/3/2024

Testing Process:

1. Check drag from landing lights:

• Steady speed autothrust on.
• Extend landing lights.
• [PASS] Check if any impact on engine parameters

2. Check door drag still works :

• Steady speed autothrust on.
• 2 turns on gravity gear handle
• [PASS] Check increased engine power from auto thrust

3. Check gear drag:

• Steady speed autothrust on.
• 3rd turn of gravity gear handle
• [PASS] Check increased engine power from autothrust

Performed a rough and soft landing as well, no issues.

Testing Results:
Passed

[donstim]

One request here. Can you change the cruise.flt file so that the landing lights are fully retracted and the nose light is off if a flight is started in the cruise condition? Just need to set the LVARs appropriately. Thanks.

[dragold]

QA Tester Report

Name: Mr.Blank#7677
Date of testing MM/DD/YYYY:03/11/2024-03/12/2024
PR Tested: 8554
Tier of testing:?

Testing technique: tryouts

Test Instructions:

Check drag from landing lights:
Steady speed autothrust on:
-Extend landing lights.
-Check increased engine power from auto thrust
Check drag from RAT:
-Steady speed autothrust on.Extend RAT.
-Check increased engine power from auto thrust
Check gear door drag still works :
-Steady speed autothrust on.
-turns on gravity gear handle
-Check increased engine power from auto thrust
Check gear drag:
-Steady speed auto thrust on.
-3rd turn of gravity gear handle
-Check increased engine power from auto thrust

Additional :
change the cruise.flt file so that the landing lights are fully retracted and the nose light is off if a flight is started in the cruise condition

Methodology
All as per instruction + Additional
Condition clear weather with/without CFD
debug aircraft drag Check

Negatives: NIL

Testing Results: passed

Conclusions: Drag and dynamic pressure data in debug aircraft drag observed, results were of normal outputs

[donstim]

Some quantitative data here. First screenshot shows landing lights and RAT retracted at FL 310, M0.78, ISA, no wind, 60 T, steady-state cruise condition (Thrust=Drag):

Total fuel flow is 1094+1081 = 2175 kg/hr

Now, with 1 landing light extended:

Added drag coefficient is 0.00023. Total fuel flow is 1101+1088 = 2189 kg/hr (increase of 0.6%)

Next, with 2 lights extended:

Added drag coefficient is 0.00046. Total fuel flow is 1109+1096 = 2201 kg/hr (increase of 0.6% per landing light)

Finally, with the RAT extended

Added drag coefficient is 0.0084. Total fuel flow is 1120+1107 = 2227 (increase of 2.4%)

I also verified that these additional drag values were applied when the lights and RAT were extended at speeds above (280 KCAS) and below (240 KCAS) the speeds at which the landing gear extension would be locked out. I also confirmed that when the gear is retracted with the lights and/or RAT extended, the lights and RAT drag remained.

[donstim]

One request here. Can you change the cruise.flt file so that the landing lights are fully retracted and the nose light is off if a flight is started in the cruise condition? Just need to set the LVARs appropriately. Thanks.

Done