Weights & Placements
- Total LG weight will be approximately 10% of the total aircraft MTOW
- MLG will be around 65% of total LG weight while NLG be 35% of total LG weight
- MLG will take 90% of applied loads on landing
- Placement is about 10% of the total aircraft length behind the CG
- NLG will take 10% of applied loads on landing
- Placement is dependent on code, the closer to the nose the better
Sizing
- Dependent on the sizing of the rest of the aircraft and can be completed very quickly once numbers for fuselage are available
LG Configuration Selection
|
|
LG Configuration |
|
|
|
|
| Figures of Merit |
Weight |
Single Main |
Taildragger |
Quadricycle |
Bicycle |
Tricycle |
| Stability |
0.2 |
-1 |
-2 |
-1 |
1 |
2 |
| Ground Clearance |
0.3 |
-2 |
1 |
-1 |
-1 |
2 |
| Manufacturing Difficulty |
0.2 |
1 |
1 |
-1 |
0 |
2 |
| Manufacturing Experience |
0.1 |
-1 |
0 |
-2 |
-2 |
2 |
| Simplicity |
0.2 |
0 |
1 |
-1 |
-1 |
1 |
| Final Scoring |
1 |
-0.7 |
0.3 |
-1.1 |
-0.5 |
1.8 |
The decision matrix shows different considerations for LG configurations and the tricycle has the largest score with the tail dragger in second place. Tricycle landing gear will be selected due to the increased ground clearance for the X-1 test vehicle and the mission requirements. This configuration also has increased stability and manufacturing experience/analysis.
Testing
- There are two main tests that are used in DBF winning reports that will try and be implemented this year
- The first is the dynamic drop test
- The aircraft or LG loaded with the MTOW will be dropped by distance above the ground to ensure impact resistance
- The second test is the static loading test
- The LG assembly will be slowly loaded until deformation or failure to ensure it reaches the proper FoS
NLG Preliminary Design
-
After viewing past top designs for the last 8 years, almost all have the same implementation of NLG
Steel Wire Design
-
Almost all past aircraft in AIAA DBF winning reports do not incorporate nose wheel steering
- NLG steering is not a requirement for this year's competition plane
- Neglecting this portion of the landing gear will greatly increase the manufacturing abilities as well as the connections to the fuselage due to tight space constraints near the nose of the aircraft
- The mass required for NLG will also be significantly reduced
-
With no NLG steering, the NLG attachment can be just a simple attachment to either the fuselage itself or a reinforced plate depending on the spacing of the nose portion of the aircraft
MLG Preliminary Design
Metal Bar with Attachment
