Hill AFB - Damaged F-35 Nose Training Fixture

Description:

Hill AFB possesses a crash-damaged F-35 nosesection—including the cockpit and nose landinggear—that could serve as a valuable training aidfor aircraft maintenance mechanics. Instead ofscrapping the component, the Air Force seeks todevelop a fixture to securely support the nosesection for use in hands-on maintenancetraining.

Design:

The design includes three main components: abase fixture, a carriage, and a hydraulic liftingsystem. The base fixture provides the ability tomove the fixture/nose if needed and acts as therail system on which the carriage moves up anddown. The carriage is directly mounted to thenose section. The carriage rides up and down onthe rails of the base fixture. The hydrauliclifting system is connected to the base andcarriage and is what allows the carriage to belifted to different heights.

Base

Carriage

Performance Review

Requirement/Constraint/Goal	Target	Threshold	Predicted Performance	Actual Performance
Weight of Payload	3500 lbs.	2300 lbs.	2300 lbs.	3500 lbs.
Weight of Stand and Payload	5000 lbs.	10000 lbs.	4950 lbs.	4867.18 lbs.
Width	7 ft	8.5 ft	9.24 ft	9.24 ft
Length	14 ft	15 ft	12 ft	12.5 ft
Raise >64 in.	>64 in.	<64 in.	64 in.	78 in
Safety Factor for Mechanics to Work Under the Stand	n>2	n<2	n>2	n>2

Two static loading tests were conducted to simulate stress and strain on the carriage. One tested the load fully supported by the pinned UHMW boxes, and the other by the hydraulic pistons during elevation. A 3,500-pound load was applied to the side I-beams at the aircraft attachment points. UHMW boxes and pistons were modeled as vertical roller supports, and all connections were assumed bonded. The figures above show yield strength, max strain, and stress, confirming a safety factor of 2 and payload weight compliance. Dimensional and mass property measurements determined compliance with other requirements.

Full Assembly

w/ Nose Section

Conclusion

Overall, the design satisfied most of the requirements and testing proved that targets were achieved within the desired threshold. Throughout the design process we learned that every detail of the design is worth reviewing before moving on to a full design assembly. There were times where one change to a simple part would require changes to the full assembly. Future work includes possible width resizing and ordering parts for fabrication and assembly.

Special thanks to our sponsors at Hill AFB:

Spencer Black, Rulon Walker, and Brett Wiggill