Servo Tab on DHC-3 Otter

Summary:  Design and Manufacturing of redundant servo-tab for installation on DHC-3 Otter for Airworthiness Directive (AD).

Client: VAZAR

Client Request: The DHC-3 Otter had a history of failures in the elevator servo-tab bellcrank. VAZAR agreed to address this issue on their turbine conversion to increase safety of the aircraft and meet the newer 23.629 requirement of flutter free after a single failure. Volant Technica was asked to develop the fix for the servo tab.

Project Summary: Volant Technica, a precursor company to Fliegen Works, worked with the FAA to address this service difficulty and produced the design data, developed loads and a structural test proposal, then DER witnessed the structural test. We also wrote the flight test plan and helped with the issuance of the TIA. The STC is a method of compliance to AD 2004-05-01. Fliegen Works currently holds PMA for fabrication of the redundant servo tab; it includes a 2nd control rod and other modification to fix in-service failure problem.

Results: STC SA01059SE was granted to VAZAR (as American Aeromotives) and is licensed to Fliegen Works for European import auto repair under PMA PQ2380NM.

External Helicopter Handle

Summary:  Field approval of external handle and personnel anchorage on MD 369E.

Client: Wilson Construction Company

Client Request: The linemen working from a rotorcraft needed a handle with an anchor point for their safety harness.

Project Summary: We provided design, detail drawings, structural substantiation, as well as a rotorcraft flight manual supplement (RFMS). This included enough data for a coordinated field approval with the assistance of Dave Swan.

Results: Multiple 337 approvals to install handle on helicopters owned by the client.

Rudder Tab On A-1 Series Blimps

Summary:  Rudder Tab certification

Project Name: Rudder Tab On A-1 Series Blimps

Client: American Blimp Company

Client Request:  The client requested a fix to balance the aerodynamic torque created by an installed Lightsign on the left side of the blimp’s envelope.

Project Summary: We did the preliminary sizing for a fixed rudder tab and worked with ABC on the detail design. Fliegen Works developed the aerodynamic loads, produced a structural test proposal and then DER witnessed the tests. The design of a fixed tab on a Rudder of ABC A-1 series airships was a challenge since a number of engineering estimations were made. From minimal available blimp flight and aerodynamic data and old NACA data an analysis was performed to design a fixed rudder tab that biased the rudder to compensate for the unsymmetrical drag on the airship due to the Lightsign on one side of the airship. This was a major change to the type design by the type certificate holder.

Results: Successful flight testing, installation and approval of rudder tab on A-1 series blimp. Pilot force required to maintain straight flight reduced to acceptable levels. Rather than complex CFD, a simple method combined with a little guesswork was applied. Minimal time and cost was required to produce the required results in this manner.

Thrush S-2R Series Conversion to Walter Turbopropellers

Summary: Thrush S-2R Series Conversion to Walter Turbopropellers

Project Name: Thrush S-2R Series Conversion to Walter Turbopropellers

Client: Cascade Aircraft Conversions

Client Request:

Project Summary:  Fliegen Works Inc. provided structural engineering substantiation, detailed designing and analysis, and DER services for an STC based project to convert Thrush S-2R series aircraft to Walter M601D-11 and M601E-11 turbine engines.

Results:

FAA Approvals:

Thrush aircraft turbine conversion

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