MEMORANDUM

TO:                  Guidance and Payload teams

FROM:            Greg Laxton

  Chief Systems Engineer

DATE:              August 20^th, 2015

SUBJECT:       EXCESS WEIGHT ON THE “WEED WETTER”

 

Our team appears to be at an impasse regarding excess weight of the “Weed Wetter”. To be successful, we must meet three objectives; be on time, be on budget and meet customer expectations. Its success is tied to our success. Currently we are 10% over weight. This takes us away from the derived requirement (Terwilliger, Burgess, & Hernandez, 2013) of two acres per hour from each Wetter. It is imperative we have a 5% improvement from both teams

To the payload team; please include the safety engineer in your discussions. There must be an area of compromise where you can find a solution with less fuel and less fertilizer. The current refuel and reload time is expected to be four minutes; if you can find efficiency in the turnaround process, perhaps you can treat the promised acreage. More flights of shorter duration may meet the target spray with the current vehicle design. Could we find room for improvement by relocating the supply vehicle closer or changing the spray pattern?

To the guidance, navigation and control team; please bring propulsion in to your discussions. Are there improved power plants that would provide more lift with the same weight? It has been a year since you finalized the engine choice, please check with NWUAV ("NWUAV EFI Multi-Fuel Engine," n.d.) again and inquire how soon the NW-45 will be available. All team members should investigate similar commercial off the shelf improvements that would help meet your target.

Traceability (Lowen, 2013) for all teams is critical. Please track any changes using the existing metric and plan to submit your improvements during the formal program review (Terwilliger, Burgess, & Hernandez, 2013) meeting next week.

We’re at a critical phase in development team, and I’ve authorized 10% overtime until Friday, the 28^th of August.

 Lowen, H. (2013). Requirement-based UAV design. Retrieved from http://www.micropilot.com/pdf/requirements-based-uav.pdf

NWUAV EFI Multi-Fuel (Heavy-Fuel/Gas) Engine. (n.d.). Retrieved from    
           http://www.nwuav.com/uav-products/heavy-fuel-engines.html

Terwilliger, B., Burgess, S., & Hernandez. (2013, September 25). MODULE #2 GLOBAL
           SYSTEM DESIGN CONCEPTS, REQUIREMENTS, AND SPECIFICATIONS
           OVERVIEW [PowerPoint].