Hammerhead

2000
Orange

The Hammerhead is an all composite, box wing design that was designed to compete in the 1999/2000 AIAA/Cessna/ONR Design/Build/Fly contest held in Wichita, KS in April of 2000.  The objective was to fly a mission consisting of alternating sorties: a short field cargo sortie where the aircraft carried water in 1L containers, and a ferry sortie in which the aircraft flew 2 empty laps.  Flight score depended entirely upon the amount of water carried, which could be done in multiple sorties.  Aircraft were subject to several design constraints such as runway length, wing span, battery type and size, motor type, etc.  The Hammerhead finished in 5th place overall at the contest after a crash due to gusty conditions prevented the aircraft from competing further.  The Hammerhead was named after the shark due to the resemblance of the cheeks on the engine cowl.

Specification List: 

Wing:

  • Wings:             2 in a staggered box configuration
  • Wing Area:       22.6 sq ft.
  • Wingspan:        7 ft (contest Limit)
  • Aspect Ratio:    4.2 (each wing)  Effective AR much higher due to box design
  • Airfoil:               S1223

Fuselage:

  • Length:    7.03 ft

Propulsion:

  • Motor:         Astro Cobalt 40 8T#20 geared 3.1:1
  • Controller:   Astro 204D
  • Fuel:           25 x Sanyo 3000 NiCd batteries
  • Propeller:    20 in

Weights:

  • Empty Weight (without batteries):    12.5 lb
  • Battery Weight:      5 lb
  • Payload weight:     13.2 (6x1Liter bottles of water)
  • Gross weight:        30.7 lb

Features:

  • Mostly composite construction (The Flight Factory and ORANGE ABISS teams built the composite curing oven while designing their planes)
  • Custom machined main gear and hydraulic main gear brakes
  • Custom cowling with cheek cooling scoops.  (This is how the hammerhead got its name)
Team Info: 

The OSU ORANGE ABISS design team was led by a Chief Engineer, and divided into three primary groups: Aerodynamics/Stability and Control, Propulsion, and Structures.

Chief Engineer: Joel Basler

Aerodynamics / Stability and Control:

  • Steve Eddy (Lead)
  • Janessa Mosier
  • Aaron McClung

Propulsion:

  • Corey Lawyer (Lead)
  • Seet Onn Ng
  • Monika Salas
  • Hoe Mun Wong

Structures:

  • Jennifer Johnson (Lead)
  • Mark Bloyd
  • Jeff Callicoat
  • Chris Cummings
  • Kenneth Fullwood
  • Foe-Shin Poo
  • Chad Robinson
  • Kok Siang Wong
  • Saito Yoshihiko

Marketing: Carolyn Robinson

Contest Summary: 

The 2000 DBF contest traded off heavy lift capability, with long range cruise.  For each mission, the aircraft had to fly a short field cargo mission by carrying as many 1L bottles of water as possible.  Then the aircraft had to perform an empty sortie of 2 laps.  The aircraft could repeat this process until time or fuel ran out.  Overall score was written report score, times the amount of water carried in three missions, divided by RAC.  RAC was a "Rated Aircraft Cost" which penalized many aspects of the design.  It included penalties for design parameters such as; aircraft empty weight, engine power, wing area, etc.  A link to the complete rules may be found below.  Two of the most significant challenges of the mission requirements were the short 100 ft. takeoff and the 7 ft. wingspan limit.  The box wing aircraft was a result of the trade studies accomplished during the design phase.

The Hammerhead aircraft aircraft finished in 5th place overall after an unfortunate crash due to very gusty wind conditions.  On landing approach the aircraft suddenly turned towards the crown due to the gust, and the pilot ditched the airplane.  The contest judges gave the following award to the team:

Oklahoma State University: "The State Farm Good Neighbor Award for intentionally crashing their plane rather than endangering the spectators"

Complete Rules

Official Contest Summary

Results Summary: 
  • Report Score:     85.75
  • Flight Score:       8 + 10 + 10  (Sum of best three missions in liters of water)
  • RAC:                  6.01
  • Total Score:        399.5
  • Overall Place:     5th
Sponsors: 

The following sponsors contributed to the project.  The ORANGE ABISS team greatly appreciates their support, and considers them members of our team.  Without their support, the project would not have been possible.

ARINC
Advanced Finance Solutions
Boh-Air
Advanced Racing Composites
Frontier Electronic Systems
Ditch Witch
Lowes
Mercruiser
Helmerich and Payne
OSU SGA
NASA Oklahoma Space Grant Consortium

Category: 
Design, Build, Fly