Raven

2001
Black

The Raven (or "Phoenix," or "Ravenstein," as the latest variant was also known)  was designed to compete in the 2000/2001 AIAA/Cessna/ONR Design/Build/Fly contest, held in Patuxent River MD in April of 2001.  The mission objective was to alternately fly a high volume payload of up to 100 tennis balls, and a high density payload of steel.  Flight score depended on how many tennis balls and how much steel could be carried in the maximum mission window of 10 minutes.  Aircraft were subject to several design constraints such as runway length, wing span, battery type and size, motor type, etc.  The Black team fought their way back to a third place finish after a major crash on Saturday resulted in an all night repair, including the construction of a makeshift composite curing oven in the hotel parking lot.

Specification List: 

Wing:

  • Wingspan:        10 ft
  • Wing Area:        8.9 sq ft
  • Aspect Ratio:    11.4
  • Airfoil:                 S1210

Fuselage:

  • Length:            5.9 ft.
  • Max width
  • Max Height

Propulsion:

  • Motor:                   Astroflight 661 brush-type geared 2.7:1
  • Controller:              ASTRO 204D
  • Fuel:                      37 SR-2400 NiCd Batteries in series
  • Propeller:               22x20 Bolly composite    
  • Maximum Power:  >1500 Watts (2 hp)
  • Maximum Thrust:   15 lb

Weights:

  • Empty Weight (excl. Batteries):      12.7 lb
  • Battery Weight:                              5 lb
  • Tennis ball payload capability:         100 balls (approx 13.5 lb)
  • Maximum Payload Weight:              18 lb
  • Max Gross Weight:                         35.7 lb

Features:

  • Composite main gear
  • Electromechanical nosewheel brake
  • Polyhedral wing
  • All carbon fiber construction
  • Molded fuselage (First use of molded construction in an OSU DBF plane)
  • Custom machined nose gear

Performance:

  • Takeoff distance at max gross wieght:    200 ft.
  • Maximum endurance:    > 10 minutes
  • Maximum Range:           > 5 miles
  • Maximum Speed:           > 88 ft/sec
Team Info: 

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

Chief Engineer: Sam Preece

Aerodynamics / Stability and Control:

  • Anthony Boeckman (Lead)
  • Eric Williams
  • Renato Zanetti
  • Po Jo-Ong Edmond

Propulsion:

  • Chad Stoecker (Lead)
  • Fei-Min Chang
  • Marita Johnson

Structures:

  • Dustin Hamill (Lead)
  • Byrony Gass
  • Justin Evans
  • Johnny Dickson
  • Chris Nault
  • Dacheng Tang
  • Yoke Chuan Tan
  • Yong Keat Chia

Pilot: Dan Bierly

Spotter: Dr. Ron Delahoussaye

Faculty Advisor: Dr. Andrew S. Arena, Jr.

Assistant: Joe Conner

*(The above team roster does not include all people involved in the project)

Contest Summary: 

The mission objective was to alternately fly a high volume payload of up to 100 tennis balls, and a high density payload of steel.  Flight score was (Ws + n/5) where Ws is the weight of steel carried, and n is the number of tennis balls carried, for all laps combined.  For all steel payload laps, the aircraft had to fly the course layout shown.  For all tennis ball payload laps, the aircraft had to fly the course twice, but without the 360 turn.  Total score was calculated as Written Report Score * Flight Score / 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.

Some of the more challenging constraints on the designs included:

  • 200 ft short field takeoff distance
  • Brushed electric motor using NiCd batteries
  • 10 minute maximum flight window (A typical mission required 5 landings to a complete stop.  This required the team to rapidly unload and load the payloads.  The time would usually run out not long after Raven passed the downwind pylon, which is where the aircraft had to pass for a lap to count)
  • Aircraft must be lifted at the wing tips at full gross weight

How "Raven" became "Phoenix"

On the first day of the contest, Raven was in 6th place, and was poised to make a flight which would have significantly improved the placement of the team.  As the plane was taking off, an unfortunate rain shower suddenly struck, and the Raven lost power on the critical crosswind turn, when she was carrying a full load of steel.  In this vulnerable position, the port wing stalled, and the aircraft crashed on the grass.  The aircraft sustained major damage to the fuselage and the wing.  Both the fuselage and the wing were snapped in half.  Although never tested, one hypothesis was that the loss of power was due to a short in the arming switch which was located at the bottom of the plane, where a small amount of water collected.

The Black team immediately mobilized to make the repairs, and set up a makeshift workshop in the parking lot of the hotel at approximately 7:00pm.  The worst damage was done to critical parts of the structure that carry the highest loads, therefore the repairs needed to be strong.  Since structural epoxy would not be fully cured by contest time, it was decided that the team needed to build a curing oven to accelerate the epoxy cure.  The team accomplished this by purchasing insulating foam board at a local hardware store, and heat lamps from Wal-mart.  The foam board was built into a box, and the lamps placed in the ceiling inside the box.  The oven was built in the OSU racing trailer, was then further covered with blankets.  The oven may be seen in the black team video above (see the video shot Sunday at 3:00am).  The team completed repairs on the aircraft by 7:00am Sunday, just in time to make the trip back to the flight field and fly their way to third place.

Complete Rules

Official Contest Summary

Results Summary: 
  • Report Score:     91
  • Flight Score:       221.7
  • RAC:                    4.754
  • Total Score:        4243.73
  • Overall Place:     3rd
Sponsors: 

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

Advanced Composites Group, Inc.
Chevron-Phillips
Ditch Witch
Frankfurt-Short-Bruza Association
Halliburton Energy Services
L. Andrew Maciula
Lockheed Martin Ft. Worth Division
Mercruiser
NASA Oklahoma Space Grant Consortium
OSU Team Black 2000 "Flight Factory"
The Pump and Motor Works, Inc.

Memorable Quotes: 

"Deep into that darkness peering, long I stood there wondering, fearing, 
Doubting, dreaming dreams no mortals ever dared to dream before;"

-                     Edger Allen Poe, “The Raven”

"Nothing can be simple"    - Dr. Arena

"No Hands!"  -Dan Bierly

Category: 
Design, Build, Fly