At one point in our lives, we had a favorite car. The hunk of metal that was our go-to. Our ol’ reliable. In the MV-22B Osprey program, that moniker goes to Aircraft No. 8—affectionately known as the ‘Eight-ball’.

After serving 20 years in test and evaluation, Eight retired to the Patuxent River Naval Air Museum in June.

Her humble beginnings started at the Boeing hangars in Philadelphia and Arlington, Texas. Eight was one of four engineering manufacturing development (EMD) aircraft built and heavily instrumented for the EMD flight test program at Naval Air Station Patuxent River.

The MV-22 instrumentation package included 1,300 analog sensors, such as strain gauges, accelerometers, pressures and temperatures that helped engineers analyze and understand aircraft and propulsion system loads, stresses and strains, and how the aircraft performs in all types of conditions. It is also capable of onboard data recording and real-time data telemetry to the ground station.

Eight’s first chance to spread her wings came Aug. 23, 1997, in Arlington. After a series of shakedowns and envelope expansion flights, the aircraft was transferred to Patuxent River.

There, Eight was directly responsible for helping the MV-22 transcend from an ordinary vertical takeoff and landing to an exceptional aircraft. During the EMD and follow-on test and evaluation flight test programs, expanding the envelope or taking an aircraft to, or even beyond, its altitude and speed limits was Eight’s objective. Whether it was a hover to the never-exceed-speed, light-to-heavy gross weight or from forward-to-extreme aft center of gravity, Eight stood her ground and gave engineers vital information on the MV-22s.

She demonstrated a maximum airspeed of 354 knots, along with other envelope expansion and flying qualities testing, including the high angle of attack, buffet, aerial refueling, external loads and structural landings. Eight was also instrumental in defining the height-velocity diagram for the aircraft. While in formation flight with another MV-22, Eight examined the change in flight characteristics caused by the wake interaction with the rotor’s super vortex.

She still has fans: Mark Hollady, the MV-22B flight test engineer lead, remembers his first time flying in the Eight-ball fondly.

“It was like half an hour, but what I remember the most was the short takeoff—we call it a STOL. The blades come over, and then they give it the power. I was amazed at the acceleration—I almost got thrown out of the seat,” he recalled. “You’re talking 12,000 horsepower and two 38-foot rotors. I didn’t think it would move that fast. You know, looking at it, she looks a little big and slow, but she’s very maneuverable. She’s fast.”

After the loss of two MV-22s in 2000, Eight was the lead aircraft for the high-rate-of-descent testing as part of the Osprey’s return to flight. Eight later became part of a comprehensive study on rotorcraft descent into its rotor wake. Ground tests also showed Eight could hold her own when faced with extreme crosswinds, takeoffs and landings on slopes, as well as taxiing and braking.

Over the years, many operational test pilots had their first training flight on board the Eight-ball. She has also flown many influential VIPs.

There were times when she showed off her skills in the skies, performing such risky maneuvers as a 360-degree aileron roll as part of her many defensive combat maneuvers. When she encountered an unexpected bird-strike in 1998, she gave engineers the opportunity to assess the structural integrity of the Osprey’s nose cone and forward fuselage bulkhead.

Eight also helped pave the way for the development and evaluation of many versions of flight controls, avionics software, engine control and inertial navigation software.

She participated in so many offsite tours, both in and outside the U.S., she was almost like a rock star. She demonstrated her prowess in the cold temperatures of Nova Scotia, Canada, in 2000, and did a couple of stints in Gunnison, Colorado, and Amarillo, Texas, for heavy gross weight and crosswind STOL/run-on-landing testing. Eight’s last offsite test was conducted in 2016 in Logan, Utah, where she evaluated bonded blade tab rotor hover performance at medium altitude.

Former project officer, Lt. Col. John Ennis, now Commanding Officer, Air Test and Evaluation Squadron (HX) 21, experienced firsthand the importance of checking your gear while in Yuma, Arizona, with Eight. The aircraft underwent a field repair in the Yuma desert in 2009 after rough-field STOL testing.

“It was Maj. Craig Merriman and me at the time, operating aircraft Eight from the desert floor in Yuma, and the test point was taxiing 10 knots over an unprepared desert floor,” Ennis said. “We’re taxiing probably 8 knots, and we’re almost done with the test point, when all of a sudden, the gear hits a really soft spot in the desert, then a pop, and the nose is sitting on the ground.”

Yuma Test Command built a tent around the aircraft and repaired the landing gear. After a month in the sweltering sun, Eight was fully functional.

Over the last 20 years of test and evaluation, the Eight Ball has been pushed, yanked, stretched and bent in every direction imaginable, persevering and providing key test data supporting the development of the aircraft. The other 350 MV-22B aircraft operated by the Marine Corps and Air Force have the Eight-ball to thank for their capability.