Famille JT8D

US firm brings modified JT8D thrust reverser to market
By Mary Kirby

A modified thrust reverser that reduces noise and augments thrust on Pratt & Whitney JT8D-200 series engines is being offered to Boeing MD-80 operators by Las Vegas-based Dugan Kinetics.

"A new stow position has been developed for the thrust reverser, where it has the new useful purpose during flight of adding thrust with no additional weight or fuel consumption. This position uses the reverser doors as an ejector during flight," says Dugan Kinetics marketing director Jack Dugan.

The EP-80 Ejector/TR surrounds the engine exhaust nozzle to suck the ambient air flow into its chamber causing this accelerated flow to mix with the engine's higher velocity exhaust flow. This mixing also reduces noise.

Dugan says the EP-80 Ejector/TR has been tested on an MD-80 and a Boeing 727.

"All tests have provided a total flight fuel savings range between 6% and 12%," he adds.

PICTURE: Dugan’s modified MD-80 reverser gets American scutiny
By Lori Ranson

Engineers from American Airlines have closely examined a modified thrust reverser on a Pratt & Whitney JT8D-200 designed by Dugan Kinetics for Boeing MD-80s that could potentially cut fuel burn and reduce noise.

The test aircraft (N789BV) completed functionality and performance testing during 9-12 December at Tucson International Airport, and then flew to American's bases in Tulsa, Oklahoma and Fort Worth, Texas at the carrier's request, says Dugan. American operates around 260 MD-80s, according to Flightglobal's ACAS database.

Dugan has developed a new stow position for the thrust reverser in which the doors are used as an ejector during flight. The new position allows for an increase in thrust while keeping aircraft weight constant.

By mixing ambient airflow with the jet exhaust, thrust is increased and substantial fuel savings is achieved during climb and cruise through use of the EP-80 Ejector/TR. Dugan has previously said the modified thrust reverser could cut fuel burn per flight from 6% to 12%.

The testing included two baseline flights and two flights with the modified thrust reverser on an MD-8. The duration of the test flights was between 3h and 5h.

Dugan says one of the primary purposes of the testing is to fully understand where the ejector is augmenting thrust to determine a definitive number for fuel burn reduction, and it expects to receive that data from flight engineers soon.

The company also expects to obtain a supplemental type certificate covering the EP-80 Ejector/TR during the later half of the first quarter, says Dugan.

Dugan Kinetics will start the second phase of testing for its new EP-80 ejector thrust reverser designed for the Boeing MD-80 in May as it targets certification before the end of the year.

Tests of the EP-80 concluded in December show a flight profile fuel burn reduction of 5-10% depending on the profile, and a 9.5% savings from brake to climb.

A second round of tests is about to start in Washington state, says marketing director Jack Dugan. Speaking at the MRO Americas exhibition in Phoenix, Dugan added that MD-80 operator SAS wants to observe the next round of tests, which are simultaneous with the effort to gain a US supplemental type certificate. Approval is expected late this year.

After functionality and performance testing of the EP-80 ejector was completed in December, the test aircraft was flown to the bases of major MD-80 operator American Airlines in Tulsa, Oklahoma and Dallas at the carrier's request. American operates almost 260 MD-80s.


Dugan Kinetics


Dugan says the company expects to have a letter of intent signed with an operator to purchase the EP-80 ejector in roughly 60 days.

The technology developed by Dugan encompasses a new thrust reverser featuring doors used as an ejector during flight, which allows for an increase in thrust while keeping aircraft weight constant. Fuel savings are achieved through mixing ambient airflow with jet exhaust to increase thrust while increasing fuel savings through cruise and climb.

Installation of the kits takes roughly 12 man hours, says Dugan, who adds that the target is to deliver 25 sets this year. Dugan Kinetics has held extensive talks with Nordam and Triumph regarding partnerships to manufacture the EP-80, says Dugan, but no firm agreements are in place.