April 13, 1987

April 13, 1987

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AERONAUTICAL ENGINEERING

Douglas Plans UHB-Powered MD-91X As Successor to Turbofan Transports

By Michael A. Dornheim11 min

TECHNICAL SURVEY: ULTRAHIGH BYPASS RATIO ENGINES

Airframe Manufacturers Near Landmark UHB Decisions

AVIONICS

British Scientists Reveal Signai Format Of Soviet Navsat

By Philip J. Klass7 min

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More Features
9091
AERONAUTICAL ENGINEERING

Douglas Plans UHB-Powered MD-91X As Successor to Turbofan Transports

Long Beach, Calif.—The McDonnell Douglas MD-91X derivative transport design features a number of significant changes—including a new, larger, all-composite horizontal stabilizer—from the MD-87 it is based on in order to replace conventional turbofans with unshrouded ultrahigh bypass engines (UHBs).

By Michael A. Dornheim11 min

5253
TECHNICAL SURVEY: ULTRAHIGH BYPASS RATIO ENGINES

Airframe Manufacturers Near Landmark UHB Decisions

108109
AVIONICS

British Scientists Reveal Signai Format Of Soviet Navsat

Washington—Analysis by British scientists of signals from the USSR’s new Global Navigation Satellite System (Glonass) reveals some notable differences from the U. S. Navstar global positioning system despite many similarities.

By Philip J. Klass7 min

6869
ULTRAHIGH BYPASS RATIO ENGINES

Rolls Skeptical About Early Propfan Service Introduction

Derby, England—Rolls-Royce has begun a technology demonstrator program aimed at producing an economically viable propfan propulsion system within 10 years, but the company sees propfans as restricted in the thrust range in which they will compete with shrouded fans and unlikely to be ready for airline service, even within a limited thrust range, until at least the mid-1990s.
5859
ULTRAHIGH BYPASS RATIO ENGINES

No. 2 UDF Engine Prototype Will Fly On MD-80 by June

Evendale, Ohio—General Electric Co. has completed flight tests of its Unducted Fan ultrahigh bypass proof-of-concept engine on a Boeing 727-100, and has started assembly of a second prototype engine, scheduled to fly on a McDonnell Douglas MD-80 transport before June.
3637
AIR TRANSPORT

Airbus Defines New A340 To Use CFM56 Turbo fans

By Jeffrey M. Lenorovitz7 min

5657
ULTRAHIGH BYPASS RATIO ENGINES

Lockheed, NASA Will Begin Propfan Test Assessment Flights

4647
AIR TRANSPORT

New Tax Laws Increase Cost Of Leasing, Buying Aircraft

By Michael Feazel6 min

8283
ULTRAHIGH BYPASS RATIO ENGINES

Airframe Makers Face Challenge Of Characterizing Propfan Noise

Los Angeles—Dealing with the high noise levels generated by unshrouded contrarotating propfans is a major design effort for airframe manufacturers. The challenge is to have acceptable sonic fatigue life and a quiet cabin without a large weight penalty.
9899
PROCUREMENT REFORM

GAO Warns of Potential Risks In Major New Weapons Programs

By John D. Morrocco6 min

April 61987 April 201987