L-1011 General Aircraft Characteristics: Takeoff Exhaust Velocities L1011-500 (25-8)

The exhaust velocity is at about 70 miles per hour, 700 feet behind the aircraft at takeoff. Of special interest here is the width of the wind affected area. It is well within runway parameters, and should not affect runway lights nor stabilized shoulders, such as packed snow.

L-1011 General Aircraft Characteristics: Exhaust at Ground Idle (25-7)

The high bypass ratio provides for lower exhaust temperatures than attained with current [as of 1974] jets with a lower bypass ratio.

With the center engine at idle, exhaust velocity is at 50 miles per hour at 200 feet behind the tail. From the wing engines, this velocity occurs 140 feet behind the tail.

Lockheed suggested that you you apply breakaway power with the wing engines only, and that you exercise special caution at Gates, especially those with large windows.

L-1011 General Aircraft Characteristics: Number Two Engine 'S" Duct (25-6)

The number two engine is installed in the aft fuselage. Like the wing engines it is a 50,000 pound thrust Rolls Royce engine. Its inlet is a curved "S" duct which provides performance equivalent to that of a straight through duct.

There are several advantages to using an "S" duct. First, this lowers the No. 2 engine, which gives a low center engine thrust line, reducing pitch up tendencies. Second, the lower engine allows for a one piece rudder which gives improved effectiveness. The "S" duct design also reduces aircraft weight. The engine is mounted in the aft fuselage, eliminating the need for heavy structural supports (up to 800 lbs.). Those supports, if would be used, would reduce the passenger cabin by 64 square feet, or 11 seats.

L-1011 General Aircraft Characteristics: Wing Engine (25-5)

The L-1011-500 is powered by three RB.211-524B engines. Each engine has three compressors and three turbine assemblies. While the three spools rotate about a common axis, each is mechanically independent of the other two.

Each engine produces 50,000 pounds of thrust. 75% of this thrust is generated by the FAN (N1) due to the high By-Pass Ratio of 4.4 to 1.

The L-1011 is the quietest [well at least was at the writing of this document in 1972] of the new generation aircraft and currently meets all existing and planned community noise requirements. It accomplishes this by means of two significant features:

• Absence of FAN INLET GUIDE VANES
• Sound absorbing material in the inlet.

By the way, here is a link to Justin Wooglar's BLOG ... he is doing amazing stuff with jet engines in his backyard ... including a RB.211 !

L-1011 General Aircraft Characteristics: Control Surfaces (25-4)

The primary flight control system includes controls for the horizontal stabilizer, rudder, ailerons, and the spoilers. Conventional control wheels, columns and rudder pedals are provided in the flight station for the Captain and First Officer. These controls are linked to (and govern) hydraulic actuators which determine the positioning of hydraulic servos. Thus the control surfaces are fully powered by the hydraulic system. The L-1011 has a flying stabilizer and slaved elevator. Other flight controls include the ailerons and spoilers. Both the inboard and outboard ailerons are full time ailerons. The spoilers, in addition to being speed brakes, are used in a Direct Lift Control System (DLC). The DLC is used in approach to Landing and modulates the spoilers, changing wing lift, greatly increases approach and touchdown accuracy.