Airframe

While essentially retaining the same dimensions of a two-seat Eagle, the F-15E's structure has been redesigned and strengthened, allowing an increase in takeoff weight from 68,000 to 81,000 pounds. Approximately 60% of the aircraft saw this redesign which has created a fatigue life of 16,000 hours and has allowed up to 9g of maneuvering. Due to the redesign, the bring-back capability of the aircraft has been increased as well, reflected in a maximum landing weight of 44,300 pounds.

A variable camber wing was rejected during the design due to weight and complexity concerns. As a result, the wing is of fixed leading edge with conical camber. This results in only a marginal drag penalty at supersonic speeds and slightly reduced subsonic performance. Wingtips have been modified from their original shape, with 3 sq. ft. clipped from each to eliminate severe buffeting present both at high g loads and at high subsonic speeds at altitudes in excess of 30,000 feet.

Wing Specifications
Wing Area Wing Sweep Aspect Ratio Incidence Anhedral Max. Loading		608 sq. ft. 45 deg. 3 0 deg. 1 deg. 133.2 lb./sq. ft.


The twin vertical fins found on all F-15s allow for greater directional stability at high angles of attack by using the vortex flow that emerges from the wing. Further aiding in the aircraft's performance at high angles of attack are a pair of variable geometry engine intakes located on either side of the fuselage, providing a straight path to the engines. These variable intakes are capable of adjusting their angle in order to provide an adequate airflow to the engines at various speeds and at high angles of attack. Controlled by an air data computer, and manipulated hydraulically with the fulcrum at the bottom edge, the intakes are capable of angles varying between 11 degrees below the aircraft's horizontal and 4 degrees above. Within the intakes themselves, mechanically controlled ramps are present to suppress shockwaves that may result due to air entering the inlets at speeds at or above Mach 2.

Flight Controls

Flight control provided by a Lear Astronics digital system. Triply-redundant with a mechanical back-up, the system can be coupled to the terrain-following radar for full hands-off flight. Tailplanes are all-moving with notched dog-tooth leading-edges to prevent flutter. Plain ailerons and flaps. Rudders make use of no spoilers or trim tabs. Control surfaces powered by hydraulic actuators. Speedbrake is located on the upper-fuselage just aft of the cockpit and opens upward, hinged forward of the surface. Flight column features a boost and pitch compensator.

Control Surface Areas
Ailerons Flaps Tailplanes Vertical Stabilizers Rudders		26.48 sq. ft. 35.84 sq. ft. 111.36 sq. ft. 105.28 sq. ft. 19.94 sq. ft.

Conformal Fuel Tanks (CFTs)

Giving the F-15E a beefier appearance are two Conformal Fuel Tanks (CFTs) which attach to either side of the fuselage, serving a dual role. Each CFT is capable of carrying 723 US gallons of fuel with less drag than would be present using standard external tanks. Each CFT also features six stub-pylons for the mounting of ordnance. The stubs are placed tangentially, causing less drag than would be present with the use of the standard Multiple Ejection Racks mounted to the wing stations. Their placement arranges the bombs in two rows along the sides of the aircraft. This reduced drag translates into slightly higher speeds and increased range.

Powerplant: F100-PW-229

Since 1991, the Dash 229 version of the Pratt & Whitney F100 series has powered the F-15E starting with the 135th production aircraft (90-0233). Prior to that time, power was supplied by the Dash 220. The PW-229 provides a 24% increase in thrust through increased airflow and fan pressure ratio. This translates into 17,800 pounds dry thrust and 29,100 pounds of thrust at full augmentation. One of the most distinctive features of the PW-229 is the bluish tinge that colours its afterburner plume. The updated DECU (Digital Engine Control Unit) allows the Dash 229 to spool up from idle to full augmentation in under four seconds, approximately half the time required by the Dash 220. The compression ration for the PW-229 is 0.36:1 while the overall pressure ration is on the order of 32:1. With a weight of 3,740 pounds the Dash 229 delivers a thrust-to-weight ration of 8:1 at full augmentation.

The F100 series of engines has flown since July 1972 in the prototype F-15 and has assisted the F-15 in achieving a number of time-to-climb records during the 1970s. A low-bypass turbofan, the P&W F100 series features a 3-stage fan, a 10-stage compressor, a 2-stage compressor-drive turbine, and a 2-stage fan-drive turbine. The F100 series also features an augmentor for afterburning.

F100-PW-229
Thrust (Dry) Thrust (A-B) Weight Length Inlet Diameter Maximum diameter Bypass ratio Overall pressure ratio		17,800 pounds 29,100 pounds 3,740 pounds 191.0 inches 34.8 inches 46.5 inches 0.36:1 32:1

Engine accessories such as drive shafts supplying power to the aircraft systems, are mounted to the airframe rather than the engine. As a result, any engine can be mounted in either the port or starboard engine bays. This provides greater ease to maintenance crews while at the same time eliminating what could be a logistical nightmare during times of war. Engines are removed by sliding them out the rear of the aircraft on rails built into the airframe. Each engine needs disconnection from only ten attachment points before it may be removed. From that point, it is slid out onto an elevated trolley for transport or immediate maintenance.

The engines are separated by titanium walls to minimise the possibility of damage to both engines when one is hit. Between the two barriers, there is a pressurised extinguisher bottle which can release fire-suppressing foam into either engine bay or into the void between the firewalls. Power for engine start is provided by an APU (Auxiliary Power Unit) manufactured by AlliedSignal. This unit also generates limited electrical and hydraulic power on the ground when the powerplant is not operating.




Undercarriage

Tricycle landing gear features a single wheel on each hydraulically forward-retracting unit. Single oleopneumatic shock absorbers and Michelin AIR X radial tire at each point of the carriage system. Braking for all wheels provided by a Bendix five-rotor carbon disc brake.

Undercarriage Specifications
Wheel Track Wheel Base Tire Size (Nose) Tire Size (Main) Tire Pressure		9' 0.25" 17' 9.5" 22 x 7.75-9 36 x 11-18 305 lb/sq. in.






Aircraft Systems

Since 1991, oxygen has been provided by a molecular sieve oxygen generating system (MSOGS) manufactured by Litton Industries. This replaced the older liquid oxygen system that was standard in the F-15E. Hydraulic power provided by three independent hydraulic systems rated at 3,000 lbs/sq. in. powered by engine-driven pumps. Electrical power provided by a Lucas Aerospace generating system featuring constant-speed drive units rated at 60/75/90 kVA.

Hydraulics for the F-15E are supplied by three separate systems, isolated from each other so that battle-damage will be less likely to cause a system-wide failure. The hydraulic system is capable of isolating leaks and routing the path around the breaches._