Flight Testing of the F/A-lSE/F Automatic Carrier Landing System] Arthur L. Prickett Christopher J. Parkes Naval Air System Command Naval Air System Command 2 1947 Nickles Rd. Bldg. 1641 2 1947 Nickles Rd. Bldg. 164 1 Patuxent River, MD 20670- 1500 Patuxent River, MD 20670-1500 (301) 342-0774 (301) 342-4645 prickettj [email protected] [email protected] .mil Abstract-The F/A-lSE/F is the U.S.Navy’s premier strike upon which the aircraft was initially qualified for Mode I, fighter aircraft, manufactured by the Boeing Company. The totally automatic, approaches and landings to the aircraft F/A-l8E/F aircraft, while maintaining a hgh degree of carrier. The paper briefly describes the key components of commonality with the F/A-l8C/D aircraft, has a lengthened the F/A-l8E/F’s ACLS, including cockpit displays and fuselage, larger wing and control surfaces, strengthened controls, antennas, autothrottles and flight control landing gear, an improved propulsion system including a implementation, and interface with the shipboard AN/SPN- growth version of the General Electric F404 engine 46(V) ACLS. Test procedures and methodology are designated the F414-GE-400, and larger high performance presented as well as test results and interpretation. Finally, inlets. This paper concentrates on the development, test, lessons learned are presented and recommendations are and evaluation of the F/A-l8E/F Automatic Carrier Landing made for future aircraft ACLS developmental test and System (ACLS) up to and including the Third Sea Trials, evaluation efforts. U.S. Government work not protected by U.S. copyright. 5-2593 TABLEOF CONTENTS The paper briefly describes the key components of the FIA- 18E/F's ACLS, including cockpit displays and controls, NOMENCLATURE antennas, autothrottles and flight control implementation, 0 INTRODUCTION and interface with the shipboard AN/SPN-46(V) ACLS. 0 RESULTS AND EVALUATION Test procedures and methodology are presented as well as SUPPORTING DATA test results and interpretation. Finally, lessons learned are CONCLUSION presented and recommendations are made for future aircraft RECOMMENDATIONS ACLS developmental test and evaluation efforts. LESSONS LEARNED Description of Test Aircraft and Equipment REFERENCES 0 BIOGRAPHIES F/A-18E/F General Description-The FIA-18E is a single seat carrier based strike fighter aircraft built by the Boeing NOMENCLATURE Company. The FIA-18F is the two-seat model of the Super Hornet and is configured with tandem cockpits. Due to the ACLS Automatic Carrier Landing System similarity in flying qualities in the ACLS operating FCC Flight Control Computer envelope, both versions were treated as a single aircraft, and FOST Follow-on Sea Trials used interchangeably, for the ACLS development and test ICLS Instrument Carrier Landing System effort. PALS Precision Approach and Landing System PQR PALS Quality Rating The aircraft is powered by two General Electric F414-GE- TST Third Sea Trials 400 afterburning turbofan engines utilizing Full Authority WOD Wind Over Deck Digital Ehgine Control (FADEC). The aircraft features a variable camber mid-wing with Leading Edge Extensions INTRODUCTION (LEX) mounted on each side of the fuselage. Twin vertical tails are angled outboard 20 degrees from the vertical. The Background aircraft is designed with relaxed static stability to increase maneuverability and to reduce approach and landing speed. The FlA-18ElF Super Hornet is the U.S. Navy's premier c 'The aircraft is controlled by a digital fly-by-wire flight strike fighter aircraft, manufactured by the Boeing control system through hydraulically actuated flight control Company. The FIA-18EE was designed to provide surfaces: ailerons, twin rudders, leading edge flaps, trailing additional range, payload flexibility, payload recovery, edge flaps, LEX vents, LEX spoilers, and differential survivability, and growth capabilities over the FIA- stabilators. The leading edge of the wing incorporates a 1SA/BIC/D aircraft. The F/A- 18E/F aircraft, while "snag", which increases outboard wing area and increases maintaining a high degree commonality with the FIA- of roll authority in the approach and landing configuration. 18C/D aircraft, has a lengthened fuselage, larger wing and Basic weight is approximately 31,500 pounds for the FIA- control surfaces, strengthened landing gear, an improved 18E and 32,000 pounds for the FIA-18F. Additional propulsion system including a growth version of the General information on the FIA-18EE aircraft may be found in Electric F404 engine designated the F414-GE-400, and reference [l]. larger high performance inlets. The aircraft also incorporates additional wing stations and provides two AN/SPN--46(V) Automatic Carrier Landing System added internal volume, power, and cooling provisions for (ACLS)--The shipboard based ANISPN-46 ACLS consists growth avionics. of a prec:ision tracking radar, general purpose computer, and data link transmitter, and is designed to automatically As part of the Navy's acquisition program phase known as control an ACLS equipped airplane to touchdown when Engineering, Manufacturing, and Development (EMD), the operating in it's highest mode (referred to as Mode I). FIA- 18E/F's compatibility with the ANISPN-46 Automatic Radar tracking of a beacon system (ANIAPN-202) in the Carrier Landing System (ACLS) had to be developed and airplane establishes the airplane's position in space. demonstrated. This paper concentrates on the development, Computer software, containing the necessary control test, and evaluation of the F/A-l8E/F ACLS up to and equations, generates airplane vertical rate and bank angle including the Third Sea Trials, upon which the aircraft was commands to direct the airplane along the desired glide initially qualified for Mode totally automatic, approaches I, path. Commands are sent to the airplane via the data link. and landings to the aircraft carrier. The FIA-18EE's A more detailed description of the ANISPN-46 can be found predecessor, the F/A-l8C/D, with a history of outastanding in reference [2]. ACLS Mode I performance (tailhook longitudinal touchdown dispersion typically less than 25 ' (lo)), The AC',S provides for three modes of operation which can the to be met Or exceeded by the be selected by the pilot. The first is the Mode I approach FIA-18EE. which provides for fully automatic approach from the ACLS 5-2594 4 Mode I aDDrOaCh - The pilot couples the aircraft to the ACLS commands, which automatically flies the approach to touchdown. Mode IA amroach - Mode I coupled approach to 200 ft AGL, then pilot takes over to manually fly the approach to touchdown. Mode n aDDroach - The pilot manually flies the cockpit displayed guidance to touchdown. Figure 1. Typical Mode I Approach pattern entry point to touchdown on the carrier deck. The Airborne ACLS Components (FIA-lgE/F)--The airborne approach can be downgraded to a manual approach (called ACLS system of the FlA-18EE is made up of several Mode IA) at 112 nmi to touchdown. The second is a Mode different components which integrate to provide glide path I1 approach where the pilot manually controls the aircraft error displays, system status and command discretes, and in using error signal guidance provided to the cockpit displays its highest mode automatic control of the aircraft to by the ACLS from radar acquisition until touchdown. The touchdown. The shipboard ACLS radar sends out Ka-band third is a Mode I11 or Carrier Controlled Approach (CCA) interrogation pulses which are received by the RT-1028 where manual talk down control is provided from the radar radar beacon which then augments and sends back an X- acquisition gate to the point at which the pilot can acquire band return pulse via the R-1623 radar augmentor. This the Fresnel Lens Optical Landing System (FLOLS) or to the return pulse allows the shipboard subsystem to calculate the weather minimums (200 ft altitude and 112 nmi visibility). aircraft position in space relative to the ship’s ideal glide The use of an autothrottle is required for Mode MA, but is path. The errors between the aircraft’s position and the ideal optional for a Mode I1 or a Mode 111 approach. The glide path are processed by the shipboard computer to Instrument Carrier Landing System (ICLS) is an calculate appropriate lateral and vertical error signals, independent landing system that also provides monitoring of ACLS discretes, and vertical rate and bank angle commands ACLS operations. A diagram of the typical ACLS landing which are sent to the aircraft via a UHF data link in a Link-4 pattern is shown is figure 1. A simplified block diagram of format. This information is received by the aircraft’s RT- the ACLS vertical axis closed loop is shown in figure 2. 1379 data link and distributed to the Mission Computer 5-2595 Airplane b Equation IRadar Position Feedback Figure 2. Simplified ACLS Block Diagram (Vertical Loop Only) (MC), Flight Control Computer (FCC) and Commuinication rate and bank angle commands may be coupled to the Flight System Control (CSC). The MC and CSC process .the error Control Computer for an automatic approach. The vertical signals and discretes for display on the Heads-Up Display and lateral error signals may be displayed on the HUD to aid (HUD), Up-Front Control/Display (UFCD), Multi-purpose the pilot in monitoring an automatic approach or for Color Displays, and Digital Display Indicators @XIIS). If guidance during a manual approach. In addition, ACLS the pilot elects to engage the autopilot and couples to the discrete messages are transmitted via the data link and uplinked commands, the FCC uses the vertical rate and bank displayed on the HUD and/or Horizontal Situation Indicator angle to steer the aircraft onto the ideal glide path. A more (HSI). Data link signals are received by either the upper or detailed description of the aircraft's ACLS subsystems can lower forward UHF communications antennas.