Interesting reading about aspects of carrier landings here - specifically about usefulness of the HUD (and of course there is more interspersed in report but this'll do):
GS=Glideslope; FPA=Flight Path Angle rate of change
REVIEW OF THE CARRIER APPROACH CRITERIA FOR CARRIER-BASED AIRCRAFT PHASE I; FINAL REPORThttp://rhef.net/docs/HQs/NAVAIR_2002_71.pdf (2.9Mb)
"The human part of this pilot-aircraft system is limited in the ability to control multivariable problems. A human with sufficient control authority can control one dynamic variable very precisely, two variables precisely, three variables passably. The pilot’s performance deteriorates severely trying to simultaneously control more than three. Fortunately, the multiple constraints of a CV landing are satisfied by the pilot's control of just three variables – GS, lineup, and AOA. Pilot performance is affected by the allowable tolerance of the accepted deviations, the dynamics of the particular variable, the responsiveness of the aircraft to control inputs, the environmental conditions, and the quality of the information used to determine GS, lineup, and AOA error. It is important to note that tactical Naval Aviators, in the context of CV landings, speak interchangeably about speed and AOA. Though they are reading AOA in their indicators, they refer to themselves as either "fast" or "slow".
....Ideally, from the start of the visual pass (½ to ¾ mile aft), no radio communication takes place between the pilot and LSO other than an optical signal or a simple radio call to confirm open two- way communication. Virtually all day landings are performed "zip lip," meaning that the pilot receives only a flash of green lights to confirm that the aircraft is cleared to land and that the LSO’s are monitoring the approach. At night, most landings take place with only a "Roger, Ball" transmitted over the radio signifying the same.
....
Heads-Up Displays (HUD’s), such as that found in F-14D and all
F/A-18 models have dramatically transformed the landing problem. First, an Inertial Navigation System (INS)-driven velocity vector precisely displays the projected flightpath of the aircraft. Ashore, the velocity vector permits a pilot to superimpose the symbology directly on the intended point of landing and achieve very precise results. At sea, since the ship is typically moving relative to the inertial frame, the velocity vector does not reliably indicate the point of touchdown. It does, however, provide very precise rate information with respect to GS, with some small bias term. The typical habit for F-18 Hornet pilots is to place the Velocity Vector near the intersection of the decks (“crotch”) of the ship, and then gauge the GS trend. In doing this, the pilot is effectively leading the ship by placing the velocity vector at some point out in front of the wires where the ship and aircraft trajectories will intersect. This initial placement ensures that the flightpath will very nearly hold the aircraft on GS. The precision of the FPA data also means that the effect of an input correction is immediately assessed in a variable that is very nearly GS rate (the state information necessary for the pilot to attain the elevated performance). As the aircraft approaches the in-close to at-the-ramp position, the velocity vector is allowed to drift aft to the point of touchdown. The fielding of HUD’s largely bears the responsibility for the improvement in boarding rate demonstrated by F-18 Hornets and F-14D model Tomcats over the aircraft that preceded them...."
