Not being in the USN today nor have I ever been in the USN it can be difficult to say - however my understanding of the requirements would be that given a period of time when a pilot is not only not carrier qualified but may no longer be qualified on a particular carrier aircraft then there is a refresher period of flying that will include day FCLP and when 'refreshed' that pilot will then start night FCLP with usually getting the most 'bounces' as possible in any one night session. I'll guess there is a practical limit for any aircraft.
Day FCLP is a waste of time for an experienced pilot. New carrier pilots have to become comfortable with FCLP in daytime but then that is that. No more daytime FCLP. Why? Because there are too many cues during the day to either distract from ball flying or 'just make it too easy'.
For example during the day the runway and landmarks are visible along with the horizon. It is easy to 'deck spot' to get into the groove and stay there. In fact with experience, at the same field during the day, a pilot can simulate flying the ball without looking at it and do well. Not so at night. At night it is more difficult obviously so that the pilot has to concentrate on flying the ball and lineup on the teenytiny simulated carrier deck, and not crash. At the beginning night FCLP is a real chore but then it gets easier with practice, much the same as any form of flying, especially flying the ball. Probably after 6 or 7 approaches at night any pilot is tuckered out for that session anyway. Perhaps having a break by being hot refuelled, or changing to another aircraft that same night, is helpful but I would wager after two FCLP sessions at night for a total of say 14, most pilots would have had enough and probably regulations say the same thing [especially if that same pilot has flown during the day - often in preparation for the night FCLP session(s)]. Carrier pilots are humans too.
The reason the day/night FCLP circuit heights are different is also due to the 'danger nature' of night flying close to the ground. It ain't easy on a black moonless cloud covered night without external ground lights for some kind of orientation. It is just instrument flying until downwind visual with the lighted carrier box, abeam and then base turn from 1,000 feet AGL. This same circuit done during the day at NATOPS height is probably impossible at night. It is too easy to have some height wandering during the night FCLP circuit (within limits obviously). Remember during night time carrier pilots are not doing a visual circuit at sea. They carry out an instrument approach for good reason. One of the most difficult things I did for the first time was fly downwind on instruments at 1,000 feet after my first night deck landing attempting to listen to the LSO give a précis of my first night approach. They had not done it before either during FCLP or during day carrier circuits so that 'debrief' was a huge distraction and thankfully they never did it again. Anyway I was on my way at one thousand feet to be positioned for the next approach via CCA Carrier Controlled Approach (GCA from carrier) as I had been positioned for the first approach. Bloody hell it was black out there. I had NEVER been in such a black environment before at 1,000 feet.
Pilots will use the ball during the day to land at an airfield with a mirror/IFLOLS. If there is no such apparatus then the pilot will attempt to land in the same manner simulating such an approach.
Remember FCLP is supposed to be done at night. Day FCLP is useless once the basics mastered. When at sea during the day there are no visual cues except the horizon, the sea and the ship. Yes there are instruments today saying stuff but really the pilot needs to be visually able to position the aircraft around the ship. The chaps doing the SH$THOT breaks are probably not flying instruments. Once a pilot is competent and able to carry out day approaches regularly then they start to get SH$THOT but not before being really good at it anyway. Try being a SH$THOT newbie and there will be tears before teatime back at the beach.
Compare a test NIGHT FSX FCLP "height wandering up and down" with a dusk FCLP session (to get familiar with flying just as you see in the video - using only the HUD view as shown for the purpose of making the videos - try it - it is bloody difficult). Also I'm not familiar flying with a HUD. I'm old school flying visually (or non HUD instruments at night) looking at only the AoA Indexer and what else? MeatBall LineUp and AirSpeed (Optimum Angle of Attack).
These videos made during testing for the PADDLES / FSXNAVYPILOT new IFLOLS and FCLP missions at Coupeville many moons ago now.
Having watched the night video again I must repeat that this is also a TEST of the calls by the LSO for accuracy and I was demonstrating as best I could for FSXNP that the calls sometimes were not accurate. YMMV. So rather than wave off from an erroneous call I continued because IMHO the approach was within limits. However in real life the LSO MUST BE OBEYED. OK?
And BTW the night conditions particularly for Mission 5 were carefully selected so that the moon was in an optimum position during a cloudless night to best make use of whatever cues can be seen. This was done to make life easier - bearing in mind mostly it ain't easy. I'll bet if one can master night FCLP then anything else is easy for sure. YMMV.
