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Squiz
Mar-30-2014, 19:38
There has been an ongoing problem with AI aircraft in formation at high level, particularly as they descend. At seemingly random times during a descent, the wingmen begin to twitch and a short while later they perform a confetti break, darting all over the sky, sometimes colliding with each other and often (but not always) reforming at low level prior to landing. The twitching occurs when an aircraft starts a sequence of full up elevator, full down elevator, full up elevator and then level elevator before starting the sequence again. You can observe this if you follow a twitching aircraft in external view.

Each type of AI aircraft performs its antics differently and at different stages during a similar flight plan which make detailed investigation very difficult.

I noticed that during a turn of an He-111 formation of nine aircraft at 7,000 metres, the two outside aircraft began to twitch indicating that they had seemingly reached a limiting airspeed whilst trying to keep up with the leader.

I lowered the default airspeed from 300 kph to 270 kph and the twitching stopped.

Again, to descend an AI He-111 formation from 7,000 metres at 300 kph without them breaking formation, steps of no more than 200 metres must be planned in the FMB. I then found that if the formation is slowed to 200 kph just before descent and the descent is planned at 200 kph then the steps can be increased to 500 metres between 7,000 and 5,000 metres and then one final step can be made to 500 metres before the aircraft land. (20% fuel and no weapons except guns).

I found that each aircraft has a different IAS at which twitching occurs and that this IAS decreases with increased height (probably related to TAS).

The rate of descent seems quite high during an AI descent and the aircraft speed builds up rapidly hence the need to level off and slow down to 200 kph at each descent step before the aircraft reaches its twitch speed. Added weapons and fuel load will increase the rate of descent, as well as the speed and the likelihood of a formation break up. However when the aircraft is hand flown within the formation, no such limitation occurs even if the rate of descent (and therefore the speed) is increased significantly beyond that of the AI aircraft.

All aircraft on both sides are affected, some more than others. Fighters are very prone to formation breakups and conversely, those with high drag profiles such as the Condor needs very few descent steps, if any, to maintain formation.

Another example is a formation of fully loaded Ju87s climbing from 3,000 metres to 5,000 metres at the default airspeed of 300 kph. The climb IAS is around 200 kph and when level at 5,000 metres, the aircraft accelerate. When passing 250 kph, the formation breaks up. However, at a reduced speed of 240 kph, the formation will climb and cruise normally. An anomaly occurred in that when the aircraft tried to re-join formation, they reach speeds of 300 kph without control problems. Additionally, when the aircraft entered the bombing dive with speed brakes out, the IAS rose to 550 kph without any apparent twitching or adverse formation effects.

The problem could be partially solved if the default rates of descent in AI aircraft could be significantly reduced. A permanent fix would require the total removal of the limiting “twitch speed” in each AI aircraft.

The problem will be posted in Bug Tracker.

bolox
Mar-31-2014, 01:40
Thank you very much for your work on this:thumbsup::thumbsup::thumbsup:

Fits very much with my own observations ( tho I can get away with 250-300m 'steps' in descent- the interpolate waypoints function in fmb can be useful here)

Mysticpuma
Mar-31-2014, 02:59
Excellent and very detailed breakdown of the information provided. Very much appreciate the effort.
Hopefully a complete re-write of the Ai will be done in v5.0 and this can be rectified as-well as much more being improved upon. ;)
Cheers, MP

Mattias
Mar-31-2014, 03:45
Thank you for your hard work squiz :dthumb:

Squiz
Apr-02-2014, 06:23
BOMBER DESCENT TABLES

It appears that it may be some time before twitches and confetti breaks can be addressed by TF.
The interim tables below are for planners in the FMB who work with bomber formations and wish to avoid erratic flying during their descents.

Always slow the formation to 200 kph at cruise level before commencing descent. Ensure that enough level flight time is left in each step to allow the aircraft to slow back down to 200 kph. All aircraft except the Ju-87 must drop their weapons before descending.

Do not make any significant turns at 200 kph as aircraft on the inside of the turn may stall and those on the outside could fly erratically when the speed builds up during descending turns. Also, bump the speed back up to at least 250 kph at the bottom of descent and before reaching the circuit area.

The maximum step size will need to be reduced if the fuel quantity is increased above 30%.

Ju-88 30% Fuel, Full bomb load
Cruise Alt, Max IAS, Max Step size
7,500 m 250 kph
7,500 m 200 kph 1200 m
6,000 m 200 kph 2000 m
5,000 m 200 kph 4,000 m

He-111 30% Fuel, Full bomb load
Cruise Alt, Max IAS, Max Step size
7,500 m 250 kph
7,500 m 200 kph 300 m
7,000 m 200 kph 400 m
6,000 m 200 kph 600 m
5,000 m 200 kph 800 m
4,500 m 200 kph 4,000 m

Do-17 Z-1 30% Fuel, Full bomb load
Cruise Alt, Max IAS, Max Step size
7,000 m 250 kph
7,000 m 200 kph 500 m
6,000 m 200 kph 500 m
5,000 m 200 kph 700 m
4.000 m 200 kph 700 m
3,000 m 200 kph 1,000 m
2,500 m 200 kph 2,000 m

Ju-87 Full fuel, Full bomb load
Cruise Alt, Max IAS
5,000 m 250 kph
At 5 km from target reduce the formation speed to 200 kph as aircraft will descend 500 m before commencing their dive.
Exit from dive at 2,000 m and make any further descents in 500 m steps at 200 kph.

Wellington 30% Fuel, Full bomb load
Cruise Alt, Max IAS, Max Step size
7,000 m 250 kph
7,000 m 200 kph 500 m
6,000 m 200 kph 800 m
5,000 m 200 kph 1,000 m
4.000 m 200 kph 1,500 m
2,000 m 200 kph 1,500 m

Blenheim IV 30% Fuel, Full bomb load
Cruise Alt, Max IAS, Max Step size
7,500 m 250 kph
7,500 m 200 kph 500 m
7,000 m 200 kph 600 m
6,000 m 200 kph 600 m
5,000 m 200 kph 1,000 m
4,000 m 200 kph 1,000 m
3,000 m 200 kph 2,000 m

ZG15_robtek
Apr-02-2014, 07:22
Maybe it would help if the ai was programmed to descend at 'descend- waypoints' as in RL, not with the elevator but by reducing throttle.
So the whole descend - landing part would be done with the exchange of throttle and elevator -> speed controlled by elevator and altitude by throttle.

Ivank
Apr-02-2014, 17:45
Great work Squiz

Squiz for TFARDU CO :)

RAF74_Buzzsaw
Apr-02-2014, 18:39
Thanks for your work on this Squiz. :thumbsup:

Squiz
Apr-03-2014, 19:54
See video at

http://youtu.be/qQ9swR7o1RU

Osprey
Apr-04-2014, 07:11
Oh very good, thank you. I have been experimenting myself because the AI is a bit trickier than on 1946. Some questions if I may.

1. Is the waypoint speed TAS or IAS?
2. What does 'interpolate speed' actually do?
3. What is 'inbetweening'
4. I have trouble with the dive-bombing sometimes, not sure if it's a bug
(i) Inaccuracy. I pick a target for dive bombing (87 and 88) and they miss it by bloody miles, sometimes going in themselves in the process
(ii) Fusing. Not sure if it is fusing but I set up dive bombing, set a dive bombing detonator yet when bombs hit the water they don't explode, not always

I've also found that if you want a smooth formation it helps to put the pilots to Ace and max their basic flying but advanced flying to nothing. This way they do the simple stuff.

The ability to adjust everything for each aircraft is wonderful but it's cumbersome and immensely time consuming. It would be a nice feature if you could set up one aircraft in the formation and 'apply to all'.

~S~

bolox
Apr-04-2014, 08:24
1) IAS
2+3) Inbetweening allows you to set 'inbetween' waypoints.
Say ypu have a flight descending from 5000m to 500m. Normally you just do 2nd waypoint as 500m.
If with this 2nd waypoint selected you then add in say 6 in the waypoints box, make sure before is selecteed in current waypoint drop down and tick interpolate altitude, you are set up to create 6 new waypoints between 1 and 2, each one will be an equal amount lower than the last. They are created when you hit the create button. Similar thing with speed and carry over type, which carries over waypoint action.
Using after in current waypoint drop down you would have to select first waypoint for it to have any effect with a 2 waypoint setup.


The ability to adjust everything for each aircraft is wonderful but it's cumbersome and immensely time consuming. It would be a nice feature if you could set up one aircraft in the formation and 'apply to all'.

you can, set skill in group properties tab, just below detonators. (Use custom button if you want).
You want to try setting individual crew skill settings in a large bomber formation if you think that is boring:-P

Osprey
Apr-07-2014, 10:34
Thanks bolox, this is stuff I can play with now, I never really had a problem with inbetweening then by the looks of things, I used to just create my own waypoints - I'll give it a whirl.

I know about the bombers, my point is that I put bomber pilots and aimers at Ace because I want them to very good at their job, but the gunners I set to rookies. Bombers are there for the taking and to get our action together, plus I use large formations (40+) usually. So yes, presently I have to set to Ace, then go through each bomber removing the 'advanced flying' and put gunners to Rookie. Rookie gunners are bloody effective though!!

bolox
Apr-07-2014, 11:53
yes 40+ rookie gunners are still rather effective to put it politely:whacky:

There's no simple way of doing this, but it is possible to manually edit the .mis file.
A formation of 3 he111's set up how you want it looks like this

[AirGroups]
BoB_LW_KuFlGr_706.01
[BoB_LW_KuFlGr_706.01]
Flight0 1 2 3
Class Aircraft.He-111H-2
Formation VIC3
CallSign 26
Fuel 86
Weapons 1 1 1 1 1 1 4
Person0_0 0 1 1 1 1 1 1 1 1
Person0_1 1 1 1 1 1 1 1 1 1
Person0_2 2 0 0 0 0 0 0 0 0
Person0_3 3 0 0 0 0 0 0 0 0
Person1_0 0 1 1 1 1 1 1 1 1
Person1_1 1 1 1 1 1 1 1 1 1
Person1_2 2 0 0 0 0 0 0 0 0
Person1_3 3 0 0 0 0 0 0 0 0
Person2_0 0 1 1 1 1 1 1 1 1
Person2_1 1 1 1 1 1 1 1 1 1
Person2_2 2 0 0 0 0 0 0 0 0
Person2_3 3 0 0 0 0 0 0 0 0
the block of 'person' lines replacing the skill line in single group AI mission