1.09 : Get Rid of Autoretracting Flaps...

[Drano]

Preachin to the choir bro!

This is prolly the one glaring problem I have with AH so far. The whole autoretract thing makes no sense to me at all in a sim that screams out for realism. I'm against auto-anything pretty much. Mo' workload=mo' better to me. Just sayin.

                Drano

Originally posted by Tac
... or make it an option in the SETUP, just below the Combat Trim.

Gripe: The one plane that heavily relies on its flaps (P38) is getting KILLED because they retract automatically the instant the speed ticker hits 250mph. Any kind of prolonged loop fight in which the 38 does not pull hard will make the plane go beyond 250mph for a second b4 the plane goes nose up again and bleeds the speed down to 120'ish.. but before that, the flaps retract, and you're pulling while they retract, SPIN, and the happy con you were following turns on your 6.

And lo if you have more than 1 notch deployed, 250mph mark reached, retract one, spin, while trying to recover plane goes below 250, flaps stop retracting, recover ( IF the con hasnt shot you down by then:  plane quickly goes to 250, ANOTHER flap is retracted, SPIN again! . Oh joy.

Can we please have the option to not make them autoretract? If the flaps are down at 250mph make the plane start to shake, the higher above 250mph the worse it shakes until maybe 320mph at which point you could have the flaps ripped out and some kind of damage to the wings.

[HoHun]

Hi Tilt,

>I have just read in another publication that the hydraulic actuating cylinder for the Lagg3 flaps had an inbuilt pressure relief valve that allowed oil to flow (in both directions) across the piston in the event of over pressure.

Knowing nothing about hydraulics, I wonder if this overpressure valve was actually meant to limit the forces once the piston had run against a stop?

Regards,

Henning (HoHun)

[Tilt]

Originally posted by HoHun
Hi Tilt,
>I wonder if this overpressure valve was actually meant to limit the forces once the piston had run against a stop?

It may well have been Ho Hun but the point was that the relief valve is explicitly described as operating "when the plunger (piston) is in either end position".

Ie it was not the more common use of a relief/non return valve that most hydraulic systems have to protect them today.

This quite clearly shows that given a high enough force the flaps linkages could push the piston down the cylinder allowing oil to pass from one end to the other by means of the pressure relief valve.

Again I do not know at what IAS that would occur or even if the linkages were strong enough to do so.

I can advise that pilots notes only ever refer to them as landing flaps.

Tilt

[Sorrow[S=A]]

Unfortunatly Tilt those posts were in the old beta forum at BB that is now wiped and was never archived

He indicated at that time that the flaps were used as brakes during dive bombing and that they had ample pressure to open at high speeds. I suspect that the pressure to that cylinder was far higher than 35kg. The Lagg and La5 systems seemed to have too crude a construction to have items like a pressure limiter involved.

However I emailed him asking him for more information, he is back from his vacation now, I assume he is horribly busy but he might answer soon.

[Widewing]

Originally posted by funkedup
Nice research Tilt.

I will try to find hydro schematics for US planes.  If they all used cylinders I wonder if they had pressure relief valves too.  

A more modern setup is to use a rotary hydraulic motor driving a gearbox and shaft system, or driving a jackscrew.  These would probably not backdrive due to the gear ratios and/or friction in the jackscrew.  But I don't know if this was used in WWII aircraft.

I think most of the UK planes used pneumatics, which I'm pretty sure would backdrive as well.

P-39 and Fw 190 used electric flap actuator.  I don't know details of the Cobra but I think the 190 had an electric motor driving a jackscrew.  In general jackscrews will not backdrive so that system shouldn't "autoretract".  I'll look into this further.

Neither do the P-38's flaps "blow up". They are mounted in roller tracks, moving aft and down. They cannot "back drive". To do so means they must move forward and up within the roller tracks. Cannot happen. Go too fast in the P-38 with flaps down and you will start bending metal, but they will not retract.

My regards,

Widewing

[Tilt]

Originally posted by Sorrow[S=A]
Unfortunatly Tilt those posts were in the old beta forum at BB that is now wiped and was never archived

He indicated at that time that the flaps were used as brakes during dive bombing and that they had ample pressure to open at high speeds. I suspect that the pressure to that cylinder was far higher than 35kg. The Lagg and La5 systems seemed to have too crude a construction to have items like a pressure limiter involved.

However I emailed him asking him for more information, he is back from his vacation now, I assume he is horribly busy but he might answer soon.

Agreed re crude construction etc.......

The oil used was from the central engine sump it was not a separate circuit although it had its own pump etc.

35kg/cm^2 is nearly 500 PSI..........  from the sketches the cylinder would have a piston of about 30 to 40mm giving a force at the piston of between approx 150 to 350 kg. (after deducting the shaft/rod)


This is across both flaps. The actual force at the flaps to push them down is subject to the mechanical advantage gained by the linkage set up. I have no idea what this is.

The pressure relief valve of the type described could be equally crude. It need be no more than a ball bearing and a spring tensioned by a screw.

This relief valve that is mentioned could indeed be set to a much higher (or lower) pressure than that of the relief valve at the hydraulic pump (which is the main system limiter).

Unfortunately (in the absence of other data) logic would lead me to suspect that it would be used to limit the main system pressure further ( ie lower) to protect the flap linkages.

It would be the cheapest way to do it. The main function of the Hydraulics was to raise and lower the gear. This is pretty heavy weight stuff with the hyd cylinders directly pushing and pulling the gear strut. Higher pressures would be advantagious so as to keep the cylinders as small and compact as possible.

Having designed the gear system to its optimum the easiest way to protect the flap system is to also construct this to its optimum weight and load bearing capabilities then protect it with a simple relief valve in the hydraulics.  REM constant efforts were made to lower the overall weight of Laggs/ Lavochkins.

However given all this I still have no evidence as to what air speed would cause the flaps to lift. Olegs statement could still be true. The force and mechanical advantage could have been such that they would work safely at much higher speeds than AH currently models.

Previously my understanding of the La hydraulic flap circuit was one of a three position valve with a closed centre position that would have locked the flaps in position.

Hence the flaps would have stayed in place until some thing broke.

Now I believe that there was a speed at which they would have lifted........ I do not know what that speed was...


Tilt

[Widewing]

Originally posted by Widewing


Neither do the P-38's flaps "blow up". They are mounted in roller tracks, moving aft and down. They cannot "back drive". To do so means they must move forward and up within the roller tracks. Cannot happen. Go too fast in the P-38 with flaps down and you will start bending metal, but they will not retract.

I forgot to mention that the P-38 flaps are actuated by hydaulic screwjacks, which will not "back drive" either.

My regards,

Widewing

[hitech]

So TAC: Basicly you want the flaps on the 38 to work at higher speed?

The auto retract flaps is a very intentional choice, when they exceed there max speed they must either break,or be retracted.

Breaking them would be more of a pain and detract, not add to the fun of combat.

HiTech

[Tilt]

Originally posted by hitech
So TAC: Basicly you want the flaps on the 38 to work at higher speed?

The auto retract flaps is a very intentional choice, when they exceed there max speed they must either break,or be retracted.

Breaking them would be more of a pain and detract, not add to the fun of combat.

HiTech

Same could be said for gear................ but we do get an audible warning..............

Tilt

[BigCrate]

Hitech we just want more control over the planes we fly..
I flew AW for years before I started to fly AH and the 38 and f4u were my main rides.. I could have one click of flaps down in a 38
up to but 325mph before the controls hardened up an the nosed tucked badly.. But after a month or so I learned not to exceed
a certain airspeed. With  flaps down on a 38.. And doing high speed high G moves having a notch of flaps down in a 38 at about
320-300mph I could bleed my E down to the point where I was at corner speed and shortly there after the bogey I was fighting would be dead. Hitech we just want more control over the planes we fly...  As for this Breaking them would be more of a pain and detract, not add to the fun of combat. After the 1st few times the flaps rip it would suck but after I would just remember to raise the flap.. And yall would have to give us some speed between 250-320mph before they did rip out.. But if yor are already above 250mph with no flaps down you shouldn't be able to to put any flaps down.. But if you aleady some some flaps down make to where we have some space before they did rip out..
I also have some requests





Give the F4u a little mirror in the top of the canopy
like in real life so we can see our 6 alittle better.. The 38 also had a mirror in the canopy but I don't have any trouble with see in a 38. And loosen up on the 38s compressiblty I'll come down to yalls office this week if yall will listen to what I have to say.. I live in Ft. Worth and i have the week off

Cw
Cody

[Tac]

"So TAC: Basicly you want the flaps on the 38 to work at higher speed?

The auto retract flaps is a very intentional choice, when they exceed there max speed they must either break,or be retracted.

Breaking them would be more of a pain and detract, not add to the fun of combat."


No HT, the 38L did have locks to prevent the fowler flaps from deploying if the plane was 250mph +

All I ask for it for the flaps to not retract on their own if the speed indicator goes past 250mph. Or give it a higher threshold for retracting, like 350 mph, a speed that does not come up during manouvering with flaps.

250mph is a speed thats easily attainable on the bottom portion of a loop, specially at hi alts. And thats when they royally kill the 38 by making it spin.

Hopefully, when ye folks add the 38F/G/H those could not have the lock that prevented flaps from deploying past 250.. would be much fun

Making the plane shake/buffet if its speed is past 250 and flaps are still down would be a nice thing, tells the pilot his flaps are under stress... if they are not retracted at, say, 350 mph, ye can rip them out or have them "freeze" in their deployed position (as if the structural damage had jammed the flap)...or both! Have them freeze at 350 and ripped out at 400 *G*

I would consider it as the equivalent of the rip-wing problems other planes have at high speeds/pulling a high G.

I dont know if other planes in AH besides the P38 have this problem, when I fly them I dont use the flaps that much.. and never had a stall from them auto-retracting. But then again, I dont fly them as much as the 38. Ill let others comment on that.

[Widewing]

Originally posted by hitech
So TAC: Basicly you want the flaps on the 38 to work at higher speed?

The auto retract flaps is a very intentional choice, when they exceed there max speed they must either break,or be retracted.

Breaking them would be more of a pain and detract, not add to the fun of combat.

HiTech

Let's play Devil's advocate for a moment. Flap VnE for the "maneuver" setting is extremely conservative. I suggest that you consult with Stan Richardson, one of the foremost experts on the P-38 alive today. I'll be happy to provide his e-mail should you so choose. Stan will tell you that it was perfectly safe to push well into the 300 mph range without damage. The real danger would arise if you attempted to dive with the flaps at this 8 degree setting. Why? Because it greatly exacerbated the nose tuck problem associated with the P-38.

My suggestion is this: Model the flaps to provide the groan warning at 250, jam at 300, detach at 350. Once jammed, the flaps cannot be retracted and will effect flight characterisitics throughout the balance of the sortie. Should they be detached, there will need be a loss of overall lift, as the flaps were integral to the wing structure and profile. I'd also employ a random event generator to determine if the separated flaps cause damage to the horizontal stabilizer. This gives guys like TAC some relief, while providing greater realism, albeit with a potentially severe penalty for inattentiveness.

While you guys are on the topic of the P-38, consider remodeling the dive recovery flaps for it and the P-47D-30. Currently, they do not induce pitch-up. They should. Trimmed neutral, the P-38 should pull out of a dive, hands off, at a steady load of three Gs.

My regards,

Widewing

[Tac]

I think HTC is modeling the factory settings for the planeset in AH Widewing. If not we'd have P47's running at unholy manifolds field mods.. and Drex & Frenchy would wipe the floor with our red tulips

I believe the late 38J and all 38L's had a lock to prevent the flaps from deploying when faster than 250mph. That's fine with me, I do expect to see that setting in the L model (it already is woot!) in AH, but not in the F/G/H models when introduced.

"Should they be detached, there will need be a loss of overall lift"

Losing a flap (shot out) in the 38 now makes that wing be really touchy in any kind of manouver. I dont fly real planes so I dunno, but I wouldnt try sustained turns while missing a flap in AH

"Model the flaps to provide the groan warning at 250, jam at 300, detach at 350"

Me like. I imagine a below horizon low g turn with 1 notch of flap at 200mph, accel'ing to 250.. hearing the groan of the plane like when its compressed... retracting the sucker.. or else getting 300mph and hearing the "door.wav" (whine-like mechanical sound) as the flaps jam into place.. panicking, con in 6, diving.. 350mph "RRRIIIP" .

[Drano]

Originally posted by hitech
So TAC: Basicly you want the flaps on the 38 to work at higher speed?

The auto retract flaps is a very intentional choice, when they exceed there max speed they must either break,or be retracted.

Breaking them would be more of a pain and detract, not add to the fun of combat.

HiTech

Don't confuse >>deploy<< with >>retract<<, which is what I *think* we're talking about.

I'd be dead against being able to DEPLOY flaps at ridiculous speeds a'la IL-2. That doesn't make a damned bit of sense to me.

As to the autoretract thing, I'd much rather have something similar to what AW had. (Yeah I know, I know!--just hear me out)

There you *couldn't deploy flaps* until your speed dropped to a certain speed that varied from plane to plane depending on whether said plane had combat flaps or not and what speed they would have been available. This much is common to AH.

Once flaps were deployed they'd stay out *until you retracted them yourself*. This could be a very bad thing tho. If speed increased past a certain point, the flaps would jam down but could be retracted again if you slowed to below flaps speed (again depending on plane). If you continued, they'd become damaged and you *couldn't* retract. If you allowed your speed to still continue to build with flaps out the plane would start to do some bad stuff! For starters you'd get a nasty buffet followed by a sharp nose down pitch (tuck-under) that didn't respond to the stick. This condition often made for  "ye olde lawn dart" as often times by the time you discovered what you'd screwed up it was too late! Even if things didn't degenerate to near this level, if you forgot to retract your flaps after takeoff or whatever--you wouldn't accelerate because of the drag.


I'd much rather have control over my own flaps. I wouldn't like to see folks using flaps at 400 mph so as to make "bat turns" but I like to use flaps in a turn fight to maintain a certain speed range and as it is now I'll lose flaps when nose low even with throttle chopped. This leaves me in the wrong configuration to be pulling as little as 3 G's with no warning and with no input from me--other than I passed 151 MPH (or whatever) even momentarily--flaps just aren't there and I'm in a snap roll--! I hate that!

I like the flaps for the extra lift yeah--but I like the extra drag that even one notch can provide to help maintain my speed and therefore, turn rate better.

If I lost a fight or auger'd because I messed up my plane's flap configuration then so be it. Hehe just add that to the list! You're not gonna hear me whine about that--as its my fault! As it is now the game does that *for me* a lot of times that I could have maybe avoided if I'd had control over the situation myself . Seems I have control over most everything else.

Generally I'm against auto-anything. Pile on the workload amigo! That's where the fun is for me!

                                Drano

[HoHun]

Hi Tilt,

>The oil used was from the central engine sump it was not a separate circuit although it had its own pump etc.

>It may well have been Ho Hun but the point was that the relief valve is explicitly described as operating "when the plunger (piston) is in either end position".

>Previously my understanding of the La hydraulic flap circuit was one of a three position valve with a closed centre position that would have locked the flaps in position.

Did the hydraulic pump run continuously? If so, I'd assume the centre position of the three position valve returned the pressure oil to the sump. The other two positions would guide the oil to either side of the cylinder.

Since the valve was hand-operated, it would be standard procedure to let the piston run against the stop and then return it to centre position manually after a finite amount of time. Since oil is incompressible, a force-feeding pump might build up destructive overpressure during that delay. Hence the need for the bleed valve in the cylinder.

Just some speculation :-)

Regards,

Henning (HoHun)