Skewgear

This continues to affect the current Open Beta build.

I think grafspee and Yo-yo are talking about two separate things. Grafspee talks about the 80C minimum *oil* temperature. Yo-yo talks about the minimum *coolant* temperature. On the Packard V-1650-3 and -7 engines, which are licence built Merlin derivatives, the minimum coolant temperature is 60C because at that temperature the coolant return circuit warms the carb air intake enough to prevent carburettor icing on takeoff. I don't yet know for certain but I'm pretty sure the Merlin 66 has the same automatic carb heat arrangement. We are unhappy at the Spitfire oil temp and pressure because according to the Pilot's Notes manual for the real aircraft, oil temp should not fall below 80C due to a thermostatic valve in the *oil system* that cuts out cooling below that point. The schematic for this is in the DCS Spitfire IX manual in this thread.

We're seeing a recurring bug on the 4YA Project Overlord server where trucks no longer refill some types of flak unit. This affects the British Bedford truck, the Third Reich Blitz truck, the Germany Blitz truck and whatever the US equivalent truck is called. It appears that heavy flak (so TR Flak36/Flak37/Flak41; Germany same unit names) no longer refill their ammo supply when the truck is nearby (on F10 map view, the units are within the truck's black circle). For the British and US coalitions, 37mm and 40mm Bofors guns will not refill their ammo supply. In all cases this applies whether or not the truck is part of the same group as the AAA units. This affects the latest 2.8 Open Beta build: v 2.8.33006 Steps to reproduce (sorry, no time to produce a track at the moment): 1. Select the Third Reich coalition. Place a group of the following units: 1x Kdo.40; 2x Flak36; 2x Flak 37; 1x Opel Blitz. 2. Create a target aircraft for the Third Reich unit to fire at. Make it invulnerable to ensure the flak units run out of ammo shooting at it. Expected behaviour: the flak units slowly refill their ammunition while the truck is nearby. Actual behaviour: the flak units run out of ammo and the presence of the truck has no effect.

I'm not sure the engine should exceed 90psi in normal operation unless it's very cold. The main oil pressure relief valve in the Merlin V-1650-3 and -7, as well as the Merlin 68 and 69 (all Packard built 60 series Merlins, almost identical to the M66 in the Spitfire IX) operates at 90psi to divert oil from the main lube oil circuit to the low pressure circuit via a low pressure (I.e. reducing) valve. The diagrams and system descriptions I have access to in the RCAF V-1650 service manual aren't very clear about how these interlinked circuits operate, or where high pressure oil goes if the low pressure circuit is fully pressurised already. Like you, my real world experience is oil pressure starts at 0 and rises when a cold aero engine is started. The Spitfire in DCS is roughly correct at the moment even though the numbers are all wrong (when you start the engine its oil pressure rises, peaks and then slowly falls as temperature rises). The Mosquito modelling after the recent cooling revamp is completely wrong (oil pressure goes off the scale and stays there, eventually settling at 120psi indicated). Let's hope if the Spitfire cooling is updated that it isn't just copy and pasting wrong numbers and behaviour in again.

The reason you crack the throttle is partly for greater fuel flow but also to give the pilot a clear indication of when the engine has caught and the starter motor can be disengaged. Forgot to crack the throttle starting a motor glider once. I was quite surprised when I turned the key away from start and the engine kept turning on its own!

I'm not surprised people think the Fw190A is a terrible air-to-air aircraft. The instant action dogfight missions start you at a substantial disadvantage in speed and height and with a wingman who seems to be of a very low skill level.

It seems most likely to me that the intended point of failure within the flap system during an overspeed is one of the hinge pins in the torque tube linkage assemblies - in fact given the lack of a pressure relief valve in the flap sub-system, I'm sure the pins must have been designed to shear at a given load, that load being well below overpressure and failure of any hydraulic system component in the flap circuit. The alternative is flap overspeed causing total hydraulic system pressure loss through catastrophic component failure, which is not something a sensible designer would choose. Once that pin shears, the flap system cannot be commanded by the pilot or the flap control valve self regulating mechanism. Nothing holds the flaps in place so they, er, flap around. It doesn't matter if that's smooth or not, though it would be a big coincidence if the pins for both sides sheared at exactly the same moment. Suggested feature change for the P-51: Flap overspeed scenario. Current ingame behaviour: The flaps are smoothly pushed back up by airflow during an overspeed. The flaps gradually move back to their selected position when airspeed drops below the overspeed point. The pilot can select the flaps as normal after aircraft speed drops below the overspeed point. No damage is caused to the hydraulic system. Desired behaviour: the flaps are suddenly and sharply pushed back up by airflow. This should be assymetric at slightly different speeds per side. The flaps remain up until airspeed drops below [some plausible speed, maybe 100mph?]. At that point they gradually extend, uncommanded, unless speed increases again. The flap system is destroyed by overspeeding. The pilot can move the flap selector handle in the cockpit but the system does not respond. No damage is caused to the hydraulic system.

Seems about right. Wikipedia says the Samuel Chase has a draft of 8.1m, whereas Dunkerque harbour varies between 7m and 9m deep depending on tide. See http://www.worldportsource.com/ports/portCall/FRA_Port_of_Dunkerque_385.php If you squint at this low-res chart extract the waters around Dunkerque harbour are very shallow in places.

I have done some more thinking about this and actually I think the way it is modelled in-game is almost right. To move from abstract discussion of real world systems to how failures work in DCS: 1. The failure mode for flaps after an overspeed should be sudden failure of the flap system to keep the flaps at their commanded position. The flaps should be pushed by airflow back to the fully retracted position when the system fails. This is already modelled in-game as the flaps being blown back up during an overspeed. 1a. What component of the flap system fails first in an overspeed scenario? The hydraulic system can accept very high pressures: the P-51 E&M manual mentions applying 2000psi from an external source during some test procedures. Therefore it seems likely that in an overspeed, a physical component in the flap system will fail (break) first rather than the hydraulics. I guess perhaps one of the hinge pins in the torque tube arm assemblies (figure 155, in Magic Zach's first post) would be a likely point of failure. Perhaps a check valve upstream of the flap selector valve (FSV) might fail if an FSV poppet is forced open by backpressure from the flaps, but I find this unlikely. 1b. Once the flaps have been oversped and blown back to the retracted position, the flap system cannot be used again. Is this modelled in DCS? If so, then in my view the flap system overspeed scenario is correctly modelled. 2. After an overspeed causes failure of the flap system, the flaps should droop at low airspeeds. This seems to already be modelled below 100mph.

I'm inclined to think @Magic Zachis right. P-51D E&M manual here: https://ww2aircraft.net/forum/threads/mustang-manuals.9051/#post-241325 Hydraulic circuit is split between PDF parts 1 and 2 and some pages are out of order, very annoyingly. Figure 309 (pp264, PDF part 1 page 292, copy attached below) is the main hydraulic system schematic. It shows two check valves fitted to the main system reservoir. It also shows check valves fitted to the supply and return pipes immediately upstream of the flap selector valve. Figure 329 (pp284, PDF part 2 page 13, copy attached below) is the flap system schematic. It starts from the flap selector valve and shows everything downstream of it. There are no check valves downstream of the flap selector valve, just a flow restrictor. -- When the flap system is in a steady state (i.e. flaps are stationary at their selected position) all four poppets in the flap selector valve are closed, as shown to the bottom right of Figure 309. This means hydraulic fluid cannot flow. Therefore air pressure on the flaps cannot back drive the system through the flap operating strut shown on the right of Figure 329. In this scenario an overspeed should lead to hydraulic overpressure in the flap system downstream of the flap selector valve. The flaps will press on the operating strut until something gives way. If I've understood the schematics correctly, the only place for excess hydraulic pressure is bursting one of the pipes or joints shown in Figure 330 (attached). The schematics do not show any pressure relief valve downstream or inside the flap selector valve, a partial exploded drawing of which is at Figure 331 (attached). This should lead to total loss of hydraulic pressure. Edit - but that depends on the max pressure the flap system will accept before catastrophic failure, which must be a design feature of the system and also depends on airspeed. It seems sensible to me that the flap system will withstand pressures well above those in the pilot's notes. Expressed in a different way, the system must withstand the max flap limiting speed plus a safety margin.

What's the TLDR?

It's the rangefinder unit. Quick and dirty fix for the lack of an Allied KdO.40 equivalent. However the accuracy reduction for Allied heavy flak hasn't been implemented. You'll find AAA is laser accurate unless you use German 88mm units.

The easiest solution is if a third party was to make a 1945 Germany map. Then all the historical match up problems disappear. We only argue about it now because the available WW2 terrains are all earlier than the plane set we have.

At max continuous the Spitfire will settle around 270mph IAS. Top speed is 320mph IAS.

CSU speed selection will affect top speed. It's a question of balancing boost vs RPM for the situation you're in. High RPM gives better acceleration when you open the throttle (increase boost) but increases fuel consumption. At lower RPM settings (say 2650) you'll find the Spitfire very slowly accelerates to around 270mph IAS. Guns are harmonised in a spot pattern to a fraction over 300yds. The gunsight range/wingspan setting is accurate and works as designed. I have it in my head that the guns should be zeroed to a group pattern at 250yds but I need to visit the National Archives to find the Armament Staff Instruction that applied to 2TAF in June/July 1944. As mentioned above the Spitfire carburettor automatically sets mixture. The big red cockpit lever is basically an on/off switch for fuel flow.

The nav already can use the map to navigate. Press F10 or open the kneeboard.

post updated for the 25th October event taking place this coming Saturday.

A quick post to say we had 70 players online during UK/Euro evening time today. Awesome to see so many enjoying the server!

The electric fuel pump toggled from the switch on the left hand panel is a substitute for the wobble pump on the cockpit RHS. Turn it on before engine start until the fuel pressure light goes out; at altitude (~17,000ft+) you need it on otherwise the engine will cough and die from fuel starvation. Oxygen is not modelled in the DCS Spitfire. Compare and contrast with the Me109K, where failing to use it at high altitudes means your pilot eventually blacks out.

We limit it to around 1/3 of Me109Ks per mission. It was generally available from May 1944 but we try to balance that with the fact that the Me109K didn't enter squadron service until Q4 1944, which is well after the period available on the Normandy map. Obviously we don't limit it on the 4YA WW2 PVE server and I can't speak for other public multiplayer server providers. It is really difficult to build a historically faithful environment circa June/July/August 1944 using late war aircraft.

We tried that earlier in the year. Turns out there's a number of people out there who either only own the Fw190D or won't fly in multiplayer unless they've got a perceived advantage over the other side. We compromised by removing it from the earliest two missions. Part of the flip side of the problem is that all of our plane set is Q4 44/Q1 45. It would be quicker if a terrain maker built northern France / Belgium Netherlands / Germany than asking for aircraft updates to bring our fleet back to Q2 44 standard. As for 25lbs boost / 150 octane, in dev terms that's a change to the boost gauge graphic and the engine parameters. Relatively easy, I'd have thought.

The Paris area hosted most of Luftflotte 3's main operating bases. The 8th and 9th US Air Forces made multiple raids on Paris, its surrounds and the airfields in the region, bombing out marshalling yards, striking reinforcements headed for thr Normandy front and sweeping the area for the Luftwaffe. I find it odd that you say you're interested in the history of the region (whether or not covered by the new map) and then show a lack of knowledge about it. With my multiplayer mission designer's hat on I'm looking forward to having the Paris area as it adds so much more potential for bomber escort sorties, deep strikes and fighter scrambles woth a realistic timeframe to get airborne and up to altitude.

Don't know if this topic is still monitored by LotATC's creator, but just in case... With the last LotATC update chat messages are no longer visible. How do I fix this?

Recently we ran a player survey on Project Overlord's Discord to understand who flies what, which side they fly, why they were buying DCS WW2 addons and some other information. Here are the results: https://projectoverlord.co.uk/blog/2022/10/15/project-overlord-player-survey-october-2022/

Can you get it airborne off Manston or Beny sur Mer aerodromes? They're the widest runways on their respective maps. Are you setting takeoff flap? I forgot to mention that before. 15-20 degrees is about right. The trick with the rudder on the takeoff run is to tap-dance on it: correct any swing the instant it develops and then rapidly return the rudder to neutral. If you press the rudder and leave it there until the next swing, you will lose control. Jabs of brake help with this process. Do not slam the throttle fully open unless you absolutely need to (obstruction or runway end approaching)