S3 Series

If you look at the changes file in the new update you will see most of the American and German fighters have been updated considerable in the FM department. Please report any issues on the FM board at IEN or here.

Robert rightly pointed out to me that in Frame 1 only the FW190A8 was a new 2018 FM. The rest of the fighters were just tweaked FMs from last year.
In that later frames you will see new P47D, P51D and FW190D new 2018 FMs. As always feedback here or on IENs boards is appreciated.

Can we validate the Dive parameters for the P51? You (I) tend to lose Stab, Ailerons, Rudder, & Elevator at 475 MPH IAS. Haven't looked at the data, but the humble Buffalo and P40 can dive up to 500 MPH.

Thnx

Oskar

P51 experiences structural failure at 475 in a dive. Not sure that is correct.

P40 flaps fail (fall off)at 200 MPH without warning, similar t P47. Very annoying & needs to be looked at.

<S> Oskar sir!
The P-40 flaps don't have the automatic blowback feature as there was no mention of it in any of the P-40B, E, F or N manuals. Many of the new flightmodels don't have this feature. The manuals state "don't lower landing flaps above 140 mph", which is the speed limit set for full flaps. For 10° angle flaps though the speed limit has been set to 205 mph, since smaller angles don't cause as much stress on the flaps mechanism from wind forces. If you lower flaps and exceed their structural speed limit for the angle for any non-blowback flaps system, the flaps mechanism will take damage and become inoperable (In Warbirds this is simulated by them simply falling off). As such it's important to listen to the creaking sound which warns you that you are overstressing the flaps and about to damage them unless quickly raising the flaps or slowing down. In real life pilots were thoroughly taught at what speed they were allowed to lower the flaps in order to not cause damage, and many planes even had these speed limits clearly written on the flaps control in the cockpit. If anyone has evidence that the P-40 series had automatic blowback flaps then I'll ofc change this setting.

P-40 series flaps limits (mph IAS):
10°: 205 mph
20°: 175 mph
30°: 155 mph
45°: 140 mph


Explanation of how maximum speeds are set
The Brewster Buffalos were in fact very good divers, something which the B-339 manual states and pilots who flew them have praised their diving capabilities in interviews. Numbers found for max speed limit for the Buffalos ranges from 500-520 mph (IAS). The P-51D speed limit is set to 480 mph (IAS), which is clearly stated as it's max permissible speed limit at 10000 ft in the P-51D manual (Mach 0.75). This is with a 15% tolerance (used for all FM's), which means that it can take damage anywhere between 480 mph to 550 mph (IAS), with the likelyhood of damage increasing by every mph above the limit. I do agree though that overspeed damage in Warbirds is a bit to severe, and a wing should not simply fall off. Unfortunately I have no idea how to rewrite the code for this.

A very important aspect when remodeling all flightmodels is consistency. There needs to be a global rule of how to model things in order to get the match-ups between the fighters historically correct relative to each other. For max dive speed this has been agreed on by the FM Team as the various fighters max permissible dive speed at 10000 ft, as stated in their pilot manuals or from ww2 trial reports. A popular number on Google for the P-51D's max permissible speed is 505 mph IAS, although this number is for altitudes lower than 10000 ft, and it's mach number at 10000 ft equals to 480 mph. We've also agreed not to go by any hearsay that cannot be proven by factual data, or from rare freak occurrences like "Capt. John Doe once dove his F4U to 600 mph IAS and lived to tell the tale". Otherwise if we give the P-51 series a higher dive speed due to some test pilot managing to exceed the stated max speed limit, then how will we model the max dive speed for all other fighters in order to be fair across the board? The Bf 109 has a max permissible speed of 460 mph stated. If we allow the P-51 a higher speed than the manual states, then what speed do we need to set the Bf 109 to? It could probably exceed 460 mph in most cases for short periods of time without damage.

However if someone can present actual data that it was a widespread practice to dive the P-51 above 500 mph IAS without any risk of structural damage, then of course it's max dive speed should be set to a higher number for the next update. Just need to be presented with written facts . With a 15% tolerance though one should not normally experience damage until like 520+ mph. If you get damage consistently at 480 mph then the code might not be working as it should. I will bring this up with the FM Team. According to the report below the P-51 should experience damage if flying extended time above 480 mph IAS (mach 0.75 at 10k), and take damage for sure above 530 mph IAS (mach 0.85 at 10k). Should not lose a wing though as overspeed damage currently works in Warbirds.


WW2 trial report, Notes from dive testing the P-51D (Mach 0.75 = 480 mph at 10000 ft):
6. Vibration.- At a Mach number of 0.76 a true effect of compressibility becomes evident in the form of a complete vibration of the airplane. This vibration is caused by a combination of compressibility effects on the wing and the horizontal stabilizer. The condition becomes increasingly severe as the Mach number increases and could eventually cause a primary structural failure.

7. Maximum Limit of Combat.- The airplane has been dived to a maximum Mach number of 0.85 and on several occasions to 0.84. In each case the pilots reported that the vibration became extremely heavy beyond 0.80. In each dive to 0.84 or above the vibration became so severe that the airplane was damaged. The leading edge skin of the wing flap was buckled between rivets, a coolant radiator cracked and hydraulic line broken due to vibration on various dives to 0.84 and above. In extreme war emergency the airplane can be dived to a Mach number of 0.83 (400 m.p.h. Indicated Airspeed at 25,000 ft.), if a very gradual pull-out is made.






<S>!
/Robert

Thanks for the explanation Robert. Totally makes sense and data supported. I suppose the only issue is that the same structural fail models should apply to all flight models (random chance for structural failure after specified speed) to be consistent. I have been flying the P40 and the flaps are pretty worthless in combat unless u are in very slow turns or landing. I often deploy flaps at the top of a climb for control and quicker reversals, then pick up speed after the reversal. Once you hear the creaking sound, it's too late the flaps fail (fall off). Hard to image that is a fair representation of the actual flight characteristics of the P40. Same with P47 flaps.

Good day flyboys,

There will be a fairly large update forthcoming in the next week or two.
This covers both continued work updating the existing flight models and also the introduction of some new plane variants.

Revised FMs for all Spitfires & Seafire Marks
Revised FMs for all Hurricaine Mark II's
Revised FMs for all Mosquito Marks.

New Mosquito NF30 variant
New Mosquito BXVI variant
Additional Hurricaine and Spitfire mk 1 *early pre BOB 87 octane versions for event purposes
New Typhoon Ib early version (1942)
New Seafire mk III variant.
New F86 and MiG15 models

The Spitfire IXe and Spitfire Vc have been re-purposed.
These are now both "LF" versions with engines designed for better performance at lower altitudes.

There will also be some new PPV skins released, terrain updates and also some other fixes.

For all info on the latest updates from the Volunteer FlightModel Team, please visit: http://bhlanding.ient.com/warbirdsforum ... um.php?f=8
You can also find all our updates compiled at: http://bhlanding.ient.com/warbirdsforum ... um.php?f=5

This update is now live!
---== UPDATE FL2057: FORK-TAILED DEVILS ==---
By: Robert, Bollok and Grumpy
All made possible by: Bcamel (creator of the program used to model the airplanes), and Idunno (who has previously shared a vast amount of aerodynamical knowledge).


--= P-38 Lightning series =--
The whole P-38 series has been fully remodeled. See further below for details.

--= Spitfire series =--
* All Spitfires have had their pitch authority at high speeds slightly lowered to reduce the risk of overstressing the airframe due to the G's spiking.
* Slight PitchDiv raise to all Spitfires in order to decrease the nose bounce when pulling G's.
* The Spitfire Vb now suffers from neg G cutout like the Spit I & II. The "Miss Shilling's Orifice" wasn't standard carburetor equipment until the Vc model.
* The Spitfire IXa didn't have the Bendix-Stromberg carburetor, and as such now has the same neg G behaviour as the Spit LF Vc. (the "Miss Shillings Orifice" installment)
* Both Seafires now have the tail hook enabled.

--= N1K1-J =--
* Now has a featherable propeller (this is done automatically when the engine is turned off). This improves it's gliding distance with a dead engine due to reduced propeller drag.
* Flaps dragco increased somewhat.

--= P-51 series =--
* Slight PitchDiv raise to the A-36 Apache, Mustang Mk 1, P-51B and P-51D in order to decrease the nose bounce when pulling G's.


--== THE NEW P-38 LIGHTNINGS ==--
The P-38's fought against the Axis airforces in several theaters during ww2. The Lightning really shined in the Pacific with boom n zoom tactics against the slower Japanese fighters, but even in Africa/Europe the P-38 had a positive kill-to-loss ratio. The Germans nicknamed it "Der Gabelschwanz Teufel" (The Fork-Tailed Devil). While being active in the Pacific to the end of ww2, in Europe it was phased out by Jimmy Dolittle in second half of 1944, in favour of the P-51 Mustang. The reason was mainly the fact that the Lightning had problems with a high rate of engine failures, it cost over twice the money to produce compared to a P-51 and had bad cockpit heating that was better suited for the warmer Pacific theater. The P-51 also had a longer fuel range and was faster.

Some of the P-38's weaknesses, that J. Dolittle also was concerned about, is that the Lightning has a quite slow roll rate and compresses in a high speed dive due to it's aerodynamics disturbing the airflow around Mach 0.67. On the bright side the P-38 has good firepower and ammo capacity though with 4x .50 cals and 1x 20 mm cannon. These are all located in the nose so convergence isn't a problem. The two engine propellers are counter rotating and as such this fighter doesn't suffer from torque like single engine fighters do. The Lightnings also have a nice selection of ordnance and are potent in ground attack roles. A common misconseption about the Lightnings is about them being "unagile" fighters. Many people and also flightsimulators have this wrong as if the P-38 should be turning like a truck. It definitely shouldn't. The P-38 not being agile has to do with it's poor roll rate and weight, making it unsuitable for low n' slow maneuver combat like going into scissors. When it comes to turn fighting though this twin engine fighter has a good power/weight ratio and a large wing area with a 16% root thickness ratio. The long wing span also helps with induced drag and when using the combat setting at 8° for it's Fowler flaps, this bird can hold a turn quite well. It's not like a Spitfire or A6M Zero, but can definitely hold it's own against many opponents. The P-38's best envelope is as a high altitude interceptor, and as such a P-38 pilot would generally benefit from doing bomber escort or in other ways taking the fight up high. While being able to fight down low, at high altitude is where the "Fork-Tailed Devil" shines and can take it all the way up to 39000 ft.

--= P-38F =--
The P-38F is powered by the Allison V-1710-49/53 engines, producing 1225 hp each. For it's era this is the fastest American fighter above 15000 ft, and also the best climber. The turn rate is comparable to that of a C.205 Veltro or F6F-5 Hellcat. The firepower is good and it's a great fighter for boom n zooming while also able to turn a few laps with the bandit. Avoid low n' slow maneuver fights though as the roll rate is poor and it's a heavy bird. A wise Lightning pilot fights the enemies between 20000-39000 ft.

--= P-38G =--
The P-38G is very similar to the P-38F but 120 lb lighter and can run at 41" of manifold pressure for a longer time with it's V-1710-51/55 engines. It has the same max power of 1225 hp though. An important difference is that the P-38G can use an 8° combat flaps setting which improves the Lightning's turn rate quite a bit.

--= P-38J =--
The J-version had notably improved engines, the Allison V-1710-89/91, capable of producing 1570 hp. It has a slightly higher drag but is 10-13 mph faster than it's predecessors. Also the climb rate is improved due to it's better power/weight ratio. The weight is around 833 lb heavier than the P-38G though and while being able to turn well, it holds a somewhat larger turning radius. The P-38J can use rockets for attacking ground targets which is a nice addition. The service ceiling is around 40000 ft.

--= P-38L =--
While being the heaviest of the Lightnings, weighing in at 18055 lb, the P-38L has several improvements. The most significant one is the power boosted ailerons. This gives the P-38L a much needed increase to the roll rate at high speeds, and also a slight improvement at lower speeds. The code does not allow for modelling the historical special designed dive recovery flaps of the P-38L, but the flightmodel is instead able to dive 20 mph faster before compression occurs. The L-version's V-1710-111/113 engines are very similar to the P-38J engines and also able to produce 1570 hp. The ordnance is even more enhanced with the P-38L able to carry 2x 2000 lb bombs, making it very effective for jabo missions.


Below is data from my recent tests of the new flightmodels:











free image hosting


<S>
/Robert