Mosquito wing comes off at as low as 4.9G

[J13 Serenity]

Hi

I could not find, in any manuals, a G load limitation for this Mosquito model
But is says Fighter-bomber
Here is a track, where I did a few 5-6G pulls with 50% fuel and no bombs or rockets.
One manual from 1950 specifies that at weights below 19000 pounds there are no limitations on aerobatics
Most of my pulls were about 5.5G, maximum and one of about 6.3G according to LCTRL+Y Stripe
Eventually, at about 4.9G the wing came off.

Mosquito has no accelerometer, and even at 320MPH IAS its easy to reach 5G 

It doesn't make sense to me.
How are you supposed to use this plane as a fighter, if even a 5G maneuvering is enough to , eventually, reach structural failure.

Any time you engage in any kind of prolonged air combat, you almost guarantied to lose a wing...
Even if you do a overhead attack on an enemy bomber, or dive bomb...
Its so easy to exceed 5G on Mosquito in DCS, that any combat manuevering will, eventually, lead to a structural failure... 
And its almost impossible to control your G factor due to no instruments available.
And if 4-4.5G is the max, then the maneuvering safety speed would be below 300MPH IAS, which questions the fighter designation for this Mosquito model...

I tried different fuel management tactics
For example emptied the outer wing tanks and the fuselage ones.
But is seems to make no difference
I tried 10% fuel - same results.

I tried maneuvering at below 5G, and even then, after some time, the wing came off


Is this normal or a bug?

Here is a track:
 

Mosquito over G test.trk

Edited September 18, 2023 by J13 Serenity

[Art-J]

Don't fly it as a fighter then, at least not in traditional sense. Remember the plane was designed as a fast bomber at first, as an answer to Air Ministry specification for a fast bomber indeed. Granted, after the prototypes flew, in 1940 the Ministry opted for putting a radar on it and convertng it into a more multirole plane, but the airframe with its bomber-like structural design limits was already there.

Sources posted by robi-Wan on page 1 and 2 of this thread...

https://forum.dcs.world/topic/279674-expected-mossie-performance-vs-current-plane-set/

... seem to indicate a 6 G limit, also with counterweight added in pitch control system to keep pilots from going above 3-3.5 G too eagerly. So that't about it.

Moreover, keep in mind how accumulated structural damage works in DCS in general - you can go a little beyond limit a couple of times, but each time lowers the limit by a few of tenths of G so that eventually, the last pull can take the wings off noticeably below "fresh" limit of a new airplane you had at the beginning on the mission.

All and all, much smoother maneuvering is required, although I agree it's quite difficult to figure out if you're smooth enough with such sensitive elevators and lack of G-meter in this bird.

[Bozon]

Mosquito wings come off pretty easily. Maybe too easily, but the exact value is not the root of the issue.

The real issue is that the Mosquito modeling does not convey any feel or feedback to G load or any airframe stress for that matter. 

The purpose of the elevator counter weight was to add force-feedback to G load (plus some oscillations damping) to the pilot’s hand - we can’t feel that. There are little to no sound cues, no noticeable increasing vibrations - unless you look behind at your wingtip vortices trail you have no clue that you are pulling G at all.

These feedbacks need to be enhanced - even slightly exaggerated, to compensate for the fact that our actual stick is connected to a simple spring, and our ass is seated in a stable chair at exactly 1G no matter how hard we pull on the stick.

Only then it will matter if the wings come off at 4.9 or 5.5 G.

[J13 Serenity]

Thanks for the insight

Something does feel wrong
May be the control feedback is to blame indeed...
Like Spitfire, where even at flatter speed controls are light enough to exceed 10G easily
While on BF109 its almost impossible to over G due to stick forces...

[Art-J]

I agree some extra visual or audible feedback, even if exaggerated, would come in handy. I don't expect it to ever come, though. If such thing hasn't been implemented in early stage of module's post-release period, it won't be implemented later.

I suppose the only workaround for player who doesn't want to "cheat" by flying with info-bar always on, is to do some test-flying with it temporarily on and memorizing how much one can pull to avoid going above 5 G. With a bit of experience one does actually develop a feel of angular speed of the aircraft in DCS just by watching how fast the scenery moves around.

[J13 Serenity]

null"Forces over 3G are very difficult to impose"
Yea, right...

[feuervogel]

Regarding the opening post:

I like to fly the Mossie very much, it is a wonderful detailed model and a joy to fly. But the fragile wings really are a show stopper for me. Just came back from a raid at an online server. Attacked in a shallow dive pulled out and "woops" the left is gone. This happens almost every time a doing this!

Do I overstress the structure? Maybe, but that behavior seems to be weird to me. I am doing nothing "extreme" and compared to other fighter/bomber like P-47 I even try to be very careful when pulling out, but a bit too much stick ends in a dismounting wing. And I cannot believe that it is accurate, a fragile plane would be useless in real life.

[Art-J]

^ In real life pilots could feel the load and knew how close they were to this rated 6G limit, especially after bobweight was added in elevator control channel. We virtual pilots have no such feedback. As I said previously, turn on the info bar (Ctrl-Y if I recall correctly) and watch how many Gs you're doing while pulling out of a dive.

[Skewgear]

Max permissible diving speed for the FB.VI with external bombs or rockets was 350mph. You're probably doing two things wrong: exceeding the speed and pulling out too sharply.

[feuervogel]

Thank for reply, I will try this.

[Bozon]

4 hours ago, Skewgear said:

Max permissible diving speed for the FB.VI with external bombs or rockets was 350mph. You're probably doing two things wrong: exceeding the speed and pulling out too sharply.

Makes no sense. 350 mph is lower than max level speed at altitude and in case it is in IAS then it’s near the max level speed at sea level. This speed should be very far from any structural limit.

The problem with diving the mosquito in DCS is that you have no feel for G and at these speeds the sensitive stick response can easily over stress the airframe.

ED believes that Mosquito wings were fragile. The wings were actually considered as very rigid, and DH during the design phases reduced the number of struts inside the wing to save weight and material because it was deemed unnecessarily stiff.

Historically, Mosquitoes did suffer from broken wings by over-stressing the wings in pullouts. Accidents like that were prevalent in post-war mosquitoes. This has a lot to do with the main issue with wood construction - the variance. Metallurgy is very predictable - you can make thousands of metal beams all with exactly the same limits. Wood properties on the other hand vary from forest to forest and tree to tree. Wood also continues to change as it ages and how it changes depends on many parameters, so no two beams are exactly alike. This means that while the average Mosquito wings were strong enough, some were extra strong and some… weaker than average. So if you stressed your airframe and happened to be in one of the latter, its bye bye wings.

[Skewgear]

57 minutes ago, Bozon said:

Makes no sense. 350 mph is lower than max level speed at altitude and in case it is in IAS then it’s near the max level speed at sea level. This speed should be very far from any structural limit.

See the attached flying limitations for the Mosquito FB.VI, taken from the Royal Australian Air Force's Mosquito Instruction No.1 dated 8th December 1944. Page 24 of the first PDF at the following link:

Remember that post-war editions of RAF pilots' notes (meaning the digitised original copy that everyone always refers to in online Mosquito FB.VI discussions, with speeds in knots) do not include a significant amount of information that was in the wartime documents. This is because after the war, the requirement to carry bombs and rockets on these aircraft largely fell away as they were relegated to second line duties and training roles.

My personal view is the post-war FB.VI pilots' notes omit important information for the pilot including many of these limitation speeds. I fly in accordance with them and I don't find myself tearing off my wings.

Adding link because the forum software swallowed it: https://ww2aircraft.net/forum/threads/raaf-mosquito-reports.55455/

[[HOUNDS] CptTrips]

I think there should be an option to show a G-load up in the corner.  It's not something you can guess visually like speed or alt.  You'd feel it in our butt. And it is often vital to know to push the envelope.

I've seen it shot down by mods saying they won't add anything that "gamey" just read it off the hud.  

I can't find any such hud on the P-51 and not a G-meter in the cockpit.  Does a pony have a G-meter on the dash?

 

 

[razo+r]

8 minutes ago, [HOUNDS] CptTrips said:

...Does a pony have a G-meter on the dash?

 

 

Yes, yes it has.

[[HOUNDS] CptTrips]

11 minutes ago, razo+r said:

Yes, yes it has.

Oh good.  I'll look again.

I s till think it would be a good option.  Hard to guess based on visual clues like alt or speed or pitch when you are in a turn fight looking behind you.  You'd jsut feel it rather than have to take eyes off to go look at dash.

[Edit]  Found it thanks.

Edited April 14 by [HOUNDS] CptTrips

[Qcumber]

Maybe someone could invent a "G-meter" feedback. A pressure cuff on your ankle which increases pressure according to the G force? 

[NAM]

44 minutes ago, Qcumber said:

Maybe someone could invent a "G-meter" feedback. A pressure cuff on your ankle which increases pressure according to the G force? 

That is not bad idea.. perhaps get mini-bass shake strap to your angle.. a program similar to simshaker.. filter only G-force from DCS telemetry and start to vibrate G-force > 5

[Qcumber]

3 minutes ago, NAM said:

That is not bad idea.. perhaps get mini-bass shake strap to your angle.. a program similar to simshaker.. filter only G-force from DCS telemetry and start to vibrate G-force > 5

I was thinking of a pressure cuff; like on a blood pressure monitor. Then you could have an analogue representation of the relative g rating. Basically, like a G-suit but only on one ankle, and not enough pressure to cause any significant arterial occlusion. I wonder if there are any BP monitors with USB ports. 

[NAM]

In Simshaker, There is an option one can set minimum G-force. I set it to > 5 for warbird and 7.0 for Tomcat

When the bass shaker start to vibrate (The G effect quite distinc from others) then I would ease back pulling the stick.

This way you can react much quicker than looking at G meter in the display.

Edited April 15 by NAM

[Bozon]

17 hours ago, Skewgear said:

See the attached flying limitations for the Mosquito FB.VI, taken from the Royal Australian Air Force's Mosquito Instruction No.1 dated 8th December 1944. Page 24 of the first PDF at the following link:

Remember that post-war editions of RAF pilots' notes (meaning the digitised original copy that everyone always refers to in online Mosquito FB.VI discussions, with speeds in knots) do not include a significant amount of information that was in the wartime documents. This is because after the war, the requirement to carry bombs and rockets on these aircraft largely fell away as they were relegated to second line duties and training roles.

My personal view is the post-war FB.VI pilots' notes omit important information for the pilot including many of these limitation speeds. I fly in accordance with them and I don't find myself tearing off my wings.

Adding link because the forum software swallowed it: https://ww2aircraft.net/forum/threads/raaf-mosquito-reports.55455/

Thanks @Skewgear. I think these limits are more procedural than structural - meaning, the danger was not the speed in the dive, but the stress during pull out. I find this interesting for two reasons:

1. There is no dive angle associated with the limits. Pulling out of a long shallow dive is not the same as pulling out of a 70 degree dive, even when the air speed is the same.

2. Apparently Mosquito pilots had no difficulty in pulling way more than 3 G and rip their wings off. I always said that “that” test report which claimed the Mosquito stick gets heavy and does not allow pulling more than 3 G was a “pilot’s exaggeration” and not a real limit. The test pilot was probably a Spit pilot who was used to pulling 5G with his pinkie finger.

 

[Bozon]

15 hours ago, Qcumber said:

Maybe someone could invent a "G-meter" feedback. A pressure cuff on your ankle which increases pressure according to the G force? 

In DCS the “G meter” should be sound and to a lesser degree screen shakes. When pulling G there should be another wind noise on top of the regular one that sounds like “irregular flow” like turbulent wind (for lack of better words to describe it) and increases with G load. When approaching stress limits there should be some kind of crackles and shakes to indicate it.

No it’s not very scientific, but in this case the “feel” is more important than pure “fidelity”.

[NineLine]

On 4/14/2024 at 12:38 PM, [HOUNDS] CptTrips said:

I think there should be an option to show a G-load up in the corner.  It's not something you can guess visually like speed or alt.  You'd feel it in our butt. And it is often vital to know to push the envelope.

I've seen it shot down by mods saying they won't add anything that "gamey" just read it off the hud.  

I can't find any such hud on the P-51 and not a G-meter in the cockpit.  Does a pony have a G-meter on the dash?

 

 

You can open the info bar at the bottom, this shows you several things including G.

[[HOUNDS] CptTrips]

On 4/15/2024 at 7:54 AM, Bozon said:

In DCS the “G meter” should be sound and to a lesser degree screen shakes. When pulling G there should be another wind noise on top of the regular one that sounds like “irregular flow” like turbulent wind (for lack of better words to describe it) and increases with G load. When approaching stress limits there should be some kind of crackles and shakes to indicate it.

No it’s not very scientific, but in this case the “feel” is more important than pure “fidelity”.

I'd settle for anything that gives me direct feedback on G-load between nothin and greying out.  

So I can better judge where I am on the E-M.

I like the idea of a cuff.  Business opportunity.   But there needs to be a non-peripheral alternative for poor folk.

Subtle frame stress noises, changes in breathing, creaking leather or rubbing restraint straps.

Info-bar is a bit much.  A bit more immersive compromise.   

Imagine flying a warbird with no wind noise.  Sure, you can look at the dial, or info-bar.  You can fly like that, but it would feel something was missing.  Some dimension of the simulation wasn't being conveyed. 

I don't think it would be any gamier than having show controls position overlay.

 

[Nealius]

Heatblur added a lot of rattle noises to the F-14 but that's mainly for the AoA rather than G. Breathing noises would be a good option. We have a cool heavy breathing/heartbeat/greyout effect when hit.