Damage Model...?

[Skoshi_Tiger]

Wo

Not uncommon in the early days to fly around in your smokeless powder coated airplane, sitting next to gallons of fuel, and taking a castor oil shower while enjoying a nice relaxing cigarette.

Ah! Those were the days!

[89-]

Another ROF physics vid - having lost a wheel in midair collision (my sparring partner faired much worse) I then had to land the darned criple  I did my best to land the plane not flat but angling it onto the wheel with rudder and ailerons , but the wheel ended up digging in due to "ground loop effect".

 

Edited January 7, 2013 by 89-

[89-]

If that Fokker was still in the least controllsble then that indicates a physical modelling problem to me. The assymetric lift should have generated a corkscrew that would immediately spin you into the ground.

 

Yes, it is hard/many times impossible to recover, but sometimes one can compensate with rudder and healthy ailerons...

 

 

 

 

 

 

 

This one is fake though (just saying in advance): 

Edited January 7, 2013 by 89-

[Crump]

Are you seriously suggesting that it was possible to smoke a cigarette while flying an open-cockpit aircraft?

 

Sure, it was not only possible, it was done.

 

I know plenty of motorcycle riders that smoke going down the highway.  Do you think a cigarette just goes out at 80 mph?

 

Smoking was something almost everyone did back then and pilots were no different.

 

http://photosofwar.net/war-photos/avro-504/

[AndyJWest]

How do a series of images not showing anyone smoking while flying an open-cockpit plane prove anything, Crump?

[Bearcat]

I am just curious.. why is this something that has to be proved in the first place..?

[Krupi]

I think you will find that this "proof" thing comes from a certain yellow forum, don't ask me for proof though

[AndyJWest]

Erm, no. I'm banned from the banana forum for lack of paranoia or something.

 

Anyway, Bearcat is right - it doesn't need proof,and is off-topic. Back on topic, I had a good example of RoF damage modelling flying online the other night. Taking off in a Fokker D.VIIf (which doesn't have a lot of prop clearance), I hit a bump, and noticed a momentary drop in engine revs. It didn't seem to be damaged, so I carried on - only for it to start throwing oil five minutes later. I'd been gentle with the altitude throttle (a crude 'extra carburettor' gadget that gives more power at altitude - but you need to open it slowly as you climb, or the engine makes a funny noise, and will blow within a minute or two), so it wasn't that. Either I'd nicked the prop on the bump, or the engine had been shock-damaged by the bump itself - no way to tell for sure, but a nice demonstration of subtle engine failure modelling.  

Edited January 7, 2013 by AndyJWest

[wiseblood]

I think that's my favourite thing about it.  The critical damage model of planes coming apart is fine too, but the best thing is all of those 'maybe?' sorts of moments where you're not quite sure how damaged the plane really is and have to look around and listen to it to find out.  There's such a large range between components being alive or dead, and such a lot you can do to try and keep the plane landable/controlled crashable when it has been damaged.  The moments playing DID career where you're not quite sure how long the engine/fuel will last and you're not quite sure how hard the wind is going to push you once you lose power (eg. back over the other side of the lines) are pretty amazingly intense.

[MiloMorai]

If you had a prop hit, the prop would be unbalanced from damage and there should be all kinds of vibration.

[Krupi]

If you had a prop hit, the prop would be unbalanced from damage and there should be all kinds of vibration.

 

Very true! 

[AndyJWest]

If you had a prop hit, the prop would be unbalanced from damage and there should be all kinds of vibration.

 

I've not got force feedback, maybe there was? Or maybe they don't model the vibration - it doesn't alter the fact that they've apparently modelled the damage: from a minor prop strike, or the direct effects of the bump, I can't tell. I don't think I've seen another sim do this. IL-2 '46 seems to treat any prop strike the same, and if it models other shock loadings on engines, I'm unaware of it. I've had a prop strike in CloD which seemed to behave as IL-2 does. A Major prop strike in RoF will shatter the (wooden) prop, as one would expect.

[MiloMorai]

An old WW2 was telling stories about his service time. He and several other pilots were delivery Spits to Egypt from the south. One of the pilots (Polish W/C) had a tip strike on take off but didn't know it (rough dirt strip). There was all kinds of vibration and almost aborted but decided to carry on. Several hundred miles later landed in Egypt and found he had ground off ~6" of the blades.

[Krupi]

Clod has both wooden and metal props damage modelled. 

[NZTyphoon]

If you had a prop hit, the prop would be unbalanced from damage and there should be all kinds of vibration.

I know I have read somewhere about a Spitfire that bent about 9 inches (?) of the tip of one prop blade while landing - seems the ground crew just sawed 9 inches off the other blades and the Spitfire still flew okay. (Starts hunting in books...)

 

The most famous, at least on the Allied side, would be the Mosquito - known as the "Wooden Wonder"

And for BoS there would be the LaGG-1/3 series and Yak-1.

[migmadmarine]

And then, there is this, a P-47 in Italy that had a prop strike when pulling out to low during a strafing run, then managed to fly home. 

[Crump]

I bet that P-47 was a beast to fly back home after that!!

[MiloMorai]

I bet that P-47 was a beast to fly back home after that!!

 

But it flew tho there are those that say it shouldn't.

[JG1_Pragr]

 

From the P.W. Stahl book "Ju88 over snow and Sahara". During the low level night rtb, screws were cut off by surface of Mediterranean sea near Tunisian coast. The plane itself and its crew still could rtb to Sicily. Anyway it's very rare thing. More often such accident ended in fatal crash.

Edited January 8, 2013 by JG1_Pragr

[NZTyphoon]

And then, there is this, a P-47 in Italy that had a prop strike when pulling out to low during a strafing run, then managed to fly home. 

 

The damage to the lower cowling speaks volumes. Wonder what the crew chief said?

[Krupi]

The P-47 is a beast of an aicraft I would choose it other any other american aircraft screw the mustang, this and the F4U were bloody awesome!

[DD_bongodriver]

Shouldnt those prop tips have bent forward if it was under power........it really shouldn't have picked up damage on the cowling if it just clipped the ground on a pullout, hitting the gound at an agle that puts the cowling on the deck is going to end badly, that looks more like damage from noseing over on a landing roll with low power set.

[Krupi]

I believe that cowling damage was caused by one of the bent props.

[DD_bongodriver]

I believe that cowling damage was caused by one of the bent props.

 

Hmm....not sure, if the prop was hitting the cowling under power then the cowling should be shredded, none of the props tips look quite in line with the damage area (the bent tips all look to be well clear of the periphery of the cowling)

[FlatSpinMan]

Some really interesting information in here - Bongo, Crump, Skoshi (hiking the Kokoda Trail - 'spect!) - canvas, airframe construction, highly flammable fuel tanks near ashtrays. Thanks. This is the kind of thing I always liked on flightsim forums.

The points about the disparity between what is modelled by the FM and what is displayed visually is a fairly key one, it seems.

 

What we need to sort out this "bending vs snapping off" issue is an aerodynamics engineer. There've been some good ideas advanced, and some interesting supporting photos and anecdotes, but it'd be nice to have a qualified opinion. Anyone? 

[Krupi]

Aeronautical engineer here :D

 

Currently an aicraft designer

Edited January 8, 2013 by JG52Krupi

[FlatSpinMan]

Another great thing in this thread is people actually acknowledging things that are opinion vs fact, and, possibly a first for an internet flightsim forum - admitting error or that other points may be valid.

Someone should screenshot this for posterity, just to prove that it can happen.

 

But enough of the meta-posting.

Wahaaay! So what's the answer Krups?

[DD_bongodriver]

Commercial pilot here, with a good engineering sympathy for aircraft and their construction.

 

It's fairly simple, no need for scientists, bending...propper bending can only occur with metal construction, wood just does not bend and stay bent.......not under the circumstances we are discussing here anyway, both wood and metal will shear.

Edited January 8, 2013 by bongodriver

[FlatSpinMan]

Shouldnt those prop tips have bent forward if it was under power........it really shouldn't have picked up damage on the cowling if it just clipped the ground on a pullout, hitting the gound at an agle that puts the cowling on the deck is going to end badly, that looks more like damage from noseing over on a landing roll with low power set.

 

The point about the cowling damage sounds truthy to me. As for the prop tips, I always thought they'd bend backwards hitting the ground given that the momentum is behind the plane. Pics I've seen of prop damage seem to show that, but then I haven't seen many.

What about damage from flying into tree tops, maybe clipping the top of a roof or something? No idea about those ideas though.

[DD_bongodriver]

with props the chances of them bending forward are increased if the tips strike the ground with some graduation, if the aircraft makes a heavy drop to the ground them more often than not they will bend backwards, there is a picture of a corsair on a carrier deck that illustrates a half and half sittuation, at least 1 blade is bent forward (prob the one that struck first)

 

Found it...

 

http://ussfranklindroosevelt.com/wp-content/uploads/2009/06/WheelsUpLanding-51-52Cruise.jpg

 

 

another example..

 

http://www.flickr.com/photos/runway27r/5191923939/

Edited January 8, 2013 by bongodriver

[FlatSpinMan]

"Posted Today, 21:11

Commercial pilot here, with a good engineering sympathy for aircraft and their construction."

 

 

Cool. It's much more satisfying for me to read these ideas now. 

 

So from your post about prop damage, in the situation where the plane drops heavily, the blades tend to bend backward. This does suggest it would be harder for a plane to fly home, doesn't it?

[DD_bongodriver]

"Posted Today, 21:11

Commercial pilot here, with a good engineering sympathy for aircraft and their construction."

 

 

Cool. It's much more satisfying for me to read these ideas now. 

 

So from your post about prop damage, in the situation where the plane drops heavily, the blades tend to bend backward. This does suggest it would be harder for a plane to fly home, doesn't it?

 

It simply makes me doubt the annectode completely WRT this particular P-47, it simply looks to me like a nose over while either taxing or on a landing roll.

 

Having said that I am not claiming such a situation could not happen, in fact I'm certain it has happened more often than actual accounts might record.

Edited January 8, 2013 by bongodriver

[Crump]

The damage is consistant with a nose over.

 

 

[FlatSpinMan]

Good stuff. 

[Krupi]

Then you will love this.....

 

http://www.vintagewings.ca/VintageNews/Stories/tabid/116/articleType/ArticleView/articleId/325/language/en-CA/Lower-than-a-Snakes-Belly-in-a-Wagon-Rut.aspx

 

 

Manufactured Victory, found this a few months back really great stuff...

 

http://www.vintagewings.ca/VintageNews/Stories/tabid/116/articleType/ArticleView/articleId/367/language/en-CA/Manufactured-Victory.aspx

 

Edited January 8, 2013 by JG52Krupi

[Crump]

Then you will love this.....

 

http://www.vintagewings.ca/VintageNews/Stories/tabid/116/articleType/ArticleView/articleId/325/language/en-CA/Lower-than-a-Snakes-Belly-in-a-Wagon-Rut.aspx

 

 

Manufactured Victory, found this a few months back really great stuff...

 

http://www.vintagewings.ca/VintageNews/Stories/tabid/116/articleType/ArticleView/articleId/367/language/en-CA/Manufactured-Victory.aspx

 

 

Great Stuff JG52Krupi. 

 

I bought an airplane off a man whose first assignment in World War II was flying low level Recce in a P39.  The camera's where mounted facing out the side of the fuselage and the mission was to fly the roads of Europe below tree top height looking for equipment/aircraft staged beside the road.

 

Col. Lacey told me they practiced in the Everglades with the instructor above using the student airplanes wake in the sawgrass to talk the young pilot down in order to become comfortable at such extreme low level and speed.

 

He put in a transfer to the 8th Fighter Command and flew P51's out of England.

[FlatSpinMan]

Cheers Krupi

I'd already seen Lower than Snake's Belly, but that Manufactured Victory was superb.  It must be brilliant to see fighters blowing by at high speed just metres from you. I'd seen some shots before but most were new to me. As an NZer I was surprised to see how many times the RNZAF popped up.

I would love to check out that Mach Loop place in the UK.

[MiloMorai]

Every September, Micheal Potter and his Vintage Wings puts on an air show.

[FlatSpinMan]

Great Stuff JG52Krupi. 

 

I bought an airplane off a man whose first assignment in World War II was flying low level Recce in a P39.  The camera's where mounted facing out the side of the fuselage and the mission was to fly the roads of Europe below tree top height looking for equipment/aircraft staged beside the road.

 

Col. Lacey told me they practiced in the Everglades with the instructor above using the student airplanes wake in the sawgrass to talk the young pilot down in order to become comfortable at such extreme low level and speed.

 

He put in a transfer to the 8th Fighter Command and flew P51's out of England.

Transferring to the 8th to take part in some of the biggest air battles ever (at extreme ranges) sounds far safer. Flying BELOW tree-top level to photograph stuff BESIDE you?

 

Out of interest, what plane did you buy?

[migmadmarine]

The P-47 is a fairly well documented event, the basic synopsis being the following. I'll see what more I can find.. 

 

"A P-47 of the 64th Fighter Squadron, while on a mission to Milan , struck the ground during a low level strafing run. Despite the bent props and crushed chin, the pilot nursed the Jug 150 miles home to Grosseto . Photo via Hebb Russell"