Mossie vs Ju88

[parsifal]

I dont doubt that 3cm fire would make a mess of them. But is that worse, or better than a metal framed aircraft. I have seen photos of the sort of damage a single 3cm can do to a B-17......its not pretty.

I think also that you have to admit that Welters is a bit suspect as a source. He claims 25 kills in his 262, to which the RAF can only confirm the loss of three Mosquitoes in the time specified (or something like that).

I equally dont necessarily accept the non scientific appraisals made by RAF members, that simply describe the type as "rugged" or "tough". It doesnt get to the core of the question in my opinion

 

[FLYBOYJ]

The wood will start to burn but it takes time for the wood to burn.

And more time for aluminum

Say you have a 2X6 and ignite it uniformly on all sides, How long does it take to to burn (char) it 1/2in deep all around? at this point you have about a 1X5 which while quite a bit weaker is still there.
What condition will the aluminum piece be in given the SAME duration of flame impingement?

Again it depends what type of aluminum piece - Casting? Forging? Extrusion? Plate? Sheet? 2024? 2114? 7075? For the most part a piece of 7075 T6 the same size of your wood example will not burn and will probably melt when its eutectic point is reached, and comparing it to a same size piece of wood, (as the sizes you've given) could actually take more than minutes and depending on application and the fire source, hours to completely fail.

The picture are B 757 Nacelle fittings made from 7075 block - they were probably heat treated to T-6 and possibly shot peened and probably have a tensile strength of over 200K (tons) PSI. There is no way you're going to get a piece of wood to have the same properties or have it with better burn properties.

I know that aircraft members are not made of 2x6s but I hope you get the point. Flames/heat can do a lot more to glues and joints than to solid bits of wood (and cut outs don't help) but there is a difference between setting something on fire and having the same thing structurally fail.

I do get the point - you need to understand how aluminum is made, the type of aluminum alloys that go into structural components and how they are put together. Be it set on fire or taking it a point where it will structurally fail, an aluminum structure will be more resilient to any type of wood.

each design, or even each area of each design is going to respond differently depending on the exact materials, the cross section, the amount of heat both temperature and total btu's and other factors.

All true, but again we need to specify material

I think that to say one type of construction is always superior to the other is not realistic. Again I am talking about the time from the start of a fire to the point of something failing structurally.

So am I and I'm telling you from experience you're wrong. I've inspected many a wood aircraft and they could be very troublesome if not properly maintained and stored. I've seen wood aircraft have structural failures that aluminum aircraft would never have and seen leftovers after a crash that resulted in fire. All these reasons are why many manufacturers today stay away from wood and only home builders still use it as a building material.

 

[FLYBOYJ]

For those who are interested, I found this study into the auto ignition properties needed to make certain woods burn

http://www.waset.org/journals/waset/v47/v47-13.pdf

The Link attached below is a study into spruce plywood, a major component of the Mosquito. I believe the Mosquito also used hardwod laminar framing, which, depending on the materials used and its moisture content, apparently, has an auto-ignition temperature of around 550-600 C (which I was unaware of until today)

http://www.doctorfire.com/wood_ign.pdf

Good info but I couldn't find the reference to spruce plywood

 

[Shortround6]

I am not expecting the aluminum, especially in large sections to burn.

"...same size of your wood example will not burn and will probably melt when its eutectic point is reached"

The aluminum doesn't have to reach it's eutectic point in order to fail structurally. It just has to reach a point at which is strength is considerably diminished. This can be several hundred degrees below it's melting point.


"So am I and I'm telling you from experience you're wrong. I've inspected many a wood aircraft and they could be very troublesome if not properly maintained and stored. I've seen wood aircraft have structural failures that aluminum aircraft would never have. All these reasons are why many manufacturers today stay away from wood and only home builders still use it as a building material."

I thought we were talking about the different types (materials) of structure and how they might fail under a fire load. There is no doubt that your last three sentences are true but they don't have a lot to do with behavior in a fire do they?

 

[parsifal]

Good info but I couldn't find the reference to spruce plywood

My mistake...but the intro does refer to spruce, though I am unsure if the data collated refers to this timber. Spruce was an important component to Mosquito airframe construction

I am referring to the second article. If you are interested in materials characteristics, they are worth a look i think

I am still studying these reports myself, incidentally

 

[Timppa]

For the most part a piece of 7075 T6 the same size of your wood example will not burn and will probably melt when its eutectic point is reached, and comparing it to a same size piece of wood, (as the sizes you've given) could actually take more than minutes and depending on application and the fire source, hours to completely fail.

You seem to have the idea that aluminium alloy member has to melt in order to fail.
In reality it will fail long before that, as the yield point is reduced by temperature.
(The twin towers in 911 collapsed when the steel members were weakened by fire, along with additional stresses by thermal expansion, they did not melt.)

PS. This is pretty academic anyway, any aircraft that has a fuel fire is pretty much doomed. In US Navy study 80% of planes that had been hit in fuel system were lost.
I agree that aluminium alloy is the better material for aircraft, but there were some good reasons for using wood in Mosquitos and Russian fighters, and history shows they did just fine.

 

[Erich]

parsifal

we never personally interviewed Welter as he died before we could, I mean 3 gents of his unit that flew ops in the jet, all shot down 1-2 Mossies, one of them blew a Mossie NF out of the sky early in the morn.

sure metal or wood it did not matter and is actually really im-material to the whole thread.

 

[riacrato]

"Just fine" is a pretty general statement though. History also showed that HE ammunition had a devastating effect on wooden wings when compared to conventional aluminium skins. Sure a 30mm hit will likely be fatal to both, but if hit by a single 20mm HE or even Minengeschoss there's plenty of cases the aluminium wings survived the hit... a plywood wing I guess would shatter and break with a much higher probability. And as far as Soviet planes go, they DID have a lot of problems with their wooden constructions including delamination and so on.

 

[Erich]

2cm HE-I M rounds would either tear a wing off or tear the tail off...........interviews by former 10 (N)./JG 300 members flying the Bf 109G-6/AS, it will all be in our book

 

[FLYBOYJ]

I am not expecting the aluminum, especially in large sections to burn.

"...same size of your wood example will not burn and will probably melt when its eutectic point is reached"

The aluminum doesn't have to reach it's eutectic point in order to fail structurally. It just has to reach a point at which is strength is considerably diminished. This can be several hundred degrees below it's melting point.

True - it has to reach a temperature where any heat treat temper is diminished. Ultimate failure will most likely depend on thesize of material and alloying.

"So am I and I'm telling you from experience you're wrong. I've inspected many a wood aircraft and they could be very troublesome if not properly maintained and stored. I've seen wood aircraft have structural failures that aluminum aircraft would never have. All these reasons are why many manufacturers today stay away from wood and only home builders still use it as a building material."

I thought we were talking about the different types (materials) of structure and how they might fail under a fire load. There is no doubt that your last three sentences are true but they don't have a lot to do with behavior in a fire do they?

Yes. If we were to paint this discussion with a broad brush, an aircraft with an aluminum primary structure will hold up better to fire and elevated temperatures than wood.

 

[FLYBOYJ]

You seem to have the idea that aluminium alloy member has to melt in order to fail.
In reality it will fail long before that, as the yield point is reduced by temperature.

Read my last post and the example I was giving. I never said "melt" in that statement. An aluminum material such as 7075 may reach its lower eutectic point without melting. Structural failure may already occur, depending on the alloy and material size, that's the point I was making.

Great charts!

 

[Timppa]

Read my last post and the example I was giving. I never said "melt" in that statement. An aluminum material such as 7075 may reach its lower eutectic point without melting

For the most part a piece of 7075 T6 the same size of your wood example will not burn and will probably melt when its eutectic point is reached!

Sorry, I don't really understand.
1: What is your definition of "eutectic point" ?
2. What's is the relation to strength (defined as yield point or proof stress)?

Merry Christmas btw.

 

[FLYBOYJ]

Sorry, I don't really understand.
1: What is your definition of "eutectic point" ?
2. What's is the relation to strength (defined as yield point or proof stress)?

Merry Christmas btw.

The eutectic point of a metal is basically where it begins the melting process. The Lower eutectic point may be where one or more of the material's alloying elements have started the process to turn from a solid to liquid. At a material's lower eutectic point, the material may still be in tact but may have begin the process of plasticizing. At that point it has lost most if not all its strength properties if its been previously heat treated. Depending on the type and size of material will determine its strength properties during that period.

And Merry Christmas!

 

[wwii:)aircraft]

Both the mossie and ju 88 are my favorite aircraft of the war. So far in this post many people have picked the Mosquito over the Ju 88 as the better of the two. In the bomber role, yes the mosquito was better being much faster, but in other roles I would pick the Ju 88. Yes the mosquito was much faster but aircraft like the JU 88C or P had more armor as well as a defensive armament (the fighter bomber variants of the mosquito were slower than the bomber versions), not to mention the Ju 88P did well agianst tanks while the Mosquito Mk. XVIII Tse Tse failed to do so (instead it served as an anti-shipping platform). The mosquito couldn't carry torpedoes, the Ju 88 could carry two, and the Ju 88 was able to dive bomber being more accurate.

In the night fighting role i'd would completely give to the mosquito having better radar as well as being faster. The only variants I think that could have been close to the Mosquito night fighter would be the Ju 88G-7b or c.

In the end the mosquito wins in the Mk XVI, 30 or any other kind late war variant only because the germans were under a lot of pressure and could manufacture more advance variants of the Ju 88 such as the Ju 188 or 388 in enough numbers

 

[Erich]

the Ju 88P was experimental in use only never saw action on the Ost Front.

also there was no Ju 88G-7b or c variant this was an RAF after war designation as all known operational Ju 88G's were G-6's by wars end. the G-7 was to be a proposed model in fact they were being built but am not sure what NJG's had them in their line-up

 

[Colin1]

Interesting snippet taken from Testing Years by Roland Beamont; p42-3, Junkers Ju88:

At Tangmere in June 1945 the Tactics Branch of the Central Fighter Establishment had access to the Enemy Aircraft Flight and one of the aircraft on their charge was the Ju88 Nightfighter.

The large paddle-bladed propellers revolved readily and sprang into smooth life with a rumble reminiscent of a vintage car, but this soon changed to a higher-pitched and aggressive noise level as power was increased. In fact, this turned out to be a noisier than expected aeroplane but that was about the only criticism. On initial taxying in the nose-high, tail-down attitude of this tail-wheel aircraft with its tall main undercarriage there was an awkward feeling that it could easily overswing on the turn, especially downwind: but once lined up on the runway the feeling of being in a much larger aeroplane than one's previous experience had practically gone and the 88 felt a compact and well-organised aeroplane.

A short run-up to full power caused the pedal-operated brakes to slip and produced a crescendo of sound that was impressive. I had decided to increase the power progressively on take-off to forestall any unbriefed tendency to swing. This was not necessary and the 88 unstuck at less than full throttle and without any further elevator activity after my initial action to lift the tail conventionally with forward wheel to an appropriate take-off attitude. The initial climb was brisk and I needed to retract the undercarriage before increasing the power to avoid overstepping the undercarriage limit.

Cleaned up, the rate of climb in this light configuration was similar to a Mosquito and the aircraft responded pleasantly to the controls with light ailerons and conventional harmonisation. I noticed that it needed commendably little trimming also, and only when levelling out at 4,000ft and throttling back to cruise at about 230mph* were small tweaks of the elevator and rubber trim switches required.

Rapidly gaining confidence with the aeroplane I tried a few partial rolls, tight turns, rolling pull-outs and dives, climbs and wing-overs; and in all of these the aircraft was stable, responsive and apparently quite viceless except for the noise level which reached crescendo in a dive and was distracting.

Returning towards Tangmere I was about to slow down to look at low speed behaviour when I noticed a Mosquito in the circuit below. Thinking it might be Bob Braham, also a member of the Tactics Branch and the leading exponent of long-range Mosquito fighter tactics, I rolled down toward him and increased power; it was immediately apparent that it was Bob and that he wanted a fight.

The Mosquito wound into the turn in my direction and with full throttle and fine pitch I pulled the 88 into a vertical bank after him. The results were impressive for although I did not know the aircraft it was easy to hold firmly on the opposite side of the circle to the Mosquito and begin to make progress towards getting on his tail. Bob got down to it and took the Mosquito on to its stall boundary with wings rocking perceptably, but I could still see him in my forward arc. I was not far off getting into a firing position but after a number of descending full power turns over Tangmere which had the station out watching, I felt that discretion had to be the better part. I was getting into areas in which I could not possibly know the 88's characteristics so I eased up and out of the turn and Bob was promptly round and on my tail.

This flight and another the next day were enough to show why the 88 was regarded by the Germans as their best large aircraft of WWII. The performance of this nightfighter version when matched against the latest Mosquito of 1945 was remarkable when it is realised that apart from increased power in the nightfighter version, the basic 88 airframe was largely unaltered from the 1940 bomber version.

*British standard ASI fitted for trials

Below: Ju88 nightfighter flown at Tangmere in June 1945 IWM

 

[Milosh]

The mosquito couldn't carry torpedoes

Do a search for Mosquito TR33. Btw, TR stands for torpedo-reconnaissance.

The Mosquito Mk. XVIII Tse Tse was designed from the get go as an anti shipping a/c for Coastal Command.

Ju 88P did well agianst tanks

Not from what I have read.

 

[Erich]

Colin am not sure which bomber or recon variant that is of the Ju 88 but it is not a night fighter

 

[Colin1]

Colin am not sure which bomber or recon variant that is of the Ju 88 but it is not a night fighter

Probably
but it's the pic that came with the piece

Here's the only other plate associated with the section. Mottle scheme seems reminiscent of nightfighter livery

 

[timshatz]

Good post Colin.