There are many posters here better read and more experienced than me but the idea that a test pilot was scared of slats opening is ridiculous. Many WW2 aircraft types have a note in their development about a test pilot being killed in is development. I believe the mosquito killed 2 or3 test pilots pulling out of dives before the reason was found (something to do with the undercarriage or its doors dropping under high G loads) To me, if I was a test pilot, the thing that would make my rear twitch would be pulling out of a dive, what if it doesnt and cant? As Rochie said if it stalls and doesnt recover jump out.
improving the 109??
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Shortround6
Major General
The British had used quite a number of aircraft with slats by 1939, Granted a lot of them used some pretty crude slat arrangements compared to the 109 (external tracks/hinges) and not only had they built a lot of designs with slats some of those designs had been built by the hundreds. Like the majority of Hawker Hart Family. Again they were only fitted on the upper wing in front of the ailerons. This was to maintain aileron effectiveness just before or during a stall to prevent spinning.
The idea that test pilots at Farnborough were not familiar with slats is ludicrous. Westland Lysander had full span Slats and first flew in 1936.
The idea that test pilots at Farnborough were not familiar with slats is ludicrous. Westland Lysander had full span Slats and first flew in 1936.
Shortround6
Major General
Thank you.
You should not be complimented on posting pictures of those ugly muthas, did the Brits ever put a slat on a pretty aircraft, what is that bomber? I think it would give the 109 a run for its money. The conversation /statement was not so much about per se but about their sudden deployment. I have read that some aces said inexperienced pilots felt that newly qualified pilots did not push the 109 to the limits and combat frequently involved the slats opening, that is not the same as a test pilot. Those guys were used to flying planes which had never been flown before and in the case of captured equipment had very little information.
No newly qualified pilot would have been pushing his aircraft to the limits - that is what comes with experience - knowing exactly how far you can push the aircraft.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
The Mosquito prototype had leading edge slats as did the Whirlwind.
Been ages since I've read up on the Mossie, so I don't recall why they weren't retained for production.
Been ages since I've read up on the Mossie, so I don't recall why they weren't retained for production.
Shortround6
Major General
Westland Whirlwind for pretty aircraft?
Slats didn't work well and were fastened shut.
The middle picture was an airliner and the bottom picture a combination bomber/transport.
While captured aircraft were often treated gently (can't send it back to factory to get repaired) while feeling out the quirks the statement was made that British pilots were unfamiliar with slats and didn't push the aircraft to it's limits because of that and so under estimated the real turning ability of the 109. As shown the British pilots as a whole had a fair amount of experience with slats, some of the old biplanes actually had some pretty vicious stall characteristics and the slats were beneficial in reducing the accident rate.
Some British companies used them quite a bit, others didn't use them at all (didn't want to pay royalties to Handley Page?)
The person doing that post is confusing the effect of full span slats with the effect of partial span slats.
Shortround6
Major General
It may be because the wing section had a decent stall anyway? Even Handley Page stopped putting slats on the Halifax after the first 50. 4 engine bombers shouldn't be operating at angles of attack over 12-14 degrees. under that and the slats don't deploy.
wuzak
Captain
It was found they were not needed.
The slats can been seen on W4050,
View: https://www.flickr.com/photos/64209520@N05/22722970433
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View: https://www.flickr.com/photos/64209520@N05/22722970433
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GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
The Bf109 was limited as to what could be placed in the wing, because the wing remarkably thin.
Earlier in this thread, I posted photos of the Bf109's wing, showing the wing's upper skin surface from inside the wheel-well, including the bulge to add clearance for the tire.
Earlier in this thread, I posted photos of the Bf109's wing, showing the wing's upper skin surface from inside the wheel-well, including the bulge to add clearance for the tire.
GregP
Major
In the end, I think the Fw 190 series was better below 20 - 22,000 feet and the late Bf 109s were better above that height. I could be wrong here, but the combat reports I have read don't support it if so.
Up above 25,000 feet, nobody in a WWII fighter was doing 90° banks or they fell out of the sky and exited the scene in a spin or dive. They flew around in shallow banks and tried to get an advantage. That's for horizontal fights. In a WWII fighter, vertical fights from high altitude meant descent, not a climbing fight. All climbs at that altitude were gradual except zooms from sufficient speed. If you are within several thousand feet of the service ceiling, you can't loop even if the want to; there is insufficient speed / lift available. It's like trying to climb out of a canyon at just above stall ... NOT a good place to be.
I can easily believe the slats on the Bf 109 were quite effective at high altitude and low IAS. But the vertical ability up there just wasn't present in large quantities for anyone.
Our Hispano Ha.1112 doesn't have any wing fences.
Up above 25,000 feet, nobody in a WWII fighter was doing 90° banks or they fell out of the sky and exited the scene in a spin or dive. They flew around in shallow banks and tried to get an advantage. That's for horizontal fights. In a WWII fighter, vertical fights from high altitude meant descent, not a climbing fight. All climbs at that altitude were gradual except zooms from sufficient speed. If you are within several thousand feet of the service ceiling, you can't loop even if the want to; there is insufficient speed / lift available. It's like trying to climb out of a canyon at just above stall ... NOT a good place to be.
I can easily believe the slats on the Bf 109 were quite effective at high altitude and low IAS. But the vertical ability up there just wasn't present in large quantities for anyone.
Our Hispano Ha.1112 doesn't have any wing fences.
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They were fitted to some versions. Spanwise flow is always likely to be a problem on a short, straight wing and by reducing this the 'fences' improved the wing lift patterns across the wing.
Whether Shooter8 likes it or not the wing of the Bf 109 is a far more conservative and less sophisticated design, including more compromises, than that of the Spitfire.
The debate over the relative merits of elliptical type wings and square tapered wings raged in the mid 1930s, and developed into heated argument following the 1936 publication by Lachmann (he of slats fame) of an article entitled "The Stalling of Tapered Wings". Both have advantages and disadvantages, which is why in the ensuing debate one famous name confounded another before being himself confounded and so on.
Both types featured on great aircraft, think P-51, Bf 109, Fw 190 for straight, Spitfire, P-47, Tempest for ellipsoidal.
Cheers
Steve
Didnt the Tempest designer say that it had to look like a Spitfire or no one would buy it?
GregP
Major
I'm about to go on a trip this Saturday, but will get pics when I come back. I should be back there on Saturday, 9 Jul 2016. The airframe is basically a stock Bf 109 G-2 with a Merlin on the front. Then only really noticeably difference is that ours has fitted covers where the cannons came out, and there is a hole in the wing spar where the cannons used to go through, trimmed in Aluminum edging.
Ours had also been modified at some point for racing and had an ADI tank in the starboard outer wing that caused a piece of main spar far outboard to be removed as well as a "Y" connection in the fuel line going to the supercharger impeller for the ADI when the solenoid was actuated. When we removed the ADI tank, we (Fighter Rebuilders) patched the spar, so it is pretty much back to stock in that department. No more ADI injection. Pretty much a stock Merlin 224 with a neat new carbon fiber carburetor airscoop fabricated by Steven Hinton Jr. The lower cowling will be made MUCH more Bf 109-like since we (Fighter Rebuilders, not volunteers) relocated the oil cooler and worked specifically toward that goal.
It is about 98% ready to fly again. Hopefully sometime soon.
Interestingly, the slats are somewhat unusual in that they are basically wood with Aluminum skin. Is super glue an "approved adhesive?" I hadn't expected wood. The radiator scoop structures on the lower wing are also of wood, with metal doors at the back. Basically the flap trailing edge spreads apart for airflow exit control on both sides and the lower wooden lip of the scoop is controllable for intake size (the leading edge moves up and down). So, airflow control is mostly composed of wood parts.
I would not have known much of any of that had I not seen it and worked on it a bit. Altogether an interesting aircraft, but somewhat of a problem due to the difficulties in finding metric aircraft hardware locally. So, ours is a mixed bag of metric and SAE. Nothing wrong with metric hardware at all. We all have metric tools and are comfortable with metric anything, but finding some specific fasteners for the Bf 109 is basically NOT an exercise in sourcing standard metric parts. Many are tapered and are simply not available from standard sources. So you do the best you can and proceed. Try finding metric pushrod ends for the rudder cables that fit the Ha.1112! They are rounded with definite flats areas on them and are NOT easy to find. About all that is left is the lower cowling airscoop and a starter than developed a leak. We removed the starter last weekend and the airscoop needs a few days attention from Stevo Hinton when he isn't running hot laps around Reno.
Perhaps soon. Perhaps not. Depends on the level of interest by the museum. At least we know it runs.
That was before paint. I'll get shots in a couple of weeks.
Slats had been around for long time before the Bf 109 had them ... since 1918. Not sure the F-86 owes anything to the Bf 109. Perhaps a bit to the Me 262, but mostly in the area of wing sweep. The sweep is what made the Sabre a great fighter ... well, that and the all-flying tail, which was head and shoulders better than the stab and elevator of the F-86A.
You can see slats on the Bell L-39.
That's a funny-looking plane, huh?
Ours had also been modified at some point for racing and had an ADI tank in the starboard outer wing that caused a piece of main spar far outboard to be removed as well as a "Y" connection in the fuel line going to the supercharger impeller for the ADI when the solenoid was actuated. When we removed the ADI tank, we (Fighter Rebuilders) patched the spar, so it is pretty much back to stock in that department. No more ADI injection. Pretty much a stock Merlin 224 with a neat new carbon fiber carburetor airscoop fabricated by Steven Hinton Jr. The lower cowling will be made MUCH more Bf 109-like since we (Fighter Rebuilders, not volunteers) relocated the oil cooler and worked specifically toward that goal.
It is about 98% ready to fly again. Hopefully sometime soon.
Interestingly, the slats are somewhat unusual in that they are basically wood with Aluminum skin. Is super glue an "approved adhesive?" I hadn't expected wood. The radiator scoop structures on the lower wing are also of wood, with metal doors at the back. Basically the flap trailing edge spreads apart for airflow exit control on both sides and the lower wooden lip of the scoop is controllable for intake size (the leading edge moves up and down). So, airflow control is mostly composed of wood parts.
I would not have known much of any of that had I not seen it and worked on it a bit. Altogether an interesting aircraft, but somewhat of a problem due to the difficulties in finding metric aircraft hardware locally. So, ours is a mixed bag of metric and SAE. Nothing wrong with metric hardware at all. We all have metric tools and are comfortable with metric anything, but finding some specific fasteners for the Bf 109 is basically NOT an exercise in sourcing standard metric parts. Many are tapered and are simply not available from standard sources. So you do the best you can and proceed. Try finding metric pushrod ends for the rudder cables that fit the Ha.1112! They are rounded with definite flats areas on them and are NOT easy to find. About all that is left is the lower cowling airscoop and a starter than developed a leak. We removed the starter last weekend and the airscoop needs a few days attention from Stevo Hinton when he isn't running hot laps around Reno.
Perhaps soon. Perhaps not. Depends on the level of interest by the museum. At least we know it runs.
That was before paint. I'll get shots in a couple of weeks.
Slats had been around for long time before the Bf 109 had them ... since 1918. Not sure the F-86 owes anything to the Bf 109. Perhaps a bit to the Me 262, but mostly in the area of wing sweep. The sweep is what made the Sabre a great fighter ... well, that and the all-flying tail, which was head and shoulders better than the stab and elevator of the F-86A.
You can see slats on the Bell L-39.
That's a funny-looking plane, huh?
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wuzak
Captain
I believe the Merlin rotated the other way to the DB. It also sported a bigger prop and the thrust line was higher.
I think, but am not certain, that the Bf 109 had the fin angled to help compensate for torque reaction.
Does anybody know if the Spitfire/DB 605 had any stability issues when tested by the Germans?
I can't recall if the Merlin and V-1710 rotate the same way, but in any case the Mustang X suffered with stability issues caused by the extra power and a bigger prop. Rolls-Royce ended up adding quite a bit of fin/rudder area to it.
Even the P-51B and -D had some stability issues, not completely solved until the larger fin/rudder was introduced with the -H.
Given the endorsement earlier in this thread that contra-props aided stability it is interesting to note that, according to Buttler, British Experimental Combat Aircraft of World War II, when Tornado prototype R7936 was fitted with de Havilland 6 bladed contra-props "Hawker's wartime notes state that the contra-prop was found to have a marked destabilising effect on the aircraft".
Once again just adding a larger fin can be fraught with problems. A larger fin doesn't just create more drag, it can create a problem of aerodynamic side loading as the designers of the P-51 discovered. These forces are complicated and stem from the design of the rest of the aircraft and the airflow off the wing and fuselage.
When late Mark Spitfires got a significantly larger fin wasn't the fuselage boom also lengthened, reducing drag? I can't find a reference for this and memory is not always reliable
Cheers
Steve
When late Mark Spitfires got a significantly larger fin wasn't the fuselage boom also lengthened, reducing drag? I can't find a reference for this and memory is not always reliable
Cheers
Steve
wuzak
Captain
When late Mark Spitfires got a significantly larger fin wasn't the fuselage boom also lengthened, reducing drag? I can't find a reference for this and memory is not always reliable
I suppose the fuselage was lengthened ahead of the firewall with the Griffon engines. I'm not sure that they were behind the firewall.
Not sure about whether the Spiteful type tail also involved an extension to the rear fuselage.
