Author Topic: 109G/la-5/7 and the slats  (Read 7172 times)

Offline pipz

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109G/la-5/7 and the slats
« Reply #135 on: March 11, 2005, 02:16:30 PM »
In Angus's defence I belive I saw the same video of Rall maybe it was one of the other Aces saying they didnt like the wing slats.Ill have to go back and watch it again.I thought he said somethin about them being upredictable as to when they deployed.May have been Wings Of the Luftwaffe me109 show.Also on Wings Of The Luftwaffe 262 episode they show a mechaninc with a pair of plyers adjusting a set of leading edge slats so they would work properly.

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Offline Glasses

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109G/la-5/7 and the slats
« Reply #136 on: March 11, 2005, 04:21:09 PM »
I Flew an archer to get my PPL PA-28 and it had a placard that said that under no circumstances would spin or other type of acrobatic maneuver could be performed,and for good reason since the airplane was very touchy,and whewn it was power off it fell like a ton of tiny bricks .

The cessna 172 that I flew 3 times later on I did several power off and power on stalls, in the power on however where in the archer you would stall in teh C172 we almost went vertical and the damned thing didn't stall :D  When it did it went into take off speed inmidietly.

If and when I fly again somewhere in the future( God I hope so)  I'd like to go back flying Cessnas compared to an Archer they're friggin awesome :D
« Last Edit: March 11, 2005, 04:23:53 PM by Glasses »

Offline Angus

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109G/la-5/7 and the slats
« Reply #137 on: March 14, 2005, 04:44:24 AM »
My quote from Rall does not come from a video.
I was chatting with him :D
(not joking actually)

But I have seen him say something similar on video, trying to get that copied into MPEG. That is from the Duxford BoB anniversary year 2000.
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline StarOfAfrica2

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109G/la-5/7 and the slats
« Reply #138 on: April 06, 2005, 09:59:37 PM »
Alright.  I know I'm probably beating a dead horse here, and lots of folks wont thank me for digging this thread back up.  It seemed to light a few tempers.  However, a few weeks ago I was digging in one of the local used book stores and came upon "The Illustrated Directory of Fighters" by Mike Spick.  I own a few of his books, and they seem very well written and researched.  I have heard more than one person praise his books.  So I doubt he would make flat out statements about things if there was a doubt.

Quote
In the quest for performance, the Bf 109 was the smallest and lightest airframe that could be wrapped around the most powerful engine then under development.  It was angular, with squared-off wingtips and a rectanglular braced tailplane.  The canopy enclosing the cockpit was of heavy metal framing, side-hinged.  This made it rather unpopular with pilots, many of whom preferred the open cockpit of the He112, which had a very similar performance.

Wing loading was comparable with the Spitfire and Hurricane, but, with an eye to future weight increases, automatic slats were fitted to the outboard sections of the wing leading edge, with large slotted flaps to the trailing edge, supplemented by slotted ailerons which drooped when the flaps were lowered.


(Some parts here about the narrow track landing gear).

The test flight programme uncovered problems with wing flutter, tail buffet, a tendency to drop the port wing before touchdown, a strong tendency to swing on takeoff and landing, leading edge slat malfunctions, and the inherently weak undercarriage.  Despite these faults, the Bf 109 was selected as the future Luftwaffe fighter, and for the most part its pilots had to learn to live with its shortcomings.

(Several paragraphs here on the line from prototypes up to the Emil).

The Emil handled well in the low- and mid-speed range, although above 300mph (483kph) the controls became progressively heavier; the ailerons in particular becoming almost immovable at 400mph (644kph).  During hard manoeuvering the leading edge slats tended to open asymmetrically, which did nothing for precision gun tracking.  In combat, its greatest advantage was fuel-injection which allowed it to perform negative-g manoeuvers without loss of power.  However, it remained touchy on takeoff and landing, and the accident rate, both in training units and operational formations, was horrendous.  Bf 109 ace Werner Molders tested a captured Spitfire and a Hurricane in 1940; he described them as childishly simple to fly, unwittingly making an adverse comparison with the Emil.

(In all the rest of the article, I note only one reference to changes in the design)

(The 109F) .............. had a much sleeker nose with a larger spinner.  The wings were redesigned, with rounded tips, shallower underwing radiators, Frise-type aileron surfaces and plain flaps.  The bracing struts to the tailplane vanished, and the tailwheel was made retractable.

(Some bits I left out here on 109F armament).

Performance was given priority over manoeuverability.  Creeping weight growth had set in, and while greater engine power allied to a cleaner aeroydynamic design gave the Franz a far better performance than the Emil, increased wing loading (about 40 percent greater than that of the Bf 109 prototype), adversely affected turn radius.  This last was not particularly important so long as the Messerschmitt pilots stuck to dive and zoom tactics, and avoided mixing it.


I attempted to note in ( ) when I skipped an area I didnt feel at all weighed on the subject at hand, and what was in the skipped over material.  I wanted it to be as contiguous as possible.
« Last Edit: April 08, 2005, 02:50:24 AM by StarOfAfrica2 »

Offline Charge

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109G/la-5/7 and the slats
« Reply #139 on: April 07, 2005, 04:43:01 AM »
Spick...  :rolleyes:

-C+
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Offline StarOfAfrica2

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109G/la-5/7 and the slats
« Reply #140 on: April 07, 2005, 12:58:20 PM »
Quote
Originally posted by Charge
Spick...  :rolleyes:

-C+


Thanks for the intelligent input.  If you know of a reason to disregard his writing then say so, because I'd truly like to know.  I know alot of people who have put alot of stock in his writing for many years.  You are the first one who has had anything bad to say, and you just make the childish rolleyes thingie instead of commenting?  Several times in this thread documentation was asked for, I found documentation and posted it.  If you can show me it's not reliable, then it has alot of bearing on what I posted, since he doesnt show any of his sources.

Offline Angus

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109G/la-5/7 and the slats
« Reply #141 on: April 07, 2005, 05:15:14 PM »
The horse is alive....and kicking

Interesting about the slats actually.

It lives...I hope
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline GScholz

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109G/la-5/7 and the slats
« Reply #142 on: April 08, 2005, 02:48:48 AM »
Like I've said before, in 10 years of Bf109 development you'd think they would get rid of the slats if they were no good.
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Offline StarOfAfrica2

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109G/la-5/7 and the slats
« Reply #143 on: April 08, 2005, 03:06:30 AM »
Something that made me curious, on the Emil wings, the book stated the ailerons would droop when flaps were deployed.  The picture shows the flaps themselves in two separate parts, the section closest to the fuselage having another piece that sticks down further.  I cant see much "droop" to the ailerons, but the angle really isnt right for it either.  I most certainly do not see any change from level in the ailerons of an F model on the next page that has flaps deployed.  Wouldnt affecting the ailerons with the flaps cause a reduction in manuverability?  

As for whether or not they would have changed the slats if they had problems................why would they?  It was an integral part of the design.  They never tried to find a way to increase the landing gear track.  That was a problem (just like the slats) from the prototype stage.  Matter of fact, after the F model, they made no significant structural changes other than what would be necessary to fit the larger engines in place and some changes to accomodate changes in armament.  I'm not trying to make a case either way on the slat issue, I'm just making the point that it could very well have been a problem that plagued them all the way through to the final plane built in postwar Spain.  Who knows?  The book did say it only happened under "hard maneouvering" and did not say that it caused accidents or anything else other than it made shooting more difficult.  Then again, maybe they fixed it with the wing changes in the F model.  Again, someone asked for documentation in this thread, I found a mention of it in this book I picked up, so I shared what I found.  Some of you guys have forgotten more about WWII fighters than I'll ever know, this just happens to be a thread I'm interested in because I like 109s.

Offline GScholz

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109G/la-5/7 and the slats
« Reply #144 on: April 08, 2005, 03:13:52 AM »
Why would they? ... They are Germans. If it isn't mechanical perfection they will work on it till the Sun explodes to get it right.
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Offline Charge

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109G/la-5/7 and the slats
« Reply #145 on: April 08, 2005, 04:41:24 AM »
Sorry SOA2. To explain a bit: To me M.Spick uses such expressions in all his writing that gives out his obvious bias.

On subject: Wing loading was not comparable to Spitfire of Hurricane but pretty much higher on 109. There were other qualities that made 109 competitive with those planes.

All those test flight problems could be overcome with careful handling in take-off and landing, but despite that it was a difficult ride for rookies.

I don't know what he means by precision gun-tracking in hard maneuvers? I don't think those words belong in the same sentence. As stated before the transition of flight states COULD cause asymmetrical opening of slats but hard maneuvers certainly forced them open quite evenly.

An "easy to fly" aircraft is not always the best fighter. I think Mölders referred mostly to their qualities which were possible by their low wing loading ie. very easy to land and take-off.

I'm not sure if the landing accidents were "horrendous", but surely higher than those of Spit and Hurricane.

Some anecdotal sources state that the F was in fact better turner than the E. Once again it is not simply a matter of wingloading as he likes to bring up (quess why ;-)). AFAIK its turn rate was better than that of E. Plus it was considered the best variant of 109s by many. The G6 was probably the worst model after which more engine power could compensate worsened handling caused by weight escalation.

On aileron drooping: actually the drooping effect changes the profile of the whole wing from tip to root to suite better conditions required by slow flight. Without that droop the 109 would be a potential "tip staller" and that would be very bad as root stall is more controllable and you do not want to tip stall upon landing in low level. (You might want to check the mysterious Buchon accident which happened to Mark Hanna). Anyway, nearly all modern aircraft use similar system nowadays.

On landing gear: They did change it quite a bit, strengthened and wider track, more forward rake and bigger tyres for bad runways, but they could not change the most crucial thing: they were center line (just as in Spitfire which had even narrower track and even softer tyres...)

Thanks for yor input StaroA2 and I'm sorry for my initial attitude to your writing. :(

-C+
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Offline StarOfAfrica2

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109G/la-5/7 and the slats
« Reply #146 on: April 08, 2005, 02:01:32 PM »
Quote
Originally posted by Charge

Sorry SOA2. To explain a bit: To me M.Spick uses such expressions in all his writing that gives out his obvious bias.

I can see where one could get that opinion.  I dont know one way or the other.  In his book I have about the Luftwaffe aces, he seems very objective.  But then I've only read 4 or 5 of his books, including this one which is as much illustration as it is record.

On subject: Wing loading was not comparable to Spitfire of Hurricane but pretty much higher on 109. There were other qualities that made 109 competitive with those planes.

I believe he was only referring to the prototype here.  Its not completely clear.  His transition from pure prototype discussion to Emil is not completely clear.  I'm sure that by the time they reaced the E model 109 the wing loading was much higher than originally.

All those test flight problems could be overcome with careful handling in take-off and landing, but despite that it was a difficult ride for rookies.

I don't know what he means by precision gun-tracking in hard maneuvers? I don't think those words belong in the same sentence. As stated before the transition of flight states COULD cause asymmetrical opening of slats but hard maneuvers certainly forced them open quite evenly.


Here, to me, he is saying that if the pilot were to make a harsh maneuver (not just a high G turn or other "normal" fighter plane movements), say in the effort to gain a quick snapshot, the slats could come out asymmetically and throw off the aim.  I can see instances where the G load might be different momentarily between the wings and perhaps cause one to have some added impetus to speed it to full deployment.  Even if only that way for a second, it could throw your aim off.

An "easy to fly" aircraft is not always the best fighter. I think Mölders referred mostly to their qualities which were possible by their low wing loading ie. very easy to land and take-off.

I would agree with that.  I am limited in experience to Ultralights, hoping to expand that very soon to Sport class but thats still nowhere near even the complexity of a full size airplane, let alone the complexity of even a WWII technology fighter plane.  "Easy to fly" usually means compromise; and while everything has to be a compromise, I would think a fighter design would try to have as few as possible.

I'm not sure if the landing accidents were "horrendous", but surely higher than those of Spit and Hurricane.

I have no evidence of that either way, but I have read in more than one source that the narrow landing gear, coupled with the high torque and the relatively light frame could cause inexperienced pilots to flip the plane over on its back during takeoff or landing.  It wouldnt surprise me.  But then, its just my opinion based on what I've read.  If there were inaccuracies or bias in what I read, it would show in my opinions.  I dont know how to verify it as I have no access to official records.

Some anecdotal sources state that the F was in fact better turner than the E. Once again it is not simply a matter of wingloading as he likes to bring up (quess why ;-)). AFAIK its turn rate was better than that of E. Plus it was considered the best variant of 109s by many. The G6 was probably the worst model after which more engine power could compensate worsened handling caused by weight escalation.

I have read many times how pilots preferred the F-4 over all other models of the plane.  Some liked one aspect or another of different models later on, but all pilots who flew the Bf 109 F-4 seem to have had a lasting impression of quality.  I believe it was Galland who was quoted as calling it "an artist's" plane.  

On aileron drooping: actually the drooping effect changes the profile of the whole wing from tip to root to suite better conditions required by slow flight. Without that droop the 109 would be a potential "tip staller" and that would be very bad as root stall is more controllable and you do not want to tip stall upon landing in low level. (You might want to check the mysterious Buchon accident which happened to Mark Hanna). Anyway, nearly all modern aircraft use similar system nowadays.

Now that you have mentioned that, I remember seeing something like that when flying on commercial planes.  It didnt connect until you said that.  Duh.  I find it ironic though, that "tip stall" is exactly what everyone who flys the AH version complains of.  

On landing gear: They did change it quite a bit, strengthened and wider track, more forward rake and bigger tyres for bad runways, but they could not change the most crucial thing: they were center line (just as in Spitfire which had even narrower track and even softer tyres...)

Thanks for yor input StaroA2 and I'm sorry for my initial attitude to your writing. :(

-C+


No problem, I wasnt in the best of moods myself that day.  I didnt realize they did actually upgrade the landing gear.  I dont think that was anything I read that made me believe that way, probably just assumption since I have always read about the narrow track being a problem.  Thanks for the response, much appreciated.

Offline Angus

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109G/la-5/7 and the slats
« Reply #147 on: April 08, 2005, 04:01:34 PM »
Rall's impression on the 109F was
"Lovely, - highly maneuverable. Absolutely the best model. The 109G was overloaded"
On the slats (once again) he said that they were necessary for the landing in particular, otherwise the landing speed would have been too high. However he did not prefer them in combat, for they would be snapping and throwing the plane around. Being asked, he said that in a rough turn, the outboard slat would jump out and completely snap the aircraft (say left to right).
Asked whether he knew any that had the slats fixed, his answer was a NO.
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline agent 009

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109G/la-5/7 and the slats
« Reply #148 on: April 11, 2005, 07:43:25 PM »
Well well, new here. loads of "slat" data. I do recall a Finnish pilot saying that they did not affect steering. Didn't mention whether aim was affected. Will try & find this quote.

Spit wing was designed by Heinkel I have read. Before war there was quite a bit of sharing. Handley page slats etc.

Offline Panzzer

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109G/la-5/7 and the slats
« Reply #149 on: April 12, 2005, 05:51:51 AM »
Welcome, Agent 009. :)

Check out the pilot comments on slats in the "Messerschmitt 109 - myths, facts and the view from the cockpit" article.
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