Perk the P51 B

[funkedup]

Yep the La-5FN and La-7 have the Ash-82FN motor with direct injection and very macho overboost WEP aka "augmented power" in the translations from Rooskie.

[Vermillion]

Quite frankly, I would be suprised if any of the prop driven aircraft used by the North Koreans, were aicraft in peak condition and maintenance.

These were used up rejects sent to bolster what was to them, a third world country.

[F4UDOA]

Funked,

WEP and Overboost are not the same thing as modeled in AH. WEP is use of water/meathonal to keep cylinder head tempetures down at higher MAP.

Overboost IMHO is the use of higher octane fuels to sustain higher MAP ala the V-1 chasers using 150octane or the F4U-4/P-47M using 150octane because thay had R2800C engines that could handle sustained higher temps.

Also any A/C with a multistage super-charger could overboost at will. And F4U-1 had a two stage mechanical supercharger with Neutral, low blower and high blower. Any pilot could swith to high blower at lower below 10K instantly OVERBOOSTING his engine into higher MAP. He took the chance of blowing up his engine but for limited time he could run at excess of maximum boost.

So was the La-5/7 running in WEP or overboost?

[Guppy]

Originally posted by Vermillion
Quite frankly, I would be suprised if any of the prop driven aircraft used by the North Koreans, were aicraft in peak condition and maintenance.

These were used up rejects sent to bolster what was to them, a third world country.

Don't forget that the pilots flying them would most likely be worse than second-rate. From my readings, I get the impression that the average North Korean MiG-15 pilot was pretty mediocre; how much worse would be the crews assigned to less modern aircraft?

[Puke]

From my readings, I get the impression that the average North Korean MiG-15 pilot was pretty mediocre; how much worse would be the crews assigned to less modern aircraft?

A lot of them were USSR or Chinese pilots which is becoming common knowledge now-days.  In fact, the Soviets were told they cannot bail anywhere near Allied lines for fear of being found out.

[-ammo-]

well this thread took an abrupt detour:D

as far as the Korean War. In reading Gabreski's book, he stated that on one occasion a  N Korean fighter pilot bailed from his downed fighter and a member of the 4th FG in the area buzzed the guy in the chute. He was pale skinned, red haired, and very angry:)  Didnt look orienetal in the least.

[Soulyss]

WEP is use of water/meathonal to keep cylinder head tempetures down at higher MAP

Just a point of contention ( ) WEP in AH is not always the use of a water/methanol injection system.  None of the production P-51's in WW2 had a water/methanol system according to America's Hundred Thousand.  At least in the -51 WEP seems to model a combat power setting on the throttle that is a step above military power and that's why I imagine that P-51 runs out of WEP so quickly, it's because of the lack of water injection to help cool the engine.

[F4UDOA]

Soulyss,

I didn't mean it was water and methonal. I meant water or methonal. And the P-51 did have a water tank for WEP. It was for cooling so the engine so it could be temorarily overboosted without overheating. Once the water ran out the engine would overheat rapidly hence the 5 minute limit. Some A/C had larger water tanks and had longer WEP time. Like the P-47 had a very large water tank. The F6F had 10 minutes worth and the F4U-1D had 8.5 minutes. Of course AH only gives you 5 minutes in the game. The German A/C used combinations of water and methonal I believe. I am no expert on German A/C for sure. However they are given far more WEP time in AH.

However it should be said that most American aircraft could be overboosted by the pilot at his own risk because of the manual blower controls. I know the FW190A series had automatic controls and would not allow the pilot to do this.

[HoHun]

Hi Guppy,

>I didn't keep a copy of the link, but a translation of a German test of an La-5 (Rechlin Test Centre, Test No. 90014) was posted to allaboutwarfare.com's forums a while back.

I'm afraid that the La-5 in queston had an unrecognized engine problem. The test pilot Hans-Werner Lerche mentions elsewhere in his book (which has the report in the annex - unfortunately, the rest of Lerche's reports didn't survive the war!) that operational Luftwaffe pilots did believe that Rechlin had faked the numbers to make the German fighters look better.

Lerche considered his tests to be thorough and accurate, but one more indication for an engine problem was that he almost suffered carbon monoxyde poisoning in that La-5. That hints at problems with the exhaust system, which can have quite a negative effect on performance.

Lerche had to fly with oxygen mask as a result, but noticed that the original Soviet system fitted to the La-5 obviously had never been used. This might indicate that the exhaust leak had only occurred after the capture.

In short, I think Rechlin tests were generally realiable, but occasionally failed to give realistic results. Testing captured equipment is not easy, and I think all major air forces failed to get the best from a prize aircraft occasionally.

Regards,

Henning (HoHun)

[niklas]

just a question, has anyone seen so far an original flight test report of ´44/45 backing up those 380mph sealevel speeds for La-7?

[Puke]

Ammo, similar stories abound from pilots.  My interest is the Vietnam War and not WW2, but in my readings I do come across some Korean War stuff and it seems to me that lately the Russian military is admitting more and more to having flown for the North Koreans during that war.  There has also been some talk of UN pilots shot down in Korea having been seen in the USSR but never returned after the armistice.  That's probably common in all wars though.  In fact, this even goes for one USN pilot from the Desert Storm war.

(To get us back on topic...)  The P-51B is a beautiful bird.  But between it and the LA7 and TA, the 51B seems to me to be the least lethal.  It's still a good weapon and very deadly in capable hands though.  Also, the last time I flew I got into chasing a 51D around and he seemed to out accelerate my 51B (or maybe he just outflew me since I'm still getting used to the Mustang.)

[Pongo]

Originally posted by HoHun

Lerche had to fly with oxygen mask as a result, but noticed that the original Soviet system fitted to the La-5 obviously had never been used. This might indicate that the exhaust leak had only occurred after the capture.

)

more likely it was because the soviets flew with open cockpits to make up for poor venting in the cockpit and lack of trust in being able to get the canopy open in case of an emergency.
The venting in the La7 was even worse then the la5-fn. they had removed some to increase speed.

"At maximum power the cockpit tempreture rose to 104 f even when operating in the bitter cold of the russian windet. the tempereture rise was casued by the elimination of the cockpit air inlets and poor thermal insulation between the cockpit and the engine bay. The situation was worsend by the hot oil liines running between the oil cooler and the engine and passing directly beneath the pilots feet. Additionally, poor internal sealing allowed exhaust gases to enter  the cockpit. The lack of proper venilation also increased  the condensation in the cockpit."
thats from the La in action book.
I have read Czeck preports on the LA7 that basically confirm all those points. The planes were often flown with cockpits open..

The Germans did not have a plane with a mystery engine problem..they had a typical production quality La5...they didnt perform anything like thier prototypes.

[funkedup]

WEP and Overboost are not the same thing as modeled in AH. WEP is use of water/meathonal to keep cylinder head tempetures down at higher MAP.

Overboost IMHO is the use of higher octane fuels to sustain higher MAP ala the V-1 chasers using 150octane or the F4U-4/P-47M using 150octane because thay had R2800C engines that could handle sustained higher temps.

Whether we are talking about aviation terminology or AH terminology, WEP does NOT always imply injection of anything special like water/methanol.  It's just an emergency power setting that allows increased performance for a brief period.

Overboost just means you are running more boost than normally permitted.  You don't need fancy fuel to do this if you are willing to sacrifice long term durability and overhaul intervals.  Hence the short time limits.

I didn't mean it was water and methonal. I meant water or methonal.

AFAIK no production aircraft in WW2 used pure methanol injection.  ADI (anti detonant injection) aka Water Injection aka MW 50 was used.  The primary ingredient was water.  Methanol was only added to lower the freezing point of the solution so that it would remain liquid even after flight at high altitudes or in very cold weather.

And the P-51 did have a water tank for WEP. It was for cooling so the engine so it could be temorarily overboosted without overheating.  Once the water ran out the engine would overheat rapidly hence the 5 minute limit.

That's false.  The only production P-51 with ADI was the P-51H.  Get the manuals for the P-51D (they are available through many online shops or just read AHT to enlighten yourself.

However it should be said that most American aircraft could be overboosted by the pilot at his own risk because of the manual blower controls. I know the FW190A series had automatic controls and would not allow the pilot to do this.

The part about the Fw 190A is false.  The Fw 190A-8 had a boost control override system.  And earlier A models (A-3 through A-7) had an emergency power setting (which increased boost and RPM) that could only be sustained for a few minutes.

Nothing personal F4UDOA, I just don't want people to get bad information.

[-ammo-]

F4UDOA will be very interested in this, if he hasnt already see this. This website has several detailed reports of tests of several navy birds. I was turned on to this information on a newsgroup by someone else.  I appreciate it  Guy if you are reading this.

some more information in regards to the orginal subject, the P-51B true top speed.  Pllease review this report of a comparison between a P-51B and a F4U-1A.  From what I understand. The pony's were both slightly modified from production condition. The racks were removed and some sanding of the wings was accomplished. Additionally, the F4U was modified to some extent. Details in the report.



As you can see, this test shows a 450 MPH pony.  Also it is quite revealing in the regards to the relative performance difference between the pony and the corsair, wit the evauator s giving the f4U the nod as the better AC below 25K.

report http://www.geocities.com/slakergmb/id95.htm

[Wilbus]

Can't believe it! The discussion is still civil and calm and organized!

Ok, sure, it's organized about the La7 now instaed of the Ta152 and P51 B but hey, gotto make some sacrifices

All!