F6F-5 sans Water Injection

[Shuckins]

I have in my possession (somewhere) a short history of the development of the F6F Hellcat series.  In it there is a beautiful cutaway illustration of the Pratt and Whitney R2800-10W engine that powered the F6F-5.  According to the author, the water injection units were usually removed in the field to save weight and eliminate one maintenance headache.

That raises a number of interesting questions, if true:

1.  Does this imply that Hellcat pilots were more interested in squeezing every last ounce of maneuverability out of their aircraft rather than every last knot of speed?

2.  Were these water-injection units really that troublesome to service?

3.  How badly would the removal of these units have affected the Hellcat's top speed?

4.  Could this be the source of some of the anemic top-speed figures posted by some authors of similar developmental histories for this 2000 hp fighter?

Have any of you other posters ever run across a similar statement in any of your sources on the F6F series?

Curious, Shuckins

[F4UDOA]

Shuckins,

I have never heard that before.

Where did you read this?

It does show the somewhat unrealistic aproach of flight simms using water injection almost as part of regular engine management instead of a last ditch effort.

[Arlo]

F4UDOA ... you appear to be a VF-17 fan. Are you affiliated with a squad? I hear VF-17 is actively recruiting.

[HoHun]

Hi Shuckins,

>2.  Were these water-injection units really that troublesome to service?

The German experience with MW50 which is basically the same as "water injection" was that it quickly wore out the spark plugs. The rest of the engine seems not to have been affected adversely.

It could be interesting to find how out difficult it was to replace the spark plugs of the R-2800. If it took much more time for this  big radial than for an inverted vee as used by the Luftwaffe, this might be the answer.

>3.  How badly would the removal of these units have affected the Hellcat's top speed?

Maybe this site has the answer:

http://www.history.navy.mil/branches/hist-ac/fighter.htm

Regards,

Henning (HoHun)

[SKurj]

mebbe I have the same book, but a book I have also says the water injection was removed to save some weight in F6's.


SKurj

[F4UDOA]

What book??

Arlo,

I am a fan Naval and Marine aviation in a big way.

However I have been with Ripsnort and the 323 Death Rattlers for a while. Thanks for asking

[joeblogs]

I'll check there when I get home.  

Recall the F6f-5 was comfortably faster than its opposition so speed did not matter.  It was not carrying 2,000lbs of bombs so it WEP wasn't needed for take-off.

When speed did become essential with th ekamikazi threat, USN substituted the corsair.

-Blogs

Originally posted by F4UDOA
What book??

Arlo,

I am a fan Naval and Marine aviation in a big way.

However I have been with Ripsnort and the 323 Death Rattlers for a while. Thanks for asking

[Montezuma]

Originally posted by SKurj
mebbe I have the same book, but a book I have also says the water injection was removed to save some weight in F6's.

SKurj

'Aces Against Japan' by Eric Hammel has at least one story where pilots say they used water injection during fights in the hellcat.

[SKurj]

Great Book of WWII Airplanes, big silver one.

It also mentions F6 pilots lowering their gear for divebombing.  The gear would not lock down at speeds over 130mph I believe, so it just added more drag.


SKurj

[Shuckins]

The wife has been rearranging the house so I'm having trouble finding the book...lol!  But the statement is in it.

I can only assume that against the opponents that Hellcat pilots faced in 1943 and 1944 the 10 to 15 mph of extra speed that the WEP units delivered weren't really worth the extra 500 to 600 pounds of weight they added to the F6F's airframe.  The empty weight of the -5 Hellcat was 9153 pounds.  Subtract 500 pounds from that weight when the water-injection system was deleted and the empty weight dropped to about 8600 pounds.

According to Corky Meyer, a factory-fresh F6F-5 with wep had a top speed of 409 mph at 20,000 feet.  Tests conducted by NAS Patuxent River which compared the performance of the -5 against a Zero 52 corroborated Meyer's figures, giving a top speed only 4 mph slower than the F4U-1D at their rated altitudes of 20,000 feet.  That top speed was 74mph faster than the Zeke's best top speed of 335mph at 18,000 feet.

So the extra performance of the water-injection unit may have seemed superfluous to the Navy pilots who flew the Hellcat.  The lighter Hellcat, sans water-injection, would have been more maneuverable at all speeds.  And maneuverability would have definitely been appreciated by any Navy pilot caught low and slow against lighter Japanese opponents.

Regards, Shuckins

[Arlo]

Ahhh ... no prob. Ripsnort's group, eh? Yeah, good group. Ripsnort's a good guy. I used to fly with VF-17 in AW (before the Groverats) and later with WB (short tour ... I was the only one flyin' 2.77). I'm back flyin' with the GRs (though we don't seem to be flyin' together much online right now. I saw Reschke promoting the Jolly Rogers here and I when I saw your tag, I figured wth. Did you use to fly AW or WB ... the handle sounds damned familiar.

Originally posted by F4UDOA
What book??

Arlo,

I am a fan Naval and Marine aviation in a big way.

However I have been with Ripsnort and the 323 Death Rattlers for a while. Thanks for asking

[F4UDOA]

Shuckins,

I did some looking into the weight of the F6F water injection system and it doesn't really seem viable for pilots to have removed it for the purpose of maneuvering because it just isn't that heavy.

From "America's Hundred Thousand"

F6F-3 (Pre water)
Empty weight = 8,951.1lbs


F6F-5(with water)
Empty Weight= 9078.8LBS
Weight from the water injection system= 41.5LBS

F6F-5
Fully loaded weight= 12,482.7LBS
Weight from just water in water injection= 119.4LBS

So that is 161.9LBS for water injection+water. Seems like more of a benifit than extra weight?

I tried to verify the weight of the water injection system against the P-47 and F4U but it doesn't list the weights of the water systems as it does the F6F.

Do you have the full report of the A6M5 vrs F4U-1D and F6F-5? I only have the summary in the "Zero Warbird History".

FYI, I just received a copy of the original AAF report of the A6M2 vrs all AAF fighters and F4F-4 and F4U-1.


Arlo,

Yup, I go back to AW2 and AW3. I was just DOA back then. When I came to AH in Jan.99 I could only get F4UDOA. In AW I was with the 1st NASTY for a while when BOER was CO.

[Shuckins]

F4UDOA,

Sorry, but Zero Warbird History is my source for that report as well.  I saw it reprinted years ago in an old copy of Wings magazine.

You obviously have a lot more information at your fingertips than I do.  I remembered that the GM-1 unit of the ME-109G weighed over 400 pounds.  I just assumed that the water-injection system of the Hellcat was similar in weight.  I'll keep digging for that other book.  Maybe it will lead me to other sources for that quote about the removal of the wep units.

By the by, that NAS report in the Zero Warbird History contains a fascinating comparison of the Zeke 52 and the FM-2.  it states that the turn rates of the two were very similar;  the Zero could gain one turn in eight at 10,000 feet.  I wonder how accurately AH has modeled THAT!?

Regards, Shuckins

[Arlo]

1st Nasty! Boer! Know `em well! You were DOA, huh? Slats flew VF-17 when I first joined up. We used to wing up with 1st Nasty every opportunity we got.

Good2cu

Originally posted by F4UDOA


Arlo,

Yup, I go back to AW2 and AW3. I was just DOA back then. When I came to AH in Jan.99 I could only get F4UDOA. In AW I was with the 1st NASTY for a while when BOER was CO.

[F4UDOA]

Hehe Arlo,

Those were the days. I saw some old sceen shots recently and I can't believe how different it looks. I was on the NASTY email list until they killed AW. They moved to AH you know but I don't recognize anyone.

Shuckins,

It is so hard to find some of these docs. I know someones got them. I feel like agent Molder in the X files. The truth is out there!!