Maneuverability vs Speed (1 Viewer)

[GrauGeist]

Read a memoir of a B-25 pilot in the Aleutians, who was taxiing in fog so thick he couldn't see his wingtips. He got to the end of the runway, waiting for the mission to be scrubbed. As he sat there the tower cleared him for takeoff. He was so overcome with fear, he couldn't lift his arm to reach the throttles. After several minutes the tower finally cancelled the mission.
He was no coward, flying many missions against Attu and Kiska, and even a few against the Kurile Islands.

Some of the stories our friend shared about his experiences with the B-24 were incredible.
He mentioned that he'd rather face the Flak and Fighters over the assembly process any time.

For example, on one such occasion, he was climbing through thick overcast and he could clearly hear another B-24's engines over his. He and his co-pilot were looking out the windows to see where it was coming from when the engineer yelled "sonofabitch, look up!!" to which they did and there was a ball turret just above them appearing out of the murk.

 

[SaparotRob]

Yikes!

 

[pbehn]

Yikes!

During the war there were 5 airfields within 15 miles of where I live, Catterick and Greatham (fighters) Middleton and Croft (bombers) and Thornaby (coastal command). I went to a wedding at Catterick, my place of work was built on Greatham, Middleton is still my local airport, my wife gets her hair cut on what was Thornaby and this is me making the only proper use of an old airfield, RAF Croft. (orang jacket means its one of my first 10 races)

 

[SaparotRob]

During the war there were 5 airfields within 15 miles of where I live, Catterick and Greatham (fighters) Middleton and Croft (bombers) and Thornaby (coastal command). I went to a wedding at Catterick, my place of work was built on Greatham, Middleton is still my local airport, my wife gets her hair cut on what was Thornaby and this is me making the only proper use of an old airfield, RAF Croft. (orang jacket means its one of my first 10 races)
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I awarded you a bacon in case you didn't win that race.

 

[pbehn]

I awarded you a bacon in case you didn't win that race.

Oh I deffo didnt win the race because I never won at Croft. Last race of the season before it shut for about 10 years I got a second place, one guy made a hail Mary last ditch move and fell off, moving me up from third to second.

 

[Reluctant Poster]

Bomber engine fires from one of my previous posts

 

[GregP]

Let's look at Reluctant Poster's last post about bomber engine fires. He posted that, for the 3rd quarter of 1944, there were 8 B-29 engine fires per 100,000 hours of flying time. For Dec 1944, there were 14 per 100,000 hours and for the 1st 20 days of 1945, there were 27 per 100,000 flying hours. Note, those are not number of engine fires, they are engine fire rates.

In the Statistical Digest of World War Two, it shows that, for the third quarter (Jul, Aug, Sep) of 1944, B-29s flew a total of 29,368 hours. An engine fire rate of 8 per 100,000 hours means they experienced 2.35 engine fires. I'm estimating they didn't have all the numbers and really experienced 2 engine fires in those 29,368 hours.

In Dec 44, B-29s flew 13,119 hours at an engine fire rate if 14 per 100,000 hours, meaning they actually experienced a total of 1.8 engine fires. I'll round up and estimate two.

For the first 20 days of 1945, I don't have correct data. But I have data for the entire month of Jan 45. B-29s flew 17,734 hours in Jan 45. Usage was WAY up from the other two above. The rate was 27 fires per 100,000 hours, so they experienced 4.78 engine fires in Jan 45. I'll estimate 5.

That's a grand total of 9 engine fires in 60,221 flying hours in a 4-engine bomber that was under some pressure to sortie day after day. I doubt if the cowlings were exactly clean of oil. During the total 3rd quarter 1944, Dec 44, and Jan 45, B-29s flew a total of 2,444 sorties with 4 engines each, so they operated 9,776 engines and experienced 9 engine fires. Looking at sorties (2,444) that is .003682%, or 1 engine fire every 99.6 sorties out of 100 sorties.

That ain't bad at all for a piston engine in combat. Also, we have no idea how many of the 9 engine fires were caused by combat damage to oil lines. All we have is the number of engine fires from all causes.

These engines may not have been exactly great during the war, but their engine fire rate was not too bad.

 

[rochie]

During the war there were 5 airfields within 15 miles of where I live, Catterick and Greatham (fighters) Middleton and Croft (bombers) and Thornaby (coastal command). I went to a wedding at Catterick, my place of work was built on Greatham, Middleton is still my local airport, my wife gets her hair cut on what was Thornaby and this is me making the only proper use of an old airfield, RAF Croft. (orang jacket means its one of my first 10 races)
View attachment 724376

nice picture.
remember going to a bike race at Snetterton with a family member, he was riding a bright orange laverda 1000 or 1100 i think, !

 

[pbehn]

nice picture.
remember going to a bike race at Snetterton with a family member, he was riding a bright orange laverda 1000 or 1100 i think, !

I raced against a Jota 1000 at Croft, a guy called Bob Carney in his first race, I beat him in his first race but never again, when you are right up close you can see what a handful they are, big, heavy and powerful and you cant get racing tyres for them, exactly the opposite of my X7 (250 Suzuki). I loved Snetterton, won three races in a day there, but had a massive first lap "off" at the end of the back straight.

 

[drgondog]

No disrespect to your dad, who I'm sure was a far greater man than I, I just think conditions in some of the more remote Theaters of operations were a bit more harsh than England, were harder to get supplied, and this was reflected in maintenance issues per the original branching out of this particular subject.

Apologies to the board of course for mentioning "the aircraft that shall not be named"

No apologies - he never complained about ETO 'conditions' save that he was cold most of the time. Easier to heat than cool off - making the tropics tougher comfort wise and having shelter and tolerable consistentliving conditions close to places likeCambrige and London were incomparable anywhere else. Environmental Conditions at 25,000 feet were far worse than 15-20K in Pacific and CBI but near comparable in Aleutians. T-Storms about the same, icing worse (save Aleutians).

Ah, but the flak and fighters were always 'there' from time the Channel was crossed, all the way in - and all the way out, so the enemy threat threshold was higher in the ETO.

 

[drgondog]

Bomber engine fires from one of my previous posts
View attachment 724385

I haven't checked but speculate that when LeMay took them 'down' at night in March that engine failures went much lower?

 

[Reluctant Poster]

I haven't checked but speculate that when LeMay took them 'down' at night in March that engine failures went much lower?

The mechanical failure rate did drop in March but before that the B-29 record was very poor with the power plant accounting for almost 1/2 the failures. Also I was surprised to see that the 8th AF B-17s and B-24s had such a high mechanical failure rate.

I have attached the reports the excerpts are from.

 

[Wild_Bill_Kelso]

19% definitely seems like a lot

 

[GregP]

The R-3350 didn't start off very well, but it turned out to be reliable in airline service post-war.

It would be interesting to know what the WWII-era issues were. If you listen to the old flight engineers, they say the WWII pilots just didn't know how to run an engine correctly. Even today, big the R-3350 does NOT like to be over-revved and, if you do rev it higher, it can throw a scrap-iron fit. That said, it's more tolerant of over-revs than the Bristol Centaurus is, The Sanders people at Reno went from an R-3350 to an R-2800 for the Sea Fury Argonaut in order to reduce blown R-*3350 radials.

The old flight engineers point out that the last thing a big radial needs is to be throttle-jockeyed while taxying and ground maneuvering. They like to run at a constant rpm and not be accelerated except slowly and smoothly. When decelerating, you take off maybe 2 inches of MAP at a time and slow it down while keeping it warm. With tha in mind, I wonder how many R-350s were destroyed by guys who just didn't know or care how they ran the engine. Might be tough information to dig out, but maybe not.

I've seen very similar things when people get checked out in a P-38. I watched that twice.. They get told the big checklist items but when they actually fly it, they forget to check temps and almost always leave the cowl flaps closed when they land, at least the first time or two. You have to call them on the radio to remind them to open the cowl flaps to avoid overheating the Allisons while taxying in to park. I heard the engines were at redline twice in 4 flights when parked. Doesn't mean I heard the truth; it just means that's what I heard.

It wouldn't surprise me at all to learn WWII B-29 pilots were a bit overwhelmed when operating a B-29 and while also having relatively low flight hours in it. It was and IS an impressive airplane, but could likely also be very intimidating to a new pilot and have a LOT of things going on simultaneously.

 

[Wild_Bill_Kelso]

For sure. P-38 too. They were training a lot of people to fly these planes as quickly as they could get them out to the field. They tried to cover everything they needed to know, but for sure in my relatively brief military experience, a lot of the actual learning was OJT.

 

[drgondog]

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The mechanical failure rate did drop in March but before that the B-29 record was very poor with the power plant accounting for almost 1/2 the failures. Also I was surprised to see that the 8th AF B-17s and B-24s had such a high mechanical failure rate.

I have attached the reports the excerpts are from.

why be surprised that climbing at max continous power for less than half the time to 25-30 - for B29s heading to downtown Tokyo at 10K - is less stressful for either engine. LeMay was really smart.

 

[Reluctant Poster]

why be surprised that climbing at max continous power for less than half the time to 25-30 - for B29s heading to downtown Tokyo at 10K - is less stressful for either engine. LeMay was really smart.

From the attached report

 

[Reluctant Poster]

View attachment 724690

From the attached report

Night bombing wasn't LeMay's idea. The switch in Sept 1944 from primarily night to exclusively day occured when Lemay took command of the 20th AF. According to Craven and Cates he implemented the tactics he had used in the ETO.

This data is for the 20th Bomber Command. For the 21st it is

Full report attached

 

[Simon Thomas]

It would be interesting to know what the WWII-era issues were. If you listen to the old flight engineers, they say the WWII pilots just didn't know how to run an engine correctly. Even today, big the R-3350 does NOT like to be over-revved and, if you do rev it higher, it can throw a scrap-iron fit. That said, it's more tolerant of over-revs than the Bristol Centaurus is, The Sanders people at Reno went from an R-3350 to an R-2800 for the Sea Fury Argonaut in order to reduce blown R-*3350 radials.

You have mentioned the Centaurus over-rev failures a number of times now. How many have you personally seen? Were they using the correct Shell oil?

 

[Spindash64]

The R-3350 didn't start off very well, but it turned out to be reliable in airline service post-war.

It would be interesting to know what the WWII-era issues were. If you listen to the old flight engineers, they say the WWII pilots just didn't know how to run an engine correctly. Even today, big the R-3350 does NOT like to be over-revved and, if you do rev it higher, it can throw a scrap-iron fit. That said, it's more tolerant of over-revs than the Bristol Centaurus is, The Sanders people at Reno went from an R-3350 to an R-2800 for the Sea Fury Argonaut in order to reduce blown R-*3350 radials.

The old flight engineers point out that the last thing a big radial needs is to be throttle-jockeyed while taxying and ground maneuvering. They like to run at a constant rpm and not be accelerated except slowly and smoothly. When decelerating, you take off maybe 2 inches of MAP at a time and slow it down while keeping it warm. With tha in mind, I wonder how many R-350s were destroyed by guys who just didn't know or care how they ran the engine. Might be tough information to dig out, but maybe not.

I've seen very similar things when people get checked out in a P-38. I watched that twice.. They get told the big checklist items but when they actually fly it, they forget to check temps and almost always leave the cowl flaps closed when they land, at least the first time or two. You have to call them on the radio to remind them to open the cowl flaps to avoid overheating the Allisons while taxying in to park. I heard the engines were at redline twice in 4 flights when parked. Doesn't mean I heard the truth; it just means that's what I heard.

It wouldn't surprise me at all to learn WWII B-29 pilots were a bit overwhelmed when operating a B-29 and while also having relatively low flight hours in it. It was and IS an impressive airplane, but could likely also be very intimidating to a new pilot and have a LOT of things going on simultaneously.

when you phrase it like that, it makes me wonder how many of the supposed issues with early turbojets were actually just issues with pilots that had even less training than normal, now needing to be patient with a new type of engine as bombers blow things up around them

...probably not that many of the issues: we're still talking about infancy turbojets in this case, after all. But I could definitely see pre-existing issues being aggravated by anxious pilots noticing their super fighter isn't accelerating as quickly as they think it should (due to the fact that reaction thrust has less propulsive power at low speeds), so they try and gun the engines to compensate, only to find that the Turbines REALLY do not appreciate that