The three fastest bombers of WWII
- Thread starter Vincenzo
- Start date
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AVRoe
Airman 1st Class
What about the
Arado Ar 234 Blitz
Top Speed: 461 mph
Weapons: Rear-firing 20mm cannons; 2,000lbs of bombs
Arado Ar 234 Blitz
Top Speed: 461 mph
Weapons: Rear-firing 20mm cannons; 2,000lbs of bombs
- Thread starter
- #3
Thorlifter
Captain
The B-29 and A-26 were faster than the Do-217M, but only slight.
- Thread starter
- #6
B-17engineer
Colonel
For me there's the A-20, the Mosquito, and ahhhhhhhhhhh,,,,,,, Do-217
The He-177 was a disaster with wings, although it was the closest Germany came to a strategic bomber, it suffered from structural failure in flight.
The He-177 was a disaster with wings, although it was the closest Germany came to a strategic bomber, it suffered from structural failure in flight.
Hi Thorlifter,
>The B-29 and A-26 were faster than the Do-217M, but only slight.
I was surprised to learn that the B-29 still holds a great number of FAI records, including:
Group 1 : piston engine
Speed over a closed circuit of 1 000 km with 1 000 kg payload : 660.53 km/h
Fédération Aéronautique Internationale (FAI) - General Aviation World Records
Now I guess that was probably not achieved in normal service trim, but still very impressive!
Regards,
Henning (HoHun)
>The B-29 and A-26 were faster than the Do-217M, but only slight.
I was surprised to learn that the B-29 still holds a great number of FAI records, including:
Group 1 : piston engine
Speed over a closed circuit of 1 000 km with 1 000 kg payload : 660.53 km/h
Fédération Aéronautique Internationale (FAI) - General Aviation World Records
Now I guess that was probably not achieved in normal service trim, but still very impressive!
Regards,
Henning (HoHun)
It seems you are a little wrong. It initially suffered from burning engines because of a very tight installation. That was solved at least with the A-5.
- Thread starter
- #10
Hi Vincenzo,
>the fai record (1000 km with 1000 kg) is clearly a error in the site.
Hm, why do you think so?
The B-29 airplane commander manual provides a cruise chart that shows a top speed of about 610 km/h TAS at 9 km, at 40800 kg weight, with the cowl flaps in mid-position, at maximum power.
Removing the turrets, cutting weight down to a minimum and flying at a higher altitude you should realistically be able to achieve a higher speed, especially if the post-war engines could be run at higher ratings (and if you'd be ready to tear them down for inspection and overhaul after the flight).
Regards,
Henning (HoHun)
>the fai record (1000 km with 1000 kg) is clearly a error in the site.
Hm, why do you think so?
The B-29 airplane commander manual provides a cruise chart that shows a top speed of about 610 km/h TAS at 9 km, at 40800 kg weight, with the cowl flaps in mid-position, at maximum power.
Removing the turrets, cutting weight down to a minimum and flying at a higher altitude you should realistically be able to achieve a higher speed, especially if the post-war engines could be run at higher ratings (and if you'd be ready to tear them down for inspection and overhaul after the flight).
Regards,
Henning (HoHun)
FLYBOYJ
"THE GREAT GAZOO"
It's not an error.
There are many records still on the books from the 1930s and 40s.
Only if you exceeded CHT or red line RPM for a specified period of time.
Hi Flyboyj,
>Only if you exceeded CHT or red line RPM for a specified period of time.
Hm, I think the only limit they'd have to exceed would be the standard time limit ... have a look at the chart yourself:
http://www.ww2aircraft.net/forum/aviation/mission-moscow-hypothetics-8720.html#post262133
Cylinder head temperature would be regulated by cowl flap opening, which would have an impact on speed, but power of the turbo-supercharged engines was regulated by boost.
I wouldn't be surprised if the post-war R-3350 engines could run much higher boost pressures than the war-time engines at the same (maximum) rpm. At least that's the way R-2800 power was increased ... I don't know the details of R-3350 history.
The maximum rpm on that chart is 2600 rpm, by the way, while from a quick look into the manual the redline seems to be 2700 rpm.
Note that even the retracted radar dome subtracts 10 km/h from the top speed ... remove the two top turrets and the bottom turret, and you can expect a 30 km/h speed increase (very roughly).
The chart also is useful for estimating the impact of reduced weight - 20000 lbs weight less are equivalent to a reduction of power required by 200 HP per engine at 30000 ft. More if you are higher ...
Regards,
Henning (HoHun)
>Only if you exceeded CHT or red line RPM for a specified period of time.
Hm, I think the only limit they'd have to exceed would be the standard time limit ... have a look at the chart yourself:
http://www.ww2aircraft.net/forum/aviation/mission-moscow-hypothetics-8720.html#post262133
Cylinder head temperature would be regulated by cowl flap opening, which would have an impact on speed, but power of the turbo-supercharged engines was regulated by boost.
I wouldn't be surprised if the post-war R-3350 engines could run much higher boost pressures than the war-time engines at the same (maximum) rpm. At least that's the way R-2800 power was increased ... I don't know the details of R-3350 history.
The maximum rpm on that chart is 2600 rpm, by the way, while from a quick look into the manual the redline seems to be 2700 rpm.
Note that even the retracted radar dome subtracts 10 km/h from the top speed ... remove the two top turrets and the bottom turret, and you can expect a 30 km/h speed increase (very roughly).
The chart also is useful for estimating the impact of reduced weight - 20000 lbs weight less are equivalent to a reduction of power required by 200 HP per engine at 30000 ft. More if you are higher ...
Regards,
Henning (HoHun)
FLYBOYJ
"THE GREAT GAZOO"
Didn't see any chart - but remember if it's a chart from the POH it may be different from what the engine maintenance manuals states - a very common practice to keep pilots from pushing the limits. Exceedance on CHT and engine RPM is a definite cause for overhaul.
CHT is also controlled with mixture.
They have - here's the TCDS for the civilian 3350
TCDS E-272 Rev 9 Curtiss-Wright/Marquette, Inc.
Hi Flyboyj,
>Didn't see any chart
None at all? The URL I provided links directly to a specific post with a rather large chart. It's in post #31 in that thread if you'd like to locate it manually.
>but remember if it's a chart from the POH it may be different from what the engine maintenance manuals states - a very common practice to keep pilots from pushing the limits.
All the more reason to consider the FAI record possible
>CHT is also controlled with mixture.
Good point - the increased fuel use might be another reason that they didn't use this power level for the long distance records!
>They have - here's the TCDS for the civilian 3350
Highly interesting, thanks! But these are tubo-compound engines, I don't believe that's what they used in the record-breaking B-29.
Here is an interesting overview:
http://www.enginehistory.org/Wright/CWafter1930_2.pdf
On page 13 of the PDF, there is a minor subtype listed with only 8 engines produced for use in the B-29 in 1946: The R-3350-65 with 2500 HP @ 2800 rpm take-off rating. As the records were set in 1946, I wonder if these were the engines used for it ... the FAI page lists the basic R-3350-23, though. I think they accepted the record breakers' statements with regard to the hardware, though (as the Soviet records show
Regards,
Henning (HoHun)
>Didn't see any chart
None at all? The URL I provided links directly to a specific post with a rather large chart. It's in post #31 in that thread if you'd like to locate it manually.
>but remember if it's a chart from the POH it may be different from what the engine maintenance manuals states - a very common practice to keep pilots from pushing the limits.
All the more reason to consider the FAI record possible
>CHT is also controlled with mixture.
Good point - the increased fuel use might be another reason that they didn't use this power level for the long distance records!
>They have - here's the TCDS for the civilian 3350
Highly interesting, thanks! But these are tubo-compound engines, I don't believe that's what they used in the record-breaking B-29.
Here is an interesting overview:
http://www.enginehistory.org/Wright/CWafter1930_2.pdf
On page 13 of the PDF, there is a minor subtype listed with only 8 engines produced for use in the B-29 in 1946: The R-3350-65 with 2500 HP @ 2800 rpm take-off rating. As the records were set in 1946, I wonder if these were the engines used for it ... the FAI page lists the basic R-3350-23, though. I think they accepted the record breakers' statements with regard to the hardware, though (as the Soviet records show
Regards,
Henning (HoHun)
FLYBOYJ
"THE GREAT GAZOO"
I don't things have changed much since the B-29 record flight and flight done in later years but I could almost guess that any record event wasn't done at the expense of destroying engines. My father in law was involved in several world record flights and after those flights the aircraft were delivered to operational units.
- Thread starter
- #17
is a wrong first the b 29 wasn't a bi engine
second is very strange that a large plane like b29 can run with 5 tons payload same distance at only 595 km/h, or run 2000 km with 2 tons a 588 km/h (and with 1 ton same speed) can run 1000 km with 1 ton a 661 km/h.
I never read that b 29 run at 610 km/h, common is a max speed slighty over 570 km/h
second is very strange that a large plane like b29 can run with 5 tons payload same distance at only 595 km/h, or run 2000 km with 2 tons a 588 km/h (and with 1 ton same speed) can run 1000 km with 1 ton a 661 km/h.
I never read that b 29 run at 610 km/h, common is a max speed slighty over 570 km/h
FLYBOYJ
"THE GREAT GAZOO"
On page 13 of the PDF, there is a minor subtype listed with only 8 engines produced for use in the B-29 in 1946: The R-3350-65 with 2500 HP @ 2800 rpm take-off rating. As the records were set in 1946, I wonder if these were the engines used for it ... the FAI page lists the basic R-3350-23, though. I think they accepted the record breakers' statements with regard to the hardware, though (as the Soviet records show
Regards,
Henning (HoHun)
Hard to say - those engines being delivered might be the completion of a contract order - unless we could get the S/Ns and trace them to specific airframes, its any one's guess.
Hi Flyboyj,
>I don't things have changed much since the B-29 record flight and flight done in later years but I could almost guess that any record event wasn't done at the expense of destroying engines.
Oh, I don't think that they were destroyed - just torn down and thoroughly inspected afterwards, like normal service engines which had accumulated a certain time at emergency power settings were, too. The only difference would be that the record engines accumulated that time on a single occasion.
(For the Rolls-Royce Merlin, the operational five minute limit was simply disregarded during time-to-altitude climb tests. Of course, the Merlin was liquid cooled - I don't know if air-cooled radials would take that as easily.)
Regards,
Henning (HoHun)
>I don't things have changed much since the B-29 record flight and flight done in later years but I could almost guess that any record event wasn't done at the expense of destroying engines.
Oh, I don't think that they were destroyed - just torn down and thoroughly inspected afterwards, like normal service engines which had accumulated a certain time at emergency power settings were, too. The only difference would be that the record engines accumulated that time on a single occasion.
(For the Rolls-Royce Merlin, the operational five minute limit was simply disregarded during time-to-altitude climb tests. Of course, the Merlin was liquid cooled - I don't know if air-cooled radials would take that as easily.)
Regards,
Henning (HoHun)
FLYBOYJ
"THE GREAT GAZOO"
That's what I meant - I don't think anyone would want to push these engines into a overhaul, especially if they were brand new. If they met operating parameters and held compression I would think they kept right on using them.
I think the larger radials would be way more durable....
