#1 Jet of World War II

Subject: #1 Jet of World War II
From: nt (Gordon)
Date: 7/14/03 9:39 PM Pacific Daylight Time
Message-id:

That is a very interesting number. I can't help but compare it to the B-26
which got its best range at 180 IAS

I'd have to wonder, what was that "best range"? I was under the impression
that the Mosquito could fly several times as far as the B-26 with a full
4,000
pound bombload.

Take off the armor, take off the
guns and top turret and cut the crew to two and the B-26 may well have
outperformed the Mosquito by a large margin..

snip my own questions in reply to Art's

The way the USAAC operated planes that were unarmored and unarmed were of no
value.

Recce and Met Flights would be of at least some value, I'd hope. Same with
those legends of supply a/c.

We flew into flak in broad daylight and depended on armor and guns
for
defence.

A great strategy, too; no denying that the B-26 was exactly what the air
corps
needed in a medium bomber. The Mosquito did the same for the RAF, but used
its
speed in the same way you used your armor and guns. Price per unit was
pretty
good too.

And we carried 4,000 pounds of bombs every time.

I previously asked, how far? If a B-26 was tasked to fly from central England
to Berlin, what would its bomb load have been? I checked B26.com but
haven't
found what I am looking for, because I am really interested in how these two
machines stack up.

v/r
Gordon



We had an 1100 mile range fully loaded. What it would have been stripped of
armor with the guns and turret removed and the crew of 6 stripped down to a
crew or 2, I don't know, but I can well imagine that its range and cruising
speed would have been dramaticaly increased. But I sure wouldn't wanted to have
flown one into German flak in broad daylight. I guess our air generals felt
the same way. When they compared the Mosquito to the Marauder, they went with
the Marauder, And for that I sincerely thank them all.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

When they compared the Mosquito to the Marauder, they went with
the Marauder, And for that I sincerely thank them all.

yep, it was definitely just what the air corps needed, for its style of attack.

v/r
Gordon

In article ,
"Geoffrey Sinclair" writes:
Peter Stickney wrote in message ...

I just double checked, he numbers I gave are a bit muddied-up, too.
I've two Pilot's Handbooks for the Mosquito, one for the FB.6
(Fighter-Bomber) from 1950, and one for the various single-stage
Merlin Night Fighters, published in 1945. The numbers I quoted were
from the FB.6 handbook, and the NF.12 handbook is different. The NF.12
book lists best cruise as 220 mph IAS, which is nudging 330 TAS at
25,000'. and 360 TAS at 30,000'. It's possible that the FB.6 numbers
are for an airplane carrying external bombs and rockets, but it
doesn't say.

Sounds like the time to add the information from the book Mosquito
by Sharpe and Bowyer.

The FB6 used Merlin 21/22/23/25, the NF12 merlin 21/23.

True, but, in the case of long range cruise, irrelevant. The Merlin
XX/20 series were essentially identical in anything other than the
Combat Emergency (5 Minute) Ratings.
Merlin 21 & 23 were rated at 3000RPM/+14 in Low Blower, and
3000RPM/+14 in High Blower, corresponding to Horsepowers and altitudes
of 1460 HP at 6250' and 1435 HP at 11500', repectively. The Merlin 25
was rated for 3000RPM/+18 in both gears, giving 1640HP @ 2000', and
1550HP @ 9500'. Climb Power (2850 RPM/+9) and Continuous Power
(2650RPM/+7) ratings were the same for all angines. Well, with one
variation - Merlin 21s had a Max Lean Mixture power setting of 2650
RPM/+4, and the later engines had a Max Lean rating of 2650R/+7, due
to better carburation. In the case of cruise speeds, the particualr
engine mark is irrelevant. (And as far as the RAF was concerned, the
F.Mk II, NF. Mk XII/XIII, and NF Mk XVII were interchangable.

Appendix 8, performance of the B35 (merlin 114) versus the FB6
(merlin 25).

B35, 22,000 pounds, bomb load 1,500 pounds including 2 x 500
pounds bombs under the wings, 539 gallons of fuel, still air range
1,600 miles at 25,000 feet at 300 mph TAS, 1,250 miles at 37,000
feet at 375 mph TAS. Top speed 425 mph at 30,500 feet.

FB6 21,700 pounds, bomb load 1,500 pounds including 2 x 500
pounds bombs under the wings, 453 gallons of fuel, still air range
1,120 miles at sea level at 250 mph TAS, 960 miles at sea level
at 296 mph TAS. Top speed 378 mph at 13,200 feet.

The Merlin 72/73 or 76/77 versions (VII, IX and XIV) outward
recommended cruising speed 220 mph IAS, economic cruise
in clean condition was 295 mph TAS at 20,000 feet and 350
mph at 30,000+ feet, maximum continuous cruising, clean,
349 mph TAS at 20,000 feet, 378 mph TAS at 30,000 feet.

For the merlin 21/22/23/31 equipped versions maximum
continuous cruise was 341 mph TAS at 20,000 feet but this
fell to 329 mph at 25,000 feet, I assume in clean condition.
Again outward bound recommended cruise was 220 mph
IAS at around 25,000 feet.

The return flight recommendation was for around a 5% reduction
in cruise speed compared with outbound, 210 mph IAS.

As I explained in my other post in this thread tonight, the
differnence in Cruise True Airspeeds is due to the higher critical
altitudes of the two-stage (60, 70, and 100 series) engines. The
Cruise IAS stays the same.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

On Thu, 17 Jul 2003 00:04:08 -0400, (Peter
Stickney) wrote:

[snip]

Actually, engine power doesn't affect the speed for best cruise (L/D
Max) at all. Gavin, I don't know what you don't know, so bear with me
- I'm not trying to be patronizing, but I/m looking for a good way to
explain.

Thanks for the explanation: I freely admit to being a total ignoramus
when it comes to maths and engineering. However, I'm not sure we're
quite approaching the issue from the same angle. The instance I was
referring to was practically the same airframe between the Spitfire V
and IX (with some notable differences on the part of the IX, e.g.
marginally increased drag, increased weight, different propeller) with
a different engine, producing more power at precisely the same engine
settings and altitudes (rpm and boost) due to a different
supercharging regime *above the full throttle height of the engine*.
[Note hasty addition of qualifiers to mask the full extent of the
original ignorant assertions].

I appreciate that the airframe is a critical factor, but in the
instances I have in mind (the Spit V/IX and Mossie B.IV and IX) the
same airframes (or at least a close as it would be possible to get
with the two different engines - Merlin 20/45 variants vs. Merlin 60
variant - being used.

These latter aircraft, with almost identical airframes, had higher
speeds both at maximum and cruise, and I feel the only credible
explanation is the higher power being developed on the same engine
settings at the same (or similar) operational heights.

Note that, as far as the speed to fly is concerned, engine ratings
don't enter into it. Most reciprocating engines burn about the same
amount of fuel per horsepower (all other things, like mixture being
equal) no matter what.

Sure, but if you're flying at the same engine settings in a Spitfire V
and a Spitfire IX at the same altitude (above FTH for the M46), the IX
will go faster, even when the FS supercharger is almost identical
(Merlin 46 vs Merlin 61). The cruising regime was governed by engine
rpm and supercharger boost, and different engines produced different
outputs at different heights at the expense of differing fuel
consumption. In this case, I know this would be down to differences
in the height at which higher boost pressures could be maintained.

So the idea is to fly a particular Indicated
Airspeed that gives you the least drag.

Interesting. My (ignorant) assumptions were that the fundamental
basic factor was engine fuel consumption, with the airframe governing
exactly how fast the associated power output happened to take the
airframe concerned. For example, the Hurricane I and Spitfire I
attained different speeds with precisely the same engine, purely down
to airframe differences and weight. My point was that sticking a more
powerful engine in the same airframe increased speed all-round,
including cruising speed (albeit within the specific envelope where
the engine concerned actually *did* produce more power: in this case,
in the right altitude band). I appreciate the point you make in
another followup about IAS vs TAS, but I was originally after the TAS
cruising speed of the Mossie on operations. I should have been
specific about the height, but I assumed this would follow from the
operational profile of the relevant LNSF operations.

In the Mosquito B.35's case, Full Throttle Height for the
minumum fuel consumption power setting is 25,000'. For the Max
Continuous power setting, which is at a higher RPM setting than
minimum consumption, (and so therefore the supercharger compressors
can compress more,) it's at 37,000'. What it comes down to is a
long-winded way of saying that the higher range cruise speed of
2-stage supercharged Spitfires and Mosquitos over their lesser-lunged
brethren is due to the higher altiitudes that the engines can develop
the required power at, not that the engines develop more power.

I agree for the Mosquitos (not that my agreement is required for your
post to be entirely correct), but the Spit V/IX example is complicated
by the MS gear the Merlin 60's had. For my purposes, I was interested
at the cruising speed at operational height, which for most comparable
Mosquitos (e.g. those in the LNSF which fielded B.IVs and then B.IX
and XVIs on the same kind of operations) cruised above the FTH of the
Merlin 20's (so above the barometric governor), where attainable boost
level was falling away. I don't think the cruising speed of the
FB.VIs or NF. versions would be wildly different, bar the differences
in drag, due to the generally lower operating heights.

To return to my original assumption, I'm not bothered that the
increasing power *at altitude* was entirely due to the two-stage
supercharging above the level attainable from the single-stage
supercharger. What counted to me was the increased power output at
the same height (regardless of the source), and the assumptive link
between that and the higher cruising speed apparently attainable as a
consequence.

Another factor I just thought of would be the power being soaked up by
a second mechanical supercharger at lower heights, which would affect
the relative efficiency (well, it would do that at all heights, but I
presume the inefficiency concerned would be maximised at lower
atltitudes where the full supercharging wasn't required to reach the
maximum pressure permitted for full power. Another assumption...).

Where I think your information really comes into play for me is the
effect of supercharging below the FTH of the engine: for example, the
factors involved in the performance of the lower-altitude supercharger
peaks in the Merlin 66 (against the 61/63/64 variants). I presume
that the 66 simply passes the barometric limitations earlier in the
climb, allowing higher supercharging levels to be used sooner: but
based on what you've said, I assume this is only going to be relevant
for the highest output settings (cruising settings not involving high
rpm & high boost) where high levels of boost (e.g. +7 psi to +12 psi
or more) were attainable. Thus I'm not sure what advantage (if any)
the Merlin 66/266 variants actually had a lower altitude at engine
settings below the rich-mixture/high revs profiles. Based on what
you've been saying, I'd have to guess none: i.e. a Spit LF IX would
cruise at the same TAS as a Spit IX, although the IX would be able to
sustain +4 psi to a higher height for maximum continuous cruise. This
assumes that the 66 and 61 variants shared the same maximum boost
level, e.g. +15 psi.

Not to mention the deviation in FTH between different individual
engines of the same type... But I digress too far: neither that nor
the engine settings for maximum continuous climb were relevant to my
original post and your response.

Oh, yeah, one other thing that may seem counterintuitive. For a given
shape, (CdF, e, and AR being the same), the nest cruise speed for a
havier airplane will be faster than that for a lighter one. That's
becase more Lift needs to be generated, so Induced Drag is higher. It
still falls off quickly, which is why weight doesn't affect top speed
very much, but the point where the Profile Drag increse exceed teh
Induced Drag decrease is shifted a bit to the high-speed side of the
curve. That's why the "Out" speed for a laden airplane is 10 mph
higher than the return speed for one that's released its load, and
burned half its fuel.

That's interesting, and it does seem to contradict what little I know
abut the subject - I recall from log entries that Lancasters returning
from raids with Bomber Command cruised slightly faster than they did
on the way out on the same engine settings, although I suspect this
had something to do with the height operating band: they were
stuggling to make operating height on full load when this was over
20,000 feet.

On the other hand, I have seen log entries which give route timings
which can only be explained by atypically strong tail-winds, or more
likely the crew either cutting corners en route or increasing the revs
to get home quicker with a little polite fiction in the records for
when the squadron navigator leader became suspicious about their
marginally early returns. So I need to factor in the original context
before making some more characteristic sweeping assertions.

Thanks for the informative response meanwhile.

Gavin Bailey
--

"...this level of misinformation suggests some Americans may be
avoiding having an experience of cognitive dissonance."
- 'Poll shows errors in beliefs on Iraq, 9/11'
The Charlotte Observer, 20th June 2003

Subject: #1 Jet of World War II
From: John Halliwell
Date: 7/17/03 3:50 PM Pacific Daylight Time

All it needed was enough speed to hold a single seat
fighter at bay long enough for the latter to run out of fuel (having
already had to climb to altitude at full throttle). In this case, short
bursts of extra speed were significant.


Especially if there was a cloud nearby.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer

Hienze Knocke (sp?), however, demonstrated by his successful low-altitude
interception of a Mossie, that if the Mossie used stereotyped tactics once
too often, an experienced Luftwaffe pilot could, with the proper tactics and
positioning, exploit that lapse even while flying a standard, unmodified
aircraft.

....although I can't find a missing Mosquito for the claim made by Knoke, I
think its likely to some day be found that he either got the date wrong (as he
certainly did in other places of his book) or the Mosquito he claimed equates
to some other a/c type, or finally, it WAS a Mosquito, but from an
unconventional source (since it doesn't turn up as a loss from a normal
squadron).

Wise mossie pilots varied their flight profiles on a regular
basis.

Same is true of F-117 pilots.

I've read that the only German interceptor which reliably had a decent
chance at intercepting the Mossie was the Me-262, which had the speed
capability from level flight to run down a Mossie from behind.

I call that "Chapter 6". Two years ago, I was honored to host the first
postwar reunion for Kdo Welter, so I will have to agree with your view,
coincidentally shared by Galland and several others, like Speer and that
rat-fink Goebbels.

The Swallow's
good climb rate to altitude and even higher cruising speed made an
interception of a Mossie a less problematical affair, with the proviso that
an alert mossie crew could generally easily maneuver inside the Me's turning
circle long enough to locate cloud cover or to cause the Me to have to rtb
in consideration of fuel usage.

It was even more of a challenge under the stars.

v/r
Gordon
Stormbirds.com/recon
====(A+C====
USN SAR Aircrew

"Got anything on your radar, SENSO?"
"Nothing but my forehead, sir."

If I were a Luftwaffe Sector Controller, or the Sector Commander, my
nightmare would be a squadron or more of Mosquitos flying through my
sector spaced about 1 minute apart. Using hand plotting and voice
comms, my command an dcontrol system would be well & truly saturated.

Peter, for 36 nights in a row (Feb-Mar 45), the RAF sent forces of 20-120
Mosquito bombers to hit Berlin in a morale-crushing exhibition of the tactics
you present. As you predicted, the Grossgefechtstand at Doberitz was well and
truly saturated, managing only a handfull of successful interceptions
throughout this period. Perhaps the most successful was the March 27th
interception of Pathfinder Andre van Amsterdam and his nav, Harry Forbes by a
Kdo Welter Me 262 pilot - the B. XVI was destroyed directly over the command
station, with wreckage landing on the site. Even then, the Battle Opera Hourse
and the dedicated anti-Mosquito ILO could only give the interceptor jet pilot
vague directions until the Mossie blundered into his path. Mosquito
interceptions were absolutely the most frustrating propositions for the NJG
corps.

v/r
Gordon

On Thu, 17 Jul 2003 23:50:38 +0100, John Halliwell
wrote:

In article , Peter Stickney
writes
And just what is Max Speed for a bomber, anyway? 5 Minutes of War
Emergency Power doesn't make too much sense, or even 15 minutes at
Military Power. You can get some amazing numbers that way, that will
never show up in real life.

The Mossie used speed as a defence, and I believe it could accelerate
very quickly. All it needed was enough speed to hold a single seat
fighter at bay long enough for the latter to run out of fuel (having
already had to climb to altitude at full throttle). In this case, short
bursts of extra speed were significant.

--
John

Inasmuch as acceleration correlates closely with climb, I don't think
that the Mossie could out-accelerate any single engine Luftwaffe fighter
of the time.

Consider that the Bf-109G-10 could maintain a climb rate of nearly double that
of a Mosquito, you can be absolutely certain that the Mosquito would get chased
down very quickly should one bleed off its speed. Mossies needed to stay high
and fly at fast cruise speeds to avoid interception. Getting the Mosquito slow
was to get it dead.

As it was, most models were not especially fast when compared to the day
fighters of the time.

To veer off topic a bit....

I still shake my head in amazement when I hear the advocates of the Mossie as
a strategic bomber blubber on about how the Mosquito could have replaced
the American heavy bombers because they were fast enough to avoid
interception. Utter rubbish.

They seem to forget that it would take huge formations of Mosquitos to put
enough bombs on a target to match that delivered by the heavies. individual
Mossies could evade detection, evan small groups could be hard to locate.
But, hundreds of them would be easy to detect early in their flight. That meant
the Luftwaffe would be waiting high above them in strength. Without any
defensive or offensive guns whatsoever, the Mosquitos would be scattered and
very much chewed to pieces.

My regards,

Widewing (C.C. Jordan)
http://www.worldwar2aviation.com
http://www.netaces.org
http://www.hitechcreations.com

"Corey C. Jordan" wrote in message
snip
They seem to forget that it would take huge formations of Mosquitos to put
enough bombs on a target to match that delivered by the heavies.
individual
Mossies could evade detection, evan small groups could be hard to locate.
But, hundreds of them would be easy to detect early in their flight. That
meant
the Luftwaffe would be waiting high above them in strength. Without any
defensive or offensive guns whatsoever, the Mosquitos would be scattered
and
very much chewed to pieces.

Just as an aside, the Mossie could actually carry a bigger bomb load than
the B17. :-)

Subject: #1 Jet of World War II
From: (Corey C. Jordan)
Date: 7/18/03 5:55 PM Pacific Daylight Time
Message-id:


still shake my head in amazement when I hear the advocates of the Mossie as
a strategic bomber blubber on about how the Mosquito could have replaced
the American heavy bombers because they were fast enough to avoid
interception. Utter rubbish.

hey seem to forget that it would take huge formations of Mosquitos to put
enough bombs on a target to match that delivered by the heavies. individual
Mossies could evade detection, evan small groups could be hard to locate.
But, hundreds of them would be easy to detect early in their flight. That
meant
the Luftwaffe would be waiting high above them in strength. Without any
defensive or offensive guns whatsoever, the Mosquitos would be scattered and
very much chewed to pieces.

Let's do some numbers. The B--17 carried a 5,000 lb. bomb load on most of its
mssions. The B-26 carried a 4,000 bomb load on most of its mssions.

But a max effort of B-17's was about 22 planes. A max effort of B-26's was 56
planes. The B-17's would drop 110,000 lbs on the target, the B-26's would dump
224,000 lbs on the target and did so it from a much lower altitude and with
far greater accuracy. Now you figure what plane can replace the B-17 best. And
it sure as hell wasn't the Mosquito.

Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer