Was the De Havilland Mosquito a good fighter?

[FLYBOYJ]

Max speed bomb bay doors opened - 305 knots. "Va" - 19,000 pounds max...

From the pilot's notes, page 39. Although 305 knots is the max speed you can open the bomb bay doors, I doubt bombs were dropped at that speed.

 

[mhuxt]

OK.

Cheers. Don't wish to incur the Ban Stick but Mossie performance is close to my heart.

And please see if that is a "normal" take off weight to include max fuel or payload which might include a 4000 lb bomb with less fuel.

The 95% of takeoff weight is given as 24,000 lb. According to my computer, that's 25,263 at takeoff. Sharp Bowyer give max all up weight as 25,400. Can calculate up from the B.IX CG table, correcting for the higher tare (14,910 vs 14,464)

I'm sure they won't say bomb runs were conducted at 400 mph.[/QUOTE]

Can't right now, wife threatening me with hot oil as part of traditional family argument.

 

[mhuxt]

Max speed bomb bay doors opened - 305 knots. "Va" - 19,000 pounds max...

From the pilot's notes, page 39. Although 305 knots is the max speed you can open the bomb bay doors, I doubt bombs were dropped at that speed.

Are those the B.XVI notes, or the FB.VI notes from January 1950? The bomb door speed didn't change from wartime conditions, but FWIW, the dive speed limitations for the FB.VI were higher in wartime.

Anyway, the CG chart for a B.IX (same engines as the XVI) configured for the 4,000 lb. load and two 50-gal wing tanks gives an all-up weight of 24,570. As noted, the XVI tare was 446 lb higher, for a total of 25,016. The 8 Group Mosquitos went off to Berlin in that configuration, so, yes, the test weight is realistic.

Speaking of 8 Group, according to the appendices in Sharp and Bowyer, they recommended a max takeoff weight of 25,200 for the cookie and 597 gallons fuel (indicating 2x50-gal tanks). The Group also gave max speed at 28,500 as 408 mph before the target, 419 mph after leaving it.

Different appendix in same source gives economical cruise speed for the XVI as 320 mph at 25,000 feet, 350 mph at 30,000 feet. So, if it wanted to, the XVI was capable of dropping a cookie from an economical cruise, without having to reduce speed.

All this in an attempt to demonstrate that, in contrast to what's been posted, when a Mosquito was carrying a 4,000 lb bomb, it was capable of getting close to 400 mph, and indeed it cruised in that condition in excess of 300.

Again without wishing to incur the wrath of the Ban Stick, if what was actually meant is that Mosquitos didn't bomb at 400 mph, well, with respect, those are different goalposts from post 91, and not what I originally responded to.

I can try to scan in the A.&A.E.E. report if you/others still wish to see it.

 

[Shortround6]

Would that 305kt limitation be indicated airspeed or true airspeed?

 

[davebender]

Wasn't the Spit Mk II being replaced by the Spit Mk V by the time the Mosquito entered service?

 

[FLYBOYJ]

Are those the B.XVI notes, or the FB.VI notes from January 1950? The bomb door speed didn't change from wartime conditions, but FWIW, the dive speed limitations for the FB.VI were higher in wartime.

Its from a FB 6

Anyway, the CG chart for a B.IX (same engines as the XVI) configured for the 4,000 lb. load and two 50-gal wing tanks gives an all-up weight of 24,570. As noted, the XVI tare was 446 lb higher, for a total of 25,016. The 8 Group Mosquitos went off to Berlin in that configuration, so, yes, the test weight is realistic.

Speaking of 8 Group, according to the appendices in Sharp and Bowyer, they recommended a max takeoff weight of 25,200 for the cookie and 597 gallons fuel (indicating 2x50-gal tanks). The Group also gave max speed at 28,500 as 408 mph before the target, 419 mph after leaving it.

Different appendix in same source gives economical cruise speed for the XVI as 320 mph at 25,000 feet, 350 mph at 30,000 feet. So, if it wanted to, the XVI was capable of dropping a cookie from an economical cruise, without having to reduce speed.

All this in an attempt to demonstrate that, in contrast to what's been posted, when a Mosquito was carrying a 4,000 lb bomb, it was capable of getting close to 400 mph, and indeed it cruised in that condition in excess of 300.

Again without wishing to incur the wrath of the Ban Stick, if what was actually meant is that Mosquitos didn't bomb at 400 mph, well, with respect, those are different goalposts from post 91, and not what I originally responded to.

I can try to scan in the A.&A.E.E. report if you/others still wish to see it.

You made my point

 

[FLYBOYJ]

Would that 305kt limitation be indicated airspeed or true airspeed?

Indicated - when an airspeed restriction is placed on an aircraft due to a configuration change (lowering flaps, landing gear, opening bomb bay doors) AFAIK its always shown as indicated and some of those speeds have markings on the airspeed indicator.

 

[buffnut453]

You made my point

Flyboy,

I think we're confusing 2 separate performance attributes - the speed at which bombs can be dropped and the maximum speed at which an aircraft can fly with a full bomb load. I think mhuxt has done a reasonable job of justifying his statements re the Mosquito's performance in the latter case.

The requirement to fly straight and level from the IP to the target makes any bomber vulnerable (even today!). The Mosquito's speed would be used either before or after the target run if enemy fighters were encountered. If the Mosquito was engaged during the target run, the pilot would typically abort the attack and seek to defend against the enemy fighter, although I suspect point defence of a target would be left to AAA (ie defending fighters would be warned to keep away for fear of "friendly fire"). Hence the bomb door limiting speed is a different argument from the one mhuxt was supporting with his max speed evidence.

Regards,
Mark

 

[FLYBOYJ]

Flyboy,

I think we're confusing 2 separate performance attributes - the speed at which bombs can be dropped and the maximum speed at which an aircraft can fly with a full bomb load. I think mhuxt has done a reasonable job of justifying his statements re the Mosquito's performance in the latter case.

The requirement to fly straight and level from the IP to the target makes any bomber vulnerable (even today!). The Mosquito's speed would be used either before or after the target run if enemy fighters were encountered. If the Mosquito was engaged during the target run, the pilot would typically abort the attack and seek to defend against the enemy fighter, although I suspect point defence of a target would be left to AAA (ie defending fighters would be warned to keep away for fear of "friendly fire"). Hence the bomb door limiting speed is a different argument from the one mhuxt was supporting with his max speed evidence.

Regards,
Mark

No, his point is understood and he showed the configuration where the aircraft was able to carry a 4000 pound bomb with fuel load and achieve maximum speed while arriving at target. With that said in that configuration you are limited to what types of maneuvers you are doing and your economical cruise speed is reduced (I should have mentioned that earlier). I believe you're going to find configuration limitations common through out all models.

 

[III/JG53_Johann]

I love the mossie.. made from wood.. radar had troubles picking it up.. very good for recon and bomb missions.

as a fighter it lacks with a good turn capacity due its structural build.

But with the airspeed build up it could easily engage and zoom out if not successful.

thats my opinion.

 

[michaelmaltby]

"..... as a fighter it lacks with a good turn capacity due its structural build.

But with the airspeed build up it could easily engage and zoom out if not successful. "

A V-1 killer.

MM

 

[III/JG53_Johann]

yepz.. as i also posted But it can zoom away.. but it would be harder to redo the attack if not successful.. you are almost forced to break off.. in bad weather.. you are.. because you will almost lose visual or completely because you have to take enough distance from adversary to make a slow turn.. (because when you tight turn.. you may loose hight advantage and sertain loose airspeed) the two most important things to be a good dogfight pilot.. hight advantage and airspeed. = speed = life..

So for me its not a fighter aircraft.. it can do a devastating blow by is armament but not the maneuver capacity of a normal fighter aircraft. (in my opinion).

And dont forget.. when you have a fighter as target.. it can easily outturn the mossie.. so for me it still remains recon, low level bomber -> strafing AND a goof aircraft to take down enemy bombers..

Shame it lacks a machine gun mounted to the rear of the aircraft. because the navigator in my opinion deserves a gun!

 

[FLYBOYJ]

yepz.. as i also posted But it can zoom away.. but it would be harder to redo the attack if not successful.. you are almost forced to break off.. in bad weather.. you are.. because you will almost lose visual or completely because you have to take enough distance from adversary to make a slow turn.. (because when you tight turn.. you may loose hight advantage and sertain loose airspeed) the two most important things to be a good dogfight pilot.. hight advantage and airspeed. = speed = life..

So for me its not a fighter aircraft.. it can do a devastating blow by is armament but not the maneuver capacity of a normal fighter aircraft. (in my opinion).

And dont forget.. when you have a fighter as target.. it can easily outturn the mossie.. so for me it still remains recon, low level bomber -> strafing AND a goof aircraft to take down enemy bombers..

Shame it lacks a machine gun mounted to the rear of the aircraft. because the navigator in my opinion deserves a gun!

Spoken well from someone who's never flown a REAL airplane.

 

[mhuxt]

I have in the past helped various folks model the FB.VI for simulations, in terms of wing area, median chord, weight and moment of various components, power at various altitudes, etc. etc. ad infinitum amen.

Assuming the modelling is at least relatively accurate, the FB.VI turns fairly well, but ain't much at climbing away from said slow turns.

The low-level boys of Coastal Command seem to have been able to give pretty much as good as they got from JG 5, though tangling with SE fighters was something to be avoided wherever possible.

Remember CC had Mossies with Merlin 25s optimised for low-level grunt and tended to go in numbers sufficient to support one another, though that wasn't the case for the armed recce Norwegians of 333 Sqn.

 

[fastmongrel]

I have read many times that the Mossie was hard to detect with radar but surely with 2 big lumps of metal hanging off the wings and 2 big props spinning radar would have been able to spot it. Does anyone have any info on the radar cross section of the Mossie and was it any different in the real world to an equivalent size aircraft.

 

[FLYBOYJ]

I have read many times that the Mossie was hard to detect with radar but surely with 2 big lumps of metal hanging off the wings and 2 big props spinning radar would have been able to spot it. Does anyone have any info on the radar cross section of the Mossie and was it any different in the real world to an equivalent size aircraft.

Actually that was true, even with the props turning. The Plywood construction did absorb some of the radar energy. If I'm not mistaken the Mosquito was one of the first aircraft to use an IFF system because of this.

 

[buffnut453]

Actually that was true, even with the props turning. The Plywood construction did absorb some of the radar energy. If I'm not mistaken the Mosquito was one of the first aircraft to use an IFF system because of this.

I believe IFF was in use by the RAF long before the Mosquito entered service. IIRC fighters during the Battle of Britain were IFF-equipped to enable the radar sites to distinguish between friendly and hostile formations.

 

[FLYBOYJ]

I believe IFF was in use by the RAF long before the Mosquito entered service. IIRC fighters during the Battle of Britain were IFF-equipped to enable the radar sites to distinguish between friendly and hostile formations.

I do remember reading somewhere that the Mosquito did not use a "standard" unit because of its low RS. I have some book packs up, I'll have to go through them to find this info.

 

[parsifal]

Perhaps the references to the Mosquito carrying the first IFF for the RAF are in fact mixing up the fact that the mosquitoes were the first British aircraft that carried appartatus that could trigger German IFF systems, and thereby trigger the position of the german plan....Wiki had this to say about the issue...

The world's first IFF, FuG-25a "Erstling" (English: "Debut"), was developed in Germany in 1940. It received the radar frequencies on 125 MHz (Freya radar) and 550-580 MHz (Würzburg radar). To start the identification procedure, the ground operator switched the pulse frequency of his radar from 3,750 Hz to 5,000 Hz. The airborne receiver decoded that and started to transmit its code. Before departure, 2 mechanical keys of 10 bits each were inserted into the shown reader. The IFF transmitter worked on 168 MHz with a power of 400 Watt (PEP). Unfortunately for the Germans, British intelligence were able to build their own IFF transmitter, called "Perfectos". When mounted into a RAF Mosquito, it could trigger the FuG-25 and therefore betrayed the position of the nightfighters. To avoid that, the FuG-25 had to be switched off very often.

 

[cocky pilot]

Cocky Pilot

"ALL bombers had escorts for the simple reason that a bomber (whatever it is) needs an escort because you cannot perform a precision bombing run with even one enemy interceptor in the region, a bomb run is a perfect target."

Big word ALL. I've told you a million times not to exaggerate.

Way off line with this one chum. As a gut feeling I would hazard a guess that more raids by bombers went ahead WITHOUT fighter escort than with! And as far as having an escort over the target area, that was a luxury only afforded to a few.

Don't remember many fighter escorts for the RAF night raids over Europe from '39 through to '45.

Flexibull Please accept my appologies I was lost in the subject of the thread, I meant all precision daylight raids (the discussion I was having was about the precision mosquito daylight raids) I was referring to the few not the many, targetting a specific building in daylight makes a sitting duck of the bomber to fighters and ground fire.