Kill Ratios

[BiffF15]

Biff - if it is allowed to answer, why would you rather have had the GE-110s instead of P&Ws?

Tomo,

I love the PW's! They are robust, modular (three major components) that allow for mix and swap to keep more engines available. However, I don't work on them only fly the jet. The GE motors weigh less and make much more power. An Eagle with two GE 110s is equivalent to three -220s. That's a LOT more thrust. There is a reason in my opinion that the majority of foreign sales of the newer Eagles have had GE.

Cheers,
Biff

 

[tomo pauk]

Tomo,

I love the PW's! They are robust, modular (three major components) that allow for mix and swap to keep more engines available. However, I don't work on them only fly the jet. The GE motors weigh less and make much more power. An Eagle with two GE 110s is equivalent to three -220s. That's a LOT more thrust. There is a reason in my opinion that the majority of foreign sales of the newer Eagles have had GE.

Cheers,
Biff

Thank you
Looks like that most of the F-16s produced after early 1990s also have the 110s onboard.

 

[fastmongrel]

The trouble was that the Oerlikon came in 3 flavors and wasn't exactly trouble free either.

You had the short case guns 72-80mm case length the FF series, the FFL series with 100mm long cases and the FFS with the 110mm case (this became the famous AA gun) Weights went around 24-26kg then 30 kg and then 39--48kg for the big Oerlikon.

Some of the Oerlikons required greased ammunition to function and that was NOT looked on with favor at high altitudes with freezing temperatures.
Turns out the the Hispano also needed greased ammunition but when initially offered it didn't. Some of the cycle rates quoted for the mid 30s Oerlikons were a little on the optimistic side. But then some of the initial figures for Hispano were on the high side. At least one bbok claims the Hispano 404 was offered at 700 rpm vs the Oerlikons 520 -500-470 depending on model. French service HS 7 & 9s (licensed Oerlikons) were rated at 360-420 rpm.

If you want the velocity and hitting power of the Hispano then you need the Hispano. With similar weight shells the Hispano had a MV of 850-880 m/s the aircraft Oerlikon FFS had a MV 830m/s, the FFL series was 675-750 m/s and the FF was 600m/s.

British and Americans might have bought a shell firing gun sooner than the Hispano but it would have been a lower muzzle velocity, slower firing gun.
better in 1940-41 maybe but not as good in 1943-44-45 let alone post war.

What other cannons were available in the 1930s I have heard of the Madsen 20mm but dont know much about it.

 

[tomo pauk]

For the new Supermarine's fighter, the Type 300, there were several proposals. Apart from Oerlikon FF, Hispano was also considered, so was the Vickers 25.4 mm (280 lbs, MV 3000 fps, shell of 0.551 lb), plus several 37mm cannons (200-600 lb, 1250-2300 fps, shell of 1.1-1.5 lb).

 

[fastmongrel]

For the new Supermarine's fighter, the Type 300, there were several proposals. Apart from Oerlikon FF, Hispano was also considered, so was the Vickers 25.4 mm (280 lbs, MV 3000 fps, shell of 0.551 lb), plus several 37mm cannons (200-600 lb, 1250-2300 fps, shell of 1.1-1.5 lb).

The Vickers 25.4mm was quite a beast THE VICKERS 25
Would have made short work of all the Luftwaffes aircraft if the pilot could hit them.

 

[fastmongrel]

I have come across a couple of mentions of a prototype 0.8 inch (20mm) machine gun that was developed by a Vickers subsiduary Elswick Works in the 1920s or 30s. Google doesnt bring up any info so not sure what type of gun it was.

 

[eagledad]

Fastmongrel,

I don't remember ever coming across a Masden 20MM cannon for aircraft. However, there was a Masden 11.35MM machine gun and a 23MM cannon.
Attached are some tables of data and sources for the Masden.

Edit: upon further review, my table does have data for a 20MM Madsen.

Shell data includes

Metric Caliber 20x120
Rim Diameter mm 28.9
Body Diameter mm 29.0
Projectile
Type/Wt gm Muzzle Velocity m/sec muzzle energy Joules
AP/154 780 46,800
HE/126-112 840-890 44,400

Eagledad

 

[Clayton Magnet]

I wouldn't say a .50 strike was six times as effective as a .303 strike - probably closer to two/three times - I'd have to look over some firing trials again.

One thing that's probably different was that many Ju 88 kills in 1940 were against aircraft flying in formation - whereas I'd bet the Ju 88s the P-47s caught were on the run and evading.

Unfortunately I have no other details - just the 15 second figure. Not much to go on.

Perhaps the P-47 would have been better served with 4 Hispano's? in my opinion, the almost ideal fighter armament would be the 3, centrally mounted B-20 cannons on the Yak-3P

 

[Fighterguy]

Tomo,

I love the PW's! They are robust, modular (three major components) that allow for mix and swap to keep more engines available. However, I don't work on them only fly the jet. The GE motors weigh less and make much more power. An Eagle with two GE 110s is equivalent to three -220s. That's a LOT more thrust. There is a reason in my opinion that the majority of foreign sales of the newer Eagles have had GE.

Cheers,
Biff

I was an engine technician on F-15's A's through D's, with a three year stint on F-4G Wild Weasels. As a QA inspector, I was involved with the operational testing of the GE-110 on the F-15E. Besides performance capabilities, logistics need to be considered. The GE-110 engines we tested did not have a simple side-to-side interchangeability like the P&W's did. The F100-PW-200/220 series engines were easily interchangeable between airframes (F-15 to F-16 and vise-versa), and LH to RH on the Eagle, where the GE engine required significant engine to airframe connection modifications. Also, parts supply and procurement has to be considered. Some units operate multiple airframes, Air Expeditionary for example. It reduces your logistics tail to have subsystem interchangeability amongst different weapons platforms as much as possible. Having F-16's with a different engine from your F-15's, for example, increases the size of spare parts warehousing and tracking across the entire fleet, increasing the likelihood of procurement mistakes (getting the wrong part) and shortfalls (not having adequate numbers). I will venture, that many of the foreign procurement sales, getting the GE over the P&W, have more to do with "secret handshakes," State Department and foreign government lobbying (the CEO of GE was one of Obama's "Czars"), and some sort of special interest kickbacks, over outright performance. As it is, the P&W F100 series engines are becoming legacy. The F119-PW-100 is their new shiny toy. Maintaining support for foreign sales is sometimes not as lucrative.

 

[BiffF15]

I was an engine technician on F-15's A's through D's, with a three year stint on F-4G Wild Weasels. As a QA inspector, I was involved with the operational testing of the GE-110 on the F-15E. Besides performance capabilities, logistics need to be considered. The GE-110 engines we tested did not have a simple side-to-side interchangeability like the P&W's did. The F100-PW-200/220 series engines were easily interchangeable between airframes (F-15 to F-16 and vise-versa), and LH to RH on the Eagle, where the GE engine required significant engine to airframe connection modifications. Also, parts supply and procurement has to be considered. Some units operate multiple airframes, Air Expeditionary for example. It reduces your logistics tail to have subsystem interchangeability amongst different weapons platforms as much as possible. Having F-16's with a different engine from your F-15's, for example, increases the size of spare parts warehousing and tracking across the entire fleet, increasing the likelihood of procurement mistakes (getting the wrong part) and shortfalls (not having adequate numbers). I will venture, that many of the foreign procurement sales, getting the GE over the P&W, have more to do with "secret handshakes," State Department and foreign government lobbying (the CEO of GE was one of Obama's "Czars"), and some sort of special interest kickbacks, over outright performance. As it is, the P&W F100 series engines are becoming legacy. The F119-PW-100 is their new shiny toy. Maintaining support for foreign sales is sometimes not as lucrative.

Fighterguy,

I agree completely with the logistics side of the house. Running a war and keeping the supply line moving is a VERY important part of winning. However, I was not the guy running the logistics train, but the guy who would end up fighting with a restrictive ROE and could end up in a merge with Flankers, Fulcrums, etc. And if your motors weigh 1-2K (GE) less than the PW's, then at 8-9g's that's quite a bit less weight you are moving around (or bleeding energy for / with). Also don't forget cruise mileage will be higher due to lower weights. I speak purely to the pilot's perspective, but understand the logisticians side of the equation.

I would bet that GE cracked the code along the way to make the -110 work with Eagles as well as Vipers. The only previous twin to get the GE-110's was the refitted Tomcats. The difference in it's performance was impressive (airframe was still the limiting factor), and helped with the Bombcat versions payload.

Cheers,
Biff

PS: I watch what the others countries buy engine wise for their fighters. Sometimes they mix GE & PW, sometimes they don't. Must depend on a lot of variables not seen by the general public.