Airplane Post for Michael Kennedy

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I was going to post this later, under a “Cool Project” heading, but a comment by Michael Kennedy (in this thread) encouraged me to go ahead and put it up now. It’s indeed a good idea to occasionally take a little time to talk about something other than contemporary political issues.

The Northrop P-61 Black Widow was a premier U.S. night fighter of WWII. 742 of these airplanes were built; only 4 are left in existence. The Mid-Atlantic Air Museum owns one of these, and has a project underway to return it to flyable condition.

Airborne radar was a new technology in the early 1940s, and the P-61 was specifically designed to be a radar-carrying airplane. Early radars were heavy–over 400 pounds for the set that this plane carried–and a radar operator was required as well as a pilot. So the P-61 was a large airplane–23,000 pounds empty weight, a very big number for a WWII fighter. Maximum speed was 366mps, which is 318 knots. There were 4 fixed 20mm cannon plus 4 50 caliber machine guns in a remote-controlled turret.

The Black Widow was all about its radar system, which was known as the SCR-720. The radar operator had two screens, one displaying range and azimuth and the other showing azimuth and elevation. The operator used a range gate to select a particular target that would be displayed on the pilot’s single screen. Close coordination between pilot and radar operator was essential in order to make an attack a success.

The plane served in both the European and Pacific theaters.

MAAM has been working on the restoration of their P-61 since 1980. You can view the progress of the restoration at The Widow’s Web…it is clearly an immense project. Contributions are of course welcome; and I bet that volunteers with appropriate skills would be very welcome as well.

14 thoughts on “Airplane Post for Michael Kennedy”

  1. I had a model of this plane as a kid and loved it. I didn’t know about the weight of radar at the time but it just looked deadly.

    At the height of the troll invasion, I was going to post some videos of the XB 70. My father-in-law waked up the air intake for the engines without having to bend over. A guy has a great site with may details but I can’t find it right now. I didn’t post the videos because they were jerky and slow but it may be my internet connection here. One of the videos is of the crash.

  4. David the original TBO – time between overhauls – for that engine was believe it or not 8 hours. Certainly part because the technology and partly because they were forced to use steels because of the shortages instead of more exotic metals. I have been frequenting the Lexicans – David – you know about them – in fact told me about them – to call them “aviation central” is an understatement – talk about knowledge – many retired military pilots, test pilots…

    The only one successfully doing replicas that I know of was/is in Washington – used the Williams Engine – also used in a Cessna Citation – but as you have noticed there are others now They built 6 I believe –

    Michael – you were asking about the XB70 – this was a recent post there – I think one commenter had it right – a cross between a white swan and a striking cobra

    http://thelexicans.wordpress.com/2012/09/05/north-american-xb-70-valkyrie-nasa-flight-research-video-compilation/

    And I am with you – the trolls get tiresome – same old tired stuff – but they are easy to ignore

  5. BTW as long as we are taking about Replicas the Me109 has a replica – complete with Daimler-Benz DB605 engine – you can tell – the exhaust stacks are in the bottom of the cowling – and inverted V12. EADS – parent company of Airbus – and the Messerschmidt foundation built them. The allies ahad vitually all of these engines – the equal of the famous RR merlin – destroyed.

    http://www.youtube.com/watch?v=dph9JbBFWqQ

    BTW I picked up an interesting aviation magazine – article on Gerhard Barkhorn – second highest scoring ace of WW2 – 301 kills – towards the end he was assigned to an Me262 squadron – and he really disliked them. The only advantage they held was speed – poor handling, short time aloft – he ended up crashing on one which probably saved his life.

  6. Historical irony: Speaking of the ME-109, this was the first real combat aircraft operated by the Israeli Air Force. The planes were bought from Czechoslovakia, where they had been built to the German design…unfortunately, the regular 109 engines were not available, and the engine that came with the Czech planes had less performance. The 109s were only operated by the IAF for a brief time before being replaced with Spitfires.

  7. The ME 109 was built in enormous numbers; several countries continued to use them after the war. IIRC the 109s used in The Battle of Britain were Spanish surplus and had been re-engined with Merlins. Also IIRC, many of the Israeli 109s were wrecked in landing accidents — indirect results of a design compromise that kept the landing gear in the body of the plane and thus relatively narrow. However, when the 109 was introduced around 1935 it outclassed everything else.

  8. As a point of comparison on the size of the P-61, it was bigger than the B-25 Mitchell bomber which weighed in just under 20,000 lbs. OTOH, modern jet fighters are a lot bigger:

    F-15C 28,000 lbs.
    F-16 18,900 lbs.

    F-35A 29,300 lbs.
    F-22 43,430 lbs.

  9. Neat as they were, at the time the P-61 was considered a failed design. It was based on 1940 British concepts of how a bomber interceptor night-fighter should actually work and by the time it entered service in May of 1941 theory and doctrine had changed radically, Not to mention that the Axis bombers it was designed to shoot down no longer existed as a threat.

    The P-61 represents the most successful of a class of fighters called “turret fighters”.

    From the end of WWI until around 1935, the engine-power/weight and the fabric, wood, wire construction mandated that speed was dependent on the number of engines an aircraft carried. Large monowings also work better at slow speeds than small monowings so big aircraft got the drag reducing monowings before small aircraft. All combined, this meant that in the early-1930s multi-engine bombers were faster and higher flying than the biplane fighters that were supposed to intercept them.

    The solution of to the problem was the “turret fighter” which was supposed to be a bomber like aircraft outfitted with heavy guns in a rotating turret. Instead of acrobatic dogfighting, the turret fighter would fly up next to and usually below the target bomber, rotate/elevate its guns and blaze away. In the concept, Fighter vs Bomber duels would be more like battleships and cruisers battling it on the high seas.

    The p-62 was designed to be a turret fighter at night creeping up on its prey in the dark, aiming by radar and rotating it’s turret to target the enemy while the P-61 itself kept flying straight.

    After 1935, the technology dynamic changed to favor smaller aircraft. The engine power to density ratio of not only jumped but began to favor smaller engines over large ones. (Doolittle’s creation at Du Point of 100% octane avaiation fuel helped that along a lot.) The introduction of duralumin (a strong aluminum alloy) likewise alter the density of the airframe to the favor of smaller aircraft. In just 3-5 years, the entire dynamic of air warfare changed but doctrines did change so quickly. Both sides found themselves in the early part of the war with aircraft that technological change had rendered highly vulnerable.

    Ironically, the P-61 turret never worked. The engine power available at the time of deployment gave the aircraft to high a speed. Rotating the turret at speed set up dangerous buffeting. The turret was then just fixed forward and the entire aircraft maneuvered to bring the guns to bear on a target just like a single engine fighter would.

  10. Jonathan – right on all counts. I remember reading somewhere that the Spanish 109s were actually called something different – their nose was different from the standard 109.

    And I can believe the landing accidents – it had narrow landing gear because of the wing design – you notice they retract outwards – and subsequent versions had far more torque – P-factor – engines almost double the hp – the prop wanting to “twist: the plane”

    But in 1935 or so it was a revolutionary plane – almost got the British.

    David – that Mercedes engine – the allies had virtually all of them destroyed after the war – it was an interesting engine – designed to be inverted – easier servicing on the plane – not ladders to stoop down from – better CG – only a handful exist today –

    On the P61 – it looks like a P38 on steroids. Always wondered how the gunners could avoid shooting off their own tails in the heat opf battle – there must have been a stop preventing one to get the line of sight

    I think it only really came into its own as a night fighter – later painted black? Don’t think it was all that successful but as Shannon mentioned it’s primary purpose of design was not there any more

  13. I think the P 61 was more active in the Pacific. The Navy also used TBF, Avengers, as night fighters and Alvin Kernan was widely believed to have shot down Butch O’Hare in a mixup at night. Kernan, who has written several books about Midway, denies it and says a Japanese plane followed their formation and got O’Hare.

    It must have been incredibly difficult to find the target.

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