Simanaitis Says

On cars, old, new and future; science & technology; vintage airplanes, computer flight simulation of them; Sherlockiana; our English language; travel; and other stuff


THE 1917 P.B. 31E Nighthawk was Supermarine Aircraft’s first design, an utterly bizarre steam punk Zeppelin buster, from this English firm destined, two decades later, to produce the legendary Spitfire. In fact, Spitfire designer R.J. Mitchell had a hand in elements of the P.B. 31E.

Today in Part 1, we’ll look at the Nighthawk in its flawed World War I reality; tomorrow in Part 2, we’ll continue with WWI and then let the P.B. 31E perform, albeit only virtually, in today’s world of GMax and Microsoft Flight Simulator.

My modeling of Pemberton Billing’s Nighthawk, using Gmax for Microsoft Flight Simulator.

Noel Pemberton Billing. The Nighthawk’s P.B. designation comes from Noel Pemberton Billing, English eccentric who has already made appearances here at SimanaitisSays for a variety of reasons.

Noel Pemberton Billing, aka Pemberton-Billing, 1881–1948, British aviator, aviation entrepreneur, inventor, publisher, Member of Parliament, and conspiracy theorist.

Pemberton Billing started his own aircraft company in 1914. His P.B. 7 was, literally, a flying boat: a cabin cruiser with detachable wings and tail. Though highly touted, with several on order, no P.B.7 ever flew. World War I intervened.

The Zeppelin Terror. On January 19, 1915, a German dirigible dropped bombs on the seaside towns of Great Yarmouth and King’s Lynn. On the night of May 31, 1915, another Zeppelin bombed London. Seven people died and 35 were injured. The Zeppelin Terror had begun.

Image from War History Online.

Eight years before, H.G. Wells’ book The War in the Air predicted New Yorkers being terrorized by Zeppelins. In 1915, Pemberton Billing attempted to devise a defense against this terror: a Zeppelin Buster, of sorts. The P.B. 29E was a bizarre aeroplane with a stacking of four wings, a quadruplane.

The P.B. 29E prototype proved cumbersome in flight, potentially useless in Zeppelin-busting, and crashed in early 1916. Its 1917 P.B. 31E successor was another quadruplane, even more bizarre than the P.B. 29E.

The Supermarine P.B. 31E Nighthawk. Image from Plane Encyclopedia.

Why a Quadruplane? Predating the H.P.E.R. (Hollywood Producers’ Elephant Rule: “If one elephant is good, a thousand elephants must be a thousand times better….”), Pemberton Billing reasoned that if triplanes seemed to fly better than biplanes, then why not a four-wing craft?

Both of his quadruplane designs had modestly swept-back wings of different lengths. The P.B. 31E’s topmost wing was its largest, with a span of 60 ft. (By comparison, the nimble Sopwith Camel fighter plane’s span was 28 ft.) The P.B. 31E’s tail surfaces were multi-planed as well, both horizontally and vertically.

Image from,uk.

Impressive Firepower. The P.B. 31E’s mission as Zeppelin Buster was to cruise aloft in extended stints at night and attack any Zeppelin encountered. It carried Lewis machine guns, front and rear, the sort arming WWI fighters. These were manned by two gunners, one perched in the nose of the craft, the other covering the rear from a turret atop the cabin. The turret also had a Davis recoilless rifle with considerably more firepower than the Lewis armament. (The Lewis machine guns were .303s (7.7 mm); the David was a “one-and-a-half pounder” (about 37 mm).

Davis Recoilless Action. A 37-mm firearm generates considerable kick, quite enough to damage the fragile airframes of early aircraft. The Davis offered recoil-free operation through clever physics: It was essentially two rifles mounted opposite each other. When the business end fired its 37-mm shell, the opposing end simultaneously fired an equivalent mass of lead pellets.

The result was recoilless action, though I’ve got to wonder whether that hapless gunner up top was ever nearby. Or did he get to crawl forward and fire the Davis?

The P.B. 31E’s rear gunner had more to think about than aiming his Lewis. The Davis was up there too. Image of my GMax P.B. 31E, of which more anon.

As we’ll see tomorrow in Part 2, the dual-firing Davis and the P.B. 31E’s four wings weren’t the Nighthawk’s only oddities. And a fat lot of good they all did the craft. It sure was an interesting GMax project, though. ds

© Dennis Simanaitis,, 2020


  1. mperry
    June 14, 2020

    Thank you for a great article. I think Flight Simulator got the Davis gun wrong. They usually had the Lewis gun mounted on top of the Davis, usually on flying boats to catch U-boats on the surface. The gunner would fire the Lewis to correct his aim, then discharge his 2 to 12 lb shell downward. This plane would have to be at the same altitude as a Zeppelin or risk shooting themselves from the sky with the “shotgun” pellets ejecting rearwards. It was an interesting weapon but not very useful… much like the WWII Bazooka except the rearward blast was 2 to 12 lbs of flying pellets and grease. Otherwise, the plane had many advanced features, an enclosed heated cabin, onboard generator for a search light, and theoretical long flight times.

    • simanaitissays
      June 14, 2020

      Thanks for your kind words, mperry. Agreed, I’ve seen photos of the Davis with an attached “aiming” Lewis. However, documentation of the P.B. 31E shows its Davis unadorned. In particular, one appearing in tomorrow’s Part 2 is drawn by none other than R.J. Mitchell, a Supermarine draftsman at the time (and destined to be lead designer of the famed Spitfire two decades later). In any case, don’t blame Flight Simulator. The rendering, right or wrong, is mine.
      And I sure agree about those lead pellets (and grease!) emitted rearward!

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