Ten most important fighter aircraft guns

ImageIn August 1910 Jacob Earl Fickel shot a rifle from from an aeroplane. He repeated the feat at an air show in 1911, putting six bullets through a dinner plate while flying 200 feet (61 m) from the ground. This circus-like demonstration led directly to the creation of the gun-armed aeroplane, a type that would become known as the ‘fighter’.

The gun-armed fighter would be a decisive weapon in many 20th Century wars. The gun has been a standard part of fighter armament for over 100 years with few exceptions. Let’s take a look at the ten most important fighter guns. 

10. Vickers machine-gun (1913) ‘The Vickers’ missus’ 


The world’s first purpose-built warplane, the experimental Vickers E.F.B.1 biplane, was armed with a Vickers machine-gun (though by the time it entered service it been rearmed with the Lewis gun). The  Sopwith Camel, the SPAD XIII and virtually all Allied fighters used at least one synchronised Vickers, due, most of all to its exceptional reliability. The weapon remained in service for a long time; the Gloster Gladiator was the last RAF fighter to be armed with them, though the Fairey Swordfish carried them right up until retirement 1945.

9. Maschinengewehr 08 ‘Spandau ballet’ (1915)


The answer call to the Vickers above was frequently a barrage of fire from the Imperial German air force’s equivalent: the LMG 08/15 and IMG 08 ‘Spandau’ machine-guns. The weapon of the greatest fighter pilot of all time, the ‘Red Baron‘ and armament to almost every German fighter of the War. More than 23,000 examples of the LMG 08/15 and an unknown number of the lMG 08 were produced during World War I

8. Mauser MG 213 (1944) ‘Reich said Fred’


The only gun on this list not to have entered service, the Mauser was still extremely important. The Mauser MG 213 was a revolver cannon developed for the Luftwaffe during World War II. It was initially a 20-mm weapon, but there was a 30-mm variant. Following Germany’s defeat this innovative design was closely studied around the world and directly influenced most, if not all, aircraft revolver cannons that have followed, including the British ADEN, French DEFA and American M39 cannon.

7. Nudelman-Rikhter NR-23 (1949) ‘Hitting the Marx’


The two lower weapons are NR-23s.

The NR-23 was the gun of Cold War Soviet air power. This 23-mm autocannon armed a number of aircraft, notably including the MiG-15 of Korean War fame. It was also fitted to the obscure and under-rated Lavochkin La-15, the MiG-17, some models of the MiG-19, the Ilyushin Il-28 medium bomber and the Beriev Be-6 maritime patrol aircraft. The 1974 Almaz 2 (Salyut 3) Russian space station was experimentally armed with an autocannon for self-defence, the Rikhter R-23which would make it only space weapon on this list.


The space station’s R-23 cannon installation. 

The NR-23 was scaled up to create the 30-mm calibre NR-30 used by the MiG-19, early MiG-21s, Sukhoi Su-7s and the Sukhoi Su-17, and as the Chinese Type-30 on the Shenyang J-6. An intriguing feature of the NR-30  was the ability to distribute chaff.

(With only ten places in this list there was not room for the Afanasev Makarov AM-23, which was a far fast-firing weapon largely used as a defensive weapon in larger aircraft part from the Tu-16 and Tu-95, Antonov An-8, An-12B, B-8, B-10, Il-54, Il-76, Myasishchev M-4, 3M and M-6 bombers and transporters)

6. MG 131 machine-gun (1940) ‘Goering of thrones’


At a mere 13-mm the MG 131 appeared to be lagging behind world standards in calibre terms by the time it was committed to action over Europe. However whilst lighter than any rival gun of equivalent calibre (it weighed only slightly more than half as much as an M2 Browning), it possessed an extremely high rate of fire. Being so small it could be crammed into the nose of tiny fighter aircraft, firing from the cowling or through the spinner, resulting in a much more concentrated gun harmonisation than was possible with wing-mounted weapons. It provided tragically capable and many Allies met their death by MG 131s carried by Messerschmitt Bf 109 and Fw 190s.

5. HS.404/Hispano 20-mm cannon (1940) ‘Britain’s French Heavy Metal’914913122892638489In 1939 the French had arguably the best armed air force in the world with the superlative 20-mm Hispano fitted to all their fighters. Sadly those fighters were generally woefully inadequate in all other regards. Meanwhile the British knew they needed a cannon but experiments with the 20-mm Hispano were proving unsuccessful. Designed to be used the right way up and fastened to a weighty engine block, laying the weapon on its side in a Spitfire wing was inspired but took a very long time to get to work. Persistence paid off however and the Hispano formed all or part of the armament of every British fighter aircraft from 1941 through to the advent of the ADEN cannon (which almost made this list). The Hispano was also produced in America, being particularly popular with the US Navy who employed it extensively through the late-war period and throughout Korean conflict.

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4. ShKAS machine-gun (1933) ShKAS for questions’


The ShKAS was the fastest-firing rifle calibre (in this case 7.62-mm) aircraft armament in general service of World War II. 1,800 round per minute was virtually unheard of, and (the notoriously unreliable Ultra-ShKAS variant) unleashed a veritable firestorm of 3,000 rounds per minute! Extremely light and fast-firing, the ShKAS equipped the majority of Soviet fighters and bombers in World War II. Though not the most reliable weapon, it proved extremely effective. It influenced the ShVAK cannon (which narrowly avoided inclusion itself), and quite possibly the Mauser 213.

3. M61 Vulcan (1959) ‘Rotary club’ 


Source: JASDF via The Aviationist

When Richard Gatling conceived his fast firing rotary gun in the 19th Century he considered that its awesome destructive effect would limit the size of armies and so reduce casualties, and maybe even end wars. This did not come to be. Though Gatling’s design offered high rates of fire, it was large and required external power, and by the early 20th Century its popularity had waned. Requiring fighter weapons of a higher firing rate Imperial Germany issued a requirement in the First World War for an aircraft-powered (engine or electrical system) multi-barrelled gun, a slew of prototypes followed. None entered full service but a Siemans’ prototype achieved an aerial kill during a combat evaluation.

Following World War II the US wanted a more destructive weapon than the Browning. The new gun should be capable of destroying enemy aircraft in the fleeting opportunities offered by the new era of high speed jet-v-jet combat, and the rotary cannon was the chosen solution. USAF tried 15-,20- and 27-mm rounds for the new weapon before deciding that the second option, 20-mm, was the best. The resultant M61 entered combat in 1965, and during the Vietnam War it was responsible for at least 39 MiG kills. It has also been used to devastating effect by many other nations’ air forces, notably Israel’s (on F-4s, F-16s and F-15s) and Iran’s (on F-4s and F-14s). It has armed almost every US fighter since the F-104 and today arms the F-22. Though superficially similar, Russia’s rotary cannons use a different principle, shunning electric power in favour of gas. Though historically not as significant as others on the list, its ubiquity and longevity have earned it a high ranking. Image


2. Berezin UB ‘The Union strikes back’ (1941)


The 12.7mm Berezin entered service a mere two months before Germany turned on the USSR. Strongly influenced by the Finnish 20-mm cannon, the UB was a fast-firing and effective weapon produced in large numbers. In 1941 6,300 were produced, and in 1943 the annual total jumped to an impressive 43,690. Similar production levels would continue for the rest of the war. The weapon was carried by the vast majority of Soviet wartime aircraft and was thus enormously important.

1. Browning ‘fifty-cal’ ‘Browned off’ (1940)


The Browning was the fighter gun that won World War II: it armed Spitfires from the Mark V onwards (smaller calibre variants of the Browning were also very important -notably the .303 weapons carried by earlier RAF aircraft), provided the teeth for P-51s escorting bomber raids over Germany and P-47s destroying tanks in Normandy, and it took the fight to the Japanese over the Pacific. Browning armed F-86s were credited with the destruction of 792 MiG-15s over Korea. This is an exaggerated claim but the fifty-cal is responsible for downing more aircraft in the post-war period than any other aircraft-mounted weapon. Despite a basic design approaching one hundred years old, the Browning is going strong as a vehicle-mounted weapon for forces around the world and forms the standard armament of the Super Tucano which is still in production. It was neither radical nor particularly advanced but the fifty-cal is probably the most successful airborne weapon in history. It is certainly the longest serving.




Stingbat LHX stealth helicopter: would it have worked in real life?


In the 1980s, the concept of ‘Stealth’ was mysterious, cutting-edge and sexy. This appeal was harnessed to sell films and toys; one example of the latter was Testors’ LHX Stingbat, a notional stealthy ‘Light Combat Helicopter’. We asked Ron Smith, former Head of Future projects at Westland Helicopters how it would have fared in real life. 

“Interestingly. I was looking at real Stealth Helicopter projects from early 1982 in my role as Westland Helicopters Head of Future Projects. I remember showing an image of WG44 at a defence conference, which took place shortly after the sinking of ‘Atlantic Conveyor’.

Another related subject in which I have experience is the NOTAR™ (no tail rotor) system developed by Hughes / McDonnell Douglas Helicopters (MDH) and used on the MD Explorer. It depends (in part) on a boundary layer control system called Circulation Control, where a jet of air is ejected out of a slot (or slots) running along a curved surface. Changes in the mass flow from the slot allow rapid changes in the lift (circulation) around the aerofoil. Very high lift coefficients (>6.0) can be obtained and rapid variations can be achieved for control purposes.

My PhD related to experimental tests and a theoretical model of such a system, the latter being capable of modelling more than one blowing slot on a surface.

Andy Logan of MDH, who gave a paper on NOTAR to the Royal Aeronautical Society (RAeS) when I was the Chairman of the RAeS Rotorcraft Committee was kind enough to reference my PhD in his presentation. (A developed version of my theoretical model was used for quick look optimisation of NOTAR, as it could handle multiple blowing slots).


Having said all this, what about the Testors Stingbat LHX?

A quick look at the photographs of the model reveals some interesting features, but leaves a number of questions unanswered.

The main features include:

  • A heavily faceted airframe with (presumably retractable) skid undercarriage, although it is not clear where the latter is stowed, or why the skids appear to be in two pieces.
  • A retractable sensor of some sort below the nose
  • A three-barrel gun turret mounted centrally under the fuselage
  • Retractable weapons stowage for a small number of quite small missiles (possibly only one each side). These have the appearance of air to air rather than anti-armour weapons (such as Hellfire or Brimstone)
  • A small louvred nozzle at the tail, presumably for anti-torque and directional control
  • It is not clear how the engine intake and exhaust system are supposed to work and how infra-red shielding and suppression are managed. (I am giving the designer credit for not imagining that the exhaust is ducted out of the tail nozzle).
  • A three bladed rotor which is swept in a crescent shape from root to tip. The blades appear to have a separately controllable outboard section.
  • There is no sign of treatment to minimise the radar signature of the cockpit apertures.

As one might expect, there are a few issues with this design. My main comments relate to the tail boom and anti-torque / directional control; Infra-red suppression; viability of the gun turret solution shown; inadequate downward view from the cockpit; design of the main rotor blades; weapon load out; undercarriage.


Tail Boom & Directional control

A really quite significant thrust is required to counter main rotor torque and provide for yaw manoeuvre against the torque when in and around the hover. In the MD Explorer, the downwash across the tail boom is deflected by the circulation control air ejected from longitudinal blowing slots. This produces a side force on the tail cone that partially offsets the main rotor torque (this requires a circular section tail boom and is not consistent with the shaped rear fuselage shown. An adjustable tail nozzle (with air supplied by a gearbox-driven fan) supplements the blown tail boom. In forward flight, when the downwash no longer blows across the tail boom, directional stability is provided by twin fins (with rudder control) mounted on the end of a tailplane.


The Boeing- Sikorsky RAH-66 Comanche used a version of the Fenestron (fan-in-fin) anti-torque control, dubbed Fantail by Boeing Sikorsky) allied to a canted tailfin. The Fantail was optimised for reduced acoustic signature (compare, for example the penetrating pure tone of the Gazelle with the much quieter systems on the EC135 and later model of the Dauphin).


With no fin area and a very small exhaust nozzle, there must be serious doubts as to the directional stability and control of the Stingbat LHX design. Furthermore, the rear fuselage shaping is inconsistent with the implementation of a NOTAR system, if that was considered.

Testors 635 Stingbvg++

Infra-red suppression

The shaped tailcone of the Comanche was mainly taken up with a bulky exhaust infra-red suppression system and this was also a prominent feature of the Westland WG45 and WG47 projects. I’ll assume that the Stingbat adopts a system similar to that on the Comanche.

Gun turret

Helicopters adopt a nose down attitude in forward flight. This means that frontal ground targets appear above the nose of the helicopter when it is flying at speed. Firing the gun at such a target means firing upward relative to the helicopter, universally resulting in a forward-mounted turret with decent upward look angles. (see A129, Tiger, Cobra, Hind, Rooivalk, Apache, Havoc, etc). That shown on the Stingbat is entirely impractical.

Cockpit downward view

The flat shaped nose and wide fuselage may obstruct downward view, although this could be overcome by slaving the retractable sensor to a helmet-mounted sight. A sensor behind a mesh-covered aperture (as adopted by the F-117) might offer a lower signature solution that the retractable sensor pack shown. (Although the F-117 does find it worthwhile to implement retractable comms aerials).

Main rotor blade design

The curved blades look wrong. The primary means for reducing helicopter acoustic signature are having a modest main rotor tip speed (think Sea King and AW101), avoiding high tail rotor noise, and avoiding flight paths that result in blade slap.

Assuming a low basic tip speed, high Mach numbers will only be encountered close to the advancing blade tip. This explains why those helicopters that do feature any blade sweep only do so close to the tip. The other major difficulty is that sweep along the whole blade will introduce large in-plane bending loads in the blade due to the centrifugal loads trying to straighten the blade out. (The end result would almost certainly be increased rotor system weight).

The two-section blade looks as if it has a separately controlled outer section with a small control tab. This is a good idea as it would potentially allow higher frequency control inputs (known as Higher Harmonic Control), which could reduce external noise, possibly eliminate blade slap, and reduce on-board vibration. 

Weapon load-out

The primary targets for most attack helicopters are enemy main armour, command and control vehicles, and air defence systems. Some form of tandem warhead precision guided missile is required – these are quite large and heavy. The ones shown fitted to the model look like reduced length AIM-9s or, at any rate, air-to-air rather than anti-armour weapons.


Because each sortie carries with it a finite probability of being engaged by the enemy, it is important to carry enough weapons on each helicopter that a small group of helicopters can inflict significant damage without having to fly multiple sorties. This typically means eight weapons (assumed for WG-44 to WG47), with Apache carrying a maximum of sixteen weapons. Even the Comanche managed six weapons in its weapons bay.— 

The provision on the Stingbat does not appear to be sufficient.


It’s hard to tell exactly what is provided, but Crashworthiness (used to be based on Mil Std 1290A) is a key consideration. I assume that the skid undercarriage is retractable for signature reasons, but I cannot tell how it is stowed. It looks too flimsy to be crashworthy and the apparent introduction of shock struts may prove problematical in terms of the avoidance of ground resonance.”

Ron Smith, Co-author of Two up down under  


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You may also enjoy Ten incredible cancelled Soviet fighter aircraftTen worst Soviet aircraftTen incredible cancelled military aircraftFighter aircraft news round-up,  11 Cancelled French aircraft or the 10 worst British military aircraftSu-35 versusTyphoon10 Best fighters of World War II Su-35 versus Typhoon, top WVR and BVR fighters of today, an interview with a Super Hornet pilot and a Pacifist’s Guide to Warplanes or Flying and fighting in the Tornado.


Want something more bizarre? Try Sigmund Freud’s Guide to Spyplanes. The Top Ten fictional aircraft is a fascinating read, as is The Strange Story and The Planet Satellite. The Fashion Versus Aircraft Camo is also a real cracker. Those interested in the Cold Way should read A pilot’s guide to flying and fighting in the Lightning. Those feeling less belligerent may enjoy A pilot’s farewell to the Airbus A340. Looking for something more humorous? Have a look at this F-35 satire and ‘Werner Herzog’s Guide to pusher bi-planes or the Ten most boring aircraft. In the mood for something more offensive? Try the NSFW 10 best looking American airplanes, or the same but for Canadians. 10 great aircraft stymied by the US


World Cup Air Forces 2018: Group Stage Opening match – Saudi Arabia versus Russia


Tomorrow Russia faces Saudi Arabia in what the Financial times has dubbed the worst World Cup opener ever, leaving confused fans to drift off into their belligerent fantasies. With this in mind, who would win in an aerial war? Over to our Football & Air Defence Specialist Calista Wildenrath with a rather tasteless war/sport crossover. 

“Both Russia F.C. and the R.S.A.F Rovers have reputations for high risk tactics, excepting relatively high losses. Russia F.C. remains surprisingly uninterested in precision playing, using overwhelming force and loose management approach to achieve its results. Traditionally RSAF (which is a lavishly equipped side) has been considered a team of rich careless playboys – but some would say those days are over. RSAF has still endured many hard losses against local upstarts Yemen United. Let’s see how the two sides stack up.

Goalkeepers (SAMs)

Saudi Arabia  PAC-2 ‘Pac man’


Regarded as one of the most reliable shot-stoppers among Western long-range SAMs.

Its predecessor in this position, the original Patriot, was highly rated in the 1991 Gulf World Cup, but subsequent video replays showed that it failed to stop most of the long-range efforts launched by the Iraqi strikers.

Following its transfer to Saudi Arabia, the Patriot more recently endured a torrid season against Houthi opposition.

Russia S-400 ‘Triumph Acclaim’ 

Screen Shot 2018-06-13 at 2.56.55 PM.png

Finally, in 2017, aviation fans began to sit up and take notice of the incredible job that the S-400 has done as part of the Russia’s infamously mean backline. Russia’s goalkeeper is now more vital than ever as the team seeks to develop strength in depth.

The S-400 has it all: still young, strong command of his penalty area, expert positioning, brilliant shot-stopping ability and all of it with unerring consistency. Recently he achieved caused by his transfer to Syria, and has attracted much interest on the foreign transfer market.

The S-400 is arguably the best goalkeeper in the world right now – and might just stay there for a very long time.


RSAF : McDonnell F-15C/D Eagle ‘Regal beagle’ 


It is hard to believe that this big-shouldered American is 39 years old, but that does not stop the F-15C from making sure that his performance levels reach RSAF Rovers’ required standard. Though old, he remains the most successful defender (in term of loss-kill rate) of his generation.

Russian Air Force F.C. Mikoyan MiG-31 ‘Foxhounds of love’


The Russian stalwart has once again had a stellar season. He is as reliable as ever in the pitch and always keeps a calm and composed head when faced with high-pressure situations. The MiG-31 is an old-school defender in the sense that he values speed over the art of tackling. There are few players who can beat him aerially, while only few can beat him for speed when he is on form.

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Midfield – support asset

Russia – Antonov An-124 ‘Condor’ ‘Ukraine in the membrane’

The heaviest player in the world. This heavyweight mid-fielder has played for Blackburn Rovers, Queens Park Rangers and Antonov. Controversially, for several reasons, the An-124 is Ukrainian born.

RSAF – British Aerospace Jetstream ‘Radlett flatulence’ 


Despite a controversial sex life, the famously cheeky 38-year-old has made the squad. Expect high jinks on and off the pitch.


Russia: Tupolev Tu-160 Blackjack ‘A bigger Bone’ 



Russia FC’s talismanic Blackjack is a favourite of the manager. Far bigger and more powerful than anything possessed by the fun-loving RSAF, it’s a throwback to the 1970s style of brute force and massive long distance shooting. Though impressive, this old-style centre-forward is somewhat inflexible.


Saudi: Panavia Tornado IDS ‘Tonka Stonker’


Confounding the experts who expected RSAF to place the Strike Eagle or Typhoon in striker role, they’ve opted for the perennial IDS. While some observers argue that the ageing Tornado should have been retired from the first team some time ago, it’s continued to play a vital role in the Saudi strike force and the punchy centre-forward still has some clever tricks up its sleeve. Compared to Russia’s titanic Blackjack the Tornado is tiny with short endurance. Interestingly, both teams are putting up a swing-wing for the striker role.

Captains (AEW)

Beriev A-50 ‘Mainstay awhile longer’ 


Russia FC’s eccentric captain Beriev A-50 is a mainstay of the team with over thirty years service. Known for his short endurance and primitive approach he is a controversial figure lacking the sophistication of RSAF’s new Swedish coach.

Saab 2000 Erieye ‘Erieye for the straight guy’ 


Let’s all meet up in the Saab 2000.

RSAF Rovers’ publicity shy Captain Erieye is highly intelligent but small and short-legged. Never previously seen at a major international tournament, it has much to prove.

Surprise substitute 

RSAF: PAC MFI-17 Mushshak

Russia: Beriev Be-12



About the author: Calista Wildenrath is the creator of the Football & Aerial Warfare Blog. She has worked for many defence and football publications including: Razzle (as airline interiors corespondent), The Ultimate Soccer & AWACS Factfiles, The Rassclart Review (Shackleton Desk), The Critical Blimp, Quadcopter Perspectives and Pushpak Pushback. She lives in Hemel Hampstead with her three dalmatians Swampthing, Stratotanker and UCAV.



Despite some fancy acquisitions by RSAF Rovers this game should be Russian F.C.’s. Expect mass confusion and high losses as RSAF face a brutal onslaught from an aggressive and experienced Russian squad.

Predicted score: Russia 7 – RSAF 1


You may also enjoy Ten incredible cancelled Soviet fighter aircraftTen worst Soviet aircraftTen incredible cancelled military aircraftFighter aircraft news round-up,  11 Cancelled French aircraft or the 10 worst British military aircraftSu-35 versusTyphoon10 Best fighters of World War II Su-35 versus Typhoontop WVR and BVR fighters of today, an interview with a Super Hornet pilot and a Pacifist’s Guide to WarplanesFlying and fighting in the Tornado. Was the Spitfire overrated? Want something more bizarre? Try Sigmund Freud’s Guide to Spyplanes. The Top Ten fictional aircraft is a fascinating read, as is The Strange Story and The Planet Satellite. The Fashion Versus Aircraft Camo is also a real cracker. Those interested in the Cold Way should read A pilot’s guide to flying and fighting in the Lightning. Those feeling less belligerent may enjoy A pilot’s farewell to the Airbus A340. Looking for something more humorous? Have a look at this F-35 satire and ‘Werner Herzog’s Guide to pusher bi-planes or the Ten most boring aircraft. In the mood for something more offensive? Try the NSFW 10 best looking American airplanes, or the same but for Canadians. 10 great aircraft stymied by the US



Why the Merlin has three engines


It has been said that all naval aircraft for aircraft carrier use after the War had to fold up into the same width as a Seafire – because that determined the available lift size. Is this true?

Well, maybe not quite, but similar considerations apply to the question of the AW101 and its use of three engines.

Conceptual Design Background

To discuss this question it is worth considering how the conceptual design process works. First, the customer (through the Operational Requirement staff and with Defence Equipment & Support (or MoD PE, as it was then)) identifies a capability gap and commissions preliminary feasibility or concept studies to look at options for addressing this gap.

These options will investigate different technology options to determine what potential solutions could be available to meet the capability requirements within the required timescale at an acceptable cost and risk. (In this instance, Multi-Role Fleet Helicopter; Sea King Replacement; and WG34 (also known as SKR Option 5) studies).

The diagram below gives some idea of the subsequent process. The ‘Requirements & Constraints’ at this early stage are likely to be expressed in terms of a Target. Later on as the project matures, this will harden into a Requirement (used as the basis of a competition to down-select a contractor for the development phase).

Once the solution has been selected for development, that work and the subsequent acceptance of the design will be against a contractually-binding specification.


Operational analysis is used in this process to analyse the Concept of Operation at the system level. OA and trade studies are used to identify how changes in technology influence the effectiveness of individual sub-systems and system attributes (such as manoeuvrability, survivability, detectability, threat detection and prosecution, flight performance, environmental limitations, etc). Parametric cost assessments and risk analysis then allow optimisation in terms of cost effectiveness.

Physical integration (packaging) is likely to set hard constraints on some elements of the system and generally requires design activity (i.e. drawing of the system solution – nowadays on a CAD system).

Effects of a ‘stove-piped’ view

Now, each specialist area tends to have a strong view of how the project should emerge, based on their specific perspective. (We must use this new armour, the radar signature requires these strategies etc. This results in the sort of cartoon reproduced below:


It is the job of the Head of Projects, or the Configuration Team to make sensible cross-system trade-offs to produce a solution which, if not ideal, is acceptable to all.

Naval helicopter design drivers

In the instance of AW101, it is useful to consider the ‘influence diagram’ below, which gives some idea of how specific requirements and factors influence the design solution of a naval shipboard helicopter.

In looking at this diagram, it is instructive to consider how many aspects of the design and the underlying requirements end up driving the system weight.


Now, the system level requirements from the customer (typically driven by his Operational (and Threat) Analysis) include: Performance Requirements (including mission profile), Speed, Deck Motion, Mission Equipment, Endurance, and Crew numbers.


In addition to these there will be a number of Mandatory Requirements (sometimes driven by policy, and sometimes specific to a particular Capability), which have to be addressed. These may also be known as Key Performance Parameters or KPPs.

Examples of candidate KPPs could include

  • Crashworthiness,
  • EMC and EMP protection,
  • Sonar and radar system performance,
  • Engine failure criteria (e.g. an engine failure at a critical point during take-off must not result in jettison of weapons or stores on the ship deck)
  • Ship deck & hangar size (must be able to operate from a Type 23 ship’s deck and be stowed in a Type 23 hangar
  • Environmental (operation in specified environmental conditions – wind, temperature, icing conditions, sea state, deck motion, etc.
  • Crew numbers and anthropometry
  • Mission profile and endurance
  • Weapons and defensive aids fit and capability.

Impact on Design

A further constraint for EH101 (in the early design stage) was the desire to be able to deliver a helicopter with civil certification at the same time as the proposed military utility and naval variants. To meet project timescales, this required that the helicopter make use of an existing engine that was either already certified or on track to so being. (This is because the development and certification of a new engine in parallel to a new airframe would result in unacceptable programme timescale, performance and cost risks).

The mission capabilities for EH101 were expressed in terms of a mission endurance of some five hours with a certain number of crew, plus search radar, sensors, communication equipment, defensive aids and weapons. This mission profile and equipment and crew requirements indicated, via the feasibility studies, a take-off mass of some 13 tonnes (some 33% heavier than the Sea King).

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There was, however, a mandatory requirement (KPP) that the new helicopter be compatible with the existing Type 23 Frigate landing deck and hangar size. This restricted the rotor diameter essentially to that of the existing Sea King.

With a given rotor diameter, the power required for a helicopter to hover depends on its all-up weight raised to the power 1.5. This implies that a helicopter 33% heavier than the Sea King, with the same rotor diameter, will require 54% more power to hover under the same conditions.

A quick review of available certified engines reveals that three CT7s (or RTM-322s) providing a total 5,100 hp would meet this requirement, compared with the 3,320 hp of the two Gnomes in the Sea King. The need for three engines emerges from these factors, not from any design criteria placed at the outset by the customer.

Of course, by the time a procurement contract is written, the associated Specification will be written around the selected solution and reflect the use of three CT7 engines.

Is this an optimum solution?

The answer to this is both yes and no.

Whereas, on narrow cost and complexity grounds, the three-engine solution would probably not be favoured, a properly constructed COEIA (combined operational effectiveness and investment appraisal) would probably show that it is justified.

This is primarily because the alternative solution (using a pair of newly-developed 2,600 hp engines) would incur significant additional up-front cost, timescale and performance risk, in parallel with the required airframe development.

In this case, the Type 23 ship deck and hangar are analogous to the possibly apocryphal size of the aircraft carrier lift to suit a Seafire.

It also demonstrates that KPPs are capable of driving a design in a particular direction irrespective of the results of any Operational Analysis.

(Although, to be fair, the mission equipment (sensors, weapons and defensive aids) and their performance, mission profile, crew numbers and environmental requirements are probably all driven by appropriate OA and Threat Analysis).

I should say that I did not participate at this level in the EH101
projects, although I was on the Configuration Team of NH90 during its
Feasibility and Pre-Definition Study (up to the point where the UK
Government withdrew from the programme).

–– Former Head of Future Projects at Westland Helicopters, Dr Ron Smith


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8 ways to annoy your Air Traffic Controller


Most pilots learn to fly simply to annoy Air Traffic Controllers. We asked our favourite ATCO, Dorian Crook, for the top 8 ways to keep these coffee-sucking control freaks furious. 
1. Calling yourself  “THE Bluebird 342”. No, you’re just “Bluebird 342”.  You’re not The Dude. It makes you sound like a Hospital Radio DJ. So expect to be treated like one.
2. Reporting “Runway Vacated” when you aren’t. There are very few airports or situations where you’re required to report this. We have large windows in our Towers (for now)  and, in a lot of cases,-Surface Movement Radar. So don’t do it- and if you do, it doesn’t count if just the pilot’s feet are over the line: we need the whole aircraft clear of the runway. Especially the tail. That can cause a lot of damage and paperwork.
3. Giving your Life Story over the Radio. This is more common among Private Pilots, who are still excited about using the radio, rather than seeing it as a necessary evil, like the Big Boys do. Most common in the club rental aircraft, such as Cessna 172 /PA28. Less common amongst the exotica and vintage boys- presumably because all THEIR attention is kept on keeping the damn thing in the air/not shaking itself to pieces. There are some things you should include (see CAP413) but don’t go on like Ken Dodd at the Liverpool Empire. This is often delivered in a Nasal Voice, for which you will lose extra points.

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4. Pressing the Cabin Announcement PA button instead of the RT Transmit. If you make your Cabin Announcement to the Tower and all the others listening to it, three things will happen:
1. You’ll have to do it again with the right button.
2. You’ll look a fool
3. You’ll have blocked the Tower frequency for 40-60 seconds. Bad news for the aircraft at half-mile Final waiting for his landing clearance.
Lose extra points (and possibly any chance of starting at all) by blaming ATC for a delay which was actually caused by a flat tyre on the catering truck.
5.Having a Chat with other Pilot’s who you recognise.Hey Bruno, let’s have a beer next time we’re in Munich” is not a phrase you’ll find in the Manual. And you’re never going to have that beer, anyway. Bruno hates you.
6. Saying “Roger That”. No. It’s “Roger”. Join the Hospital Radio point 1 and go to Remote Parking.
7. Saying “seen on the Metal Detector” as a response to Traffic Information. Go and join your friends from 1) and 6).
8. Ask for opposite-direction Runway for ” performance reasons” when it’s obviously too busy. Everyone else can do it -and so can you. Either throw off the Fatties, or sharpen your Performance Pencil a bit more.



“Sometimes the Controller will say “Standby”. This means he is busy with other tasks in the Tower.

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Dorian Crook is a pilot, air traffic controller & stand-up comedian. His Maule has bigger wheels than your Cessna.

MiG-37B assessment: The Stealthy Soviet that never was


Jim Smith had significant technical roles in the development of the UK’s leading military aviation programmes, from ASRAAM and Nimrod, to the JSF and Eurofighter Typhoon. He was asked by the British Government to assess the YF-22 and YF-23; we wondered what he would make of a totally fictional aircraft, the MiG-37B model kit of 1987. 


“The Testors toy company released this model 2 years after their very successful F-19 kit and only about a year before the F-117 appeared in public. It’s a pretty ugly beast, but, let’s not hold that against it, given the impact that designing for low signature had on Have Blue and the F-117. So what have Testors’ done in ‘Russianizing’ their F-19 stealthy strike concept? Well, somewhere along the way, the Testors team appear to have heard some whispers about ‘The Black Jet’, as insiders were referring to the F-117. The MiG-37 model has outward canted fins, and has a facetted structure, while retaining the letterbox-slot exhaust of their F-19 concept. While the appearance of these features may have caused some disquiet in some circles, there was by this time some awareness of strange black aircraft operating up in Tiger Country (the far reaches of the Nellis, Tonopah and Area 51 complexes). In addition, the Pentagon was moving towards first, disclosure that the F-117 existed, and then, the presentation to families and the media which I attended.


As well as some of the F-117 features, Testors has done quite a good job of giving the aircraft a Russian look. Partly, the use of a MiG-23- like undercarriage, and partly subtle stylistic and colour scheme aspects which just convey a less-Western look. Paradoxically, the crude-looking faceted shaping turned out to be more accurate than the smooth surfaces of their F-19 concept.


From a propulsion perspective, the intakes perhaps look a little more likely to work than those of the F-19, and still bear no resemblance to those of the F-117. From a stealth perspective, however, the whole aircraft is full of changes in angle which look counter productive to maintaining a low signature. In particular, the under-surface of the aircraft does not feature the flat surface of the F-117, and appears unlikely to be successful in managing the MiG-37 ‘s signature. In addition, the changes in sweep of the planform, the gaps and joins around wing slats and other features, and the intakes all suggest a less successful stealth design.

Mikoyan-Gurevich MiG-37B Ferret E [LIMITED to 500px]

Aerodynamically, the MiG-37 concept would probably have been more efficient and easier to manage than either the F-19 or the F-117, as the moderately swept wings would allow the use of high lift devices and a significantly lower take-off and landing speed. Like the F-19, the relatively conventional cockpit would probably have resulted in a less constrained environment for the pilot than the essentially pyramidal F-117 cockpit.


I am a bit concerned about the extremely large fins, coupled with the anhedral of the wing, which might lead to unusual lateral-directional handling, but again, there is nothing terrible about the configuration (given the open-minded approach I am adopting). It is very ugly, but it is not alone in that.

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Like the F-19 forward fins, I do have a gripe – the dorsal airbrakes just don’t make sense. There-s no way this aircraft would be used as a dive bomber, and the configuration is likely to be draggy enough that airbrakes are unlikely to be needed to manage the approach. Plus they have the disadvantage that they would deny the opportunity to use uber-cool black silk parachutes deployed by the 2 F-117s that came ‘out of the black’ at Nellis in April 1990.

Summing up the MiG-37 – ugly, but closer to the appearance of the F-117 than the F-19. In the aerodynamics vs stealth trade off, perhaps the solution has better aerodynamics than stealth.”



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The F-19 stealth fighter: Would it have worked in the real world?



“Several different F-19 kits are available, I am going to comment on the Testors one, as I believe it was the first, and most successful. 


However, the one from Monogram, shown below, resembles closely a supposed Northrop F-19 concept, which, who knows, may have had some actual reality as a project.


The whole F-19 saga appears to be littered with guesswork and disinformation, but I have chosen to look at the Testors concept, partly because that is a kit I remember seeing when it first appeared.

Before commenting on the design of the ‘F-19’ and the MiG-37B ferret, I should first say a few words about the F-117. I was in the States when this aircraft first appeared in public, working for the British Embassy in Washington. Through my role, I was at Nellis AFB on April 21, 1990 when the aircraft first appeared in public. One of the reasons I was there was that we had had a pilot flying the aircraft as a RAF exchange posting for a few years prior to its existence being acknowledged.

Here’s a couple of pictures from that day – the full story is in Two Up, a book by myself and my twin brother Ron (recently reprinted in hardback and also available as an e-book). 


I put these F-117 pictures in this article to remind readers just how bizarre and unlikely-looking this aircraft was at first sight. Consequently, it is important to have an open mind when looking at the F-19 and the MiG-37B.

So, the F-117 looks pretty unlikely, but what did the F-19 concept designers get right and wrong?

Well, one thing that was clearly in their minds was that attention needed to be paid to the Infra-red signature as well as the radar signature. Consequently, they seem to have made a couple of good guesses regarding the exhaust system. This resembles the F-117 letterbox style exhaust, and also incorporates (I assume) additional cooling by mixing the exhaust with additional air drawn from the intake louvres on the upper surface of the model. The F-117 achieves the same effect through using cool engine bypass air.

The fins on the F-19 model are canted inwards. The configuration is similar to that used in the initial Have Blue demonstrator aircraft which preceded the F-117. This was either a very good guess, or suggests some awareness of Have Blue.

At the other end of the propulsion system, a shielded NASA flush inlet is used. These inlets normally work by using the shaped inlet sides to create vortices which entrain flow into the inlet. I’m not sure the Testors solution would have worked very well as an inlet, but the triangular shield over the inlet is clearly intended to block a direct line of sight to the engine face.


This advert, probably from 1987, shows another notional stealth fighter. Perhaps Northrop wanted to promote their stealth work on the B-2 without sharing secrets? Artwork by Erik Simonsen, according to whom “I created the Northrop-Loral silhouetted artwork using a model, but I didn’t come up with that design. It was just one of the concepts around at the time. I don’t know who created the other Loral rendering (flying left to right) in your article, but the U.S. insignia star/bar is on the upper right wing, instead of the upper left. That always bothered me – I prefer accuracy. All that detail work and they got that wrong and never corrected it.”

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The F-117 solution may look crude, but is actually an elegant solution to this problem. A grid is placed in front of the intake with a mesh size smaller than the wavelength of the radar systems against which the aircraft is designed. This prevents RF energy from entering the intake and being reflected back towards the illuminating radar.

The F-19 and the F-117 share one design feature in having a largely flat underside. This avoids excrescences and apertures which could reflect radar over a broad range of scattering angles. However, the F-19 designers were clearly not aware of the simple and inelegant solution adopted by Lockheed in the F-117, of using faceting, surface and edge alignment to constrain radar reflections to very narrow spikes to reduce the probability of a track on the aircraft being maintained. As a result, the F-19 under-surface is smooth and uncluttered, but not as flat as that of the F-117. The optical sensor is under the nose, rather than in front of the cockpit as on the F-117, which would perhaps be more difficult to screen.

The F-19, instead of adopting the very highly-swept planform of the F-117, uses a narrow curved-delta design, in some ways reminiscent of a stretched F-4D Skyray, with a break in sweep where the fuselage transitions into the wing, and a curved leading edge and wing tip.

Would this work as a stealth configuration? The disadvantage is that the break in planform would probably cause a local return, and the curved planform would spread returns so that they were likely to be detectable over a broader aspect. Making this sort of shape work would probably require extensive use of tailored electro-magnetic materials to control the nature and aspect of radar returns, but this would not have been available when the model emerged, in 1986, four years before Stealth was unveiled at Nellis AFB.

Would the design work aerodynamically? Well, the F-117 is no paragon of aerodynamic efficiency, and the F-19 wouldn’t be either. Given the planform, I’d expect lift dependent drag to be pretty high, and given the intake design, I’d expect a long take-off run, and great care to be required to stay on the right side of the drag curve on the approach. With questionable intake efficiency, particularly at any significant incidence, and a slender low aspect ratio design, getting into a high sink rate on the approach could be a distinct possibility. But otherwise, noting the need to keep an open mind – why not?

I am puzzled by the curious upward pointing fins on the upper surface behind the cockpit. These appear likely to de-stabilise the aircraft in yaw, which is probably not what it needs.

Overall, inefficient, yes, but arguably little more implausible than the real F-117. Testors missed some of the simple but effective stealth features of the F-117, but did identify some of the other features.” 

Firefox: Would it have been any good in real life?


Jim Smith had significant technical roles in the development of the UK’s leading military aviation programmes. From ASRAAM and Nimrod, to the JSF and Eurofighter Typhoon. He was asked by the British Government to assess the YF-22 and YF-23; we wondered what he would make of a totally fictional aircraft, the titular Firefox from the 1982 Clint Eastwood film.

Hush-Kit’s Editor has asked me for my thoughts about three fictional aircraft: the Firefox; the F-19 and the MiG-37B. Firefox featured in two films, Firefox and Firefox Down. The F-19 was the subject of a famous kit by Testors, and a completely different kit by Monogram. These very different concepts purport to be based around aircraft sighted around Area 51 at the time. The MiG-37B is a concept for a Russian stealth fighter of the F-117 genre, and was the subject of a kit also by Testors. This first study will look at the Firefox. 



Credit: Kurt Beswick

The Firefox is a splendidly ambitious design, supposed able to achieve Mach 6 and to embody a range of advanced technologies, including thought control of it weapons systems (as long as you can think in Russian). Other claimed characteristics include 2 x 50,000-lb thrust engines, flight at up to 130,000 ft, internal carriage of 6 AA-11 missiles, 2x 23mm cannon and chaff and flare dispensing pods.


Apart from a few obvious blunders, I really quite like the Firefox. If one imagines a strategic air defence aircraft, capable of taking on the XB-70, SR-71, and other high-flyers like the U-2, a configuration which borrows from the Valkyrie makes some sense.


My biggest concern with the Firefox is the propulsion system, but I’ll leave that aside for the moment, and suppose sufficient thrust is available. The highly-swept near delta wing looks to fit inside a Mach 2.9 Mach cone, and it would be plausible to achieve that sort of speed without excessive wave drag and heating, assuming the stated materials for the structure. Mach 6, even for brief periods, does not look likely, particularly given the propulsion system. I like the use of the canard and the fold-down wing tips, both clearly borrowed from the Valkyrie, and the essentially high-speed bomber/transport-like configuration would be well suited for high-speed interception of strategic targets at high altitude. I would, however, expect any kill to be achieved using internally carried long-range air-to-air weapons. There is no need to carry 2 x 23mm cannon, and one cannot readily conceive a situation where this aircraft would be used in WVR combat.

Here are a few other (unsuccessful) aircraft designed with the same sort of performance goals (M 2.5 or thereabouts):   



I particularly like the Douglas one, whose canard and wing resemble the Firefox quite closely, although it has a different propulsion arrangement and a single fin rather than twin fins.

What about propulsion? Well, what we do know about high-flying fast aircraft is that they have large engines, and truly enormous propulsion systems. Managing the intake compression process to bring airflow to the engine front face at stable subsonic speeds requires a very large and complex intake system. Look at Concorde, the XB-70, the MiG-31 (the real one) and the SR-71, and what you will find is huge engines behind bigger intake systems.


The Mach 3 XB-70 had a huge intake system for its six engines.

I used to attend meetings occasionally with Rolls-Royce at Filton. On the wall of their management conference room, occupying the entire length of the room was a fabulous full-scale drawing of the engine installation of the Olympus 593 in Concorde. Truly, engineering as art. But driven by the physics of getting the air to the engine in a usable state – stable in flow, and at the temperature and pressure required.

There is no way Firefox would work with anything that could be described as a high-bypass ratio turbofan. Something I recall being referred to as ‘a leaky turbojet’ would be more likely. But probably installed either like the Concorde in underwing nacelles, or like the Douglas supersonic transport or the XB-70.


The position of the XB-70’s six engines is apparent from the rear quarter.

The two twin-engine aircraft known to have this sort of performance are the remarkable SR-71, where the engines have been described as turbo-ramjet, and the MiG-31. For the SR-71, both the intake and ejector exhaust nozzle are critical to engine performance, and very complex airflow management is required. For the MiG-31, the powerplant is the Soloviev D-30R, which is a ‘leaky turbojet’ with a by-pass ratio of 0.57, but only about 2/3 the proposed thrust of the Firefox engine. In describing the earlier MiG 25, Jane’s stressed that most of the thrust at high speed comes from the intake and nozzle, and these are pretty complex for both the MiG-25 and 31.


Key to the MiG-25’s remarkable performance are its vast intakes.

I regard the splitting of the intake path both by the wing and the fin structure as a concern, given the known complexity and sensitivity of the intake systems for similar aircraft.  I do not believe the system, as drawn, could get the aircraft to Mach 6, and possibly not even to Mach 3.

On the whole, I suggest the aircraft would be suited to two engines installed like Concorde, or indeed like current Sukhoi aircraft essentially in nacelles fed by underwing intakes. If the target performance were to be Mach 3-ish, as suggested by the appearance of the airframe, it does not seem evident that 50,000 lb thrust engines are required, leave alone additional rockets. It’s worth noting that the stated dimensions of the Firefox are significantly smaller than those of the SR-71, supporting the view that 50,000 lb thrust engines would not be required.

But then, all you would have is a sexier MiG-31, not at all what was envisaged by the film script.


What about thought-control? We already have voice control for a number of functions in some advanced aircraft. Thought control might be quite difficult, but programs have existed where there was conceptually a progressive hand-over of autonomy from pilot to system as pilot workload went up, allowing fuel to be managed without intervention, for example.  However, I would think that thought-controlled weapons systems would be among the last to be implemented, because of the need to track ‘who did what’, both for training, and to provide an audit trail for decisions to employ lethal force.


The SR-71’s unique intake system.

I admire the ambition of the Firefox, and the recognition of the importance of advanced systems as well as the right airframe. There’s no way the stated design would achieve Mach 6, and given that, I prefer to view Firefox as a strategic interceptor, operating at a maximum of Mach 3+, heavily armed and with good systems. But no cannon, no auxiliary rockets, and somewhat smaller thrust. Otherwise, I think that the forward part of the aircraft does look somewhat crude, and would probably produce unacceptable high-speed drag.

Vertical take-off Mach 4 Lockheed Skunk Works’ Flying Cigar

ciagr 5.png

A 1957 patent by Skunk Works genius Nathan C. Price envisioned Mach 4 airliners shaped like cigars. Powered by ramjets, capable of vertical take-off and flying in the mid-Stratosphere, the designs almost certainly started as a Black project with a military application in mind. 

The Boeing Model 307 Stratoliner was the first commercial transport aircraft to enter service with a pressurised cabin, thanks to the ingenious cabin pressure regulator created by Nathan C. Price. He also developed the supercharger for the P-38 Lightning fighter without which it would had lacklustre performance at higher altitudes. He was an early champion of the axial-flow jet engine and an important figure in US jet propulsion development.


He was exceptionally far-sighted in his vision: his Lockheed L-133 design (above), work on which started in 1939, was for a blended wing-body canard delta jet fighter capable of 612mph. By the 1950s, as Lockheed’s senior engineer, he was happily designing Mach 4 flying saucers— but even these were conventional compared to his next one. He proposed an airliner with no wing, no control surfaces, no visible cockpit and it was to have a cruising speed between Mach 3-4 and be capable of vertical take-off and landing! ciagr 34.png

The machine was essentially a ramjet-powered missile, albeit full of holiday-makers. Ramjets can only function at high speeds, so in order to reach these speeds it harnessed the power of a clutch of turbojet engines. Vertical takeoff and landing would take place by directing the exhaust gases of the turbojets (using the Coandă effect Effect: the tendency of a fluid jet to stay attached to a convex surface). Without visible control surfaces steering was to be via selective vectored thrust channelled through louvres.

ciagr 3.png

Once the huge ramjet kicked in the machine was expected to reach 100,000ft, and achieve intercontinental ranges. The machine would utilise inertial guidance and have a high degree of automation — but would carry a crew to manage emergencies. It is believed that wind tunnel testing took place, though fascinating concept was never built.

It was filed as a patent in 1957 but it was not listed until late 1964. Though revealed as an airliner it seems highly likely — considering both Skunk Works history and the Cold War context —  that the study begun life as a military aircraft, most likely a nuclear strike platform or reconnaissance aircraft.

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