Identifying helicopter types: telling H135, H145, Bell, NH90 and CH-47 apart

A thumping over the field, a yellow dot above the highway, a gray behemoth with two rotors flying low: as a spotter you run into helicopters all the time – often away from the big airports and usually only for a few seconds. If you want to identify helicopter types, you therefore need a quick grid instead of long data sheets. This guide shows you the five features you use to identify the most important types in Central Europe, and then goes through the types one by one: from the Airbus bestsellers H135 and H145 through the Bell classics to the NH90 and CH-47 Chinook.

Identifying helicopter types: the short answer

You identify a helicopter type by checking tail rotor, blade count, rotor layout, landing gear and size one after another. A shrouded tail rotor in the fin points to Airbus Helicopters, an open one to Bell, Leonardo, Sikorsky or older types. Two blades on the main rotor are typical for the Bell 206, UH-1 and Robinson, five blades with a Fenestron for the H145. Two rotors one behind the other means Chinook. Skids or wheels and the fuselage size then separate the remaining candidates.

Unlike with an airliner, context helps you enormously: a yellow helicopter with skids over an accident site is very likely an H135 or H145 of air rescue, a gray helicopter with wheeled landing gear over a military training area more likely an NH90 or CH-53.

The five features that give every helicopter away

Before getting to individual types, it’s worth looking at the basic grid. You can see these features from a greater distance and in poor light too.

1. Tail rotor: shrouded or open

The tail rotor balances the torque of the main rotor and is the strongest manufacturer feature. The Fenestron runs as a multi-blade rotor in a tunnel in the vertical stabilizer. It first flew on April 12, 1968, on an experimental Gazelle and is now an identifying mark of Airbus Helicopters. An open tail rotor with two to five blades on the side of the tail boom, on the other hand, is found on Bell, Leonardo, Sikorsky, Robinson, the NH90 and older Airbus types such as the Bo 105 or the H125.

2. Blade count on the main rotor

Counting works best with the rotor stationary or slowly winding down on the ground. In flight, a photo with a fast shutter speed helps – how to freeze rotors sharp or deliberately blur them is in the guide to propellers and shutter speed. Two-blade rotors also produce the typical, deep “whop-whop” beat that you recognize even without seeing the aircraft. More on that in the article Identifying aircraft types by sound.

3. One rotor or two

Almost all helicopters you see have one main rotor plus a tail rotor. The big exception is the tandem rotor of the CH-47 Chinook, with two counter-rotating rotors front and rear and no tail rotor.

4. Skids or wheels

Light and medium helicopters such as the H135, H145, Bell 206 or Robinson stand on skids. Larger types such as the NH90, CH-53, Chinook, Super Puma or the Leonardo AW139 have wheeled landing gear, often retractable.

5. Size and proportions

The cabin length in relation to the rotor diameter, the height above the ground and the position of the engines round out the picture. A slim two-seater with an exposed tail boom looks completely different from a burly transport with a rear ramp.

Airbus H135: the rescue helicopter par excellence

The Airbus H135, formerly the EC135, is the helicopter you see most often in Germany. It goes back to MBB’s Bo 108 technology project, which was meant to transfer the strengths of the Bo 105 into a modern, aerodynamically smoother airframe. The first EC135 prototype flew in February 1994, and European certification followed in 1996. The first aircraft went to the Deutsche Rettungsflugwacht, today DRF Luftrettung, and in 2011 ADAC Luftrettung took delivery of the thousandth example.

How to recognize it:

• Fenestron in the vertical stabilizer, with small stabilizing surfaces above and below at the tail
• four rotor blades on a bearingless rotor head without classic hinges
• Skids, compact and rounded cabin with a large, curved windshield
• two engines under a common cowling on the cabin roof
• Clamshell rear doors under the tail boom, through which the stretcher is loaded in air rescue

In service, you meet the H135 in yellow with ADAC Luftrettung, in red and white with DRF, in the liveries of several state police forces and with the Bundespolizei. The Bundeswehr uses the H135 as a training helicopter for basic training in Bückeburg.

Airbus H145: bigger, taller, with five blades

The Airbus H145 is the big brother of the H135 and comes from the family of the BK 117, which MBB developed together with Kawasaki. Its direct predecessor, the EC145, first flew in 1999 in Donauwörth. The modernized EC145 T2 with a Fenestron was certified in 2014 and renamed H145 in 2015. Since certification in June 2020 there has been the five-blade version, which may be somewhat heavier with a takeoff weight of up to 3.8 tonnes.

How to tell the H145 and H135 apart:

• Blade count: Five blades with a Fenestron means an H145 for sure. With four blades, you have to watch the proportions.
• Height: The H145 stands noticeably higher on its skids, and the cabin looks tall-legged and bulbous.
• Cabin length: The H145’s cabin is longer, the sliding doors are larger, and the distance between cockpit and rear doors looks more stretched.
• Weight: With a maximum takeoff weight of 3.7 to 3.8 tonnes, the H145 is noticeably heavier and bigger than the H135.

Careful with the predecessor: the older EC145 (BK 117 C-2) looks very similar to the H145 but has an open tail rotor instead of the Fenestron. In Germany, the H145 flies with ADAC and DRF, with many state police forces and, as the H145M, with the Bundeswehr. In Switzerland, it is the backbone of Rega.

The rest of Airbus’s EC and H family

With the renaming of Eurocopter to Airbus Helicopters in 2014, the models gradually received names with an H prefix. The number roughly stands for the weight class. In databases and in everyday spotting, old and new names run side by side, so here are the most important pairs:

Current name	Old name	Engines	Tail rotor	Typical feature
H120	EC120 Colibri	1	Fenestron	small single-engine with skids, rounded cabin
H125	AS350 Ecureuil / AStar	1	open	three-blade rotor, slim tail boom, workhorse in the Alps
H130	EC130	1	Fenestron	wide cabin with large panoramic glazing, popular for sightseeing flights
H135	EC135	2	Fenestron	compact, four blades, air rescue and police
H145	EC145 T2 / BK117 D	2	Fenestron	taller and bigger, four or five blades
H160	–	2	Fenestron, canted	curved blade tips, modern smooth shape, wheeled landing gear
H215	AS332 Super Puma	2	open	large transport helicopter with wheeled landing gear
H225	EC225 / EC725 Caracal	2	open	further development of the Super Puma, offshore and military

Two practical notes: the AS365 Dauphin also has a Fenestron and wheeled landing gear and can be confused with the H160 from a distance – but the Dauphin looks more angular and older. And the Tiger attack helicopter falls outside the grid of civilian types with its narrow silhouette with two pilots seated one behind the other and its stub wings for external loads.

Bell: two-blade rotor and open tail rotor

Bell from Texas shaped the helicopter world for decades. In Central Europe, you see Bell types less often than Airbus types today, but they turn up with charter companies, utility flights, foreign police forces and armed forces.

• Bell 206 JetRanger / LongRanger: Single-engine light helicopter with a two-blade rotor, skids and a slim tail boom with an open tail rotor. The Bell 206 first flew in 1962, and around 7,300 were built through 2017. The stretched LongRanger has a longer cabin with additional seats. ICAO code in flight plans: B06.
• Bell 407: Developed from the LongRanger, but with four blades and larger cabin windows. If you see a 206 silhouette with a four-blade rotor, you usually have a 407 in front of you.
• Bell UH-1 “Huey”: The classic with a two-blade rotor, a long cabin with large sliding doors and the loud “whop-whop” sound. The Bundeswehr retired its UH-1Ds in 2021 – in Germany it is now mainly a historic type for museums.
• Bell 412: Further development of the twin-engine Bell 212, outwardly similar to the Huey, but with a four-blade rotor and an engine hump on the roof. In Europe it flies with Italian authorities, among others, often as the license-built AB412 from Agusta.

A Bell helicopter has an open tail rotor on all common models. Two blades plus an open tail rotor plus skids already narrows the selection considerably. There is a risk of confusion with the Robinson R44, which also has two blades – but the Robinson is much smaller, has a piston engine, a teardrop-shaped cabin and a conspicuously thin, tubular tail boom.

NH90: the angular multirole helicopter

The NH90 emerged as a joint project of several NATO countries. It is built by NHIndustries, in which Airbus Helicopters, Leonardo and Fokker are involved. The first prototype flew on December 18, 1995. The NH90 was the first production helicopter with fully electronic flight controls (fly-by-wire).

How to recognize it:

• diamond-shaped, angular fuselage cross-section made of composite material with clearly slanted side walls
• four-blade main rotor and open tail rotor at the end of a sturdy tail boom
• Wheeled landing gear with side sponsons
• Engines on top of the cabin roof, with a distinct gearbox hump behind them
• on the TTH transport version, optionally a cargo ramp at the rear

In Germany, the army flies the NH90 TTH as a transport helicopter. The navy uses the naval version NFH as the Sea Lion (search and rescue, transport) and is introducing a version for anti-submarine warfare with the Sea Tiger. The naval version has a folding tail boom and reinforced landing gear for landings on ships. Some countries have retired their NH90s early in recent years or decided to withdraw, including Australia and Norway; in Germany, however, the type remains a central type.

CH-47 Chinook: two rotors, no tail rotor

The Boeing CH-47 Chinook is the only helicopter you can recognize beyond doubt from its basic shape. The prototype first hovered on September 21, 1961, and since then Boeing has built well over a thousand.

How to recognize it:

• Tandem rotor: two large three-blade rotors, one above the cockpit, one on a tall pylon at the rear
• no tail rotor – the two counter-rotating rotors cancel each other’s torque
• two turbines on the outside left and right of the rear fuselage, under the rear rotor
• long, box-shaped fuselage with a rear ramp and four-part wheeled landing gear

In Europe, Chinooks fly with the British Royal Air Force and the Dutch air force, among others. In 2023, Germany decided to procure 60 CH-47Fs. They are meant to replace the air force’s aging CH-53G; delivery is planned from 2027 according to current plans, with Holzdorf intended as the main base. Until then, a Chinook in Germany is mainly seen at exercises, air shows such as ILA Berlin or on visits by foreign armed forces.

The CH-53: the big brother with six blades

As long as the Chinooks aren’t here yet, the Sikorsky CH-53 is the Bundeswehr’s heavy transport helicopter. The first CH-53G went to the army in 1972, and since 2012 the fleet has flown with the air force. You recognize it by its six-blade main rotor, the engines on the sides of the forward fuselage, the tall tail pylon with a four-blade tail rotor and the cargo ramp under the tail boom. More on the large transport types is in the guide Identifying military transports.

All the important types compared

Type	Main rotor	Tail rotor	Landing gear	Engines	Where you see it
Airbus H135	4 blades	Fenestron	skids	2	air rescue, police, training
Airbus H145	4 or 5 blades	Fenestron	skids	2	air rescue, police, Bundeswehr (H145M)
Airbus H125	3 blades	open	skids	1	utility flights, Alps, sightseeing flights
Bell 206	2 blades	open	skids	1	charter, training, utility flights
Bell 412	4 blades	open	skids	2	foreign authorities and armed forces
Leonardo AW139	5 blades	open	wheels, retractable	2	offshore, rescue, authorities
NH90	4 blades	open	wheels	2	army, navy
Sikorsky CH-53G	6 blades	open	wheels	2	air force
Boeing CH-47	2 × 3 blades (tandem)	none	wheels	2	exercises, air shows, air force in the future

The Leonardo AW139 is in the table because it is often confused with Airbus types: medium-sized, twin-engine, but with an open tail rotor, five blades and retractable wheeled landing gear.

How to read civilian registrations is explained in the guide Understanding aircraft registrations – in Germany, the “H” directly after the “D-” stands for helicopter, more on that in the article German aircraft registrations and weight classes. The numeric IDs of the armed forces are decoded in the article Bundeswehr aircraft registrations.

Where to see helicopters best

Helicopters are the spotter subjects away from the runways. You have good chances at hospitals with an air rescue base, at police helicopter squadrons, at small airfields and at airports with helicopter operations at the edge of the apron. How to go about it and which places are worthwhile is described in the guide Helicopter spotting. You can often follow rescue and police helicopters live as well – what is visible and what isn’t is in the article Finding helicopters on a flight tracker.

If you want to see many types at once, head to the Hubschraubermuseum Bückeburg (helicopter museum). There you find historic types such as the Bo 105 or the UH-1D, which you hardly experience in the sky anymore – ideal for studying blade counts, rotor heads and tail rotors up close.

If you don’t just want to identify helicopters but fly them yourself, you’ll find the way there in the guide Becoming a helicopter pilot. If you’re just starting with type identification, the introduction Identifying aircraft types for beginners helps too. Many basic ideas – check features in a fixed order, don’t rely on the livery – apply to helicopters just the same.

Conclusion

At first glance, helicopters look more alike than airliners, but a fixed grid lets you tell them apart well. Tail rotor and blade count do most of the work: Fenestron plus four blades usually means H135, Fenestron plus five blades H145, two blades with an open tail rotor Bell or Robinson. In the military, fuselage shape, wheeled landing gear and rotor layout separate the NH90, CH-53 and Chinook from each other. The livery helps place the operator, but it easily leads you astray on the type.