A Guide To Telling Narrow-Body (aka Single Isle) Aircraft Apart

In my last post, I wrote about how one is able recognize wide-body jets and distinguish them from each other. While I was originally going to write a mega-post for both wide-body and narrow-body jets, by the time I got to the end of my previous post, the article was already extremely long, so I decided to split it up into two articles, with the latter focusing on narrow-body jets. In this article, I’ll tell you how to recognize and tell apart narrow-body jets in a similar fashion to my previous article. Unlike my previous article where I pretty much covered every wide-body aircraft in existence, in this article, I’ll only cover the most popular narrow-body aircraft in service still, while omitting most historical aircraft not in or in limited service.

But first, what even are narrow-body jets? According to Wikipedia, “a narrow-body aircraft or single-aisle aircraft is an airliner arranged along a single aisle permitting up to 6-abreast seating in a cabin below 4 metres (13 ft) of width.” So basically, narrow-body aircraft essentially are all commercial aircraft which aren’t wide-body jets, meaning that they only have one aisle between two sets of seats (going up to a 3-3 configuration), which in addition includes smaller regional commercial aircraft, and generally are shorter and have less range than wide-body jets. That covers anything from your standard 737s or A320s, to your regional E175s or CRJ-900s, to your Douglas DC-4s, to even your commuter Beechcraft 1900s.

Based on that definition, it should be quite easy to tell narrow-bodies from wide-bodies, especially if there are two aircraft right next to each other of opposite type, given that narrow-bodies are significantly shorter in length and height, in addition to generally having less exit doors. It’s even easier to tell if you’re on (or looking at a picture of) a narrow-body or wide-body aircraft from the inside, as narrow-bodies only have one aisle, while wide-bodies always have two (at least on the main deck). Like in my previous article, I tried to create diagrams for most of the aircraft, though I didn’t for all of them, especially if the only difference between an aircraft type is an extra window.

The Boeing 737

The Boeing 737 is probably the most iconic narrow-body aircraft ever, being the backbone of many airlines’ fleets for decades. There are four generations of the Boeing 737: the original 737, including the 737-100 and 737-200, the 737 Classic, including the 737-300, 737-400, and the 737-500, the 737 Next Generation, including the 737-600, 737-700, 737-800, and the 737-900, and finally the infamous 737 MAX, including the 737-7, 737-8, 737-9, and the 737-10. The original 737 variants are for all practical purposes out of service (although are in service with a couple of small Canadian and African airlines), while the 737 Classic is only in limited service with a few airlines here and there. The 737 Next Gen is by far the most popular series in service now and is in service with countless airlines around the world, although with the 737 MAX, it’s basically finished in terms of being produced in commercial service. And I think we all know about the 737 MAX.

Since the original 737 and the 737 Classic are both only limited service, it’s quite difficult to compare them from the 737 NextGen, and since I would like to keep this article more concise, I would cover the latter two series of the 737. As stated earlier, the 737 Next Generation consists of the 737-600, the 737-700, the 737-800, and the 737-900. All series feature the older 737 engine shape (in comparison to the 737-600), like on the 737 Classic, in which the bottom of the engine is flat, making it easy to recognize. The 737 also has a distinct nose shape which is pointier than those on other aircraft, making it also easily recognizable, in comparison to say, an A320.

The 737-600, the direct successor to the 737-500 is the smallest variant of the 737 and is also the least popular (by far), making it pretty much a flop. I don’t believe it has any winglets, in comparison to the latter three variants, which pretty much all have winglets. It can be easily confusable with the 737-700, as both have three exit doors per side, the middle one being an over-wing exit, although one can tell the difference through looking at the number of windows between Door 1 (meaning either Door L1 or Door R1–just means the first door of the aircraft) and the over-wing exit: the 737-600 has 12 while the 737-700 has 16. Also, very few airlines operate the 737-600, most prominently being WestJet, Tunisair, and Air Algerie.

The second smallest 737 Next Generation variant is the 737-700, which has been a massive success with airlines such as Southwest Airlines or United. It is similar to the 737-600, although again, most have winglets and it has 16 doors between Door 1 and the over-wing exit instead of 12. The vast majority of 737-700s, 737-800s, and 737-900s have blended winglets, although there are a few exceptions.

Most 737 NextGens have blended winglets (think of them as your more traditional winglets), which are very similar to the blended winglets (and are intended to decrease fuel usage), called Sharklets, which are on many A320 series aircraft. Some 737 NextGens (of all variants besides the 737-600) have split-scimitar winglets, which have a bottom part to them (hence the “split” name) and have curved edges (and hence the scimitar bit of the name). These are similar to the winglets on the 737 MAX, which also split apart and have two edges, although they point outwards more than split-scimitar winglets do. Just for reference, in the pictures below, the 737-700 does not have split-scimitar winglets, while the ones of the 737-800 and 737-900 do.

Meanwhile, the 737-800 is the most popular of the 737 variants, being extremely popular with airlines such as Ryanair or American Airlines. The 737-800 is the smallest of the 737 NextGen variants to have four exit doors per side, having two over-wing exit doors per side. In contrast to the 737-900, it also has between 17 and 19 windows between Door 1 and the first over-wing exit, while the 737-900/737-900ER has about 21, although some configurations have as little as 17 (i.e. on United), although then they have large gaps in the fuselage without windows for an extra lavatory. The 737-800 also doesn’t have a fifth door (or a plugged fifth door, like many airlines have on the 737-900ER) between the second over-wing exit and the rear exit.

Meanwhile, there are actually two versions of the slightly less popular 737-900–the 737-900 and the 737-900ER, the latter being the more popular version. The 737-900ER (obviously) has much more range than the 737-900, while it also has an extra door between the second over-wing exit and the rear door, which is inactive on most airlines, although is active on a couple airlines such as Lion Air.

That fully accounts for the 737 NextGen series of commercial aircraft. Next up is the (infamous) 737 MAX, which currently only has the 737 MAX 8 and the 737 MAX 9 in commercial service (although, of course, they are still all grounded). The 737 MAX 7, the 737 MAX 10, and the 737 MAX 200 (which is a high density version of the 737 MAX 8, basically specifically made for Ryanair) are expected to come into commercial service relatively soon, although who knows at this point.

The main distinguishing factors of the 737 MAX in comparison to the 737 NextGen are its winglets and its engines. Firstly, it features distinct winglets which have two edges on it (like split-scimitar winglets), are more pointy and go further outwards than split-scimitar winglets do, and aren’t as curved at the ends as they are. Secondly, the 737 MAX’s engines also have serrated edges to its nacelles, just like the engines on the 787 and 747-8. Additionally, the 737 MAX’s nose also looks similar to the one on NextGen aircraft. In order to tell the different variants of the 737 MAX apart, the 737 MAX 7 has three exit doors per side (one being an over-wing exit), the 737 MAX 8 has four (two being over-wing exits), while the 737 MAX 9 and the 737 MAX 10 have five per side (two also being over-wing exits).

Airbus A320 Series

The Airbus A320 series is probably the second most iconic narrow-body aircraft. Its inaugural flight was in 1988 and was Airbus’ first and only narrow-body aircraft. There are two series’ of the A320–the original A320 family, containing the A318, A319, A320, and A321 (now called the A320ceo series, for Current Engine Option), while their newer series is called the A320neo series, containing the A319neo, A320neo, and the A321neo. Notably, to make matters even more confusing, there also are a couple sub-sub variants of the A320 series, including the A319LR, A321neoLR, and the A321neoXLR.

The A320ceo and the A320neo series are nearly identical aesthetically, but there are a couple of subtle differences which can help you tell the difference. In terms of size and shape, the A319neo (which isn’t very popular due to the similarly sized A220-300) and the A319ceo are nearly identical, similarly to the A320ceo and the A320neo, and the A321 and the A321neo.

The original design for the A320 actually did not have winglets (the A320-100), though I believe that all of those aircraft are now retired. Airbus’ subsequent versions had wingtip fences, which are only equipped on some Airbus aircraft, the A320 series being the only narrow-body aircraft to have them (see them in the photo of the A318 and A319). Meanwhile, Airbus later introduced ‘sharklets’ in order to save fuel, similar to the 737’s blended winglets, to their A320 series aircraft, introduced on their A319s, A320s, and A321s, in addition to being on all of their A320neo series aircraft.

The smallest variant of the A320 series is the A318, which does not have a corresponding model in the A320neo series. It only has three exit doors per side, like the A319, with one being an over-wing exit. All have wingtip fences, and none have sharklets. There are between 10 and 11 doors between Door 1 and the over-wing exit, as opposed to the A319, which has on average 13. It also was the least successful model of the A320ceo series and is being retired by most airlines operating it, and is only in service with a few airlines, such as Avianca, TAROM, Air France, and British Airways.

The A319 is the second smallest variant of the A320 series and is extremely similar to the A319neo. The vast majority of A319s have only three exit doors per side, with one over-wing exit per side, although some airlines, such as EasyJet, have two over-wing exits per side, making it similar to the A320. Many A319s do have sharklets, including all of the future A319neo model, though many, if not most, still have the standard wingtip fences, like in the picture below.

The A320 is the most popular of the A320 series and was the original variant. All A320s, including all A320neos, have four exit doors per side, two of which are over-wing exits. Unlike the A319, there are approximately 15 windows between Door 1 and the two over-wing exits. The EasyJet A320 pictured below has sharklets instead of wingtip fences, though many A320s don’t have them. However, all A320neos do.

The A321 is the largest variant of the A320 series and also has been quite popular worldwide. Most A321s and A321neos have four full exit doors per side, none of them being over-wing exits–one each at the front and rear, and another two being behind and in front of the wing. However, not all A321s are in this configuration–some A321neos (including all A321LRs, A321XLRs, and A321neos in their special “cabin flex” configuration) have a different door configuration which is outfitted with one door in the front and rear (per side), and then with one door between the wing and the rear of the aircraft, and then between one and two over-wing doors, with a total of between four and five doors per side. Many A321s and all A321neos also have sharklets, as pictured below.

Now, there are two major questions which I’m sure many of you are asking, which are: how do you tell an A320 from an A320neo, and an A320 from a 737? It’s quite easy to tell an A320 series aircraft from a 737, although telling an A320 series aircraft from an A320neo series aircraft is a bit trickier.

Firstly, the 737 and A320 series have vastly different nose shapes. The A320’s nose is more curved around the front and has flatter cockpit windows, while the 737’s nose is more pointy in shape and its cockpit windows on the bottom of each side form a sort of obtuse angle, if that makes sense (look back at the 737 pictures above to get a better understanding). Also, their winglets are different from each other–most A320 series aircraft have wingtip fences, while no 737s do, although some A320 series aircraft and the vast majority of 737s have blended winglets, which are called sharklets on the A320. Only a few 737 NextGens don’t have winglets, and only the very earliest A320s don’t. Additionally, some 737s have split scimitar winglets, making it easily recognizable as a 737 NextGen and not as an A320, while all 737 MAXs have a completely different type of winglet. If you still can’t tell which aircraft it is based on those first two criteria, then look at the aircraft’s engines–737 NextGen aircraft engines are flat at the bottom, whereas 737 MAX engines aren’t, though have serrated engine nacelles, whereas there are a few different types of A320 engines, though none have serrated nacelles or are flat at the bottom.

It can also be quite tricky telling an A320 series (aka A320ceo) aircraft from an A320neo series aircraft, though there are two ways to tell the difference, which are through its wingtips and engines. Firstly, all A320neos have sharklets, or blended wingtips, though not all A320ceos do, as some non-retrofitted ones have wingtip fences. In other words, all A320neos have sharklets, though not all A320ceos do. So if you do see an A320 series aircraft with sharklets, then it’s quite tricky to tell if it’s from the older series if it’s an A320neo. The main difference besides the winglets is that A320neos have larger engines which have a small flap/tray/extension at the bottom and top rear of the engines. The difference is subtle and is kind of hard to see, though I do believe that it is the main way to differentiate an A320ceo from an A320neo.

Boeing 757

The Boeing 757 (more specifically the -300 variant) is the largest narrow-body aircraft, making it relatively easy to spot. It’s not in production anymore, as it ceased production in 2004. It shares many similarities (from a technical perspective) with the Boeing 767, and has been used by many, if not most, major airlines at some point. Most airlines are now starting to retire their 757s, as most are quite old and are less fuel efficient than more modern aircraft, such as the A321neo. There are two main commercial variants of the 757, including the Boeing 757-200 and the Boeing 757-300. The -200 was the original variant and, although originally intended as a short-haul aircraft, because of its long range, many aircraft such as United and Delta operate it on transatlantic flights. The -300 was significantly less popular than the -200 and has a shorter range and is longer than the -200.

The 757 has a couple distinguishing factors, such as its nose, which is rounder than the 737’s nose. The 757-200 also has two different exit door configurations, though both of them have one exit door at the front and rear (per side) and one right in front of the wing. However, some 757-200s have two over-wing exits, while some instead have another larger exit door behind the wing, which is the same exit door configuration as on many A321s. Additionally, most 757-200s at this point now have blended winglets, though some still do not feature them.

Meanwhile, the 757-300 is much rarer than the 757-200, being only in service with a few airlines, including United, Delta, Condor, and Icelandair. It can easily be recognized by its six exit doors per side (which tells you something about its capacity, similar to that of many wide-body aircraft), including one each at the front and back, one right in front of the wing, one right behind the wing, and two over-wing exits per side. Additionally, most (actually by now I think all) 757-300s feature blended winglets.

Airbus A220

The Airbus A220, otherwise known as the Bombardier C Series, before they sold it to Airbus, is now Airbus’ second narrow-body aircraft, and, since they bought it from Bombardier, is basically their new solution as a replacement to older A318s and A319s. It has two variants–the A220-100 and the A220-300–the former being similar in size to the A318 and the latter being similar in size to the A319. Unlike the 737 and A320, the seat configuration in economy class is 2-3, making it more favorable among many passengers.

The A220 can be recognized by a few features, firstly being its unique canted winglets, which turn upwards sharply are different than the blended winglets on the 737 or A320, which turn up with a smooth curve. Secondly, all A220s have three exit doors per side, one being a smaller over-wing exit. Additionally, its nose is more sleek and pointy looking than the A320 or 737, giving it a look similar to the 787. In order to tell the A220-100 from the A220-300, the A220-100 has only 12 windows between Door 1 and the over-wing exit, while the -300 has 16.

Compare that to this Delta A220-100:

Boeing 717

I would normally (or I guess I should say historically) have included the MD-80 in this section, as it was the predecessor to the Boeing 717, though now that Delta has officially (and sadly) retired its last MD-80, no major airlines now operate the aircraft type, making the aircraft now scarce and hence not making the list of widespread narrow-body aircraft. The Boeing 717 was originally created by McDonnell Douglas as the MD-95, as a replacement to the prior DC-9s and MD-80s, though Boeing took up production of the aircraft when it bought McDonnell Douglas. The 717 looks aesthetically very similar to the MD-80 series and DC-9, though some models were noticeably much longer than the 717. The Boeing 717 never gained popularity, although a few airlines such as Qantas, Hawaiian Airlines, AirTran, and Midwest Airlines took delivery of the 717 and became quite popular among them. Currently, only 4 airlines operate the 717: Delta, the largest operator, along with Hawaiian, Qantas, and Volotea.

Unlike the 737, the Boeing 717 has a 2-3 configuration, meaning that it’s fuselage is significantly narrower than that of the 737. There also is only one variant of the 717–the 717-200–unlike the MD-80. The 717 also has two aft mounted engines, making it distinguishable from other narrow-body aircraft and making it look similar to many regional aircraft. However, the 717 is much longer, wider, physically taller, and has larger windows which are closer together than most regional aircraft do, making it distinguishable from them. Also, no Boeing 717s have winglets, unlike the CRJ series. The Boeing 717 also only has three exit doors per side, one being a full door at the front and two being over-wing exits, with one window in-between the two over-wing exits. Additionally, the horizontal stabilizer is located over the vertical stabilizer, making it even easier to distinguish from the 737 or A320.

Embraer E Series

Embraer’s main regional jet (in recent history) has been the Embraer E Jet series, consisting of the E170, E175, E190, and E195. You can generally clump those into two groups–the E170 and E175 are very similar in size, while the E190 and E195 are generally very close in size. In America, the E Jet series is generally operated by regional contract airlines, such as Republic Airways or SkyWest Airlines. The E-Jet series first debuted in 2004 and has since become one of the world’s most popular regional jets.

All E-Jets (though not the Embraer E-2 series) have winglets (however, they don’t curve up like on the 737 or A320neo), though on some E175s, the winglets angle outwards (which they call enhanced winglets) more so than on all E170s, E190s, E195s, and on older E175s. Unlike other regional jets, the E-Jet series’ engines and horizontal stabilizer are positioned in a more “traditional” way, similar to the 737, with the engines underneath the wings and the horizontal stabilizer underneath the vertical stabilizer. All Embraer E170s and E175s only have two exit doors per side, with no over-wing exits, though all Embraer E190s and E195s have one over-wing exit. In order to tell the difference between each variant, the E170s have 17 windows per side, while the E175s have 20. Meanwhile, E190s have 11 windows between Door 1 and the over-wing exit, while E195s have 12. Overall, the E175 and E190 are the most variants, whereas the E170 an E195 are slightly less popular, although the E175 is almost solely operated within the US.

Meanwhile, this is the E175, with enhanced winglets, which only newer E175s have:

Here’s a JetBlue E190, which is very similar to the E195, although can be easily differentiated from E170s and E175s through its over-wing exit:

And finally, here’s an Austrian Airlines Embraer E195, which is a slightly stretched version of the E190 (pretty hard to tell the difference between them).

Embraer also relatively recently came out with a newer version of the E-Jet series–the Embraer E-Jet E-2 family. It contains three aircraft–the E175-E2, the E190-E2, and the E195-E2. Each aircraft is roughly comparable to its original generation counterpart. The E2 series hasn’t been very popular though, with only slightly over 170 orders in total, which isn’t great for a regional aircraft, although I would guess that orders will start to increase eventually, as original E-Jet aircraft start to show their age. The E175-E2 actually doesn’t have any orders yet, while the E190-E2 and the E195-E2 are both in limited operation. There only are about 20 in operation at the moment (none of which are in North America), so you won’t be encountering them often at the moment.

Unlike the original E-Jet series, E2 aircraft don’t in fact have winglets–instead, they have raked wingtips, like the Boeing 777-300ER or the 767-400. The E175-E2, though not in operation yet, is quite similar to the E175, though it has 22 windows, and, like all E-2 variants, has raked wingtips. The E190-E2 and E195-E2 look quite similar, though the E190-E2 has nine windows between Door 1 and it’s one over-wing exit (per side), while the E195-E2 has 12 doors between Door 1 and the first of two over-wing exits per side.

Bombardier CRJ Series

The Bombardier (though the program is now technically owned by Mitsubishi) CRJ series actually is two separate aircraft families. The CRJ-100 series debuted in 1992 and finished production in 2006 and was made up of the CRJ100 and CRJ200 (along with a couple other sub-variants), which only differed in their engines, and can hold up to 50 passengers. Bombardier later developed the CRJ700 series which contained three variants–the CRJ700, the CRJ-900, and the CRJ-1000 (and I guess the CRJ-550, which is only operated by United and is identical to the CRJ-700), which are elongated versions of the CRJ-200 with a few modifications and debuted in 2001. All aircraft have a 2-2 configuration in economy class, making them wider than the ERJ series.

All CRJ series aircraft are equipped with canted winglets (though they are not as tall as the ones on select E145s), along with engines at the rear of the plane, along with the horizontal stabilizer being located above the vertical stabilizer. The CRJ100 and CRJ200 both have one main exit door and one over-wing exit per side, along with having only seven windows between Door 1 and the over-wing exit, no exit at the rear, and five windows behind the over-wing exit, which can be useful when comparing it to an ERJ145 or CRJ700.

Meanwhile, the CRJ700 and CRJ550 (which is identical to it, besides only seating 50 passengers, as it has more first class seats and storage–it shouldn’t exist, but United’s management created it as a loophole for their scope clauses) are a stretched version of the CRJ200 and have the same door and engine configurations, along with similar winglets. However, instead, it has 13 windows between Door 1 and the sole over-wing exit.

The CRJ-900 is an even longer version of the CRJ700, its main distinguishing factor being that it has two over-wing exits instead of one, making it easy to confuse with the CRJ1000, which also has two over-wing exits per side. However, the CRJ900 has 14 windows between Door 1 and the first over-wing exit and 6 windows behind it, while the CRJ1000 has 16 windows between Door 1 and the first over-wing exit and 9 behind it.

Embraer ERJ Family

The Embraer ERJ family is probably the closest competitor to the CRJ-200, also having been created at about the same time period. It contains three variants–the “flagship” ERJ145, along with the shrunken ERJ140 and ERJ135, though the latter two are quite rare. The E145 is can only seat 50 passengers, while the E145 can seat 37 and the E140 can seat 44. In contrast to the CRJ series, the vast majority of ERJ series aircraft don’t have winglets, though some E145s do. Like the CRJ series, the engines are at the rear of the aircraft and the horizontal stabilizer is located above the vertical stabilizer. All ERJ series aircraft also have one door at the front and one over-wing exit per side. However, the nose of E145 series aircraft is a lot pointier and longer than the nose of CRJ series aircraft, making it a good distinguishing factor.

In order to distinguish different variants of the ERJ series, there are 9 windows between Door 1 and the over-wing exit on the left side of the aircraft and 4 behind it on the E135, there are 10 windows between Door 1 and the over-wing exit on the left side of the aircraft and 5 behind it on the E140, and there are 11 windows between Door 1 and the over-wing exit on the left side of the aircraft and 6 behind it on the E145.

The ATR 42/72 Vs. The Dash 8

The ATR 42/72 and the Dash 8 (containing the Q Series, which are later variants of the aircraft) are easily recognizable, as they are the only two major turboprop aircraft still made and both have their wings over the fuselage, making them easy to confuse. ATR, a joint-venture between Airbus and Leonardo, manufactures the ATR 42 and the ATR 72, of which there have been many different generations, though they have maintained the same general shape.

Meanwhile, the Dash 8 series was originally made by De Havilland (with early variants being the DHC-8-100 and DHC-8-200, which aren’t in wide scale operation anymore and later variants being the DHC-300 and DHC-8-400) until it was bought by Bombardier, which later called it the Q Series and manufactured the Q200 (a later version of the DHC-200, same with the next two with their corresponding aircraft), Q300, and the Q400. However, Bombardier sold it back to De Havilland in 2019, although they aren’t manufactured en mass anymore. There are many other sub variants of the aircraft, but the main three versions you need to know are the Q200 (which is the same size as the -100), the Q300, and the most popular and largest Q400.

Firstly, the ATR series consists of the ATR 42 and the ATR 72, the former being smaller than the latter. Both aircraft are very similar in shape, although are different in length. In contrast to the Dash 8/Q Series, ATR aircraft have the cargo bay at the front of the aircraft and is in between the passenger section and the cockpit of the aircraft. Because of that, passengers board ATR aircraft at the rear. Additionally, on each side, there is an over-wing exit at the very front of the passenger cabin, in addition to the main doors at the rear. Note that on the left side of the aircraft, the over-wing exit is the first window, while on the right side, there is a window in front of the exit. Unlike the Dash 8, on the ATR, the aft landing gear is embedded in the fuselage of the aircraft and not in a compartment underneath the engine. There is no easy way to tell the difference between an ATR 42 and an ATR 72 besides looking at its length; it should be evident based on its length if it’s a 42 or a 72 (which is much longer), though if you are having a hard time telling them apart, the ATR 42 has about 16-17 windows per side, while the ATR 72 has about 24-25, which should make them easy to distinguish.

Meanwhile, Dash 8 aircraft have a few differences from ATR aircraft. Firstly, it has a much larger engine nacelle than ATR aircraft do, in which its landing gear is stored and comes down from, giving it a very different look than the ATR. Secondly, all Dash 8 besides the Q400 aircraft have two main exit doors in the front (on each side of the aircraft) where passengers board from, while Q400s also have a second pair of exit doors (one on each side) at the rear. However, the DHC-8-100, along with the Q200 series and Q300 series both have a pair of emergency exits underneath the wing (one on each side). Finally, the Dash 8 also has a significantly more pointy nose than ATR aircraft do. In order to distinguish each individual variant, the easiest way to tell are the locations of the exit doors, in which on most Q200s (including the DHC-8-100), there are only three windows between Door 1 and the emergency exit, on most Q300s, there are 11 windows between Door 1 and the over-wing exit, whereas the Q400 doesn’t have an emergency exit.

Conclusion

5,000 words later, this article is much longer and took a lot longer than I intended it to be–and I only was able to cover aircraft which are in widespread commercial service! However, I do hope that this article helped you be able to recognize narrow-body aircraft with greater ease. Also, be sure to check out my previous article on how to recognize wide-body aircraft.