B3 Bomber Jacket Guide: History, Fit and How to Wear It
Few jackets carry a story as dramatic as the B3. It was designed for men flying in open or unheated, unpressurised aircraft, where the air at 25,000 feet could be colder than anywhere on the ground. Today, it's a winter classic worn on city streets, at football matches and on cold weekend walks, often by people who have never been near a cockpit.
That heritage is part of the appeal, but it also creates questions. What actually makes a B3 bomber jacket a B3? How is it supposed to fit, when the original was cut to go over layers of flying gear? Is real shearling worth the extra cost? And how do you wear something this bulky without looking like you're heading to a costume party?
This guide answers all of that. We'll cover the B3's history, its defining features and close relatives, how to choose the right size, how to style it for men and women, and how to look after it so it lasts. If you already know what you want, you can browse our B3 bomber jackets as you read.
What Is a B3 Bomber Jacket?
A B3 bomber jacket is a heavy, hip-length flight jacket made from sheepskin that has been tanned with its wool left on. The leather side faces out, the wool faces in, and the whole jacket works as one thick, insulating layer.
The defining features are easy to spot:
- A large shearling collar that can be turned up to cover the neck and lower face.
- Leather collar straps with buckles, used to hold the collar closed against the wind.
- A waist belt or side adjusters to cinch the hem and keep cold air out.
- A heavy front zip, often with a protective flap or reinforced edges.
- Hand-warmer or slash pockets at the front.
- Visible seams and panels, because sheepskin pelts are relatively small, so a B3 is pieced together from multiple sections.
Many modern B3-style jackets also add details the original didn't have, such as detachable hoods, inside pockets and contrast-dyed wool.
The History of the B3
From the open cockpit to the bomber stream
In the early 1930s, military aviation was moving to faster aircraft that flew higher, but cabins were still unheated and unpressurised. Crews needed clothing that could cope with extreme cold for hours at a time. Britain's RAF had already adopted the Irvin sheepskin flying jacket, and according to reproduction maker Eastman Leather Clothing, that jacket was a major influence on the American design.
The United States Army Air Corps introduced the "Jacket, Winter Flying, Type B-3" in 1934. Sources give slightly different dates for its approval. Eastman says it was standardised on 8 May 1934, while Japanese reproduction specialist Buzz Rickson's says it was officially adopted in 1934. Researchers on the Vintage Leather Jackets forum, working from a declassified Air Corps file, describe a service test beginning on 28 April 1934 and the specification being approved for procurement in May 1935. Either way, the B3 was the first American shearling flight suit, issued alongside matching Type A-3 shearling trousers.
Wartime service
The B3 became one of the defining garments of the Second World War air war, particularly for bomber crews in Europe. The National Museum of the US Air Force notes that at 25,000 feet, the altitudes typically flown over Europe, temperatures could fall below -60°F. B-17 gunners at open waist positions were especially exposed, and photographs show them wrapped in bulky shearling flying clothing.
Several companies made B3s under government contracts, including Rough Wear Clothing Co., Aero Leather Clothing Co. and Werber, among others. Over the years the details changed. Early jackets had a chest buckle and different back construction; later ones used three- or four-panel backs. Buzz Rickson's notes that early two-panel backs used more leather and were considered especially luxurious. Eastman says the finish colour changed over time, ending in a dark seal brown by late 1942.
Retirement and civilian life
The B3 was warm but heavy and bulky, which made it awkward to wear in cramped turrets and cockpits. As electrically heated flying suits and lighter jackets such as the cotton-shelled B-10 (introduced in 1943) arrived, the B3 was gradually phased out. The 303rd Bomb Group's historical site notes that the heavy B-3 jacket and A-3 trousers were among the first items crews dropped as newer gear became available. The B3 was declared obsolete in 1946.
Surplus jackets then found their way into civilian wardrobes, and the B3's rugged look became a lasting part of menswear. For a deeper look at its story, read our deeper look at the B3's history.
B3 vs Other Classic Flight Jackets
The B3 is often confused with its relatives. Here's how they differ:
| Jacket | Introduced | Material | Warmth | Key features | Best for |
|---|---|---|---|---|---|
| A-2 | 1931 | Horsehide or goatskin, fabric lining | Low to moderate | Knit cuffs and waist, shirt collar, flap pockets | Mild weather, smart-casual |
| B-3 | 1934 | Sheepskin with wool left on | Very high | Big shearling collar, collar straps, waist belt | Deep winter, cold climates |
| B-6 | WWII era | Lighter sheepskin | High | Shorter, lighter build than the B-3 | Cold days with more movement |
| B-10 / B-15 | 1943 / 1944 | Cotton, then nylon shell, synthetic or alpaca-style collar | Moderate | Knit cuffs and waist, fur-style collar | Lighter, more casual wear |
If you like the B3's warmth but find it too heavy, a B-6 shearling bomber is worth a look. Ours is made from short sheared sheepskin with leather welted seams, a single-buckle throat latch and a heavy-duty YKK zip.
A note on naming
Retailers use "B3," "aviator," "flight jacket," "flying jacket" and "bomber" almost interchangeably. You'll also see "RAF B3," as on our dark brown B3, even though the B-3 was an American designation and the RAF's equivalent was the Irvin. In practice, "RAF" in a product name usually signals a vintage British-inspired look rather than a historical reproduction. Our guide to aviator, bomber and flight jacket names untangles the terminology.
Shearling, Sheepskin and Faux: What's Inside Your B3?
The single biggest factor in how a B3 performs is what lines it.
Genuine shearling is sheepskin tanned with the wool still attached. The wool grows from the hide, so the lining and shell are one piece. It is very warm, breathable and long-lasting. Our B3 with a detachable shearling hood, for example, lists a real sheep fur lining including the sleeves.
Leather with a separate wool or fleece lining looks similar but is constructed differently. It can still be warm, though usually less so than one-piece shearling.
Faux fur or faux shearling linings are synthetic. They're lighter and usually cheaper, and they suit people who prefer to avoid animal fur, but they don't breathe as well and tend to flatten over time. Our black B3, for instance, pairs a sheepskin leather shell with a faux fur lining.
Product names don't always make this distinction clear. Before you buy any B3, check the lining line in the specifications, not just the product title.
How a B3 Bomber Jacket Should Fit
The original B3 was cut generously so it could go over layers of uniform and flying clothing. Modern versions are usually a little trimmer, but they're still a substantial jacket, and fit makes the difference between looking rugged and looking swamped.
The fit checklist
- Shoulders: The shoulder seam should sit at or just beyond the edge of your shoulder. If it drops several centimetres down your arm, the jacket is too big.
- Chest: You should be able to zip it over a medium-weight sweater without strain. Shearling is thick, so there's less spare room inside than the outside measurements suggest.
- Length: A B3 is hip-length. The hem should finish around the top of your hips or just below your belt. Longer than that and it starts to look like a coat.
- Sleeves: With your arms relaxed, the cuffs should reach your wrist bone. Reach forward as if holding a steering wheel; the sleeves shouldn't ride far up your forearms.
- Collar: Flip the collar up and fasten the straps. It should close comfortably around your neck without pressing on your throat.
- Waist: Use the belt or side adjusters to bring the hem in slightly. The jacket should blouse a little above the waistband, which is part of the classic silhouette.
Sizing tips
- Measure your chest over the layer you'll wear underneath. Eastman's sizing advice, for example, is to measure over a T-shirt with the tape snug but not tight. If you'll usually wear a thick knit, take that into account.
- Compare with a jacket you already own. Lay it flat and measure across the chest from armpit to armpit, then double it. Compare that number with the size guide.
- Don't size up out of habit. A B3 that's too big looks boxy and feels heavier on the shoulders. If you're between sizes, think about what you'll wear underneath.
- Use adjusters. Waist belts and buckles, such as those on our women's hooded B3 flying jacket, make it easier to fine-tune the fit.
- Consider made-to-measure. If you have broad shoulders, long arms or a build that standard sizes don't suit, a made-to-measure B3 built from your chest, arm and waist measurements can solve the problem.
Fit differences for women
Women's B3s are usually cut with a narrower shoulder, a shorter body and more shaping through the waist. Some women prefer a men's B3 for a deliberately oversized look. If you do, size down from your usual men's equivalent and use the waist belt to stop it swamping you.
How to Wear a B3 Bomber Jacket
The B3 has a strong personality, so the key to wearing it well is simplicity underneath. Let the jacket do the talking.
The classic Americana look
This is the B3's natural habitat. In a December 2025 MR PORTER Journal feature, style director Benedict Browne described tan shearling with a cream lining as "super versatile," and suggested pairing it with light-blue jeans and a flannel shirt. Add leather boots and you have a look that has barely changed since the 1950s.
Try:
- Mid-wash or raw denim jeans
- Flannel or Oxford shirt, or a grey crew-neck sweater
- Brown leather work boots or chukkas
- A knitted beanie on very cold days
The modern, monochrome look
For a sleeker take, the same MR PORTER piece suggests a dark navy or black shearling bomber worn tonally. A black B3 over a black roll-neck, dark jeans or charcoal trousers and black boots looks clean and urban.
Smart-casual
A B3 can dress up a little, but it's still outdoor wear at heart. MR PORTER contributor Stephen Doig advises against wearing shearling for evening or corporate settings. For a sharper weekend look, try:
- Wool or cord trousers in navy, olive or brown
- A fine merino or lambswool knit
- Suede boots or leather loafers with thick socks
How women can wear a B3
The B3's volume works beautifully with slim or fluid shapes underneath.
- Over slim jeans and knee boots for an easy weekend outfit.
- With a knit dress and tights for contrast between soft and rugged.
- Over wide-leg trousers and a roll-neck for a more fashion-forward look.
- Belted at the waist to add shape when wearing a men's or oversized cut.
Our women's B3 styling tips go into more detail.
Colour combinations that work
| Jacket colour | Wool colour | Pairs well with | Mood |
|---|---|---|---|
| Tan or mid-brown | Cream | Blue denim, ecru, navy | Classic, warm |
| Dark brown / seal brown | Cream or brown | Olive, khaki, grey | Vintage, military |
| Black | Black or cream | Charcoal, black, white | Urban, modern |
| Brown with distressed finish | Cream | Raw denim, plaid | Rugged, lived-in |
For more combinations, see our guide with more B3 outfit ideas.
What to Look for When Buying a B3
Not all B3-style jackets are made to the same standard. Whether you're shopping in person or online, these details separate a jacket that will last from one that won't:
The lining
Check whether the lining is genuine shearling, a separate wool or fleece lining, or faux fur, and whether it continues into the sleeves. Sleeves lined with thin fabric are noticeably colder than fully lined ones.
The outer finish
B3s come in several finishes, and each wears differently:
- Smooth or nappa-finished leather looks clean and sheds light moisture better than suede.
- Distressed or antiqued finishes give a vintage, worn-in look from day one and hide scuffs well.
- Suede-faced or rough-out finishes feel soft and look rugged, but mark more easily in rain.
None is better than the others; it depends on the look you want and how much weather the jacket will face.
Seams and construction
Because a B3 is built from many pieces of sheepskin, the seams carry a lot of load. Look for even, tight stitching, neatly finished panel joins and reinforcement at stress points such as pocket corners and the base of the zip. Welted or bound seams, like those on our B-6, add strength.
Hardware
The zip should be heavy-duty and run smoothly over thick shearling without snagging. Collar strap buckles and waist adjusters should feel solid, not flimsy, and should fasten easily with cold hands.
Weight and feel
A B3 should feel substantial. A jacket that feels surprisingly light for its size may use thin pelts, a synthetic lining or a fabric-backed shell. That isn't necessarily bad, but it won't perform like a traditional B3.
The listing details
Online, the product page is your inspection. Look for the outer material, lining material, closure and pocket details. If something important is missing, ask before you buy rather than after.
Common B3 Mistakes to Avoid
- Going too big. Over-sizing is the most common B3 mistake. It makes the jacket look like borrowed costume and adds weight.
- Layering too heavily underneath. A B3 is already a coat. A thin knit or shirt is plenty; a hoodie plus a sweater makes it tight and bulky.
- Leaving the collar flat with the straps dangling. Either fasten the straps or tuck them neatly under the collar.
- Wearing it in mild weather. A real shearling B3 can be uncomfortably warm above about 10°C (50°F). Save it for genuinely cold days.
- Adding military patches without thought. Replica insignia can read as costume. A plain B3 looks more versatile.
- Treating it like a rain jacket. Sheepskin isn't waterproof. Heavy rain and road salt can mark and stiffen it.
- Assuming "shearling" means natural wool. Check the lining specification if it matters to you.
Caring for Your B3
A well-cared-for B3 can last for many years. A few habits make a big difference:
- Brush the wool regularly with a soft brush or wide-toothed comb to keep it lofty, especially at the collar and cuffs.
- Wipe the leather with a soft, dry cloth after wear. For suede or rough-finish B3s, use a suede brush instead.
- Dry it naturally if it gets wet: shake off excess water, blot with a towel and hang it on a broad hanger at room temperature, away from radiators and hair dryers.
- Avoid washing machines and general dry cleaners. When it needs a deep clean, use a specialist leather and sheepskin cleaner.
- Condition the leather sparingly with a product suited to its finish, testing on a hidden area first.
- Store it well on a wide, shaped hanger in a breathable cotton garment bag, never in plastic.
Our shearling cleaning guide explains each step in detail.
Products and Collections to Explore
If you're ready to choose, here are a few starting points from our range. Always check the product page for the current price, lining material and size options.
- For a traditional look: the classic brown B3 lists sheepskin leather, a wool lining, a turn-down collar and a zip front.
- For extra protection from the weather: the B3 with a detachable shearling hood adds a removable hood to a real sheep fur lining.
- For a sleeker, darker look: the black B3 has a sheepskin leather shell with a faux fur lining.
- For women: the women's hooded B3 flying jacket and the wider range of women's aviator jackets.
- For layering: B3-style shearling vests give you the look without the sleeves.
You can see every style in our B3 bomber jackets collection, or browse our broader range of flight jackets.
Frequently Asked Questions
What is a B3 bomber jacket?
A B3 is a heavy, hip-length sheepskin flight jacket with the wool left on as its lining. It has a large shearling collar with leather straps and a waist belt or adjusters. It was introduced by the US Army Air Corps in 1934 for high-altitude flying.
Why is it called a B3?
"B-3" was the US Army Air Corps' type designation for this winter flying jacket. Earlier designs were the B-1 and B-2, and the matching trousers were the Type A-3.
How should a B3 bomber jacket fit?
The shoulder seams should sit at your shoulder edge, the hem should fall around your hips, and you should be able to zip it over a medium-weight sweater. Sleeves should reach your wrist bone. It shouldn't look boxy or drop off your shoulders.
Should I size up in a B3 jacket?
Usually not. Shearling is thick, but sizing up often makes a B3 look oversized and feel heavy. Measure your chest over the layer you'll wear underneath and compare with the size guide.
What's the difference between a B3 and an A2 jacket?
The A-2 is a lighter leather jacket with a fabric lining, knit cuffs and waistband and a shirt-style collar, made for milder weather. The B-3 is a heavy sheepskin jacket with a wool lining, a big shearling collar and collar straps, made for extreme cold.
Is a B3 bomber jacket too warm for everyday wear?
It depends on your climate. A real shearling B3 is ideal for cold winters but can feel too warm in mild weather or heated buildings. In milder climates, consider a B-6, a shearling vest or a fabric-lined bomber.
Can women wear a B3 bomber jacket?
Absolutely. Women's B3s have a narrower shoulder and more waist shaping, and many women also wear men's B3s for an oversized look, belted at the waist.
Conclusion
The B3 bomber jacket started life as survival gear for aircrews facing temperatures below -60°F, and that purpose still shows in every detail: the big collar and straps, the cinched waist and the thick, one-piece sheepskin. That's why it remains one of the warmest and most characterful jackets you can own.
To get the most from a B3, choose the lining that suits you, fit it to your shoulders and the layer you'll wear underneath, and keep the rest of your outfit simple. Look after it with regular brushing and careful drying, and it will see you through many winters.
When you're ready to choose yours, explore our B3 bomber jackets, or consider a made-to-measure B3 built to your measurements.