You're in seat 14C somewhere over Kansas. The flight attendant rolls the beverage cart past. Someone in 14B orders a Woodford Reserve. Someone in 15D orders a glass of Chardonnay. And you start wondering whether owning Delta Air Lines stock is a problem.

Airlines are another one of those "probably fine, maybe not" industries in Shariah investing. The alcohol sales are visible and annoying, but they turn out to be a relatively small portion of total revenue for most carriers. The screening problem for airlines usually isn't the in-flight bar. It's the debt load.

Let me walk you through Delta, United, American, and a few others, and show you where they actually fail (if they fail) and why.

Alcohol revenue: smaller than you think

People assume alcohol is a meaningful revenue line for airlines. It isn't. Estimates vary by carrier and fare class, but industry figures typically put alcohol revenue at somewhere between 0.5 percent and 2 percent of total passenger revenue for most US legacy carriers. For budget airlines it can be higher as a percentage because overall ticket prices are lower, but it's still small in absolute terms.

That puts alcohol revenue for Delta, United, and American well within the 5 percent non-permissible income tolerance used by most Shariah screening methodologies.

Combine alcohol revenue with a few other small non-permissible income items (interest on cash holdings, some ancillary fees treated as impermissible under certain methodologies) and you're typically still under 5 percent for the big US airlines.

Sector-wise, airlines pass. The transportation service itself is obviously permissible. Moving people between cities is one of the most benign business activities you can think of.

So why does almost every US airline fail Shariah screening anyway? Let's follow the money.

Delta Air Lines (NYSE: DAL)

Core business: Passenger air transportation, cargo, loyalty program (SkyMiles), credit card partnerships. Sector passes.

Non-permissible income: In-flight alcohol, interest income on cash, some other small items. Estimated at 2 to 3 percent of revenue. Passes.

Debt-to-market-cap: This is where the story changes. Delta carries around $17 billion in long-term debt as of early 2026. Market cap sits around $33 billion. Debt-to-market-cap is about 52 percent. That's well above the 30 percent threshold used by AAOIFI. Fail.

Cash and interest-bearing securities: Delta holds around $4 billion in cash. Ratio ~12 percent. Passes.

Accounts receivable: Under threshold. Passes.

Result: Delta fails Shariah screening on the debt-to-market-cap ratio. The sector passes. The alcohol passes. The balance sheet does not.

Delta's debt load ballooned during and after COVID when every airline in the world had to borrow heavily to survive the pandemic. Even as revenue has recovered, the debt is still on the books.

United Airlines Holdings (NASDAQ: UAL)

Core business: Same as Delta. Passes sector.

Non-permissible income: Similar 2 to 3 percent. Passes.

Debt-to-market-cap: Long-term debt around $24 billion. Market cap around $22 billion. Debt-to-market-cap is over 100 percent. Fail, and by a mile.

Cash ratio: Passes.

Result: United fails Shariah screening catastrophically on the debt ratio. The airline is basically financed by debt at this point.

American Airlines Group (NASDAQ: AAL)

American is in the worst shape of the three.

Core business: Passes sector.

Non-permissible income: Passes.

Debt-to-market-cap: Long-term debt around $31 billion against a market cap of ~$9 billion. That's over 300 percent debt-to-market-cap. American is more liabilities than equity on the market's valuation. Fail by an absurd margin.

Result: American is uninvestable for Shariah purposes. The fundamental capital structure is almost entirely debt-funded.

Southwest Airlines (NYSE: LUV)

Southwest is the interesting one. Historically, Southwest was the most disciplined airline on debt.

Core business: Passes.

Non-permissible income: Southwest, unlike the legacy carriers, doesn't serve hard liquor on most flights and has a relatively minimal beverage revenue line. Non-permissible income is typically under 2 percent. Passes.

Debt-to-market-cap: Long-term debt around $8 billion. Market cap around $17 billion. Debt ratio about 47 percent. Above threshold. Fail.

Southwest used to be the cleanest US airline on this metric. The pandemic and subsequent operational issues pushed the debt load higher and the market cap lower. The combination broke the ratio.

Result: Southwest currently fails Shariah screening on debt, though it's less catastrophic than the big three legacies.

Alaska Airlines (NYSE: ALK)

Core business: Passes.

Non-permissible income: Similar to other US carriers, under threshold.

Debt-to-market-cap: After the Hawaiian Airlines acquisition in 2024, Alaska's debt load increased. Current debt-to-market-cap is around 60 percent. Fail.

JetBlue (NASDAQ: JBLU)

JetBlue has had a rough few years. Failed Spirit merger, operational challenges, shrinking route network.

Debt-to-market-cap: Extremely bad. Market cap is tiny relative to the debt load. Fail by a wide margin.

International carriers

Let's look internationally because the picture is slightly different.

Emirates is privately held by the Investment Corporation of Dubai, so there's no stock to buy. It's also one of the few airlines that Muslim investors actively point to as halal-operational. Emirates pork products are banned. Alcohol is served on flights but revenue share is small. Still, since it's not public, it's a moot point for retail investors.

Qatar Airways is also privately held (state-owned).

Saudia (Saudi Arabian Airlines) is state-owned, not public. Saudia is also alcohol-free on flights since Saudi Arabia prohibits alcohol consumption anywhere including aircraft.

Air Arabia (AIRARABIA) on the DFM is the region's largest low-cost carrier. It's publicly traded, Shariah-compliant, and it doesn't serve alcohol on flights. Passes all screens cleanly. This is basically the easy button for Muslim investors wanting airline exposure.

International Airlines Group (IAG.L) which owns British Airways and Iberia: fails debt ratio.

Lufthansa (LHA.DE): fails debt ratio.

Air France-KLM (AF.PA): fails debt ratio.

Ryanair (RYA.IR): historically has been one of the more financially disciplined European carriers. As of early 2026, Ryanair's debt-to-market-cap is around 18 percent. Passes. Non-permissible income is small. Sector passes. Ryanair is one of the cleanest European airline names from a Shariah perspective.

The airline industry's structural problem

There's a reason so many airlines fail the debt ratio. The industry is brutally capital-intensive. A new Boeing 787 costs around $280 million at list price. A new A350 is similar. A fleet of 200 to 400 planes is standard for a major carrier. Those aircraft are financed, usually through long-term debt or operating leases (which often show up as debt on the balance sheet under IFRS 16 / ASC 842).

On top of that, the industry has cyclical revenue tied to travel demand. When demand collapses (think 2001, 2008, 2020), airlines burn cash fast and need to borrow more to stay alive. The combination (high fixed costs, volatile revenue, heavy financing requirements) leaves most airlines with chronically high debt ratios.

Shaykh Nizam Yaquby has noted on multiple occasions that capital-intensive industries often end up failing Shariah financial ratios not because of any moral issue with the sector but because the capital structure chosen by management is riba-dependent. That's the situation for most of the airline industry.

Aircraft leasing companies

Quick note on a related sector. Companies like AerCap (AER), Air Lease Corporation (AL), and others lease aircraft to airlines. These are financial leasing businesses, not airlines. Their core business involves charging lease rates that are functionally interest-bearing (operating leases are often treated as permissible, but the financing side is where the issue lies).

These companies typically fail Shariah screening on both the sector test (financial services) and the financial ratios (extremely high debt-to-market-cap). Aercap has well over 100 percent debt-to-market-cap. Fail.

So what can a halal airline investor actually buy?

The practical answer is pretty narrow:

Air Arabia (AIRARABIA on DFM): Publicly traded, Shariah-compliant, halal-operational, passes all screens. This is the cleanest name in the industry.
Ryanair (RYA.IR): Usually passes all screens. Good liquidity. Non-Muslim operator but passes methodology.
Some Asian and Latin American carriers: A few carriers like Thai AirAsia subsidiaries and certain Latin American low-cost carriers occasionally pass, but check current figures before assuming.

The big US carriers (Delta, United, American, Southwest, Alaska, JetBlue) all fail the debt ratio and have for several years. That's not a temporary situation you should expect to reverse in the next few quarters.

Can airlines ever clean up?

Possibly, but it takes years. An airline would need to generate significant free cash flow, pay down debt, and/or see its market cap rise sharply enough to bring the ratio under 30 percent. Delta has been making progress on this front, and at some point in the next cycle it might drop below the threshold if fuel prices cooperate and management keeps directing cash to the balance sheet. Keep watching.

The bottom line

Airlines are not non-compliant as a sector. The alcohol on flights is not the screening issue. The reason almost every major airline fails Shariah screening is the balance sheet. Debt-to-market-cap ratios across the industry run well above the 30 percent threshold and have for years.

If you want airline exposure in a halal portfolio, Air Arabia and Ryanair are your two real options. Everything else requires waiting for balance sheet repair, which is a slow process. Run any airline ticker through FaithScreener to see the current debt ratio and non-permissible income percentage, and you'll see exactly where the line is being crossed.

Airline Stocks: Delta, United, American and the In-Flight Beverage Issue