Should I buy crashing airline stocks?
International Consolidated Airlines (LSE:IAG) and easyJet (LSE:EZJ) saw their share prices fall today as the UK government is expected to delay its reopening by another month. IAG fundamentals  IAG owns British Airways, Iberia, and Aer Lingus, and its share price has been erratic ever since Covid-19 hit. Nevertheless, its bounced impressively above its lows and is up 31% year-to-date. 5G is here  and shares of this sleeping giant could be a great way for you to potentially profit! According to one leading industry firm, the 5G boom could create a global industry worth US$12.3 TRILLION out of thin air And if you click here well show you something that could be key to unlocking 5Gs full potential... But today, IAGs earnings per share are negative and its debt exceeds its market cap. The reason for its low valuation is the sheer uncertainty the pandemic has brought to the industry. Until airlines can get back to flying at pre-pandemic capacity, theyre losing money. Despite todays dip, the IAG share price is down less than 3% from its 52-week high. This makes me think it may have further to fall if the uncertainty continues to weigh on investor hopes. Airline stocks weighed by debt  In the past year, IAG has increased its debt burden considerably. In Q1 this year alone, its net debt rose by 1.8bn. However, by the end of Q1, IAG had 10.5bn of liquidity, beating its pre-pandemic level of 9.1bn. The faster it recovers, the quicker it can pay off debt without incurring penalties. But if this is drawn out, the penalties could severely impact its ability to offer shareholder value. I dont think theres any doubt that pent-up demand for foreign holidays is there. In theory, this should mean an upsurge in bookings for flights. But it will ultimately depend on what consumers can afford and if flight prices increase. Plus, of course, the lifting of Covid-19 restrictions. I dont currently hold IAG shares, and Im reluctant to take the risk. But, on the other hand, it could prove a phenomenal recovery play if all goes well with the reopening and the country gets back on track to a more normal future. But so far, thats not a given. easyJet predicts 15% capacity in Q3  The uncertainty ahead is just as prominent for easyJet. Its currently projecting 15% capacity for Q3, compared to 2019 levels, which is not a lot of income to look forward to. easyJet has also racked up considerable debt. But much of it doesnt mature until 2023. Although, it does have to repay 300m by November 2021. In response to the chaos caused by the pandemic, the company has brought in significant streamlining measures over the past six months. This was necessary and should greatly benefit the strength of the company in the future. easyJet is an instantly recognised and popular budget airline in the UK. I dont think its going to go out of business, but I think the challenges ahead make it a risky investment. Its share price is likely to be subject to extreme volatility in the coming years. I think there are stocks with a less uncertain future that Id prefer to invest in long term. So I dont intend to add either of these airline stocks to my Stocks and Shares ISA today.