by ROBERT BECKHUSEN

Just a short time ago, Russia planned to have 52 advanced T-50 stealth fighters by the end of the decade. At least, that was the plan.

Now the T-50 program appears to be in serious trouble, and Russia may cut back the fighters to a fraction of the planned strength.

The first sign something was very wrong appeared last month. On March 24. Yuri Borisov, Russia’s deputy defense minister for armaments, told the Kommersant newspaper that the military is drastically cutting its number of T-50s. Instead of 52 stealth fighters, Russia will build merely 12 of them.

That’s hardly anything.

The Kremlin has produced five T-50 prototypes so far — and one was heavily damaged in a fire. Meanwhile, India is co-developing the plane with Russia, and New Delhi’s funding helps keep the project alive. But now Indian Air Force officials have also stopped talking to their counterparts in Moscow.

Which all puts a spotlight on Russia’s problems building so-called fifth-generation fighter jets — which the country needs to compete with the best the United States and China have to offer.

It’s easy enough building prototypes, but developing a truly capable aircraft — all during a major economic recession — isn’t so simple. That’s especially the case when talking about more than a handful.

“Given the new economic conditions, the original plans may have to be adjusted,” Borisov said. “It is better to have the PAK FA kept as a reserve, and later move forward, while squeezing everything possible for now out of the 4+ generation fighters.”

He was referring to Russia’s modern — but non-stealthy — Su-30 and Su-35 multi-role fighters. Borisov said these fighters will fill the gap left by the T-50’s dwindling production run.

In theory, the T-50 will serve as Russia’s competitor to the U.S. F-22 and F-35 fighters. On the surface, the T-50 appears to be a capable and deadly jet. It’s big, fast and has a long range. At air shows, the blended winged-body plane has demonstrated a high degree of maneuverability.

It has huge, mean-looking twin engines — set wide apart for stability — and a 50-foot wingspan. The T-50 has a large internal weapons bay and stealthy, radar avoidance features. If there are technical problems, Russia doesn’t disclose them.

Officially, Russia’s economic turmoil is responsible for the production cut. The plane’s total development cost is unclear — anywhere from $10 billion to $30 billion. India has already spent about $5 billion. But all is not well on the technical front, either.

Because we know the Indians will disclose problems with the aircraft.