A & S Interview: Yang Guoxiang
One of China's top test pilots recalls the H-Bomb that almost backfired.
- By Bob Bergin
- Air & Space magazine, January 2010
Courtesy Yang Guoxiang
(Page 3 of 4)
Before taking off, I had reviewed our emergency procedures. I had three choices: I could abandon the aircraft by parachute and let it crash in a remote area of the vast desert that surrounded the Lop Nor Test site. I could crash-land the aircraft to assure that it was set down in place where it would harm no one. Or I could try to bring the aircraft back to base. I reflected on the time and the effort that went into the H-bomb project, and the great deal of money it cost the Chinese people, and I made my choice. I would try to bring the airplane and the H-bomb back to base.
There was a great risk in doing this. There were 10,000 people on the airbase, although only a few knew about the mission I was on. If anything went wrong, thousands would lose their lives. The bomb under the fuselage would be hanging just ten centimeters (four inches) above the ground as I landed.
All radio stations in northwest China had been shut down during my flight, and all flights in the area were banned. I radioed the tower of my decision to return, and asked that everyone on the base be evacuated into the tunnels that were dug underneath the base. It was Zhou Enlai himself who gave the order to evacuate.
A & S: Was there a possibility that the bomb could explode if it contacted the runway on landing?
Yang: There were five “safeties” that had to be deactivated to enable the bomb to explode. When the bomb was mounted to the airplane, the first safety was released. Fifteen minutes after the aircraft took off, the second safety was released; the third when the aircraft reached the target zone. When the pilot decided to drop the bomb, he released the fourth. The fifth and final safety released automatically sixty seconds after the bomb was dropped, an instant before it exploded.
No one could be sure whether or not the bomb would explode if it touched the runway, but I was confident that I could set the airplane down gently. So I landed with the H-bomb hanging under me. It was a perfect landing. When I shut down the engine, there was total silence; I was completely alone. The airfield was deserted. All 10,000 personnel were sitting in tunnels under the ground. I could not leave the cockpit: there was no ladder for me to climb down from the fuselage that was high above the ground.
I called the tower and asked for help. The tower told me to work my way back to the tail and jump. The people in the control tower were angry; in their eyes I had put 10,000 lives at risk,
And I had caused a big mess. When I notified the tower that I was returning with the bomb, the evacuation siren went off. It was lunchtime at the airbase; everyone was sitting down and eating. They had to rush out, put on gas masks and scramble into the tunnels. A big rice cooker caught fire because there was no one left to take care of the kitchen. Everyone there then still remembers my name: I could have brought them their Judgment Day.
It took a long time for anyone to come near my aircraft. Our procedures for dealing with the H-bomb meant we had to wear rubber shoes and clothing that would not create static electricity. No metal was allowed in the area of the bomb. In the nuclear weapons storage bunker, all steel columns were wrapped in copper. Now that I had unexpectedly brought the H-bomb back, there were no service vehicles equipped with the required shielding. I sat out on the field for a long while.
A & S: What had caused the hang-up?
Yang: We sent the release devices to Beijing for analysis. It was determined that one reason the shackle malfunctioned was that the mechanism was carefully kept in a heated area until just before it was mounted on the aircraft. This was not the usual procedure, but as this was the first release of a live bomb, everyone was being especially careful. When the aircraft took into the cold air, it was possible that the sudden temperature change affected the tolerances on parts of the mechanism that caused its failure to release. The shackles and release mechanism were modified so this could not happen again.
A & S: So you were not concerned on your second attempt?
Yang: The decision was to go again on January 7, 1972. Wind conditions were optimal. Weather at the Lop Nor site was good, but there was a cold front moving in. It was snowing at the airbase when I took off.
This time there was no problem. I followed procedures, and when I released the bomb, it separated from the aircraft as it was supposed to. As soon as the bomb was gone, I reversed course to get far away from the blast zone and activated shields that would protect me in the cockpit. Then I saw the flash, a very big flash. The bomb exploded in the air, at a pre-determined height above the ground. I felt the shockwave—it rocked me like a small boat in the ocean—and then I saw the mushroom cloud rising up into sky. By that time I was already 20 kilometers (12.4 miles) away from ground zero.
Watching the mushroom cloud from the air, I could see how different layers of clouds inside the mushroom were connected to one another, just like smoke from a chimney. At that moment I felt very happy. The test had been successful! And then I had to face my new concern: how to land safely on a runway covered in snow.