Engine Run Ups

[Brian Abraham]

The engineer who signed off on the construction of the ramp at Pakistan's Sialkot International Airport likely has some explaining to do after a Shaheen Air International Boeing 737-400 rearranged it some during a routine engine test. Engineers did a high power run-up of the No. 1 engine on June 19 and turned the parking area into a maelstrom of FOD. It appears the hard surface was made from the interlocking concrete paving stones that are commonly used for patios and garden walkways. They are set in a sand bed and interlock with each other, which is more than adequate for foot traffic and the occasional bicycle but not really up to 20,000 pounds of high bypass turbofan thrust from a CFM56 engine.

The jet blast threw the concrete missiles, each weighing a few pounds and with lots of pointy facets, into the fuselage and tail surfaces. A few dozen ended up on the horizontal stabilizer. It's not clear how much it will cost to fix the damage or whether the aircraft can even be repaired.