Can a human get sucked into the jet engine of a normal modern airliner? if so has it ever happened and what is the minimum or maximum weight that these engines can suck? As a safety measure, wouldn't light weight but high strength retracting safety covers that cover engines when the aircraft is parked protect both humans, equipment and engines? Of-course it would have to take into account the need to minimize weight. Also it could have the option to be controlled by the ground team supervisor remotely as an extra safety measure.
However, it happens only in rare cases- usually in case of miscommunication or a mistake, when safety procedures are not followed. The following image shows the safety hazard area for aircraft engines.
A warning poster, available from Boeing, reminds ramp and maintenance workers about the dangers of engine ingestion; image from Boeing Aero
In addition, the engines also have hazard-area warning decals on the nacelles to warn the ground personnel of the dangers.
Warning signs on engines; image from Boeing Aero.
It's happened before, both with civilian and military aircraft.
This video was shot in 1991. Crews ready an A-6E attack aircraft for launch aboard Theodore Roosevelt (CVN-71) for a night sortie over Iraq during Operation Desert Storm when a fatigued green shirt walks in front of the port jet intake at full power. He is one of the few people who had this happen to them and live to tell the tale.
A Vacuum Cleaner for an Intake
The A7-E was notorious for swallowing people on the carrier deck. In the picture below the Yellow Shirt standing in front demonstrates how low and large the intake to the turbofan engine is. There was a lot of activity on the deck especially during launches and recovery, and it was easy to step in the wrong place. We were always cautioned, over and over again, be aware of the intake.
Luckily most of the time I was around the A7-E it was not turning. I would do my preflight at the start of the flight. At the end of the flight, with the engine shut down, I would come down off the ladder and do the post-flight. I turned and headed around the nose, and worked my way back and around the air frame.
Danger Areas for Suction, Exhaust, and Radiation
The danger areas are shown in the diagram below, where:
- Yellow is idle power
- Red is military power
- The pink is the radiation (radar operating) danger area
Notice that the suction danger area at idle power extends out to 15 feet.
Hot Seat and a Close Call
As deployment neared the operations at the field shifted over to carrier qualifications. When arriving aboard the ship a pilot would have to qualify by performing a number of day and night landings. Each pass we made at the ship was graded. We started practicing at the field, and the schedule might use a procedure known as hot seating to maximize the number of pilots trained.
A pilot would start the aircraft and head for carrier landing practice. The aircraft had been previously fueled to keep us somewhere below our maximum landing weight. This was around 5,000 pounds. The pilot would finish the required number of approaches and on the way back to the squadron's apron hot fuel at the airfield fueling area. The term "hot fuel" was used to describe that the aircraft was turning while getting fuel. Once back at the squadron the crew would chock and tie down the aircraft. The pilot remained strapped in with the aircraft turning at idle.
The next pilot to fly would meet the aircraft as it came in, and do his preflight inspection, being careful to stay away from the danger areas. We would duck under the tail, and not cross close in front of the aircraft. When the next pilot was ready they came up beside the cockpit ladder and exchanged hand signs with the seated pilot. The pilots would exchange places.
The pilot finishing would then do their walk-around for the post-flight check. One night, after getting down off the ladder I did what I routinely do, which is head around the nose of the aircraft. It was dark on the tarmac, and I hadn't finished one step before I felt a hand grab me by the survival vest and pull me back hard, almost off my feet. I owe my life to that Maintenance Officer.
I remember somebody being sucked into an engine in 1989 with the accident involving United Airlines flight 811. The forward cargo door blew out, causing the cabin floor to cave in.https://en.wikipedia.org/wiki/United_Airlines_Flight_811 At least they found body parts in one of the engine - 9 people died in that incident. I remember it because it was en route from Hawaii to Auckland New Zealand (where I live) and a journey we had made several times.
Great answers already here, I'll just address the "minimum weight" part of the question.
There is no minimum weight. Foreign object damage is a very serious safety concern in aviation, because an engine can suck up pretty much any random object.
I've seen the crowd addressed en masse in air shows to please mind their garbage for the safety of the performers.