punkalouver
23rd Feb 2022, 13:18
A while back I started a thread about what you as airline pilots might do to prevent departing with a mis-loaded aircraft, as I thought there could be some good information passed around for our benefit. Perhaps, you know of an incident in your company that could provode useful information.
I was looking at an old accident thread recently and a couple of posts discussed an incident of a large airliner getting into the air after being very mis-loaded. There was information on what the crew did to help the situation and I thought that perhaps, there might be some other stories out there that could be beneficial to the rest of us. Things such as crew shifting cargo in flight, reduced flap for landing to minimize pitching moment, and what I believe to be maximizing trim range by using manual trim are quite interesting. Here is the post and reply......
Cargo Crash at Bagram - Page 2 - PPRuNe Forums (https://www.pprune.org/accidents-close-calls/513650-cargo-crash-bagram-2.html#post7818371)
"In 2004 a Korean Airlines Cargo 747-400F in Oslo, Norway was loaded incorrectly and began its takeoff roll with a CG of 37.8% MAC. Thus being loaded 4.8% past the aft limit of 33% MAC.
The aircraft began to autorotate at 120 (KCAS) and thanks to the commander immediately suspecting a load error, the appropriate action was taken. However, nose attitude reached 19 degrees before sufficient downwards stab trim hab been applied.
Once in the air they contacted KAL operations through SATCOM and determined they could improve the situation by shifting a few pallets in the air. FO and relief FO proceded to shift a few pallets and the flight continued to Seoul.
Aircraft ended up landing with CG 7.2% aft of the limit.
When taking into consideration a possible rapid and extreme load shift far aft of the limit, it becomes evident that even with quick crew action the situation could become irrecoverable."
"... actually 58kts the nose wheel was off the ground. Aircraft was actually airborne at 120kts. On taxy to the runway the NLG WOG was intermittently air mode. The guys were the luckiest pilots on the planet.
FWIW, the Cm of the flaps is beneficial with an aft cg, MLG retraction is slightly beneficial. burning off the CWT may be wonderful for WBM structural considerations but guarantees the cg shifts aft. The arrival of that aircraft resulted in it departing the edge of the runway, however that is open to interpretation as the NLG was about 3' in the air, over the grass, but the MLG was on the concrete.
Had the AP disconnected in the cruise flight the aircraft probably would have been lost, as even with the AP engaged it exhibited longitudinal instability, and the elevator dP was rapidly cycling as was the elevator TE position in smooth air.
Not the first time, won't be the last time. Loading systems have many opportunities for variation from the expected process due to human ingenuity. A control problem close to the ground is a critical and generally untrained event. The opportunities for crosschecking are limited and need vigilance. I have bene caught out on the same type where 6.5T of cargo bound for the aft cargo comp went into the fwd comp, and we got to see the end of the runway up close and personal, took an extra 3000' of runway to get a rotate in, ended up with a part flap landing and full manual stab trim and still out of trim. Nowhere near as dangerous as the opposite case which appears to be a likely condition at Bagram."
I was looking at an old accident thread recently and a couple of posts discussed an incident of a large airliner getting into the air after being very mis-loaded. There was information on what the crew did to help the situation and I thought that perhaps, there might be some other stories out there that could be beneficial to the rest of us. Things such as crew shifting cargo in flight, reduced flap for landing to minimize pitching moment, and what I believe to be maximizing trim range by using manual trim are quite interesting. Here is the post and reply......
Cargo Crash at Bagram - Page 2 - PPRuNe Forums (https://www.pprune.org/accidents-close-calls/513650-cargo-crash-bagram-2.html#post7818371)
"In 2004 a Korean Airlines Cargo 747-400F in Oslo, Norway was loaded incorrectly and began its takeoff roll with a CG of 37.8% MAC. Thus being loaded 4.8% past the aft limit of 33% MAC.
The aircraft began to autorotate at 120 (KCAS) and thanks to the commander immediately suspecting a load error, the appropriate action was taken. However, nose attitude reached 19 degrees before sufficient downwards stab trim hab been applied.
Once in the air they contacted KAL operations through SATCOM and determined they could improve the situation by shifting a few pallets in the air. FO and relief FO proceded to shift a few pallets and the flight continued to Seoul.
Aircraft ended up landing with CG 7.2% aft of the limit.
When taking into consideration a possible rapid and extreme load shift far aft of the limit, it becomes evident that even with quick crew action the situation could become irrecoverable."
"... actually 58kts the nose wheel was off the ground. Aircraft was actually airborne at 120kts. On taxy to the runway the NLG WOG was intermittently air mode. The guys were the luckiest pilots on the planet.
FWIW, the Cm of the flaps is beneficial with an aft cg, MLG retraction is slightly beneficial. burning off the CWT may be wonderful for WBM structural considerations but guarantees the cg shifts aft. The arrival of that aircraft resulted in it departing the edge of the runway, however that is open to interpretation as the NLG was about 3' in the air, over the grass, but the MLG was on the concrete.
Had the AP disconnected in the cruise flight the aircraft probably would have been lost, as even with the AP engaged it exhibited longitudinal instability, and the elevator dP was rapidly cycling as was the elevator TE position in smooth air.
Not the first time, won't be the last time. Loading systems have many opportunities for variation from the expected process due to human ingenuity. A control problem close to the ground is a critical and generally untrained event. The opportunities for crosschecking are limited and need vigilance. I have bene caught out on the same type where 6.5T of cargo bound for the aft cargo comp went into the fwd comp, and we got to see the end of the runway up close and personal, took an extra 3000' of runway to get a rotate in, ended up with a part flap landing and full manual stab trim and still out of trim. Nowhere near as dangerous as the opposite case which appears to be a likely condition at Bagram."