Put Down the Landing Gear
The usual pundits are heaping accolades on the pilot of the doomed plane who chose the Hudson River rather than some street full of buildings, and who managed to miss all bridges and river traffic with the doomed airplane. He and the passengers were extremely lucky to have survived. Most of the time a plane hitting water comes apart in several pieces and many of the passengers are killed by sharp metal edges and high speed impact, or drowned. They were very lucky. The wreckage has been hoisted out of the river today and we see the ripped up under side of the airplane. One engine was ripped off by the impact with the water and the other engine was ripped apart but still clinging to a wing. Much of the aluminum skin on the bottom of the plane was ripped apart. They were very lucky. Another plane crash into water is sometimes seen on one of those “Worst Video” disaster programs as the other plane cartwheels and kills half the passengers.
Badly damaged Airbus
Back in the late 1960s while Bob worked in the structural test engineering division at the Boeing Aircraft Company the 727 airplanes were the new thing. Unlike previous 707 planes the 727 had a much smaller wing that was efficient at high speed. Without power the small wing 727 would glide like a rock. When experienced pilots moved from the 707 to the new 727 many of them tried to land the new plane the way they had always landed the older 707s. Standard practice was to shut the engines down to idle and glide onto the runway. That didn't work with the 727 and several pilots came down short of the runway because the new 727 didn’t glide well or far. Engines used in the late 1960s took up to 30 seconds to spool up to full power from idle. Once the pilot figured out that he wasn’t going to make the runway, he couldn’t get power in time to save the plane from a crash landing short of the field.
Two of the crashed 727s came down in water, in San Francisco and Boston where the airport is next to the bay. Unlike the US Air crash in the Hudson, the 727s were prepared for a normal landing on the airfield. They had their LANDING GEAR extended. They suffered virtually NO DAMAGE at all other than salt water corrosion.
Boeing engineers who evaluate every crash of a Boeing plane concluded that the LANDING GEAR deployment saved the plane and the passengers. The landing gear is the strongest part of an airplane, and is the ONLY part of the plane that is strong enough to hit the ground, or the water, without suffering major damage. At 150 mph water acts almost like a solid, deflecting any attempted penetration. The landing gear skid first and then sink in while transferring huge momentum of the plane into the water without suffering structural failure.
Boeing structural engineers concluded that pilots had always previously been landing wrong in water ditch situations. Pilot training throughout the history of aviation tells pilots to keep the landing gear up and pretend the plane is a “flying boat” for a water ditch landing. Unfortunately a flying boat is much stronger and shaped different than the bottom of a regularly plane. A regular plane’s underbelly rips apart, the wings usually catch a wave, and the plane tumbles and tears apart into several sections. Even WW II fighter planes that ended up in water usually ended up upside down. After evaluating the 727 crash landing short of runways with the landing gear down, Boeing engineering concluded that pilots should always put the landing gear down and land as if its solid ground. A plane ditching in water with the landing gear down will remain intact and none of the passengers will be injured or killed. Somehow this jewel of safety information has not been transmitted to pilot training. Pilots are not trained to put down the landing gear for a water landing.
The US Air pilot who has received so many accolades in New York was very lucky, not very smart. He was lucky to land in calm water without waves to catch one wing first and flip the plane sideways. He was lucky that the engines dragged water uniformly. He was lucky that only the bottom of the plane was ripped apart by the force of the water. He was lucky that the top part of the plane held together. The landing gear is the only part of the plane that is strong enough to hit the water without severe damage. The plane that landed in the Hudson River was an Airbus rather than a Boeing plane, but the structural strength of the landing gear is universal to all planes.
Destroyed Airbus on a barge
There were some people injured on the US Airways plane. One woman suffered two broken legs. A stewardess was badly cut. Several other people were also injured. He failed to do the most important thing when landing on water, but got away without anyone being killed.
To the pilots who may read this, do some research. Find out about putting the landing gear down. And don’t try to pretend you are piloting a flying boat. It doesn’t work that way. If you don’t put down the landing gear people are going to be injured and perhaps many will be killed.