There are some aircraft where a small relaxation of the control column, moving it slightly forward can result in a smoother landing, but it seems like one of the worst things one can do in the flare/landing is to make a large/full nose down input while any part of or all of the aircraft is still airborne. It appears that it happens in stressful situations where a pilot wants to ‘plant’ or force the aircraft onto the ground instead of having to go-around and unfortunately, even to some highly experienced pilots. The results can range all the way to complete disaster.
In a recent event, a Dash-8 had a small bounce on landing as a thunderstorm was arriving at the airport resulting in a damaged nosegear and wrinkled forward fuselage….
“Shortly after the initial touchdown, the aircraft’s weight on wheels sensor indicated that the aircraft had briefly returned to air mode. The PF then made a full nose-down elevator input. A bang and a nose-wheel shimmy followed, and the aircraft pulled to the left as it rolled out on the runway.”
https://bst-tsb.gc.ca/eng/rapports-repo ... w0094.html
In another accident, this one on a 757, they were low on fuel with thunderstorms around at night. To make things worse, a lightning strike cut out the airport lights when approaching the flare. The reaction from the captain was to apply full nose-down pitch, I suppose to plant it on the runway....
“During the approach the crew noted that the company minimum amount of fuel for a diversion to Barcelona (2,800 kg) had been reached. At 23:46:58 hrs, at 250 feet above ground level (agl) and on the correct glidepath, the captain disconnected the autopilot and autothrottle. The aircraft began to deviate above the glidepath. Twelve seconds later, at 110 feet agl, the captain briefly pushed the control column almost fully forward before returning it to an approximately neutral position. The aircraft pitched down to -4.5° nose down attitude and then back up to -2.5° nose down attitude. During this period the captain lost his visual reference with the runway because all runway lights had suddenly failed. The GPWS then warned of the excessive sink rate and the thrust levers being retarded to idle. At 21:47:17 the aircraft touched down in a 2° nose down attitude and a recorded peak normal (vertical) acceleration of 3.11 g. The aircraft bounced, the nose pitched up to +3.3°, a roll to the right commenced, both the thrust levers advanced and the power on both engines increased to 1.18 EPR. Full nose down elevator was applied and held until a second touchdown, resulting in a rapid pitch down. The aircraft made the second touchdown 1.9 seconds after the first at -0.5° pitch attitude (nose down), with a pitch rate of 7°/sec nose down and 4.2° of right roll. After a run of approximately 343 meters across flat grassland beside the runway, the aircraft ran diagonally over a substantial earth mound adjacent to the airport boundary, becoming semi-airborne as a result. At the far side of the mound a number of medium sized trees were struck and severed, predominantly by the right wing, and the right engine nacelle struck the boundary fence. The aircraft, yawed considerably to the right of its direction of travel, then passed through the fence, re-landed in a field and both main landing gears collapsed. It came to rest after a 244 meter slide across the field, with the fuselage almost structurally severed at two points.”
https://aviation-safety.net/database/re ... 19990914-0
The worst one of all was an MD-11 in Tokyo where they got into a multiple bounce situation…..
“The direct causes which the airplane fell into the porpoise phenomenon are as follows: a) Large nose-down elevator input at the first touchdown resulted in a rapid nose –down motion during the first bounce, followed by the second touchdown on the NLG with negative pitch attitude. Then the pitch angle rapidly increased by the ground reaction force, causing the larger second bounce, and b) The PF‘s large elevator input in an attempt to control the airplane without thrust during the second bounce.”
https://www.mlit.go.jp/jtsb/eng-air_report/N526FE.pdf
Video of accident…
https://www.youtube.com/watch?v=d4iD-eWUCEY
Once the mains are on the ground, a large nosedown input to lower the nose is bad news. Boeing has an article about it here.....
http://www.boeing.com/commercial/aeroma ... ero_18.pdf
There are multiple other examples that can be found on the internet as seen below......
https://news.aviation-safety.net/2012/0 ... t-bristol/
https://assets.publishing.service.gov.u ... 507740.pdf
https://www.youtube.com/watch?v=Jw-aUVa3a0U
Don't make large nose-down inputs in the flare/landing. In fact, I can think of a couple of longbody aircraft where a large amount of aft control input is frequently needed to lower the nosewheel smoothly(or fly the nosewheel on as the manual says).
Don't make Large Nosedown Inputs for the Landing
Moderators: sky's the limit, sepia, Sulako, lilfssister, North Shore
Re: Don't make Large Nosedown Inputs for the Landing
Report of incident from last year just released....
https://flyhigh.news/delta-boeing-757-s ... reloaded=1
"After the main landing gear (MLG) touchdown, with an instant load alleviation on those same MLG, the aircraft began to derotate and, as the control column was pushed, the pitch rate increased. The pitch rate was arrested with a pull of the column, followed by a second, more rapid push."
http://www.gpiaa.gov.pt/wwwbase/wwwincl ... ebSiteMenu
Don't push.
https://flyhigh.news/delta-boeing-757-s ... reloaded=1
"After the main landing gear (MLG) touchdown, with an instant load alleviation on those same MLG, the aircraft began to derotate and, as the control column was pushed, the pitch rate increased. The pitch rate was arrested with a pull of the column, followed by a second, more rapid push."
http://www.gpiaa.gov.pt/wwwbase/wwwincl ... ebSiteMenu
Don't push.
