B737 uncommanded extreme nose up position at 20 feet RA
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B737 uncommanded extreme nose up position at 20 feet RA
A serious incident that ended well.
It's from 2009, but I didn't find any previous post.
A big applaud for the crew 
You can read the NTSB report here:
ENG09IA011
It's from 2009, but I didn't find any previous post.
According to the pilot report, the flight crew reported that, “during final approach to runway 34 for DIY at 20 feet RA without any command, the aircraft rapidly moved to an extreme nose up position of approximately 30 degrees”.
An uncommanded elevator surface deflection as a result of a left elevator PCU input arm assembly jam due to FOD lodged between the input arm assembly and the PCU housing. The FOD was a roller element from an elevator upper torque tube output crank bearing, but how or when the roller element liberated from its bearing assembly could not be determined.
The flight crew controlled the airplane through the use of full nose down stabilizer, thrust, roll and significant pilot effort by both crewmembers on their respective columns. A second approach and landing was successfully made.
You can read the NTSB report here:
ENG09IA011
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Pilots have a way to survive if they have experience. If you can't trim the horizontal stabilizer and you have a huge pitch up rolling into a bank and maybe extending flaps might make it controllable for landing. It might not work for the new guys. We always had it in our back pocket if things were going bad. They don't teach that now so most pilots would probably just crash. Kind of sad.
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bubbers
so many of the ''tricks'' of our trade are not handed on to the nexgen pilot. so sad...I remember reading that the B25 could access 40 more gallons of gasoline when the flaps were put down to 25%.
odd throttle combos...even moving passengers to change CofG in a pinch...
so many of the ''tricks'' of our trade are not handed on to the nexgen pilot. so sad...I remember reading that the B25 could access 40 more gallons of gasoline when the flaps were put down to 25%.
odd throttle combos...even moving passengers to change CofG in a pinch...
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anyone remember the Delta L1011 out of KSAN that got stuck nose up? Talk about hero pilots, they jockeyed the throttles and got into LAX...
A NASA report talking about this incident said "a less capable crew would likely
have not been able to save this airplane." Indeed.
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I was flying in SNA then but don't recall this incident. Thank God the crew knew how to think outside the box and save everybody. The new way of flying by automation and little pilot handling skills would make this outcome a lot different.
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737-100/200/300/400/500 Would fail current certification standards?
Am I reading the last section of this NTSB report correctly. Does that mean that the 300/400/500 are only certified to the old standard and based on the physical efforts required by the crew it would fail current certification?
"The design of the pitch control system on the 737-300/-400/-500 airplanes is essentially unchanged from the 737-100/-200 airplanes.
When the 737-100/-200 airplanes were certified, the FARs did not specifically require consideration of a single point failure mode (such as a single PCU rate jam) as long as the failure mode was considered extremely remote. The FARs have been modified since then..."
Still, a pharmacist friend of mine said if they discovered Aspirin today it would never get approved :-)
"The design of the pitch control system on the 737-300/-400/-500 airplanes is essentially unchanged from the 737-100/-200 airplanes.
When the 737-100/-200 airplanes were certified, the FARs did not specifically require consideration of a single point failure mode (such as a single PCU rate jam) as long as the failure mode was considered extremely remote. The FARs have been modified since then..."
Still, a pharmacist friend of mine said if they discovered Aspirin today it would never get approved :-)
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[QUOTE][Talk about 30 degrees nose up getting your attention, try 80 degrees !!
/QUOTE]
Hi TMB from JL
Suggest might be worth making a short summary of your Sydney episode for Pprune readers of this particular thread as it has a marked similarity. Although covered on earlier UA recovery posts a long time ago, it will not be readily found unless you know what you are looking for and I very much doubt if readers recall it.
In the 737 Classic simulator in Melbourne a similar upset was designed to the upset in the original post. This originated from a 737 pitch up incident from 20 years ago in USA when the pilot had a vicious pitch up near the runway. He immediately rolled the 737 through 60 degrees angle of bank to get the nose to drop. The FCTM advises to use gentle rudder to aid the nose drop if the ailerons are also ineffective.
While Airbus feel that UA recoveries are not applicable to their types because of lack of simulator fidelity, it ignores the fact that most upsets have happened in IMC and aircraft have crashed. The secret is basic instrument flying scan to recognise the upset and once that is done in a flash normal recovery action is initiated without delay.
In other words the control forces may not be replicated in the simulator but the flight instrument indications of an upset are the same for all types and basic recovery drills the same. As so many pilots have lost their basic instrument flying skills after flying glass cockpit types on autopilot, it should be mandatory for pure flying skills to be demonstrated on recurrent sim training. And that includes regular practice at UA recoveries- not merely once every three years for three minutes...
/QUOTE]
Hi TMB from JL
Suggest might be worth making a short summary of your Sydney episode for Pprune readers of this particular thread as it has a marked similarity. Although covered on earlier UA recovery posts a long time ago, it will not be readily found unless you know what you are looking for and I very much doubt if readers recall it.
In the 737 Classic simulator in Melbourne a similar upset was designed to the upset in the original post. This originated from a 737 pitch up incident from 20 years ago in USA when the pilot had a vicious pitch up near the runway. He immediately rolled the 737 through 60 degrees angle of bank to get the nose to drop. The FCTM advises to use gentle rudder to aid the nose drop if the ailerons are also ineffective.
While Airbus feel that UA recoveries are not applicable to their types because of lack of simulator fidelity, it ignores the fact that most upsets have happened in IMC and aircraft have crashed. The secret is basic instrument flying scan to recognise the upset and once that is done in a flash normal recovery action is initiated without delay.
In other words the control forces may not be replicated in the simulator but the flight instrument indications of an upset are the same for all types and basic recovery drills the same. As so many pilots have lost their basic instrument flying skills after flying glass cockpit types on autopilot, it should be mandatory for pure flying skills to be demonstrated on recurrent sim training. And that includes regular practice at UA recoveries- not merely once every three years for three minutes...
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TBC's EQA rpt has PHOTOs of tiny debris
Re' this PITCH upset of B737-400 / 14Jun09, several aspects of this ntsb UPSET-INVESTIGATION seem unusual -- in a good way.
The Board's Safety Recommendations A-11-7 through -11 & background are now available:
http://www.ntsb.gov/recs/letters/2011/A-11-007-011.pdf
The DOCKET includes TBC's EQA report (Photos of tiny debris, & actuator, totals about 14 photos and six IPC drawings):
CD List Of Contents
434452
This mishap occurred in Turkey. The airline recovered the FOD, SAVED it & photos; and the manufacturer did a good EQA examination of parts provided; & both provided information, and the USA's investigating authority provided the docket and safety recommendations.
For a minor upset, this case resulted in a high quality product from the Board. Maybe it was just lucky that this 14Jun09 occurrence happened to a SMALLER operator, & lucky that the PCU's obstructing-DEBRIS was recovered: so investigators had GOOD EVIDENCE. No rumors about the human-operator inciting this upset, no guesses about the pilot's financial challenges, nor his state of mind. So nice when a mysterious upset is explained utilizing direct evidence, rather than rumor & "human factors" specialists. [I'm wondering if perhaps there was one staff engineer, & perhaps his manager, who spent TIME & EFFORT way beyond what might normally have been devoted to such a flight control problem. Nice results.]
The Board's Safety Recommendations A-11-7 through -11 & background are now available:
http://www.ntsb.gov/recs/letters/2011/A-11-007-011.pdf
The DOCKET includes TBC's EQA report (Photos of tiny debris, & actuator, totals about 14 photos and six IPC drawings):
CD List Of Contents
434452
This mishap occurred in Turkey. The airline recovered the FOD, SAVED it & photos; and the manufacturer did a good EQA examination of parts provided; & both provided information, and the USA's investigating authority provided the docket and safety recommendations.
For a minor upset, this case resulted in a high quality product from the Board. Maybe it was just lucky that this 14Jun09 occurrence happened to a SMALLER operator, & lucky that the PCU's obstructing-DEBRIS was recovered: so investigators had GOOD EVIDENCE. No rumors about the human-operator inciting this upset, no guesses about the pilot's financial challenges, nor his state of mind. So nice when a mysterious upset is explained utilizing direct evidence, rather than rumor & "human factors" specialists. [I'm wondering if perhaps there was one staff engineer, & perhaps his manager, who spent TIME & EFFORT way beyond what might normally have been devoted to such a flight control problem. Nice results.]
Last edited by IGh; 14th Feb 2011 at 23:03.
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It Was Dangerous.
very very dangerous situation.in finall approach.we have low speed and suddenly increase in pitch attitude can stall the airplane.
recovery is very difficult and sometimes impossible for pilots.
in Iran (my country) in ground school and flight period teach us that one of some
problems that is very unsafe for flight is attitudes that they are beyond standard angle in flight.and we learn that in this situations time is very important to prevent develop this attitudes because usually this causes airplane going to out of control perocedure.
FOR a heavy airplane like 737 in the final
!!i think pilots reaction was very
proper and professional for control this .
CAN EVERYONE TELL ME ONE EXAMPLE FOR AN ACCIDENT WITH THIS ATTITUDE?(IN LAST YEARS).
recovery is very difficult and sometimes impossible for pilots.
in Iran (my country) in ground school and flight period teach us that one of some
problems that is very unsafe for flight is attitudes that they are beyond standard angle in flight.and we learn that in this situations time is very important to prevent develop this attitudes because usually this causes airplane going to out of control perocedure.
FOR a heavy airplane like 737 in the final
!!i think pilots reaction was very proper and professional for control this .
CAN EVERYONE TELL ME ONE EXAMPLE FOR AN ACCIDENT WITH THIS ATTITUDE?(IN LAST YEARS).
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Pitch Upsets at low level.
ALI -Safari - IR and other members who are or may be interested in the above subject.
This been posted before on PPRune and is now posted again in the interest of Flight Safety.
" A crew is expected to perform to the best of their ability when a problem occurs, either known or unknown. In the unknown case the crew have to attempt to control the aircraft flight path so that they have time to solve the problem."
Below are a few details of an incident that happened to a Business Jet (Falcon 20F) that experienced a pitch upset just prior to the flare at Sydney Airport. This happened about 25 years ago. The pilot flying, initiated a go round during the flare when he could not control the pitch attitude of the Jet.which went to around 80 degrees nose up. I took control of the aircraft and as the IAS was decreasing past 107knots, in an alarming nose high attitude ( I thought we were going over on to our back), I rolled the aircraft to the left and had the Pilot not Flying reduce the throttles to help in getting the nose down below the horizon. We managed to recover before ground contact and as power was applied in the recovery we went straight back to the 60 / 80 degree pitch up ( confirmed by ATC personnel ).
During the first go around, the flaps and gear were retracted and we did a series of the above manoeuvres using the roll and power off and on application techinque, each time gainging some height above ground level, although we had only very limited heading control. We worked our way up to 6500 feet and the aircraft "flew out" of the problem. We returned to Sydney and landed ..
Some brief comments:
(A) Once the first recovery had been achieved, I knew that I could control the aircraft to a certain extent whilst the fuel lasted.
(B) This could not have been possible without the excellent crew co-ordination between PF and PNF.
(C) A help to me was the knowledge of aerodynamics instilled by Instructors during my early training on Tiger Moths.
(D) the aircraft had a single electric trim system, they now have a dual system to try to prevent the possibilty of dust causing relay sticking problems .
(E) Immediately after this incident we made arrangements for the CVR and FDR to be forwarded to the BASI for their investigation.
(F) At a later date , after the BASI Investigation, we simulated the problem in a Flight Simulator which was spectacular.
(G) The ATC assistance during the Incident was of the highest order.
We were both lucky to come back from this incident to tell this story and I hope that any other crew faced with an immediate, critical situation, work as a team and do not give up.
Tmb
This been posted before on PPRune and is now posted again in the interest of Flight Safety.
" A crew is expected to perform to the best of their ability when a problem occurs, either known or unknown. In the unknown case the crew have to attempt to control the aircraft flight path so that they have time to solve the problem."
Below are a few details of an incident that happened to a Business Jet (Falcon 20F) that experienced a pitch upset just prior to the flare at Sydney Airport. This happened about 25 years ago. The pilot flying, initiated a go round during the flare when he could not control the pitch attitude of the Jet.which went to around 80 degrees nose up. I took control of the aircraft and as the IAS was decreasing past 107knots, in an alarming nose high attitude ( I thought we were going over on to our back), I rolled the aircraft to the left and had the Pilot not Flying reduce the throttles to help in getting the nose down below the horizon. We managed to recover before ground contact and as power was applied in the recovery we went straight back to the 60 / 80 degree pitch up ( confirmed by ATC personnel ).
During the first go around, the flaps and gear were retracted and we did a series of the above manoeuvres using the roll and power off and on application techinque, each time gainging some height above ground level, although we had only very limited heading control. We worked our way up to 6500 feet and the aircraft "flew out" of the problem. We returned to Sydney and landed ..
Some brief comments:
(A) Once the first recovery had been achieved, I knew that I could control the aircraft to a certain extent whilst the fuel lasted.
(B) This could not have been possible without the excellent crew co-ordination between PF and PNF.
(C) A help to me was the knowledge of aerodynamics instilled by Instructors during my early training on Tiger Moths.
(D) the aircraft had a single electric trim system, they now have a dual system to try to prevent the possibilty of dust causing relay sticking problems .
(E) Immediately after this incident we made arrangements for the CVR and FDR to be forwarded to the BASI for their investigation.
(F) At a later date , after the BASI Investigation, we simulated the problem in a Flight Simulator which was spectacular.
(G) The ATC assistance during the Incident was of the highest order.
We were both lucky to come back from this incident to tell this story and I hope that any other crew faced with an immediate, critical situation, work as a team and do not give up.
Tmb
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how do you can?
special thanks to (tmbstory).
how a bad situation.worst aerodynamical manuver for aircraft i think is this experience .yoke vibration-stall alarm-sudden decrease in speed...how you can managment this condition?
how a bad situation.worst aerodynamical manuver for aircraft i think is this experience .yoke vibration-stall alarm-sudden decrease in speed...how you can managment this condition?
