Sukhoi Superjet off runway at KEF
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Below the Glidepath - not correcting
Fatigue...
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My 2 cents
1 - fatigue
2 - poor schedule
causing
3 - several TOGA cancellations due to intermittent WOW and computer logic.
4 - Wrong throttle moved.
5 - Landing gear ordered prematurely up.
contributing factors during test flight:
- one engine turned off intentionally
- low altitude flight of 10 ft AGL
The part that interested me most was #3, and #5.
page 33
The pilot flying pressed the TOGA button on the right TQL to initiate a go-around
and, according to the cockpit voice recorder, called out “go-around.”
Almost simultaneously, at 05:23:28:70, the main landing gear touched the RW
and as a result of left main LG shock strut compression a/c avionics complex
received WOW (weight on wheels) signal.
In response to WOW signal and in accordance with AFCS logic and SC AWO
316 requirements, the left A/T disengaged automatically. At the moment of left
A/T disengagement, the left engine TQL was at 16.59°.
The pilot flying noticed at the primary flight display that the go-around mode had
not engaged. He also noticed that the flight director was not available.
After the AP disconnected, the pilot flying attempted go-around by pressing the
TOGA button on the right throttle immediately prior to the landing gear touching
the runway at 05:23:28.7. The FTI 52 recorded a short “pulse” of GA mode
engagement, which confirms that the signal from the TOGA button reached the
auto flight system and its attempt to engage the GA mode on this computational
step.
At 05:23:29.5, the left LG WOW status appeared. Therefore, in accordance with
the auto flight system logics, the A/T system was disconnected. GA engagement
was inhibited by an asynchronous acquiring of WOW status by the two auto flight
system master channel computers. The GA was not displayed in PFD. So, at
05:23:29.5 the following events had simultaneously occurred:
Actual landing touchdown, A/T disconnect and GA mode engagement inhibit.
The main landing gear only touched the runway at 05:23:28:70 for a brief
moment (0.4 seconds) and then the airplane started to climb again at
05:23:29:10.
page 34
At 05:23:30 the right engine’s SOV 53 closed as it had previously been set to
failure mode by the ATTCS panel and shut down using the ENG MASTER
SWITCH.
At this point the AP, the FD, the left A/T and the right A/T were all selected OFF,
as was the right engine. The left engine was delivering thrust at TQL 16.59°,
slightly higher than idle. Manual input from the operational engine (left engine)
was therefore required to perform the go-around.
The pilot flying started to perform go around in manual mode, by setting the right
(inoperative) engine TQL to TO/GA.
The pilot flying pitched the airplane up and the airplane started climbing.
According to the CVR, no POSITIVE CLIMB callout was made.The pilot flying
ordered landing gear retraction at 05:23:34. The landing gear was selected to up
at 05:23:36 by the pilot monitoring.
The left TQL remained at 16.59 deg, until the pilot flying discovered his mistake
two seconds before the airplane hit the runway and put the left TQL to TO/GA.
By then, the throttle input on the left engine was too late.
1 - fatigue
2 - poor schedule
causing
3 - several TOGA cancellations due to intermittent WOW and computer logic.
4 - Wrong throttle moved.
5 - Landing gear ordered prematurely up.
contributing factors during test flight:
- one engine turned off intentionally
- low altitude flight of 10 ft AGL
The part that interested me most was #3, and #5.
page 33
The pilot flying pressed the TOGA button on the right TQL to initiate a go-around
and, according to the cockpit voice recorder, called out “go-around.”
Almost simultaneously, at 05:23:28:70, the main landing gear touched the RW
and as a result of left main LG shock strut compression a/c avionics complex
received WOW (weight on wheels) signal.
In response to WOW signal and in accordance with AFCS logic and SC AWO
316 requirements, the left A/T disengaged automatically. At the moment of left
A/T disengagement, the left engine TQL was at 16.59°.
The pilot flying noticed at the primary flight display that the go-around mode had
not engaged. He also noticed that the flight director was not available.
After the AP disconnected, the pilot flying attempted go-around by pressing the
TOGA button on the right throttle immediately prior to the landing gear touching
the runway at 05:23:28.7. The FTI 52 recorded a short “pulse” of GA mode
engagement, which confirms that the signal from the TOGA button reached the
auto flight system and its attempt to engage the GA mode on this computational
step.
At 05:23:29.5, the left LG WOW status appeared. Therefore, in accordance with
the auto flight system logics, the A/T system was disconnected. GA engagement
was inhibited by an asynchronous acquiring of WOW status by the two auto flight
system master channel computers. The GA was not displayed in PFD. So, at
05:23:29.5 the following events had simultaneously occurred:
Actual landing touchdown, A/T disconnect and GA mode engagement inhibit.
The main landing gear only touched the runway at 05:23:28:70 for a brief
moment (0.4 seconds) and then the airplane started to climb again at
05:23:29:10.
page 34
At 05:23:30 the right engine’s SOV 53 closed as it had previously been set to
failure mode by the ATTCS panel and shut down using the ENG MASTER
SWITCH.
At this point the AP, the FD, the left A/T and the right A/T were all selected OFF,
as was the right engine. The left engine was delivering thrust at TQL 16.59°,
slightly higher than idle. Manual input from the operational engine (left engine)
was therefore required to perform the go-around.
The pilot flying started to perform go around in manual mode, by setting the right
(inoperative) engine TQL to TO/GA.
The pilot flying pitched the airplane up and the airplane started climbing.
According to the CVR, no POSITIVE CLIMB callout was made.The pilot flying
ordered landing gear retraction at 05:23:34. The landing gear was selected to up
at 05:23:36 by the pilot monitoring.
The left TQL remained at 16.59 deg, until the pilot flying discovered his mistake
two seconds before the airplane hit the runway and put the left TQL to TO/GA.
By then, the throttle input on the left engine was too late.
Last edited by alph2z; 31st Mar 2016 at 02:45.
Page 30 of the report:
In accordance with EASA AMC48 AWO 316, section “1.2 inadvertent go-around Selection”, an inadvertent selection of go-around mode after touchdown should have no adverse effect on the ability of the aircraft to safety rollout and stop. As a result of this EASA design requirement, the TOGA switches are automatically disengaged after touchdown to prevent inadvertent selection of go- around mode after landing.
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hmmmmm. I don't know who to believe anymore.
CS–AWO = Certification Specifications for All Weather Operations
CS–AWO 316 Go around
(See AMC AWO 316)
(a) The aircraft must be capable of safely
executing a go-around from any point on the
approach to touchdown in all configurations to
be certificated. The manoeuvre may not require
exceptional piloting skill, alertness or strength
and must ensure that the aeroplane remains
within the obstacle limitation surface for a
Category II or III precision approach runway as
specified in Annex 14 Chicago Convention.
(b) For decision heights below 15 m (50 ft) automatic go-around must be provided.
(c) When automatic go-around is provided, it must be available down to touchdown.
(d) When automatic go-around is engaged, subsequent ground contact should not cause its
disengagement .
CS–AWO = Certification Specifications for All Weather Operations
CS–AWO 316 Go around
(See AMC AWO 316)
(a) The aircraft must be capable of safely
executing a go-around from any point on the
approach to touchdown in all configurations to
be certificated. The manoeuvre may not require
exceptional piloting skill, alertness or strength
and must ensure that the aeroplane remains
within the obstacle limitation surface for a
Category II or III precision approach runway as
specified in Annex 14 Chicago Convention.
(b) For decision heights below 15 m (50 ft) automatic go-around must be provided.
(c) When automatic go-around is provided, it must be available down to touchdown.
(d) When automatic go-around is engaged, subsequent ground contact should not cause its
disengagement .
Last edited by alph2z; 31st Mar 2016 at 16:14.
The CS talks about GA being selected prior to touchdown (which wasn't the case here). The report references the AMC and not the CS itself. I don't have the full AMC available here but the text is clearly about GA activation after touchdown.
In this case the GA mode was selected after touchdown, at which point the system prevented this because of WOW activation, and a manual GA should have been carried out. If the PF had pushed the button a bit sooner, before touchdown, this would probably not have happened.
In this case the GA mode was selected after touchdown, at which point the system prevented this because of WOW activation, and a manual GA should have been carried out. If the PF had pushed the button a bit sooner, before touchdown, this would probably not have happened.
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Ahhhh ... much further down in the same EASA doc.
I'm very weary of section 1.2. Inadvertent Go-around Selection. Is this Inadvertent a big problem, does this happen often ? I'm very weary of the pilot not having the final word !!
AMC AWO 316
AMC = Acceptable Means of Compliance
Go-Around
1 Safety Considerations
1.1 Effects of Contact with the Runway: For aircraft in which a go-around from a very low altitude may result in inadvertent runway contact, the safety of the procedure should be established giving consideration to at least the following:
a. The guidance information and control provided by the go-around mode should be retained and be shown to have safe and acceptable characteristics throughout the manoeuvre,
b. Other systems (e.g. automatic throttle, brakes, spoilers, reverse thrust and alerting systems) should not operate in a way that would adversely affect the safety of the go-around manoeuvre.
1.2 Inadvertent Go-around Selection. Inadvertent selection of go-around mode after touchdown should have no adverse effect on the ability of the aircraft to safely roll out and stop.
I'm very weary of section 1.2. Inadvertent Go-around Selection. Is this Inadvertent a big problem, does this happen often ? I'm very weary of the pilot not having the final word !!
AMC AWO 316
AMC = Acceptable Means of Compliance
Go-Around
1 Safety Considerations
1.1 Effects of Contact with the Runway: For aircraft in which a go-around from a very low altitude may result in inadvertent runway contact, the safety of the procedure should be established giving consideration to at least the following:
a. The guidance information and control provided by the go-around mode should be retained and be shown to have safe and acceptable characteristics throughout the manoeuvre,
b. Other systems (e.g. automatic throttle, brakes, spoilers, reverse thrust and alerting systems) should not operate in a way that would adversely affect the safety of the go-around manoeuvre.
1.2 Inadvertent Go-around Selection. Inadvertent selection of go-around mode after touchdown should have no adverse effect on the ability of the aircraft to safely roll out and stop.
Last edited by alph2z; 31st Mar 2016 at 20:14.
And airframe written off.
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Looks like trying to complete the final tests before weather set in set these guys up for failure.
Fatigued Flight Test Crew Crosswind Accident - Aerossurance
Fatigued Flight Test Crew Crosswind Accident - Aerossurance
The RNSA concluded "that human factors played a significant role in this accident". In particular significant fatigue was evident.
The Russian Federal Aviation Regulation limits the duty period for test pilots (preflight preparation and test flight duration) to 8 hours. On the day, the commencement of flying has been slipped back several times. So whereas the first flight had been due at 14:00 it actually took off at 19:57, with the crew spending their time as follows.
The Russian Federal Aviation Regulation limits the duty period for test pilots (preflight preparation and test flight duration) to 8 hours. On the day, the commencement of flying has been slipped back several times. So whereas the first flight had been due at 14:00 it actually took off at 19:57, with the crew spending their time as follows.
- 8:30 -10:00 – preliminary preparations to flight in the hotel;
- 10:00 – 12:00 – rest in the hotel;
- 12:00 – 13:00 – lunch in the hotel;
- 13:00 – 18:00 – rest in the hotel;
- 18:00 – 18:30 – dinner in the hotel;
- 18:30 – 19:00 – transfer to the airport (start of shift according to Sukhoi);
- 19:00 – 19:35 – preflight training;
- 19:35 – 19:45 – transfer to the aircraft.
- 19:57 – 21:40 – first flight;
- 22:35 – 00:24 – second flight;
- 01:16 – 03:07 – third flight;
- 04:03 – c6:20 – fourth flight (ended at 05:23 with the accident).
The RNSA comment that each rescheduling had required some crew interaction during their rest period. They do nor detail the previous night's sleep though.
The accident occurred 10 hours and 53 minutes after the flight shift started and 20 hours and 53 minutes after the preliminary preparation started in the hotel at 08:30.
The accident occurred 10 hours and 53 minutes after the flight shift started and 20 hours and 53 minutes after the preliminary preparation started in the hotel at 08:30.
The ITSB [RNSA] concludes that although the flight crew was well rested prior to the originally planned flight duty time, it was not well rested at the time of the actual flight duty time due to significant and repeated delays.
This was done because the time for flight test campaign was about to finish and the weather forecast for the following 3 days did not have suitable weather conditions for the flight test program.
This was done because the time for flight test campaign was about to finish and the weather forecast for the following 3 days did not have suitable weather conditions for the flight test program.
Additionally, the pilot flying has remained in Iceland during the test campaign (whereas other personnel had been rotated) and was on his 30th test flight in less than a month.
The RNSA note that:
The RNSA note that:
Performance decrements associated with periods of prolonged wakefulness have been addressed in multiple research literature. Research has shown that performance on cognitive tasks, mental problem solving, vigilance and communication tasks shows a 30% decrement after 18 hours of wakefulness. After 42 hours, performance degrades by 60%. Performance degradation is therefore progressive, becoming worse as time awake increases.
Based on the above research and with respect to the preliminary flight preparation starting at 08.30 in the morning of July 20th, ITSB [RNSA] fatigue calculations estimated the task performance of the flight crew to have degraded approximately 46% at the time of the accident.
One of the more sensitive measures of performance degradation due to the fatigue associated with continuous wakefulness is reaction time. People who are fatigued, reliably react more slowly to situations and stimuli that require rapid cognitive or physical responses [as required for the accident flight test].
The accident occurred during night at 05:23, at the time of day when the performance and cognitive function of the pilot flying would have been at its low point...
An indicator of flight crew fatigue was that standard callouts were not made when initiating the go-around.
The pilot flying attempted the go-around with the use of the inoperative engine TQL and 15 seconds passed before he corrected this.
Based on the above research and with respect to the preliminary flight preparation starting at 08.30 in the morning of July 20th, ITSB [RNSA] fatigue calculations estimated the task performance of the flight crew to have degraded approximately 46% at the time of the accident.
One of the more sensitive measures of performance degradation due to the fatigue associated with continuous wakefulness is reaction time. People who are fatigued, reliably react more slowly to situations and stimuli that require rapid cognitive or physical responses [as required for the accident flight test].
The accident occurred during night at 05:23, at the time of day when the performance and cognitive function of the pilot flying would have been at its low point...
An indicator of flight crew fatigue was that standard callouts were not made when initiating the go-around.
The pilot flying attempted the go-around with the use of the inoperative engine TQL and 15 seconds passed before he corrected this.
