Dassault Falcon 900EX crash, San Diego
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Dassault Falcon 900EX crash, San Diego
This past Saturday, 13th February, 2021, a Dassault 900EX Falcon was substantially damaged when it overran the runway at KMYF (San Diego, Calif., USA) during a rejected takeoff. All three gear legs were sheared off; however, miraculously, there were no serious injuries.
Here's a link to the Aviation Safety Network Report:
https://aviation-safety.net/database...?id=20210213-0
Here's a link to to the Kathryn's Report which includes links to videos of the crash:
Kathryn's Report: Dassault Falcon 900EX, N823RC / N718AK: Incident occurred February 13, 2021 at Montgomery-Gibbs Executive Airport (KMYF), Kearny Mesa, San Diego County, California
If those links prove to not be "active", just copy and paste to your browser.
Cheers,
Grog
Here's a link to the Aviation Safety Network Report:
https://aviation-safety.net/database...?id=20210213-0
Here's a link to to the Kathryn's Report which includes links to videos of the crash:
Kathryn's Report: Dassault Falcon 900EX, N823RC / N718AK: Incident occurred February 13, 2021 at Montgomery-Gibbs Executive Airport (KMYF), Kearny Mesa, San Diego County, California
If those links prove to not be "active", just copy and paste to your browser.
Cheers,
Grog
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I've watched another video of a Dassault 900 EX takeoff and noted that there is considerable stabilizer nose up trim used. In the video supplied by Aviationking95, it appears that the stabilizer is trimmed flat, with perhaps even a bit of nose down trim dialed in. Again, referring to Aviationking95's video, at the approximately 0:37 mark, it appears that considerable nose up elevator is being used, yet, the aircraft does not rotate.
I've been wrong before, but this could be a case of a missed checklist item: the stabilizer trim setting.
Just my opinion/conjecture.
Cheers,
Grog
I've been wrong before, but this could be a case of a missed checklist item: the stabilizer trim setting.
Just my opinion/conjecture.
Cheers,
Grog
Grog,
All (modern) jet aircraft are required to be equipped with a Takeoff Configuration Warning.
Elevator trim out of range is DEFINITELY one of the items that will trigger it.
Top of page 13:
https://www.smartcockpit.com/docs/F9...t_Controls.pdf
All (modern) jet aircraft are required to be equipped with a Takeoff Configuration Warning.
Elevator trim out of range is DEFINITELY one of the items that will trigger it.
Top of page 13:
https://www.smartcockpit.com/docs/F9...t_Controls.pdf
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Grog,
All (modern) jet aircraft are required to be equipped with a Takeoff Configuration Warning.
Elevator trim out of range is DEFINITELY one of the items that will trigger it.
Top of page 13:
https://www.smartcockpit.com/docs/F9...t_Controls.pdf
All (modern) jet aircraft are required to be equipped with a Takeoff Configuration Warning.
Elevator trim out of range is DEFINITELY one of the items that will trigger it.
Top of page 13:
https://www.smartcockpit.com/docs/F9...t_Controls.pdf
https://flightsafety.org/asw-article...ed-in-overrun/
Here's a link to an FAA "Safety Alert For Operators" (SAFO) dated November 25, 2014:
http://content.govdelivery.com/attac.../SAFO14005.pdf
Thank you for the link to the Systems Summary for the Dassault 900EX. As designed, it seems to be a foolproof system; however, there doesn't seem to be any safeguard or interlock system that cannot be ignored, disabled or "worked around" by human beings.
Cheers,
Grog
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“I've watched another video of a Dassault 900 EX takeoff and noted that there is considerable stabilizer nose up trim used. In the video supplied by Aviationking95, it appears that the stabilizer is trimmed flat, with perhaps even a bit of nose down trim dialed in. Again, referring to Aviationking95's video, at the approximately 0:37 mark, it appears that considerable nose up elevator is being used, yet, the aircraft does not rotate.”
I flew a 900EX for 10 years. And I can tell you at heavy weights, full fuel, you need as much allowable (in the green band) nose up trim as possible. Full fuel runs the cg pretty far forward. And even with that much trim you’ll still have the yoke in your gut to achieve rotation, and that rotation will be much more sluggish that what you’ve been used to at much lighter weights. It’s a real eye opener if you’ve not experienced it beforehand!
I flew a 900EX for 10 years. And I can tell you at heavy weights, full fuel, you need as much allowable (in the green band) nose up trim as possible. Full fuel runs the cg pretty far forward. And even with that much trim you’ll still have the yoke in your gut to achieve rotation, and that rotation will be much more sluggish that what you’ve been used to at much lighter weights. It’s a real eye opener if you’ve not experienced it beforehand!
Last edited by 7XDriver; 17th Feb 2021 at 01:58. Reason: Forgot to include quote from previous post
“I've watched another video of a Dassault 900 EX takeoff and noted that there is considerable stabilizer nose up trim used. In the video supplied by Aviationking95, it appears that the stabilizer is trimmed flat, with perhaps even a bit of nose down trim dialed in. Again, referring to Aviationking95's video, at the approximately 0:37 mark, it appears that considerable nose up elevator is being used, yet, the aircraft does not rotate.”
I flew a 900EX for 10 years. And I can tell you at heavy weights, full fuel, you need as much allowable (in the green band) nose up trim as possible. Full fuel runs the cg pretty far forward. And even with that much trim you’ll still have the yoke in your gut to achieve rotation, and that rotation will be much more sluggish that what you’ve been used to at much lighter weights. It’s a real eye opener if you’ve not experienced it beforehand!
I flew a 900EX for 10 years. And I can tell you at heavy weights, full fuel, you need as much allowable (in the green band) nose up trim as possible. Full fuel runs the cg pretty far forward. And even with that much trim you’ll still have the yoke in your gut to achieve rotation, and that rotation will be much more sluggish that what you’ve been used to at much lighter weights. It’s a real eye opener if you’ve not experienced it beforehand!
Beginning of the takeoff roll:
Actual overrun:
Actual overrun:
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4500’ TORA is not much.
That take-off roll looked sluggish to me also. It just appeared it was being held back with weights or something.
Is the application of full/calculated take-off thrust on the brakes a common take-off procedure for these jets? It makes me think the crew felt it was going to be tight from the off.
edited to add; as the aircraft passes abeam the videographer standing on the ramp, you can see the elevators deflect upwards and then hear the engines move to idle. Appears the trim/nose heavy issue mentioned by others above could play a part.
That take-off roll looked sluggish to me also. It just appeared it was being held back with weights or something.
Is the application of full/calculated take-off thrust on the brakes a common take-off procedure for these jets? It makes me think the crew felt it was going to be tight from the off.
edited to add; as the aircraft passes abeam the videographer standing on the ramp, you can see the elevators deflect upwards and then hear the engines move to idle. Appears the trim/nose heavy issue mentioned by others above could play a part.
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From my copy of the 900EX AFM, “Full takeoff thrust is set before brake release.”
Section 5, subsection 150, p3. Additionally there is a T/O CONFIG warning light on the MCS illuminates if:
Flaps more than 22°
Airbrakes not retracted
Slats retracted
Trim outside authorized range (-4.5° to -7.5°)
Park brake engaged
Uncommanded brake press in #2 system
this warning only triggered on the ground with at least one power lever > 82°PLA
accompanied by master caution and aural warn, “NO TAKEOFF” cannot be silenced as long as T/O Config is illuminated.
Last edited by 7XDriver; 18th Feb 2021 at 15:52. Reason: Added AFM notations
Ok. Interesting. Thanks. I’d say all those parameters were within limits, tbh.
Is the inherent requirement for pronounced nose-up trim due to small elevators? Or the number 2 engine’s thrust line?
As I mentioned previously, you can see what looks like elevators deflect upwards just as it passes abeam the videographer that’s standing on the apron to the south of the runway and then the thrust reduces.
Is the inherent requirement for pronounced nose-up trim due to small elevators? Or the number 2 engine’s thrust line?
As I mentioned previously, you can see what looks like elevators deflect upwards just as it passes abeam the videographer that’s standing on the apron to the south of the runway and then the thrust reduces.
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https://jetcareers.com/forums/thread.../#post-3044662
Notice that at 0:17 of the video, upward deflection of the elevators is not apparent; however, upward deflection is apparent starting at 0:18 in the video. I'm not expert on the Falcon 900EX, but in my recent reading, I've found information to the effect that the 900EX is pretty sensitive to improper takeoff stabilizer trim. Whether or not it was a factor in this crash, remains to be seen.
Another contributor ("Anonymous") to the Kathryn's discussion thread was able to blow up a frame in this video that showed the setting of the elevator trim relative to the painted marks on the vertical stabilizer Here's a copy of his post, including the link:
"Here is the CBS 8 video link, screen grab it at 29 seconds on 1080p and take into a photo editor":
The trim setting is exactly as that shown on page 13 of the Dassault Falcon 900EX Easy Systems Summary Manual (see B2N2's post above for the link to the manual). In light of 7XDriver's remarks above, that may not have been sufficient nose up elevator trim.
Cheers,
Grog
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Ok. Interesting. Thanks. I’d say all those parameters were within limits, tbh.
Is the inherent requirement for pronounced nose-up trim due to small elevators? Or the number 2 engine’s thrust line?
As I mentioned previously, you can see what looks like elevators deflect upwards just as it passes abeam the videographer that’s standing on the apron to the south of the runway and then the thrust reduces.
Is the inherent requirement for pronounced nose-up trim due to small elevators? Or the number 2 engine’s thrust line?
As I mentioned previously, you can see what looks like elevators deflect upwards just as it passes abeam the videographer that’s standing on the apron to the south of the runway and then the thrust reduces.
“A post accident inspection of the airplane revealed that all systems were operating within allowable tolerances. Post accident simulator testing revealed that when configured for takeoff in the accident conditions, stabilizer trim set to -5.5 degrees and V speeds set for 45,400 pounds, a delay of 2 to 4 seconds was noted from the time an up elevator input was made to the time the airplane reacted in pitch. When the simulator was configured with the stabilizer trim set to -7.0 degrees and the V speeds set for 46,480 pounds, there was no delay in airplane response to elevator input.”
”In a statement dated June 22, 2007, the pilot in command reported "...an interesting call was made by the chief test pilot at Dassault to our local investigative rep. He said that at gross weight takeoffs you will not get rotation at Vr (rotation speed) and [an] anomaly occurs with the Falcon 900. That it will only occur after holding the yoke full aft for 2 or more seconds.”
”According to information provided by Dassault representatives, the Civil Aviation Authority of the United Kingdom (CAA-UK) performed an evaluation of the MF900 Airplane Flight Manual (AFM), which resulted in the CAA-UK including in their AFM findings, “There must be a simple chart relating c.g. to take-off trim position.” (Refer to “Operation of Horizontal Stabilizer” chart attached). The CAA-UK requirement was taken into account and reflected in specific AFM pages for UK-registered aircraft, which included the MF900. Had such a chart been available and used prior to the accident flight’s take-off for a calculated c.g. of 15.73% MAC, the referenced stabilizer trim setting would have been between -7 and -7.5 degrees.”
I retired in 2010, I cannot recall such a chart existed for U. S. registered a/c, neither did the other two F900 drivers I’ve been corresponding with.
The first time it happened to us, we were at a higher weight, probably in the neighborhood of 48,000#. At that weight we experienced the delay described, just a couple seconds, but definitely unexpected. I made damn sure the rest of my guys knew. 49,000# is the maximum takeoff gross weight with no runway/2nd segment, or SID gradient limitations.
Last edited by 7XDriver; 18th Feb 2021 at 23:28. Reason: Info from the NTSB SBA investigation.
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Links to reports of the 2007 overrun at SBA:
The UK AFM chart for stab trim setting vs. CG was not in FAA AFMs at the time of the crash.
Full Docket :
https://data.ntsb.gov/Docket/?NTSBNumber=SEA07LA152
Summary:
https://reports.aviation-safety.net/...900_N914DD.pdf
The UK AFM chart for stab trim setting vs. CG was not in FAA AFMs at the time of the crash.
Full Docket :
https://data.ntsb.gov/Docket/?NTSBNumber=SEA07LA152
Summary:
https://reports.aviation-safety.net/...900_N914DD.pdf
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sorry, can’t answer that one. Elevator effectiveness would be a contributing factor I would think. I went back and pulled the NTSB report on the SBA accident.
“A post accident inspection of the airplane revealed that all systems were operating within allowable tolerances. Post accident simulator testing revealed that when configured for takeoff in the accident conditions, stabilizer trim set to -5.5 degrees and V speeds set for 45,400 pounds, a delay of 2 to 4 seconds was noted from the time an up elevator input was made to the time the airplane reacted in pitch. When the simulator was configured with the stabilizer trim set to -7.0 degrees and the V speeds set for 46,480 pounds, there was no delay in airplane response to elevator input.”
”In a statement dated June 22, 2007, the pilot in command reported "...an interesting call was made by the chief test pilot at Dassault to our local investigative rep. He said that at gross weight takeoffs you will not get rotation at Vr (rotation speed) and [an] anomaly occurs with the Falcon 900. That it will only occur after holding the yoke full aft for 2 or more seconds.”
”According to information provided by Dassault representatives, the Civil Aviation Authority of the United Kingdom (CAA-UK) performed an evaluation of the MF900 Airplane Flight Manual (AFM), which resulted in the CAA-UK including in their AFM findings, “There must be a simple chart relating c.g. to take-off trim position.” (Refer to “Operation of Horizontal Stabilizer” chart attached). The CAA-UK requirement was taken into account and reflected in specific AFM pages for UK-registered aircraft, which included the MF900. Had such a chart been available and used prior to the accident flight’s take-off for a calculated c.g. of 15.73% MAC, the referenced stabilizer trim setting would have been between -7 and -7.5 degrees.”
I retired in 2010, I cannot recall such a chart existed for U. S. registered a/c, neither did the other two F900 drivers I’ve been corresponding with.
The first time it happened to us, we were at a higher weight, probably in the neighborhood of 48,000#. At that weight we experienced the delay described, just a couple seconds, but definitely unexpected. I made damn sure the rest of my guys knew. 49,000# is the maximum takeoff gross weight with no runway/2nd segment, or SID gradient limitations.
“A post accident inspection of the airplane revealed that all systems were operating within allowable tolerances. Post accident simulator testing revealed that when configured for takeoff in the accident conditions, stabilizer trim set to -5.5 degrees and V speeds set for 45,400 pounds, a delay of 2 to 4 seconds was noted from the time an up elevator input was made to the time the airplane reacted in pitch. When the simulator was configured with the stabilizer trim set to -7.0 degrees and the V speeds set for 46,480 pounds, there was no delay in airplane response to elevator input.”
”In a statement dated June 22, 2007, the pilot in command reported "...an interesting call was made by the chief test pilot at Dassault to our local investigative rep. He said that at gross weight takeoffs you will not get rotation at Vr (rotation speed) and [an] anomaly occurs with the Falcon 900. That it will only occur after holding the yoke full aft for 2 or more seconds.”
”According to information provided by Dassault representatives, the Civil Aviation Authority of the United Kingdom (CAA-UK) performed an evaluation of the MF900 Airplane Flight Manual (AFM), which resulted in the CAA-UK including in their AFM findings, “There must be a simple chart relating c.g. to take-off trim position.” (Refer to “Operation of Horizontal Stabilizer” chart attached). The CAA-UK requirement was taken into account and reflected in specific AFM pages for UK-registered aircraft, which included the MF900. Had such a chart been available and used prior to the accident flight’s take-off for a calculated c.g. of 15.73% MAC, the referenced stabilizer trim setting would have been between -7 and -7.5 degrees.”
I retired in 2010, I cannot recall such a chart existed for U. S. registered a/c, neither did the other two F900 drivers I’ve been corresponding with.
The first time it happened to us, we were at a higher weight, probably in the neighborhood of 48,000#. At that weight we experienced the delay described, just a couple seconds, but definitely unexpected. I made damn sure the rest of my guys knew. 49,000# is the maximum takeoff gross weight with no runway/2nd segment, or SID gradient limitations.
“Just received temp change # 90 to the AFM and # 29 to Operating Procedures Manual.
#90 is no big deal, DFJ revised the operations in Russian airspace and deleted the previous temp change regarding the same
#29 is regarding trim settings for takeoff with various C.G. settings and several notes pertaining to same. There is also a graph to set trim vs. C.G.
These are not in any of the appropriate manuals yet”
note the revision was to the operations manual not the AFM
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Here's a link to the NTSB Preliminary Report on this accident:
https://data.ntsb.gov/carol-repgen/a...ort/102629/pdf
It looks like this report was released just to "check a box" on some sort of check list form, because it says essentially nothing. It also appears that the author of the report did not bother to proof read his work.
Cheers,
Grog
https://data.ntsb.gov/carol-repgen/a...ort/102629/pdf
It looks like this report was released just to "check a box" on some sort of check list form, because it says essentially nothing. It also appears that the author of the report did not bother to proof read his work.
Cheers,
Grog
Here's a link to the NTSB Preliminary Report on this accident:
https://data.ntsb.gov/carol-repgen/a...ort/102629/pdf
It looks like this report was released just to "check a box" on some sort of check list form, because it says essentially nothing. It also appears that the author of the report did not bother to proof read his work.
Cheers,
Grog
https://data.ntsb.gov/carol-repgen/a...ort/102629/pdf
It looks like this report was released just to "check a box" on some sort of check list form, because it says essentially nothing. It also appears that the author of the report did not bother to proof read his work.
Cheers,
Grog