RIP Jessi Combs
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rrrr
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As I said in a post above, the North American Eagle that Jessi drove was built from the fuselage of a Lockheed F-104 Starfighter, and was powered by a 18,000 lb thrust Pratt & Whitney J-79 turbojet engine.
Driving it was a much greater risk than most LSR streamliners present. I have some comments to make about that.
I crewed on a AA/FS that set Southern California Timing Association and Fédération Internationale de l'Automobile world records at Bonneville in 2010, both of whose speeds were over 400 MPH, and two other SCTA records near 400 MPH in a different class in 2011, and therefore I have some knowledge and experience applicable to this subject.
The media is reporting the vehicle's parachute system failed, and the car was destroyed when it ran off the dry lake bed into terrain.
One can easily imagine the forces involved in a crash at speeds near 400 MPH, and an aircraft fuselage is not built to absorb that damage. The remains of the vehicle were almost certainly nothing more than bits of fragmented aluminum and a battered J-79.
I believe the main reason the runs were conducted at the Alvord dry lake bed in Oregon was because the vehicle did not meet safety standards of the Southern California Timing Association, and therefore would not be allowed to run at Bonneville or El Mirage. The SCTA conducts scheduled racing events at both venues, and SCTA safety regulations govern what vehicles are allowed to participate.
The SCTA safety standards require robust construction around the cockpit, specifying roll bar material, thickness, and placement. Other rules dictate how the running gear, drivetrain, and safety systems are to be built. SCTA inspectors have positive safety bias in evaluating the vehicles, and if they don't approve the manner of construction, the vehicle doesn't run.
The F-104 fuselage structure itself precluded the installation of a primary roll cage to protect the driver, and its aluminum monocoque construction was substantially weaker than a conventional 4130 moly steel tubing streamliner.
The Instagram post linked below shows a photo of the North American Eagle, and several areas of deficiency are visible.
One issue of particular interest is that the parachute main lanyard attachment points were on the underside of the car in the airstream, susceptible to damage from previously achieved 400+ MPH and planned Mach 1 wind loads and race course debris. The inline front wheels threw material from the dry lakebed course directly at the parachute main lanyards, so you can easily imagine what I'm saying.
The primary lanyards of the parachutes were also anchored below the vehicle center of mass. This is another safety issue. Upon deployment, the parachutes would impart a lifting force, destabilizing the vehicle at close to its maximum speed.
From the attachment points on the fuselage, the main lanyards of the parachutes were routed between the lid and body of the parachute tubes. The lid was unlatched via a driver operated cable mechanism, and a large spring between the lid and parachute was propelled into the slipstream, pulling out the parachute.
The buffeting of air at the back of the car would have caused violent whipping of the exposed lanyards at speed. Did their routing under the lid provide a point for substantial abrasion and fraying damage to occur, resulting in failure of the lanyards upon opening the parachutes?
Other issues with the modified F-104 fuselage of the North American Eagle would not have passed SCTA inspection, the biggest one being the overall vehicle itself. The driver protection provided by the fuselage was completely deficient because it did not have a rollover and crash structure. The cockpit retained the original configuration, including the ejection seat (which I assume was inoperative).
Was proper engineering scrutiny performed on the axle support struts and fuselage attachment point reinforcements? There weren't redundant load paths for the strut. Alternate load paths on critical vehicle structure are a SCTA safety requirement.
The air deflectors mounted on the axle for downforce placed huge loads on it at speed, and based on the size of the axle system, I wonder if the air loads had been calculated and accounted for. I doubt the rear axle, and particularly its support strut arrangement, would have passed an SCTA inspection.
I noticed the parachute system defects immediately when I saw the Instragram post and photo on Tuesday night. The danger of exposing the system's attachment points and primary lanyards to the airstream and their improper mounting points should have been obvious to the designers, engineers, and constructors of the vehicle.
From an overall perspective, the use of an airplane fuselage for a land speed record vehicle was, IMO, improper, because it could not be successfully modified to conform with cardinal safety requirements.
While the death of Jessi Combs is tragic, it also illustrates the burden of responsibility on designers, engineers, and constructors that build vehicles which operate at the knife edge. There is no margin for error.
https://mobile.twitter.com/TheJessiCombs/status/1165400181350776838
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This is the Flashpoint LSR streamliner, which crashed at Bonneville in September 2018 while traveling 427 MPH. The triple hoop roll cage and surrounding structure are very similar to the vehicle I crewed on. I included this photo to illustrate the strength of a conventional streamliner's construction, and that surviving a 400+ MPH crash is possible. The complete destruction of the North American Eagle in a lower speed crash shows that converting an aircraft for LSR attempts was demonstrably more dangerous than utilizing proven technology.
.
As I said in a post above, the North American Eagle that Jessi drove was built from the fuselage of a Lockheed F-104 Starfighter, and was powered by a 18,000 lb thrust Pratt & Whitney J-79 turbojet engine.
Driving it was a much greater risk than most LSR streamliners present. I have some comments to make about that.
I crewed on a AA/FS that set Southern California Timing Association and Fédération Internationale de l'Automobile world records at Bonneville in 2010, both of whose speeds were over 400 MPH, and two other SCTA records near 400 MPH in a different class in 2011, and therefore I have some knowledge and experience applicable to this subject.
The media is reporting the vehicle's parachute system failed, and the car was destroyed when it ran off the dry lake bed into terrain.
One can easily imagine the forces involved in a crash at speeds near 400 MPH, and an aircraft fuselage is not built to absorb that damage. The remains of the vehicle were almost certainly nothing more than bits of fragmented aluminum and a battered J-79.
I believe the main reason the runs were conducted at the Alvord dry lake bed in Oregon was because the vehicle did not meet safety standards of the Southern California Timing Association, and therefore would not be allowed to run at Bonneville or El Mirage. The SCTA conducts scheduled racing events at both venues, and SCTA safety regulations govern what vehicles are allowed to participate.
The SCTA safety standards require robust construction around the cockpit, specifying roll bar material, thickness, and placement. Other rules dictate how the running gear, drivetrain, and safety systems are to be built. SCTA inspectors have positive safety bias in evaluating the vehicles, and if they don't approve the manner of construction, the vehicle doesn't run.
The F-104 fuselage structure itself precluded the installation of a primary roll cage to protect the driver, and its aluminum monocoque construction was substantially weaker than a conventional 4130 moly steel tubing streamliner.
The Instagram post linked below shows a photo of the North American Eagle, and several areas of deficiency are visible.
One issue of particular interest is that the parachute main lanyard attachment points were on the underside of the car in the airstream, susceptible to damage from previously achieved 400+ MPH and planned Mach 1 wind loads and race course debris. The inline front wheels threw material from the dry lakebed course directly at the parachute main lanyards, so you can easily imagine what I'm saying.
The primary lanyards of the parachutes were also anchored below the vehicle center of mass. This is another safety issue. Upon deployment, the parachutes would impart a lifting force, destabilizing the vehicle at close to its maximum speed.
From the attachment points on the fuselage, the main lanyards of the parachutes were routed between the lid and body of the parachute tubes. The lid was unlatched via a driver operated cable mechanism, and a large spring between the lid and parachute was propelled into the slipstream, pulling out the parachute.
The buffeting of air at the back of the car would have caused violent whipping of the exposed lanyards at speed. Did their routing under the lid provide a point for substantial abrasion and fraying damage to occur, resulting in failure of the lanyards upon opening the parachutes?
Other issues with the modified F-104 fuselage of the North American Eagle would not have passed SCTA inspection, the biggest one being the overall vehicle itself. The driver protection provided by the fuselage was completely deficient because it did not have a rollover and crash structure. The cockpit retained the original configuration, including the ejection seat (which I assume was inoperative).
Was proper engineering scrutiny performed on the axle support struts and fuselage attachment point reinforcements? There weren't redundant load paths for the strut. Alternate load paths on critical vehicle structure are a SCTA safety requirement.
The air deflectors mounted on the axle for downforce placed huge loads on it at speed, and based on the size of the axle system, I wonder if the air loads had been calculated and accounted for. I doubt the rear axle, and particularly its support strut arrangement, would have passed an SCTA inspection.
I noticed the parachute system defects immediately when I saw the Instragram post and photo on Tuesday night. The danger of exposing the system's attachment points and primary lanyards to the airstream and their improper mounting points should have been obvious to the designers, engineers, and constructors of the vehicle.
From an overall perspective, the use of an airplane fuselage for a land speed record vehicle was, IMO, improper, because it could not be successfully modified to conform with cardinal safety requirements.
While the death of Jessi Combs is tragic, it also illustrates the burden of responsibility on designers, engineers, and constructors that build vehicles which operate at the knife edge. There is no margin for error.
https://mobile.twitter.com/TheJessiCombs/status/1165400181350776838
.
This is the Flashpoint LSR streamliner, which crashed at Bonneville in September 2018 while traveling 427 MPH. The triple hoop roll cage and surrounding structure are very similar to the vehicle I crewed on. I included this photo to illustrate the strength of a conventional streamliner's construction, and that surviving a 400+ MPH crash is possible. The complete destruction of the North American Eagle in a lower speed crash shows that converting an aircraft for LSR attempts was demonstrably more dangerous than utilizing proven technology.
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ArizonaKevin
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As I said in a post above, the North American Eagle that Jessi drove was built from the fuselage of a Lockheed F-105 Starfighter fuselage, and was powered by a 45,000 lb thrust Pratt & Whitney J-79 turbojet engine.
Driving it was a much greater risk than most LSR streamliners present. I have some comments to make about that.
I crewed on a AA/FS that set Southern California Timing Association and Fédération Internationale de l'Automobile world records at Bonneville in 2010, both of whose speeds were over 400 MPH, and two other SCTA records near 400 MPH in a different class in 2011, and therefore I have knowledge and experience applicable to this subject.
The media is reporting the vehicle's parachute system failed, and the car was destroyed when it ran off the dry lake bed into terrain.
One can easily imagine the forces involved in a crash at speeds near 400 MPH, and an aircraft fuselage is not built to absorb that damage. The remains of the vehicle were almost certainly nothing more than bits of fragmented aluminum and a battered J-79.
I believe the main reason the runs were conducted at the Alvord dry lake bed in Oregon was because the vehicle did not meet safety standards of the Southern California Timing Association, and therefore would not be allowed to run at Bonneville or El Mirage. The SCTA conducts scheduled racing events at both venues, and SCTA safety regulations govern what vehicles are allowed to participate.
The SCTA safety standards require robust construction around the cockpit, specifying roll bar material, thickness, and placement. Other rules dictate how the running gear, drivetrain, and safety systems are to be built. SCTA inspectors have positive safety bias in evaluating the vehicles, and if they don't approve the manner of construction, the vehicle doesn't run.
The F-104 fuselage structure itself precluded the installation of a primary roll cage to protect the driver, and its aluminum monocoque construction was substantially weaker than a conventional 4130 moly steel tubing streamliner.
The Instagram post linked below shows a photo of the North American Eagle, and several areas of deficiency are visible.
One issue of particular interest is that the parachute main lanyard attachment points were on the underside of the car in the airstream, susceptible to damage from previously achieved 400+ MPH and planned Mach 1 wind loads and race course debris. The inline front wheels threw material from the dry lakebed course directly at the parachute main lanyards, so you can easily imagine what I'm saying.
The primary lanyards of the parachutes were also anchored below the vehicle center of mass. This is another safety violation. Upon deployment, the parachutes would impart a strong lifting force, destabilizing the vehicle at close to its maximum speed.
From the attachment points on the fuselage, the main lanyards of the parachutes were routed between the lid and body of the parachute tubes. The lid was unlatched via a driver operated cable mechanism, and a large spring between the lid and parachute was propelled into the slipstream, pulling out the parachute.
The buffeting of air at the back of the car would have caused violent whipping of the exposed lanyards at speed. Did their routing under the lid provide a point for substantial abrasion and fraying damage to occur, resulting in failure of the lanyards upon opening the parachutes?
Other issues with the modified F-104 fuselage of the North American Eagle would not have passed SCTA inspection, the biggest one being the overall vehicle itself. The driver protection provided by the fuselage was completely deficient because it did not have a rollover and crash structure. The cockpit retained the original configuration, including the ejection seat (which I assume was inoperative).
Was proper engineering scrutiny performed on the axle support struts and fuselage attachment point reinforcements? There weren't redundant load paths for the strut. Alternate load paths on critical vehicle structure are a SCTA safety requirement.
The air deflectors mounted on the axle for downforce placed huge loads on it at speed, and based on the size of the axle system, I wonder if the air loads had been calculated and accounted for. I doubt the rear axle, and particularly its support strut arrangement, would have passed an SCTA inspection.
I noticed the parachute system defects immediately when I saw the Instragram post and photo on Tuesday night. The danger of exposing the system's attachment points and primary lanyards to the airstream and their improper mounting points should have been obvious to the designers, engineers, and constructors of the vehicle.
From an overall perspective, the use of an airplane fuselage for a land speed record vehicle was, IMO, improper, because it could not be successfully modified to conform with cardinal safety requirements.
While the death of Jessi Combs is tragic, it also illustrates the burden of responsibility on designers, engineers, and constructors that build vehicles which operate at the knife edge. There is no margin for error.
https://mobile.twitter.com/TheJessiCombs/status/1165400181350776838
.
This is the Flashpoint LSR streamliner, which crashed while traveling 427 MPH in September 2018. The triple hoop roll cage and surrounding structure are very similar to the vehicle I crewed on. I included this photo to illustrate the strength of a conventional streamliner's construction, and that surviving a 400+ MPH crash is possible. The complete destruction of the North American Eagle in a lower speed crash shows that converting an aircraft for LSR attempts is significantly more dangerous than utilizing proven technology.
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Thank you for the well thought out post and the "behind the scenes" look at these LSR cars. You had mentioned that the ejector seat was probably inoperative, do you think an operative ejector seat would have been beneficial in this situation? I have seen videos of ejector seats being successfully deployed from the ground on jets. Seems like it could have been a unique emergency backup plan should all other braking fail.
rrrr
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The 50-60 year old F-105 seat wasn't the "zero-zero" type that can deploy in just about any situation.
Those older generation ejection seats take a few seconds for the seat to clear an aircraft. I don't think it would be of any use in a LSR conversion that was crashing.
Those older generation ejection seats take a few seconds for the seat to clear an aircraft. I don't think it would be of any use in a LSR conversion that was crashing.
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Willie B
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...I’m assuming at some point they will release her timed speed before it all ended so tragically...
...Jessi Combs final run...RIP Girl...
...Jessi Combs final run...RIP Girl...
RitcheyRch
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The Harney County Sherriff’s said Monday that an examination of the wreckage has led investigators and Combs’ team to conclude that the front wheel of the vehicle suffered a failure, likely from striking an object on the dry lake bed at approximately 550 mph. The report added that Combs, 39, died from blunt force trauma to her head before the vehicle caught fire.
https://www.foxnews.com/auto/jessi-combs-fatal-jet-car-crash-wheel-failure
https://www.foxnews.com/auto/jessi-combs-fatal-jet-car-crash-wheel-failure
monkeyswrench
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This is in no way bashing LEO's, but I really don't know how much training the average county sheriff has on mechanical or structural failure of vehicles traveling at those speeds. Without having multiple angles of high speed cameras through the vehicles pass, it would kind of be guessing by looking at the wreckage.
At the end of the day, it really doesn't matter to most. I assume she knew the risks, as almost all racers do. If it were safe, and easy, the records wouldn't stand for long. The records may be made to be broken, but they are lofty goals most will never even get close to. We'll miss her at the offroad events. I'm sure this week she'll be thought of by many at SEMA.
In my eyes it's better to die living a dream, than to die in your sleep. RIP Jessi, not many get to ride off into the sunset at 500+
At the end of the day, it really doesn't matter to most. I assume she knew the risks, as almost all racers do. If it were safe, and easy, the records wouldn't stand for long. The records may be made to be broken, but they are lofty goals most will never even get close to. We'll miss her at the offroad events. I'm sure this week she'll be thought of by many at SEMA.
In my eyes it's better to die living a dream, than to die in your sleep. RIP Jessi, not many get to ride off into the sunset at 500+
Sleek-Jet
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Accident investigation isn't rocket science. In this day and age with cheap telematery and cameras everywhere, finding the sequence of events isn't to hard.
Now, finding the reason why the wheel failed is entirely different.
Now, finding the reason why the wheel failed is entirely different.
coolchange
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Never did like that "thing".
Struck an object...
Last thing the night before a meet is course walk. 40 people picking up debris.
Don't think the people involved in that were pros...
Struck an object...
Last thing the night before a meet is course walk. 40 people picking up debris.
Don't think the people involved in that were pros...
Flying_Lavey
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Well the article does word it as though the team assisted with the examination of the wreckage. Which would make sense.
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monkeyswrench
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This was an unsanctioned deal, but I would hope they did the same. Never been near that fast, on asphalt or dirt, but I know at 130-140 the reflectors on the highway may as well be speed bumps. I guess it wouldn't take much to wad up at those speeds.
I always thought jobsites with fatalities were rough, even if I didn't know them. I couldn't imagine losing a teammate, and then sorting through the wreckage
Flying_Lavey
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Yeah, I couldn't imagine that. Luckily I haven't had to deal with a loss on a job site either..... Hopefully I can keep that luck going.This was an unsanctioned deal, but I would hope they did the same. Never been near that fast, on asphalt or dirt, but I know at 130-140 the reflectors on the highway may as well be speed bumps. I guess it wouldn't take much to wad up at those speeds.
I always thought jobsites with fatalities were rough, even if I didn't know them. I couldn't imagine losing a teammate, and then sorting through the wreckage
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rivermobster
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52 THOUSAND HP. Jezuz...
RIP young lady. You will be missed.
RIP young lady. You will be missed.
rrrr
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I always thought jobsites with fatalities were rough, even if I didn't know them. I couldn't imagine losing a teammate, and then sorting through the wreckage
Your post reminded me of the death of CART competitor Greg Moore, who was killed in a crash at AAA Speedway on October 31, 1999. I'll never forget the aftermath of that crash.
After it was announced he had died, his crew formed up in a two man side by side formation and marched out to pit lane to take down the pit equipment and put it back in the transporter. They also had to put the remains of Moore's destroyed Reynard on the tailgate hoist and place it on the top deck storage platform.
I was devastated by seeing the crash live on TV, which I immediately knew would prove to be fatal. When I saw the crew filing out to break down the pit, grim faced and lined up like soldiers, I couldn't prevent myself from tearing up.
I couldn't then, and cannot today, imagine the raw grief those guys were experiencing. It must have been overwhelming. It was the last race of the season, and Greg had signed a multiyear contract to drive for Team Penske starting in 2000. He was fantastically talented.
The crew chief for the Bonneville LSR streamliner I crewed on was a member of Team Penske at the time. He told me Greg had gone to dinner with them that weekend, and they had happily discussed his future with the team. His death was devastating to Team Penske, just as it was for the members of Greg's Forsythe Team Players crew and everyone else in the paddock. Twelve years after Greg's death, he became visibly upset when we were talking about it.
In all forms of racing, losing your driver in a crash is the worst thing that can happen to crew members. The topic is never discussed. All crew members know that their driver trusts his life to them. It's a huge responsibility.
