MolaKule
Staff member
Do you really think the discharge of a firearm in a large pressurized vessel would result in an overpressure condition of that vessel if the bullet is lodged in the perpetrator?
Off-duty pilot in jump seat attempted to shut down engines on Horizon Airlines flight
- Thread starter y_p_w
- Start date
Less will happen to the airplane from a stray round than folks imagine. Hollywood gets that horribly wrong. Don’t believe what you “know” from movies.
However, the assailant won’t do well. Guys aren’t going to miss at three feet away. There will be several rounds used to neutralize the threat.
I think it would depend on any number of factors. Among them, accuracy and the possibility of overpenetration.
Over penetration is not a big issue with good hollowpoint ammo. Depending how the fight evolves, accuracy at three feet might be an issue.
But I doubt it.
MolaKule
Staff member
This question relates to fluid dynamics: what happens when a small volume, short time period, high pressure system is exited to a much larger volume constant pressure vessel?
You'd be surprised. I've heard of shootings where someone missed in close quarters. And overpentration. I've heard of police not willing to take a shot at close range because of people behind the target perp.
I would not be surprised. But, I am not going to discuss tactics, procedures, proficiency, training, or anything else that falls into the confidential realm.
However, the important thing is, less would happen to the airplane from a stray round than people believe.
Let me also offer this for your consideration, a hijacked airliner is capable of killing thousands. Would you rather risk a stray round hitting an innocent passenger?
Or would you rather risk the lives of thousands on the ground?
It is a cold calculus. But it is also reality.
I understand what Astro was saying, but missing can still happen, and even JHP can overpenetrate (or even fragment and exit) depending on where it hits. In addition, I'm sure there are a lot of important systems in a cockpit that won't take kindly to being hit by gunfire. Maybe an emergency ax might be a good choice for protection?
And sure I get Hollywood exaggerates explosive decompression. Is that what you were getting at?
MolaKule
Staff member
The assumption is the bullet imbeds itself totally in the perpetrator. What I am asking is what happens under these conditions?
@DanhYes. Discharging a firearm in the confines of a pressurized cockpit while at altitude could have resulted in a different outcome.
"This question relates to fluid dynamics: what happens when a small volume, short time period, high pressure system (the gun system) is exited to a much larger volume constant pressure vessel?"
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Pressurized aircraft leak air constantly. Additional air is required and delivered to keep the desired air pressure in the cabin. An additional 9mm hole in the vessel isn’t going to overwhelm the system and no one is going to be sucked out that hole.
In that case, I wasn't correct in what you were getting at. But I'm thinking of the possibility that it doesn't do that and just goes completely through soft tissue. That in addition to the possibility of missing under stressful conditions.
In addition to that, I don't believe most pilots prepare for the possibility that a jump seat passenger is going to try and interfere with their flight.
MolaKule
Staff member
Ok but none of that answers the question I asked.
Here is what I am getting at.
Cabin pressurization is a process where the air is pumped into the cabin. Cabin pressurization is achieved due to the fuselage, front bulkhead and rear bulkhead which are virtually airtight. A common misconception people have is that the entire aircraft is pressurized. However, in reality, only the fuselage section between the forward and aft bulkheads are pressurized. We call the pressurized section of the fuselage a pressure vessel. By definition, a pressure vessel is a container that is used to hold gases or liquids at a pressure higher or lower than the ambient (surrounding) pressure.
The cockpit is part of the total pressure vessel.
A short period, very low volume, high pressure burst of the gas pressure from any firearm is going to quickly equilibrate to the pressure of the larger volume, constant pressure vessel.
I.e., A short term compression wave and higher pressure gasses from the firearm is going to quickly reach equilibrium (through gas dissipation) to the pressure of the larger volume pressure vessel.
The cockpit is part of the total volume of the aircraft's pressure vessel and will not reach an overpressure condition due to the discharge of a firearm.
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An interesting sidebar to this whole situation is that somebody mentioned the possibility of the perpetrator having medications in their system, although we don't know that this was the case, but as all Pilots know having a residual amount of alcohol in ones system that does not affect them at Ground altitude can severely affect them at the reduced pressures a cabin is at when it's in Cruise. They reduced pressure that aircraft are at inside while in high flight can be enough to significantly add to an effect that a medication or alcohol can have on a person. I've often felt that people who are passengers on aircraft and had alcohol in their system and became unmanageable and had to be restrained and were there for charged with federal crimes, may have legitimately falling into a unknown trap of having the effect of the lower pressure of the cabin compared to being on the ground significantly exaggerate an effect that medications and or alcohol had on them. It's kind of a Pandora's Box that people are opening unaware of it being there. However with respect to a pilot I would highly suspect that any medication that he would have taken would have been also previously taken during his career and that if he was having some kind of adverse effects from it he should have realized that before then. Still in all, the effects of being in a lower pressure environment are something that should always be looked at regarding why a person may have acted in some way unusual. Although this is no excuse for such actions, it's still something that we have to be aware of. A right-minded person, and especially a pilot should realize that something's going on with their mind yet still not make unsafe actions if some combination of lower atmospheric pressure, combined with medications and or alcohol we're having an effect on them.
And it also makes me wonder how many passengers in the past have gotten into trouble because of the additional effect of low pressure. And taking all this into consideration I can understand why an airline would refuse a passenger access to a flight if they were already appearing intoxicated before boarding the flight.
And it also makes me wonder how many passengers in the past have gotten into trouble because of the additional effect of low pressure. And taking all this into consideration I can understand why an airline would refuse a passenger access to a flight if they were already appearing intoxicated before boarding the flight.
I'm watching local news on the incident. Apparently he had no criminal record and his neighbors were interviewed where they had nothing but positive things to say about their interactions with him. Someone found Twitter posts from him and mostly they were normal issues with furloughs during COVID.
They also noted that he was scheduled to pilot a flight on Monday. So yeah he was getting back even though that was his home base.
They also noted that he was scheduled to pilot a flight on Monday. So yeah he was getting back even though that was his home base.
MolaKule
Staff member
Whatever his mindset or medical condition, his actions were totally unjustified and as Astro stated, he is lucky he got off the plane without being carried out on a stretcher.
Cockpits are very tight quarters and you have so little room to get to an axe of any appreciable size, slide your seat back and then while chaos reigns, you have the time and space to swing an axe multiple times.
It's just fantasy to think that.
You don't have a lot of options at 38k feet and if a frangible or hollowpoint round is the solution, put it in place and with quick determination.
Planes will not go down with a bullet hole or two, or even three, that's punched through the skin. It's all Hollywood BS.
Isn’t a lot of the discussion of what might or might not happen with an armed pilot fantasy and/or speculation? There doesn’t appear to have been a single case where an armed pilot has ever intentionally fired a weapon, and just one where a firearm was inadvertently fired. Apparently at about 8000 ft.
US Airways repairs bullet hole in passenger jet
US Airways repairs bullet hole in passenger jet
www.denverpost.com
I believe that most pilots consider the possibility of any eventuality.
A lot of things have happened in the history of air travel over the last 100 years. Incluring multiple incidents of pilot suicide/homicide in which they’ve deliberately crashed airliners, including the Germanwings incident, the EgyptAir incident, and the Embraer 190 in Africa that the pilot turned into a smoking hole in the ground.
I spoke with a friend who flies the E-175 (the type in which this latest Horizon incident occurred), and he was of the opinion that this would almost certainly result in some changes in policy and procedure. And training.
MolaKule
Staff member
Fantasy and speculation, no.
Various scenarios are played out in mock situations. As new situations are analyzed afterwords, additional methodologies are incorporated.
But these methods are not to be made public.