Snowbird accident, two eject.

[bdk]

Do both crew members eject independently, or do either initiate the ejection for all?

[old iron]

Do both crew members eject independently, or do either initiate the ejection for all?

The video shows both ejecting, but maybe at only 100 m above ground.

[Randy Haskin]

I do wonder, would a "zero/zero" seat have increased Capt. Casey's survival chances in this scenario?

Perhaps, but no guarantee of survival.

Just look at the famous CF-18 ejection that there are videos of all over the place. That pilot initiated ejection in an extremely capable seat with just the slightest of sink rate, and still barely had a chance to get one "swing" in the parachute before he hit the ground. The chute swing is the survivability standard that minimum altitudes and speeds are based on, and which provides the maximum chance of the pilot landing without injury.

Sink rate is the enemy of ejection seats, and seriously decreases the capabilities and survivability of even the most capable seats.

Last edited by Randy Haskin on Tue May 19, 2020 1:02 pm, edited 1 time in total.

[Randy Haskin]

Do both crew members eject independently, or do either initiate the ejection for all?

The Tutor neither has sequenced ejection (staggering the initiation times of the seats so they don't hit each other on the way out) or command ejection (one seat can initiate ejection of both seats).

Very old, low tech, and low-capability seats.

[lmritger]

Randy, I genuinely appreciate your insights, thank you for this info. And I had forgotten about that incredible sequence of the CF-18 ejection- that's an outstanding example to compare against the performance of the older Weber seats.

Much appreciated.

Lynn

[Jim MacDonald]

Not trying to stir the pot, but have a legitimate question that maybe Randy can answer.

Could a women's slighter frame and less muscle mass result in a more serious injury during an ejection, especially in an older seat like in the tutor? In the same vain, would a smaller man (I'm 5'6") be more susceptible to being injured as opposed to another man 6'2"?

Mac

[Aeronut]

Not trying to stir the pot, but have a legitimate question that maybe Randy can answer.

Could a women's slighter frame and less muscle mass result in a more serious injury during an ejection, especially in an older seat like in the tutor? In the same vain, would a smaller man (I'm 5'6") be more susceptible to being injured as opposed to another man 6'2"?

Mac

Many years ago I was part of a UK government establishment that undertook Test and Evaluation on aircrew equipment including ejector seats. We took an interest into the inquiry on a two seat Harrier crash where the rear seater had been a female RAF Officer cadet. She was under weight for the seat limits, yet she didn't have the spinal injuries expected. This was puzzling and the investigations went back to the very early days of the Ejector seat. When Martin-Baker decided to develop their first ejector seat they conducted experiments, which included some with cadavers, to determine the acceleration rates of and maximum values of g that were survivable. The Harrier accident revealed that those early tests had used male cadavers only, as only men were going to use the seats (the 1940's were a different world) and the inquiry noted that the male and female pelvis and lower spine are different (something to do with childbirth) and it was probable that the acceptable rates of g were different for men and women.
Associated with these seat limits was the matter of some visiting aircrew from a far east nation's air force. They were smaller and lighter than the average UK aircrew and to get them within the ejector seat limits for the aircraft they were to fly the safety equipment section modified their flying suits with the addition of lead sheet ballast!

[Randy Haskin]

Not trying to stir the pot, but have a legitimate question that maybe Randy can answer.

Could a women's slighter frame and less muscle mass result in a more serious injury during an ejection, especially in an older seat like in the tutor? In the same vain, would a smaller man (I'm 5'6") be more susceptible to being injured as opposed to another man 6'2"?

Mac

I'm neither an engineer nor physiologist, but my understanding is yes.

When the seat was designed for the JPATS and F-35 there was considerable effort toward expanding the envelope of body heights and weights that could be successfully ejected because of the knowledge that more diverse pilots by both measures would be occupying those seats. So, it makes sense that small changes in both of those measures would impact capabilities of seats that were not designed with those sizes and weights in mind.

Did it make a difference with the Tutor seat? Not in my opinion, no.

[bdk]

Do both crew members eject independently, or do either initiate the ejection for all?

The video shows both ejecting, but maybe at only 100 m above ground.

Did both chutes appear to deploy and inflate?

[old iron]

old iron wrote:
The video shows both ejecting, but maybe at only 100 m above ground.

Did both chutes appear to deploy and inflate?

According to an AOPA article https://www.aopa.org/news-and-media/all-news/2020/may/20/snowbirds-crash-kills-capt-jennifer-casey, the video does not show the parachutes inflating.

[Jim MacDonald]

Not trying to stir the pot, but have a legitimate question that maybe Randy can answer.

Could a women's slighter frame and less muscle mass result in a more serious injury during an ejection, especially in an older seat like in the tutor? In the same vain, would a smaller man (I'm 5'6") be more susceptible to being injured as opposed to another man 6'2"?

Mac

Many years ago I was part of a UK government establishment that undertook Test and Evaluation on aircrew equipment including ejector seats. We took an interest into the inquiry on a two seat Harrier crash where the rear seater had been a female RAF Officer cadet. She was under weight for the seat limits, yet she didn't have the spinal injuries expected. This was puzzling and the investigations went back to the very early days of the Ejector seat. When Martin-Baker decided to develop their first ejector seat they conducted experiments, which included some with cadavers, to determine the acceleration rates of and maximum values of g that were survivable. The Harrier accident revealed that those early tests had used male cadavers only, as only men were going to use the seats (the 1940's were a different world) and the inquiry noted that the male and female pelvis and lower spine are different (something to do with childbirth) and it was probable that the acceptable rates of g were different for men and women.
Associated with these seat limits was the matter of some visiting aircrew from a far east nation's air force. They were smaller and lighter than the average UK aircrew and to get them within the ejector seat limits for the aircraft they were to fly the safety equipment section modified their flying suits with the addition of lead sheet ballast!

Not trying to stir the pot, but have a legitimate question that maybe Randy can answer.

Could a women's slighter frame and less muscle mass result in a more serious injury during an ejection, especially in an older seat like in the tutor? In the same vain, would a smaller man (I'm 5'6") be more susceptible to being injured as opposed to another man 6'2"?

Mac

I'm neither an engineer nor physiologist, but my understanding is yes.

When the seat was designed for the JPATS and F-35 there was considerable effort toward expanding the envelope of body heights and weights that could be successfully ejected because of the knowledge that more diverse pilots by both measures would be occupying those seats. So, it makes sense that small changes in both of those measures would impact capabilities of seats that were not designed with those sizes and weights in mind.

Did it make a difference with the Tutor seat? Not in my opinion, no.

Thanks for your replies to my question, Aeronut & Randy

Mac

[Lynn Allen]

Randy, could the pop be a compressor stall from maybe a bird strike?

[Randy Haskin]

Randy, could the pop be a compressor stall from maybe a bird strike?

Just as there are many reasons for compressor stalls (swallowing a bird is certainly one of them....), there are also several modes of compressor stalls. Some pop...some bang....some even buzz. Some are just a loss of power with the EGT/FTIT going through the roof and RPM rolling back.

So, yes, could be...but I don't know that is enough evidence in and of itself to determine a root cause of whatever power loss they experienced.

[DH82EH]

Randy I have another question for you.
Would the ejection of the canopy leave a smoke trail like the seat does?

regards

[Randy Haskin]

Would the ejection of the canopy leave a smoke trail like the seat does?

I'm not 100% familiar with the system on the Tutor, but I believe the canopy is jettisoned with a charge similar to the seats, yes.