"He wasn't ejecting ne'er-do-wells was he?"


Well the "Bulldog Bar " was a bit of an "In Town" weekend evening watering hole for certain RAF Institute of Aviation Medicine characters who knew him , so perhaps there was a degree of top cover !

If you don't lose control, there's a very good chance you won't be injured. In a light aircraft.

cncpc
 

In answer to your previous question, it is hard to say for certain.

A pre-take off emergency brief will usually cover warning captions and loss of thrust. We wouldn’t necessarily expect a ‘bang’ with no other warnings or indications.

I think it’s fair to say though that any audible bang would lead your brain to bird strike almost immediately (they may have seen the bird and it now seems likely that a bird was the problem). If that bird went down the engine then the bang would probably have been followed, almost simultaneously, by a rapid increase in engine temperature and associated warnings. A bird strike anywhere else on the airframe could be diagnosed as such pretty quickly due to lack of abnormal engine indications.

In any of the above situations my first instinct would be to get away from the leader. That would definitely involve some upwards movement and also a little lateral movement.

On my aircraft the lateral movement would just be enough to be clear of the lead (remember you would be naturally decelerating so separation is already achieved) and would not involve any sort of turn back towards a reciprocal runway until 280-300 knots had been reached. I cannot speak for what that speed would be in a Tutor.

BV

Thanks for taking the time, Bob.

Do you think the brief would include a return to the button of 22? That is an easier (less turning) option than trying to get round to the main runway, isn't it?

Can you give a little insight into the actual process by which a bird going into an intake causes engine problems. I know it does, but not sure of the exact mechanism, or mechanisms. I know that it goes back and into the compressor. From there? Does that lead to a visible flame from the tailpipe?

The pilot certainly acted quickly. It was less than two seconds between bang and starting the zoom.

As for your last sentence, it raises a good point. I've gone over the video and I don't notice any increased separation between the lead and Capt. MacDougall's aircraft following the bang and before the zoom. Too short a time frame for it to be noticeable?

cncpc
 

Happy to help.

Firstly, runway 22 is less than 3000’ long and very narrow. In my aircraft it would not be a consideration. I suggest (although I cannot be certain) that it would not be a viable option for a Tutor either but I stand to be corrected.

Turning back for an alternate runway (assuming it was suitable) would require less speed but since the Tutor had only just passed the upwind end of the runway I would be surprised it it would have either the turning room or energy to make it to there.

As for the bird ingestion ramifications there are two possibilities. One is an engine surge (in the Tutor they call it a compressor stall but it’s the same thing) and the other is a mechanical failure.

A surge is basically a disruption to the airflow through the engine which results in a rapid temperature rise. This can either be a self clearing ‘pop’, a similar surge that requires pilot intervention to clear it (usually throttle to idle and then slowly bring it back up) or a locked in surge where the engine will need to be relit.

Just after take off a pop surge would not be a major drama, a surge requiring idle power to clear it would be alarming but not necessarily terminal. However, a surge requiring a relight would leave you very poorly placed. Obviously more energy would give you more time.

Birds (depending on the size) can obviously do a lot of damage to an engine. It is possible for them to pass through and cause only minor damage. But bigger birds or a higher speed impact can cause an engine to destroy itself almost immediately. Regardless of the level of damage an immediate landing is sensible.

Finally, you say the reaction is quick and I agree if our established timeline is correct. I would expect any pilot of a similar aircraft to be able to react just as quickly. We brief and train for these eventualities extensively.

I/we still don’t know what happened to the Snowbirds aircraft and indeed if a bird did enter the engine whether it was still working. With the age of the aircraft (meaning I doubt there is any useable flight data) and the fact it was completely destroyed I suspect the pilots recollection will be our best hope of knowing what really happened.

BV

Thanks for the video link AM. No rockets though, the early MB seats used cordite cartridges as illustrated in the included instructional diagram. The resulting excessive acceleration led to spinal injuries that later more progressive rocket acceleration avoided. Incidentally, with the exception of the MB Mk1 seat, all subsequent MB seats used the same scissor shackle main chute deployment system up to the MB Mk10 in the Hawk. It was this system that was the subject of an illegal RTI/Hawk/059 that led to Sean Cunningham's death. The in situ service that it called for prevented the critical final check of correct release of the drogue shackle and thus main chute deployment. Such a check is only possible in a proper servicing bay. All this was known of but conveniently forgotten. The bays were closed, the RTI issued, a bolt was overtightened, Sean Cunningham died, and MB were fined £1M. Why?

Thanks, Bob. Hopefully we will see what the RCAF determines.

Canadian military knew in 2016 Snowbirds ejection seats needed upgrading but project still only in early stages

Capt Casey's parachute may well not have opened and the witness is probably quite correct, but it will be for the inquiry to determine whether this was because there was an issue with the parachute/seat combination or whether her ejection was outside seat limits. As Chug and others will know, changing the parachute part of an escape system is not a simple or quick task.

Sadly, I have been to 3 funerals of friends whose ejections were outside the seat performance envelope, which was why their chutes did not fully deploy. Whatever, it still sucks.

It's 40 years since I flew it, but the Martin-Baker Departure Lounge in the Macchi had a barometric unit which would not allow seat separation unless the height was below 10,000' (it was in this case), the deceleration was less than 3g (had to be) and speed less than 250kt (I think this was the 3rd condition.)

BUT as your MB seat moved up the rails a drogue gun would have fired to deploy a stabilising parachute. This would be ready to pull the main chute out the instant the altitude was in limits and tumbling stopped.

From the accident video I can’t help thinking that had these been MB seats, even an earlier Mk4, we would have seen drogue deployment and seat separation on the video.

MB Drogue Gun had a 0.5 Sec delay once intiated and BTDU 2.25 Sec (IIRC) - both operating simultaneously.

I have a letter from James Martin dated 4th May 1963 in which he says” I am taking steps to have the timing of the firing mechanism changed from one second to .25 seconds as one second is too long especially near the ground. In a quarter of a second the canopy is well clear of the ejection path of the seat.”
This was with reference to the 4b seat.

The Mk 4 Seat in the JP 3 and 4 had a 0.6 second delay from handle pull to primary cartridge firing to allow for canopy jettison after that the sequence was listed in the aircrew manual as follows:

As the seat ascends its guide rails, a static rod trips the drogue gun time delay mechanism. After a 1/2 second delay the drogue gun fires and extracts the controller drogue: this in turn develops the main drogue, thus checking forward speed and stabilising the seat in a horizontal attitude.

Also as the seat ascends, a second static rod frees the barostat time release mechanism. When free descent reaches 10,000feet, or at once if ejection has taken place below that height - and providing the g stop is not in operation - the barostat removes an obstruction to the gear train of the time release mechanism allowing it to operate. After 1 1/4 seconds the drogues and combined harness are released from the seat, the parachute withdrawal line pulls free of the guillotine gate and parachute deployment and seat separation follow automatically. At high airspeeds below 10,000 feet the g stop similarly impedes the gear train until the speed has dropped to a value safe for parachute deployment.

Here is quite a good example of what a bird ingestion can do to a large turbofan - it illustrates the surging Bob talks about:

CBC News reported yesterday that the ejections seat in the Oct 2019 crash became tangled in the chute risers which lead to the minor injuries to the pilot. Here's a link to the CBC Story https://www.cbc.ca/news/canada/saska...rash-1.5631647

Any whispers from the enquiry as to the seats' perfomance?

Thats not surprising ref the seat becoming entangled. An ejection with an IP/student a course ahead of me in Moose Jaw (around 1997-8) ended up with exactly the same results. It was determined that the only reason student was able to survive was that he had been an extremely experienced airborne soldier prior to cross training to pilot and was able to manually disentangle the seat from the risers/parachute. He fractured his spine and spent a couple years recovering before he was able to resume training. The fact of the matter is that this seat has been plagued with issues for decades -it doesnt really have an effective seat-man separation mechanism other than a band aid solution that was put in a couple years ago.

Still no news?

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