Philly Lear 55 crash

[GeeBee]

1 hour ago, Pinecone said:

Did not know that.

It also goes the other way. Some years back I was being ramp checked in Amsterdam and was asked to produce my "EASA Foreign Air Carrier Certificate". The inspector says a copy must be carried in each aircraft. A phone call to the Ops Center and a discussion with the  Regulatory Desk" revealed that my company had an operations specification with EASA that stated the certificates were retained at corporate headquarters. All ended well.

[DXB]

Apparently the CVR was at the base of the main impact crater - blows my mind that this thing is predicted to be readable

 

[EricJ]

2 hours ago, DXB said:

Apparently the CVR was at the base of the main impact crater - blows my mind that this thing is predicted to be readable

 

Wow.   That'll be impressive if they do get the data out.   That's some good system and implementation engineering right there if it works.

[Schllc]

I’m impressed by the energy of that impact. Those engines had to be making full thrust all the way to impact. 

[Hank]

9 minutes ago, Schllc said:

I’m impressed by the energy of that impact. Those engines had to be making full thrust all the way to impact. 

In the video, it looked at lot like a missle coming down.

Anyone know where in the Lear the CVR is installed? Cockpit or rear avionics bay? Regardless, 8' under a road or parking lot is pretty deep, meaning a large amount of kinetic energy.

[Pinecone]

46 minutes ago, EricJ said:

Wow.   That'll be impressive if they do get the data out.   That's some good system and implementation engineering right there if it works.

It doesn't have to work.

The recording media just needs to be recoverable.  

[MikeOH]

1 hour ago, Pinecone said:

It doesn't have to work.

The recording media just needs to be recoverable.  

Pretty sure @EricJ knows that.

That’s as close to a ‘black’ box as I’ve seen; the ability of the media to withstand not only the impact but the temperature is definitely impressive engineering!

[N201MKTurbo]

5 hours ago, MikeOH said:

Pretty sure @EricJ knows that.

That’s as close to a ‘black’ box as I’ve seen; the ability of the media to withstand not only the impact but the temperature is definitely impressive engineering!

I’m sure they abuse it worse than that in development.

[GeeBee]

Required to withstand 3400g and 1100 degrees C and maintain data integrity.

[redbaron1982]

13 hours ago, DXB said:

Apparently the CVR was at the base of the main impact crater - blows my mind that this thing is predicted to be readable

 

Related, but unrelated, do I need an X account now to keep updated on NTSB investigations? I know I can access X without an account, but it seems that the posts are not sorted chronologically, so it is kind of useless.

[MikeOH]

2 hours ago, GeeBee said:

Required to withstand 3400g and 1100 degrees C and maintain data integrity.

How long at 1100C?

Do you have a cite for the specs?

[GeeBee]

10 minutes ago, MikeOH said:

How long at 1100C?

Do you have a cite for the specs?

60 minutes

https://skybrary.aero/sites/default/files/bookshelf/3679.pdf

[A64Pilot]

On 2/2/2025 at 8:27 PM, MikeOH said:

Any reasonably statistical basis for that comment, or just your opinion?

Easy, search aircraft values with an XA registration vs ones with an N registration.

IF it was a maintenance induced crash, mechanic competence comes into question more than pilot.

[A64Pilot]

On 2/2/2025 at 8:44 PM, MooneyMitch said:

Someone mentioned a possible major weigh shift, due to lack of equipment securing, causing a situation rendering the flight control useless and an eventual stall.  I recall this with a 747 out of Afghanistan several years ago.  Huge cargo shift that caused that crash [on video].

Regarding the fire issue.........again someone mentioned that what appears to be the jet on fire, is possibly the aircraft forward lights reflecting [at times intermittent] off of the broken clouds during the rapid decent

I believe that there was a CG shift, but what was more of the cause of the crash was the MRAP vehicle took out the elevator jack screw taking I think the stabalitor into full or near full up.

https://en.wikipedia.org/wiki/National_Airlines_Flight_102

Edited February 5 by A64Pilot

[A64Pilot]

CVR question I believe is more of how old was it than the forces at impact, old ones often don’t work and the old tape and or wire recorders aren’t as robust as the newer solid state ones.

‘If there is still paint on it, it didn’t get that hot.

Lear 55 is an old aircraft?

Edited February 5 by A64Pilot

[hoot777]

We are all speculating but something brought this bird out of the sky. It was falling not  flying. Got my physics book out.-11000ft/min I read. .  I suspect fire or explosion from medical equipment. We will probably never know for sure. I have some time in a Lear 45xr. Great airplane. 

[Pinecone]

I am still thinking somatogravic disorientation.

There is a powerful one that when you accelerate, your body feels like you are pitching up, so you push on the yoke, which increases the acceleration, leading to feeling more pitch up, so push more ......

[dkkim73]

21 minutes ago, Pinecone said:

I am still thinking somatogravic disorientation.

There is a powerful one that when you accelerate, your body feels like you are pitching up, so you push on the yoke, which increases the acceleration, leading to feeling more pitch up, so push more ......

That is a good thought in such a hot jet. Especially if they had avionics problems or a big distraction near take off. 

[MikeOH]

It still looks to me like it was on fire on the way down.  Once that is proven false I would entertain the disorientation theory.

[Hank]

1 hour ago, MikeOH said:

It still looks to me like it was on fire on the way down.  Once that is proven false I would entertain the disorientation theory.

That was my first thought, right after "missile."

[GeeBee]

NTSB says CVR was inoperable at the time of the crash and it appears had been inoperable for some time. Guess a CVR check is not part of the pre-flight or continuing maintenance. Figures.

https://www.avweb.com/aviation-news/cockpit-voice-recorder-inoperable-in-philadelphia-jet-crash/?MailingID=FLY250306036&utm_campaign=avwebflash&utm_medium=newsletter&oly_enc_id=5912C9519189D2Y

[Schllc]

The 135 only requires planes that carry 10 or more or “require” two pilots. 
Does Lear 55 require two?

[EricJ]

1 hour ago, Schllc said:

The 135 only requires planes that carry 10 or more or “require” two pilots. 
Does Lear 55 require two?

I'm not aware of any Lears that are approved for single pilot.    Also, this aircraft was not US-registered, so it may have been operating with different requirements.

[GeeBee]

1 hour ago, EricJ said:

I'm not aware of any Lears that are approved for single pilot.    Also, this aircraft was not US-registered, so it may have been operating with different requirements.

Except it was on a US Air Carrier Certificate. So it had to be maintained in accordance with US standards. Being foreign registered makes no difference. I have lots of Boeings with foreign registrations in my log book. Mostly Ireland.