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seb146
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Why would a test flight be flying low?

Thu Mar 12, 2020 4:34 pm

We rarely get flights over us on the South Oregon Coast. I can count on one hand the number of "fresh" contrails I have seen since moving here two years ago. Two were from UPS flights ANC-ONT and one was, i assume, an engine test flight that my app said was scheduled VCV-VCV and a Boeing test flight PAE-PAE. They were all at altitudes I would expect them to be flying.

There was a test flight this week of a Boeing Poseidon. It showed PAE-PAE on my app but it was only flying at 10,000. I could see it (barely) since I knew what I was looking for. There was no trail and it was flying over the coast range hills. Why would a test flight be this low? Would they be testing a flight without cabin pressurization?
You bet I'm pumped!!! I just had a green tea!!!
 
spudsmac
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Re: Why would a test flight be flying low?

Thu Mar 12, 2020 5:52 pm

Could be a number of things. Maybe they were testing sensors, maybe engine tests with more dense air, anything really. Maybe they flew at 10,000 because they wanted to pretty low but wanted to go faster than 250kts. Go to 10, then go as fast as you can....
 
Woodreau
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Re: Why would a test flight be flying low?

Thu Mar 12, 2020 6:20 pm

We had to do a maintenance test flight once at 6000ft because it required flying with the cabin depressurized.
Bonus animus sit, ab experientia. Quod salvatum fuerit de malis usu venit judicium.
 
unimproved
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Re: Why would a test flight be flying low?

Thu Mar 12, 2020 7:48 pm

Mask drop test. Stabilize at 10, bump it up a little bit to get them to drop and descend again.
 
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seb146
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Re: Why would a test flight be flying low?

Fri Mar 13, 2020 1:36 am

I thought Poseidon is military for India or Thailand? They would not have oxygen masks like in a typical passenger configuration, would they? Oxygen tests would not make sense if it is a military craft but low altitude maintenance does make sense.
You bet I'm pumped!!! I just had a green tea!!!
 
GalaxyFlyer
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Re: Why would a test flight be flying low?

Fri Mar 13, 2020 2:15 am

It’s the Naval patrol version and yes, it’d have emergency oxygen systems like any other pressurized plane. Even the troop seats in a C-141 or -17 has passenger oxygen systems. Do you think people on military planes are either expendable in the event of pressure loss or just don’t need oxygen?
 
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dennypayne
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Re: Why would a test flight be flying low?

Fri Mar 13, 2020 2:29 am

One of its roles is to act as an anti-submarine aircraft so they could have also been testing the sonobouy systems or other similar gear.

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BravoOne
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Re: Why would a test flight be flying low?

Fri Mar 13, 2020 2:40 pm

unimproved wrote:
Mask drop test. Stabilize at 10, bump it up a little bit to get them to drop and descend again.


The auto mask drop does not occur until the cabin reaches 14,500+/-
 
citationjet
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Re: Why would a test flight be flying low?

Sat Mar 14, 2020 9:07 pm

"P-8 is also designed for low altitude missions and has already proven its abilities supporting humanitarian and search and rescue missions. Globally proven, the P-8 has two variants: The P-8I, flown by the Indian Navy, and the P-8A Poseidon, flown by the U.S. Navy and the Royal Australian Air Force."

https://www.boeing.com/defense/maritime-surveillance/p-8-poseidon/index.page
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SheikhDjibouti
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Re: Why would a test flight be flying low?

Sat Mar 14, 2020 11:30 pm

spudsmac wrote:
Could be a number of things. Maybe they were testing sensors, maybe engine tests with more dense air, anything really. Maybe they flew at 10,000 because they wanted to pretty low but wanted to go faster than 250kts. Go to 10, then go as fast as you can....
Why would they not be able to go faster than 250 kts at lower altitudes? Is the low altitude airspace over Oregon specially designated for hang-gliders and micro-lights?

These aren't anywhere near Oregon, but for some reason these guys don't seem too concerned by FAA regs and 250 kt speed limits
p.s. in two of the three images, the afterburners are definitely lit up. :D


citationjet wrote:
"P-8 is also designed for low altitude missions..."
"Also" designed? Hell, surely that's it's main mission. You don't hunt Soviet submarines from 30,000 ft.

wikipedia wrote:
The P-8 has a strengthened fuselage for low-altitude operations.
That figures....
…..although I also read;
The P-8 is to be equipped with the High Altitude Anti-Submarine Warfare Weapon Capability (HAAWC) Air Launch Accessory (ALA), turning a Mark 54 torpedo into a glide bomb for deploying from up to 30,000 ft (9,100 m)
:o Ok, maybe anti-submarine warfare has changed a bit since I last checked. :scratchchin:
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gunsontheroof
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 2:29 am

Wouldn't a Poseidon be operating at lower altitudes for many of its missions? 10,000 feet seems a little high for maritime patrol, but it's possible that the low altitude had something to do with mission profile testing (though I would guess a lot of that would happen post-delivery).
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Flow2706
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 10:52 am

Never done any test flights, but I heard that slow flight/stall tests are done at around this altitude. At high altitude (typical cruise levels, FL300+) the aerodynamics are rather different due to the effect of the mach number. Altitude loss from a fully developed stall at high altitudes can easily reach 3000-5000ft, however at lower altitude it is usually less then 1000 or even less than 500ft.
 
GalaxyFlyer
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 12:25 pm

We know it’s a test flight due to routing and type. Why it was flown at 10,000’ is on the test card and nobody’s business but the crew, Boeing Flight Ops and US Navy. It didn’t seem to violate any regulations at that height, which then would be an issue for the FAA.
 
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Starlionblue
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 2:38 pm

Flow2706 wrote:
Never done any test flights, but I heard that slow flight/stall tests are done at around this altitude. At high altitude (typical cruise levels, FL300+) the aerodynamics are rather different due to the effect of the mach number. Altitude loss from a fully developed stall at high altitudes can easily reach 3000-5000ft, however at lower altitude it is usually less then 1000 or even less than 500ft.


Mach effects, and also lack of excess thrust. At high altitude, the only way to regain energy is to descend. At low altitude, TOGA is a powerful thing. :)
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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seb146
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 4:05 pm

GalaxyFlyer wrote:
We know it’s a test flight due to routing and type. Why it was flown at 10,000’ is on the test card and nobody’s business but the crew, Boeing Flight Ops and US Navy. It didn’t seem to violate any regulations at that height, which then would be an issue for the FAA.


It was not something I was used to seeing. I was curious. I know we have our differences in Non-Av but here?

I do not have experience with military aircraft like others do. I ask questions so I can understand and learn things. I don't know why that would be an issue.
You bet I'm pumped!!! I just had a green tea!!!
 
BravoOne
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 5:10 pm

seb146 wrote:
GalaxyFlyer wrote:
We know it’s a test flight due to routing and type. Why it was flown at 10,000’ is on the test card and nobody’s business but the crew, Boeing Flight Ops and US Navy. It didn’t seem to violate any regulations at that height, which then would be an issue for the FAA.


It was not something I was used to seeing. I was curious. I know we have our differences in Non-Av but here?

I do not have experience with military aircraft like others do. I ask questions so I can understand and learn things. I don't know why that would be an issue.


Do you have to turn everything into some sort of a political statement?
 
GalaxyFlyer
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Re: Why would a test flight be flying low?

Sun Mar 15, 2020 7:07 pm

I’ve spent 40+ years in aviation, it can be a highly compartmentalized business. We had NDAs at all my civilian jobs; we even had them in the military. Despite today’s world of everything being a public matter, a lot isn’t and shouldn’t be unless it’s a violation of law or public safety. I was given a number of NDAs to sign in the military (and I had a TS clearance, too) and just recently signed one for work as a contractor. I’m sorry, but things that aren’t my business, I’m pretty used to ignoring.
 
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seb146
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Re: Why would a test flight be flying low?

Mon Mar 16, 2020 2:04 am

GalaxyFlyer wrote:
I’ve spent 40+ years in aviation, it can be a highly compartmentalized business. We had NDAs at all my civilian jobs; we even had them in the military. Despite today’s world of everything being a public matter, a lot isn’t and shouldn’t be unless it’s a violation of law or public safety. I was given a number of NDAs to sign in the military (and I had a TS clearance, too) and just recently signed one for work as a contractor. I’m sorry, but things that aren’t my business, I’m pretty used to ignoring.


As I said in the first post, we do not see much of anything flying over. I think is unusual for a modern commercial jet to be flying that low anyway. It was odd. I was not asking for state secrets. I was wondering what, in general, they would be doing. I was not blaming anyone, I was not wanting classified information.
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rjsampson
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Re: Why would a test flight be flying low?

Mon Mar 16, 2020 2:20 am

seb146 wrote:
As I said in the first post, we do not see much of anything flying over. I think is unusual for a modern commercial jet to be flying that low anyway. It was odd. I was not asking for state secrets. I was wondering what, in general, they would be doing. I was not blaming anyone, I was not wanting classified information.


:checkmark:

You asked a great question, and I hope you (like me) have enjoyed the responses. Asking why would is not asking why is? Regardless of who's "business it is," speculating on possible answers is what this thread is all about. Thanks for the great question, and to all who have provided interesting thoughts - thank you as well! Cool discussion so far.
"..your eyes will be forever turned skyward, for there.." yeah we know the DaVinci quote. But GA is so dang expensive these days! :(
 
Woodreau
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Re: Why would a test flight be flying low?

Mon Mar 16, 2020 2:13 pm

Since it is a P-8 and not a 737, (speculation here) it’s probably not operated under FAA rules, but under NATOPs.

For example, P-3s would routinely shut down engines inflight to extend on station time. Even though a P-8 is a derivative of the civilian 737, no civilian 737 operator would ever consider operating a 737 single engine in flight, but under NATOPs operating single engine might be a normal or supplemental procedure. (More speculation on my part - I do not have access to P-8 NATOPs)

The point is that anything can be going on - certification, testing - whatever. Depending on who is operating the flight, the manufacturer, the operator, different rules apply.

Unless you were on that specific flight or were involved in the planning for that flight, no one else would know either. And the people who do know, either they can or cannot disclose or whether they want to if they can.

I guess if they’re flying around the hills, maybe they’re testing the surface search radar that I imagine a P-8 would carry that I really liked having access to on the P-3s when I had P-3s assigned to my ship for SSC, extending my own ship’s surface search capability. Now whether I could interdict what the P-3 found or not, well... prosecute, no issue, interdicting was more iffy depending on whether it was freshly fueled or was waiting around for a mother ship to refuel and dependent on how much fuel I had.
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