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Aviation Thread - News, facts, questions, photos, videos, etc.

Started by Taaroa, June 04, 2017, 09:15:23 AM

Uncle Duke

Quote from: Taaroa on November 01, 2019, 10:45:47 PM
https://twitter.com/AeronewsGlobal/status/1190209891778072576

There are different types of foam with varying degrees of corrosiveness and environmentally impact. No idea if any of the foams damage LO coatings.  Not sure what's used today, especially in Europe, but it's a fair assumption the a/c is going to get an extensive cleaning and somebody is filling out a shitload of paperwork.


Taaroa

Quote from: Uncle Duke on November 02, 2019, 10:15:01 AM
There are different types of foam with varying degrees of corrosiveness and environmentally impact. No idea if any of the foams damage LO coatings.  Not sure what's used today, especially in Europe, but it's a fair assumption the a/c is going to get an extensive cleaning and somebody is filling out a shitload of paperwork.

Especially since whatever coating/materials are used on the F35 isn't your typical stuff. There's been a lot of controversy in Australia over aviation fire suppressants the past few years because of how carcinogenic they are and some leakages into water supplies.

https://twitter.com/ron_eisele/status/1190412982351740935

https://twitter.com/EmirLouise/status/1191511458351386624




Uncle Duke

Quote from: Kidnostad3 on November 16, 2019, 01:00:09 PM
Crewless aerial refueling tanker?  What a concept!


https://www.businessinsider.com/navy-aircraft-carrier-john-f-kennedy-seal-has-mq25-drone-2019-11 M

Not all that impressive considering the USN uses the probe & drogue for aerial refueling, that system puts the onus on the pilot of the receiving aircraft.  The extended drogue remains in place and the probe is flown into it. 




Taaroa

Quote from: Jackstar on November 18, 2019, 01:22:37 PM
Is this as impressive as it looks?

This is just an opinion so take it with a grain of salt: probably not in this plane. The danger of spins varies depending on the type of plane, what features the plane has, and how well trained the pilot is.

I think in this case you have a high performance aircraft already capable of aerobatics (and some russian fighters are renowned for their unique tricks) and it has thrust vectoring - ie the nozzles where the exhaust/thrust comes out at the rear can position themselves to provide extra steering that wouldn't normally be possible.

https://youtu.be/2O9q6EJhssQ

Quote from: Taaroa on November 18, 2019, 09:28:01 PM
This is just an opinion so take it with a grain of salt: probably not in this plane. The danger of spins varies depending on the type of plane, what features the plane has, and how well trained the pilot is.

I think in this case you have a high performance aircraft already capable of aerobatics (and some russian fighters are renowned for their unique tricks) and it has thrust vectoring - ie the nozzles where the exhaust/thrust comes out at the rear can position themselves to provide extra steering that wouldn't normally be possible.

https://youtu.be/2O9q6EJhssQ

I think what we all want is a CGI of that plane in a spin and the getting lit up by an A-10.   Brrrruuuup.   

https://www.youtube.com/watch?v=e1otYo17sQI

Hog

Quote from: Walks_At_Night on November 18, 2019, 07:30:31 PM
Mav and Goose did it first.


There was a lot of Naval Aviators that paid with their lives departing controlled flight in the Tomcat.  Since 1970 and when she entered service in 1974 32 year long service it averaged just under 4 losses per year, with some years having 10+ aircraft losses.

The flat spin is a killer because as the spin develops the G forces build higher to the front Pilot than the rear RIO as the front seat is further from the center of rotation.  Anyone with any school or park "merry go round" experience knows that the faster the "Go-round" is spun and the further from teh center of the ride, the greater the induced forces are acting upon you.. These forces can pin the pilot forward in a bad ejection posture and/or make Pilot initiated ejection impossible, which is why the NATOP calls for the backseater to initiate a "command ejection".  During ejection the RIO goes out first then 0.4 seconds later the Pilot. Apparently since the canopy peels backwards during jettison, with the a/c in a flat spin, the canopy may not clear the RIOs ejection trajectory and you see what happens.

In 1995 LT Hultgreen was killed when she stuffed in zone 5 a/b into a single engine out F-14A, even with full rudder deflection there was not enough control authority to overcome the of axis thrust authority of the remaining engine.  Even though Hultgreen did not declare and emergency nor told her RIO to eject, the RIO LT Flemish pulled his handles for a "Command ejection"  When his seat left, he was within the seats envelope and with the added 0.4 seconds the jet had rolled over so that when her seat left the a/c, she was ejected directly into the water.

There was a system called the  Marconi Digital Flight Control System (DFCS), it was to be installed in all F-14's in 1994 but the Navy kept deferring due to cost. 
"DFCS drastically decreases the chance of entering out-of-control flight and improves the F-14's ability to recover, if a spin is entered. Departure from controlled flight has been a primary causal factor in 35 F-14 mishaps. "
The upgrade to DFCS began in July 1999 and the fleet was completed in April 2000 with the VF-102 Diamondbacks. These mods affected the 211 active duty and 16 reserve F-14 aircraft in service at the time. there were over 25 a/c lost during this deferment of the adoption of the DFCS.

The Topgun movie got the "flat spin" scenario surprisingly correct. Though in the F-14A, which is the only variant of the F-14 in service at the time, there is a set of ejection handles above each crewmembers head AND a handle between their legs.  The movie shows Maverick flailing in an attempt to pull the overhead/face curtain handles when there is a handle down near his crotch.

peace
Hog

Hog

Here is the Marines removing the wing of a Harrier at a base in Afghanistan.  I've never seen that before.  I've always heard that the wing had to come off for major engine work.  The loading that goes on through that wing must be intense.




peace
Hog

Uncle Duke

Quote from: Hog on November 19, 2019, 09:18:59 AM

The flat spin is a killer because as the spin develops the G forces build higher to the front Pilot than the rear RIO as the front seat is further from the center of rotation.  Anyone with any school or park "merry go round" experience knows that the faster the "Go-round" is spun and the further from teh center of the ride, the greater the induced forces are acting upon you.. These forces can pin the pilot forward in a bad ejection posture and/or make Pilot initiated ejection impossible, which is why the NATOP calls for the backseater to initiate a "command ejection".  During ejection the RIO goes out first then 0.4 seconds later the Pilot. Apparently since the canopy peels backwards during jettison, with the a/c in a flat spin, the canopy may not clear the RIOs ejection trajectory and you see what happens.

A similar situation exists with two seat F-16s (B & D models) command ejections during high yaw rate conditions.  The canopy jettison rockets are not powerful enough to cleanly jettison the heavy, one piece polycarbonate canopy, instead  it yaws relative to the longitudinal axis of the a/c from the canopy hinge.  This has resulted in the decapitation of backseaters as the canopy sweeps across them.


Hog

Quote from: Uncle Duke on November 19, 2019, 04:27:02 PM
A similar situation exists with two seat F-16s (B & D models) command ejections during high yaw rate conditions.  The canopy jettison rockets are not powerful enough to cleanly jettison the heavy, one piece polycarbonate canopy, instead  it yaws relative to the longitudinal axis of the a/c from the canopy hinge.  This has resulted in the decapitation of backseaters as the canopy sweeps across them.

Wow, the dual seat canopies are quite a bit bigger.

a)F16 bubble canopy.  That visibility looks great.

b) F16-C single seat,short canopy  Hellenic AF

C)  F16-D two seat, long canopy Polish AF

d) F16-I two seat, longer canopy  Israeli AF


peace
Hog

Taaroa

Quote from: Uncle Duke on November 19, 2019, 04:27:02 PM
This has resulted in the decapitation of backseaters as the canopy sweeps across them.

As if you already didn't have to worry about being high enough to eject, not ejecting into the ground, becoming a few cm shorter, or just outright snapping your neck in the airstream.

https://youtu.be/UPIboTdIYyQ

Taaroa

The Long-Forgotten Flight That Sent Boeing Off Course - A company once driven by engineers became driven by finance
https://www.theatlantic.com/ideas/archive/2019/11/how-boeing-lost-its-bearings/602188/

An interesting article. I'd heard before that McDonnell Douglas had ended up 'on top' from the takeover by Boeing, but you'd think (hope) that even they were more safety conscious than most companies.




Uncle Duke

Quote from: (Sandman) Logan-5 on November 25, 2019, 08:24:56 PM
Smooth, quiet, powerful for the time, Sleeve-Valves.
Good resource page...  https://aviationshoppe.com/sabre-ii-sleeve-valve-engine-p-256.html





These were used on the Hawker Typhoon, and had a lot of problems early.  Here is a two part article I ready early this year about a former RCAF pilot who flew Typhoons.  The guy is a hoot, he's a very plain speaker

https://legionmagazine.com/en/2018/12/douglas-gordon-part-1-bail-out-or-glide-for-england/

https://legionmagazine.com/en/2019/01/douglas-gordon-part-2-the-troubles-with-typhoons/

Quote from: Uncle Duke on November 25, 2019, 09:35:18 PM
"..."
LOL - So that's where the 'Prison Stripes' came from.  (IFF)
Good articles UD, Thanks.  :)
Yeah, I like the 'Tell it like it is" narrative too. My grandparents were the same way; No bullshit - straight to the point, with subtle humor.


Off Tangent: Why the hell is my spellchecker giving me Limey grammar ?   :P 

albrecht

"Shortly before 2 p.m., NORAD confirmed that there was no airspace violation. The security scare may have been caused by a flock of birds appearing on radar, ABC7's Sam Sweeney reports."

https://wjla.com/news/local/white-house-reportedly-on-lockdown



Hog






Quote from: Uncle Duke on December 11, 2019, 04:55:31 PM
https://www.avgeekery.com/avgeekery-exclusive-mig-killing-army-ov-1-mohawk-pilot-ken-lee/

Never heard this story before

I had not heard of it either.  Dude nukes a MIG and can't talk about it!  Poor bugger was lucky the Army did not ding him for the expended ordinance............

Did you see the article on the Republic XF-84H Thunderscreech below it?   Never heard of that thing either.  Damn thing induced seizures for those on the ground and could be heard 25 miles away while warming up.  One bad ass bird.

Uncle Duke

Quote from: Walks_At_Night on December 11, 2019, 06:22:32 PM
I had not heard of it either.  Dude nukes a MIG and can't talk about it!  Poor bugger was lucky the Army did not ding him for the expended ordinance............

Did you see the article on the Republic XF-84H Thunderscreech below it?   Never heard of that thing either.  Damn thing induced seizures for those on the ground and could be heard 25 miles away while warming up.  One bad ass bird.

An A-4 pilot did basically the same thing, shot down a NVAF MiG-17 by salvoing a pod of unguided Zuni rockets at it.  I think the A-4 got the MiG on take-off.

Yes, I've heard of the Thunderscreech and all the stories associated with it.  There is one at the USAF Museum.

https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/195748/republic-xf-84h/


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