All Things Aviation Related

[gordner]

I don't think it is necessarily a situation of "can't" so much as afterburn is not practical or as beneficial on a high bypass.
There is just no situation where a high bypass fan is the favoured powerplant but you also want afterburners. Afterburners are really a military thing, high stress on the engine, super poor economy, just a lot of power right now, which isn't really applicable to commercial aviation. Commercial aviation does not look for ways to burn as much gas as possible or drive down the life cycle of the engines.

[flipper35]

Not unless they are trying to cross the ocean in the shortest amount of time.

I don't think a 747, modified or not, will hold together at supersonic speeds.

[gordner]

You only cross the ocean in the shortest amount of time if you are trying to set a record. Otherwise, you cross as efficiently as you can, which falls far short of as fast as you can. It is quite rare for modern commercial aviation to reach the upper speed limits of the aircraft for sustained flight, it just is not economical.

[gordner]

https://simpleflying.com/supersonic-boeing-747-20-years/

Allegedly supersonic, and landed safely.

[Seahawk]

This will be boring to some, but I got a ride in a C-2A many moons ago.

I was riding in the back. Long story. Flew over in the SH-60B, dropped off and launched 45 minutes later for San Diego.

Business trip

[gordner]

It is amazing what they can throw off the decks of those carriers.

[svandamme]

Originally Posted by flipper35

Air Force one has had to take evasive maneuvers in the past, even if mistakenly.

I'm calling BS on that.
the
increased complexity of systems
decreased reliability (complexity goes up reliability goes down)
increased maintenance reqs (more complexity in systems to check and test )
increased cost for parts not used on any other application

vs
the low actual chance of using it effectively...
=
Zero ROI

And if it at all were true.. We'de have seen a picture of a 747 in Zone 5 by now..
It would be too awesome and impossible to keep that a secret.

AF1 has
https://en.wikipedia.org/wiki/General_Electric_CF6

No mention of any variant with AB. at all.

[colingreene]

The most simple reason to not be able to run a afterburner on a high bypass turbo fan is that you will overspeed the large fan disk on the front at full load.
Plus all supersonic aircraft have a indirect air path to the motors in order to slow the air down to subsonic speeds allowing the engine to "Process" it.
Simply put the way the engine pods are configured on a 747 its not feasible.
Sure you can potentially do it in a dive The DC-8 was known to be able to do this but you risk inertia coupling and other issues.

[svandamme]

Well I think the supersonic part is not relevant on a 747 the plane has wrong elevators, need moving planes for that.

Burners also work in non supersonic regime.

Not sure how afterburner would affect the fan disk, since it's basically something that happens in the exhaust, not in the compressor ??

[flipper35]

Originally Posted by svandamme

I'm calling BS on that.
the
increased complexity of systems
decreased reliability (complexity goes up reliability goes down)
increased maintenance reqs (more complexity in systems to check and test )
increased cost for parts not used on any other application

vs
the low actual chance of using it effectively...
=
Zero ROI

And if it at all were true.. We'de have seen a picture of a 747 in Zone 5 by now..
It would be too awesome and impossible to keep that a secret.

AF1 has
https://en.wikipedia.org/wiki/General_Electric_CF6

No mention of any variant with AB. at all.

You have confused me with someone that thinks AF1 has reheat. I only mentioned the maneuvers in the 707 version.

[svandamme]

That would appear to be the case indeed !
I blame lack of coffee in the morning

[Seahawk]

My favorite fixed wing airplane:



I have about 100 hours in various jets, mostly trainers and with an aggressor squadron when I was a "stash Ensign" at VA-42 in Virginia Beach, then VT-10 in Pensacola riding backseat in T-2's and A-4's during maintenance hops.

Up and away is great, but there is, to me, no better flying than down low in the weeds.

135kts at 25 feet in an H-60 made me happy. The A-10 is the only thing that would have made me happier.

[A930Rocket]

I thought I recalled the A-10 being phased out, but looking online, it still seems active. Is there a modern day version aircraft that meets or exceeds the capability of the A-10?

Favorite sound: Brrrrrrrrrttttttt…

[Esel Mann]

Yes, there is. Drones. Look for them at your corner 7-11!!!!

[flipper35]

Originally Posted by svandamme

That would appear to be the case indeed !
I blame lack of coffee in the morning

That excuse is believable!

Paul, I have a book on the A10 and in it they talked abut a Red Flag exercise where two Warthogs got jumped by two Vipers down at their level. The Vipers found out that a 6 G turn at support speeds is a higher rate of turn than a 9 G turn at fighter jet speeds. The Warthogs didn't even jettison their ordinance.

I have a tape somewhere in the basement of Gunsmoke 91 where they invited the A10. The A10 was not allowed to use the gun but they still won handily. IIRC, they had a score of 91% and a very high majority of those practice bombs hit the turret itself where the rest were happy if it hit the tank anywhere.

If I find that tape I will digitize it and send a copy to you.

[Seahawk]

Originally Posted by flipper35

If I find that tape I will digitize it and send a copy to you.

Terrific. Thank you.

Just one ride, that is all I am asking...

[edgemar]

[svandamme]

damn. How do you loose your tail boom so high up???
any other aircraft around ? midair?

or did it do something aerodynamically to bend the main rotor and have it chop off it's own tail !??
IT looks like it did just that at the 5 sec mark under heavy rotation.. But could that also have been the initial problem?

[svandamme]

video quality is so good it freese frames clean..




That looks like an aircraft malfunction/maint problem to me.

[edgemar]

mast bumping?

That makes me think twice about getting into a Robinson...