Moderators: richierich, ua900, PanAm_DC10, hOMSaR

 
Blackbird
Topic Author
Posts: 3384
Joined: Wed Oct 06, 1999 10:48 am

JT3C Engine-Pod / Blowaway Jet

Mon Jul 23, 2007 5:54 am

I know the DC-8 used a bleed-air blowaway jet to kill off a vortex which causes the engines to suck in excessive amounts of stuff on the ground. Does the 707 use a similar device, or did they figure out a way around it.

Andrea K
 
113312
Posts: 673
Joined: Sat Apr 16, 2005 9:09 am

RE: JT3C Engine-Pod / Blowaway Jet

Mon Jul 23, 2007 8:01 am

Actually, all of the DC8s had the blowaway jet.
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: JT3C Engine-Pod / Blowaway Jet

Mon Jul 23, 2007 9:51 am

No, nothing special fitted to the B707 for the stated purpose.

All 707's did have thrust recovery valves, however.
Different function entirely.
 
Blackbird
Topic Author
Posts: 3384
Joined: Wed Oct 06, 1999 10:48 am

RE: JT3C Engine-Pod / Blowaway Jet

Tue Jul 24, 2007 8:50 am

To 113312

Actually, to my knowledge the DC-8-62 and DC-8-63 didn't appear to have them to my knowledge...


To 411A,

What's a thrust-recovery valve?


To both:

Why did the 707 (and CV-880 as well to my knowledge) not need a blowaway-jet, and the Douglas design did?


Andrea Kent
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: JT3C Engine-Pod / Blowaway Jet

Tue Jul 24, 2007 9:47 am

Thrust recovery valve.

A valve mounted more or less flush with the lower fuselage, the purpose of which is to expell cabin pressurized air at approximately a 45 degree angle (rearwards).
These valves assist with cabin ventilation, and are normally fully open in flight.

Long body B707 aircraft have three, short body aircraft have two.

A Boeing exclusive, so far as I know.
 
grandtheftaero
Posts: 247
Joined: Sat Nov 29, 2003 1:05 pm

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 12:40 am

I wonder how much thrust they actually "recovered" with those.
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 1:41 am

I was told by a Boeing design engineer....the thrust recovered is about 2 MFP.
 
Blackbird
Topic Author
Posts: 3384
Joined: Wed Oct 06, 1999 10:48 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 2:19 am

What's an MFP

Andrea K
 
n8076u
Posts: 419
Joined: Mon Jun 19, 2006 10:52 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 3:15 am

Quoting Blackbird (Reply 3):
Actually, to my knowledge the DC-8-62 and DC-8-63 didn't appear to have them to my knowledge...

The -62 and -63 had the blowaway jet as well. However, the -70 series did not.

Chris
Don't blame me, I don't work here...
 
Blackbird
Topic Author
Posts: 3384
Joined: Wed Oct 06, 1999 10:48 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 4:07 am

Where were the "blowaway" jets located... I don't seem to see them in the design?

Also.... why did the DC-8 need blowaway-jets and the B-707 didn't?


Andrea Kent
 
rwessel
Posts: 2448
Joined: Tue Jan 16, 2007 3:47 pm

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 5:45 am

I don't know about the 707, but the 737s got them with the gravel kits:



View Large View Medium
Click here for bigger photo!

Photo © Aaron Hall

 
VC-10
Posts: 3552
Joined: Tue Oct 26, 1999 11:34 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 8:14 am

Quoting 411A (Reply 4):
Thrust recovery valve...........

...........A Boeing exclusive, so far as I know.

The VC10 & Concorde had them as well
 
Blackbird
Topic Author
Posts: 3384
Joined: Wed Oct 06, 1999 10:48 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 8:37 am

VC-10,
What's an MFP though?

Andrea K
 
VC-10
Posts: 3552
Joined: Tue Oct 26, 1999 11:34 am

RE: JT3C Engine-Pod / Blowaway Jet

Wed Jul 25, 2007 6:32 pm

Quoting Blackbird (Reply 12):
What's an MFP though?

I've no idea!

More info on the VC10 'Thrust Augmenters' can be found here

http://www.vc10.net/Technical/oddities.html
 
n8076u
Posts: 419
Joined: Mon Jun 19, 2006 10:52 am

RE: JT3C Engine-Pod / Blowaway Jet

Thu Jul 26, 2007 3:01 am

Quoting Blackbird (Reply 9):
Where were the "blowaway" jets located...

They were on the bottom of the nacelle near the front, and would not be obvious unless you were under the engine looking up.

Chris
Don't blame me, I don't work here...

Who is online

Users browsing this forum: 747classic and 12 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos