Fly2HMO
Topic Author
Posts: 7207
Joined: Sat Jan 24, 2004 12:14 pm

732s Have Emergency Jato Reversers?

Thu Jul 08, 2004 2:06 pm

Long story short; an uncle of mine made an emergency landing (probably a surge while cruising) in a brand new 732 (the only aircraft that fit the description and date that he said), and that when they landed "rockets" fired from the leading edge of the wing (like thrust reversers). I don't remember the airline, and I think it was from mex to houston in an american airline. Is this possible?

 Smile/happy/getting dizzy
 
HaveBlue
Posts: 2108
Joined: Fri Jan 30, 2004 3:01 pm

RE: 732s Have Emergency Jato Reversers?

Thu Jul 08, 2004 3:31 pm

In a word, no.

The military has tried lots of crazy stuff that even they abandoned as too risky, stuff that would never, ever see the light of day in civilian dressing. One of which was a C-130 reverse JATO landing, to rescue hostages in Iran. During the tests, they fired early, planed dropped out of the air, wing broke, fuel caught on fire, and the idea was abandoned. I can assure you no air carrier, much less an American one, ever had reverse rockets.

Now, there have been rare instances of airliners like the DC-9 having JATO rockets in the wing root for take off, for use in high and humid conditions in case of an engine failure at a critical phase of take off. I think after 6 months if they weren't used (not sure they ever were with passengers) the crew would do a maint. flight and expend them... easier that way then removing fully fueled rockets from a jet airplane, and disposing of them.

I can't think of anything that your uncle could have been talking about that would remotely resemble reverse rockets, with the exception of the all too obvious reverse thrust engines, but you know that.

[Edited 2004-07-08 08:32:53]
Here Here for Severe Clear!
 
liamksa
Posts: 301
Joined: Mon Oct 29, 2001 1:13 pm

RE: 732s Have Emergency Jato Reversers?

Thu Jul 08, 2004 4:45 pm

Here's the link to the "Super STOL" accident HaveBlue mentions:

http://www.avpics.de/mov/mil/c130mis.rm

As for the commercial use of rockets to reduce landing distances I highly doubt it. I think it would have been one of those topics mentioned at least once a week if it existed.

And sorry to nitpick but a JATO landing is a bit of a contradiction in terms.  Big grin
 
HaveBlue
Posts: 2108
Joined: Fri Jan 30, 2004 3:01 pm

RE: 732s Have Emergency Jato Reversers?

Thu Jul 08, 2004 4:59 pm

To nitpick even further, it probably should be called RATO, because I never understood what Jet Assisted Take Off had to do with Rockets. So it would be JAL or even more precisely, RAL.

But, I'm not sure a new acronym has to be coined for something used only once, and most likely, never ever again.

[Edited 2004-07-08 10:01:22]
Here Here for Severe Clear!
 
phollingsworth
Posts: 635
Joined: Sat Mar 06, 2004 6:05 am

RE: 732s Have Emergency Jato Reversers?

Fri Jul 09, 2004 12:18 am

To nitpick even further, it probably should be called RATO, because I never understood what Jet Assisted Take Off had to do with Rockets. So it would be JAL or even more precisely, RAL.

But, I'm not sure a new acronym has to be coined for something used only once, and most likely, never ever again.


Sometimes they are called RATO. Both descriptions are actually accurate. Since a rocket is just another type of jet engine, i.e., it uses the jet thrust principle. RATO is a more specific naming because it implies that all of the propellants are stored onboard.

I believe that some of the Mexican airlines had JATO equipped 727s for assist with Hot and High take-offs. You rarely need rockets for landing, as it is easier to stop than it is to start, unless you are trying to land on a soccer-field.

By the way none of the helicopters out there are jet powered, some are turbine powered, but none are jet powered. The V-22 is partially jet powered in some regions of flight.
 
HaveBlue
Posts: 2108
Joined: Fri Jan 30, 2004 3:01 pm

RE: 732s Have Emergency Jato Reversers?

Fri Jul 09, 2004 7:20 am

Phollingsworth, it's semantics now, but to my way of thinking a turboprop is much more akin to a jet engined airplane than a rocket powered one is. For that matter, a turbine engined helicopter is more comparable to a jet than a rocket is. At least in both the turboprop and turbine helicopter, it is in reality a jet engine, with either the forward shaft powering a prop or being 90 degreed to a shaft for a rotor. But in both instances, its an air breathing compression to combustion chamber engine driving the aircraft, albeit in slightly different ways. A rocket, imo, has nothing to do with jets. Its 1 or more chemicals combusted, self contained, with no compressors or shafts whatsoever to propel a vehicle forward.

As I said, its semantics, but I'd much sooner call a Huey or a King Air a jet than an X-15, Me-163 or a JATO rocket.

And I'm assuming that when you say the V-22(which I've been fortunate enough to have seen fly twice, and get pictures of) is partially jet propelled, that your speaking of the exhaust from the turbine when in transitional or level flight? Dunno, that's about how much I see a helicopter or turboprops performance attributed to jet flow. Clarify please if I'm wrong, which very well may be.
Here Here for Severe Clear!
 
prebennorholm
Posts: 6430
Joined: Tue Mar 21, 2000 6:25 am

RE: 732s Have Emergency Jato Reversers?

Fri Jul 09, 2004 7:35 am

Phollingsworth, you are right. Mexicana many years ago had some 727s equipped with JATO bottles in the main wheel wells.

They were only to be fired at take off in case of engine shut down after V1. And only on insufficiently long, hot and high runways.

Those of us who have ever heard a rocket engine will know that such things are totally incompatible with normal civil airport operation.

I have heard rumors about similar installations on DC-9s, but don't remember any details.

[Edited 2004-07-09 00:39:48]
Always keep your number of landings equal to your number of take-offs
 
SlamClick
Posts: 9576
Joined: Sun Nov 23, 2003 7:09 am

RE: 732s Have Emergency Jato Reversers?

Fri Jul 09, 2004 7:37 am

Jet is an airbreather, right?
Rocket makes its own oxygen?
JATO just became better known than RATO through wider usage.

It was ONA that developed the JATO mod for the DC-9. It was a freighter. There do exist photos of them being fired. A good friend of mine has ridden a JATO takeoff at ONA. The bottles did have a shelf life. All they were for was to help get the thing up through V2 with an engine out.

The total thrust was rather slight. It would take a lot of forward-firing rockets to have much effect on a 737 landing distance. Just not worthwhile.

HaveBlue your point is made by the Avco Lycoming engine. One version powers the BAe-146, a jet. One version powers the OV-1 Mohawk, a turboprop. The third version powers the CH47 Chinook, a helicopter. Turbofan, turboprop, turboshaft - all in one engine.

To further muddy the jet-powered waters, lots of turboprops gain measurable thrust from the exhaust. The Convair 240/340/440 had augmentor tubes that aided engine cooling but they too produced measurable thrust. All that from piston engine exhaust and exhausted cooling air.


Happiness is not seeing another trite Ste. Maarten photo all week long.
 
prebennorholm
Posts: 6430
Joined: Tue Mar 21, 2000 6:25 am

RE: 732s Have Emergency Jato Reversers?

Fri Jul 09, 2004 7:57 am

If memory serves me well, then the JATO equipped Mexicana 727s had four bottles, two in each main wheel well.

Each bottle would develop something between 500 and 1000 lbs thrust for some 30 seconds.

They could cut a few hundred feet off the runway requirement. And that way convert an otherwise canceled flight on a hot day into a meaningful payload capability.

But turned 180 degrees and used for breaking after landing would be totally meaningless. If needed, a drag chute would be a lot more meaningful.
Always keep your number of landings equal to your number of take-offs
 
phollingsworth
Posts: 635
Joined: Sat Mar 06, 2004 6:05 am

RE: 732s Have Emergency Jato Reversers?

Sat Jul 10, 2004 9:03 am

It is semantics, I was just pointing out that JATO is not an entirely incorrect naming, RATO is just more descriptive. As for jet powered helicopters the Fairey Rotodyne was jet powered. It is going back a bit but to consider a vehicle jet powered it typicall ~10-20% of the total thrust that needs to come from the jet flow (typically flow which has undergone heat addition, then expansion). Turboshafts, while operating on the Brayton cycle are not jet propelled.

SamClick, you are correct about the Convairs, also the P-51 achieved similar jet thrust from its exhaust and radiator cooling flow (the radiator actually qualifies as a ramjet). However, while the typical connotation is that a jet is an airbreather, the denotation does not specify it as such (rockets always carry all of their propellant on-board, or is it?). A rocket powered vehicle is a jet powered vehicle, but it is not sufficient to use the other way around. This is similar to a turbochager. A turbochager is a superchager (the full name being turbo-superchager), but a superchager is not necessarily a turbochager.

A final way of thinking about it, in chemically energized systems (those that burn fuel). A jet is a system where the propelling fluid is the working fluid, is the combusting fluid (the working fluid is the combusting fluid is what defines and internal combustion engine, e.g., the Brayton, Otto and Diesel cycles).

One last conundrum, how does a Liquid Air Cycle Rocket (LACE) fit into the whole system? Most people think of it as a rocket, but it is definitely airbreathing.
 
miamiair
Posts: 4249
Joined: Thu Jul 15, 2004 9:42 pm

RE: 732s Have Emergency Jato Reversers?

Fri Jul 16, 2004 8:22 pm

ONA's DC-9F's did have JATO. They had two pairs of rockets in wing-to-body fairings. These were the result of ONA having the LOGAIR contract for the DoD and Hill AFB was a place you didn't want an engince to burp on you. The rockets did have a shelf life and were fired when their due date was up. My father was an ONA DC-9 captain.

Also, Mexicana had JATO built in to some of their B727-200's for High/Hot conditions.

As for a 737 using rockets to slow down, why didn't they just use the arresting hook?

Molon Labe - Proud member of SMASH
 
Jetmek319
Posts: 193
Joined: Fri Sep 26, 2003 8:02 am

RE: 732s Have Emergency Jato Reversers?

Thu Jul 22, 2004 12:22 pm

Evergreen used to park several JATO equipped DC9-30F's at the old Stapleton Airport in Denver. Haven't seen any at DIA recentlythough.

Never, ever moon a werewolf !!
 
miamiair
Posts: 4249
Joined: Thu Jul 15, 2004 9:42 pm

RE: 732s Have Emergency Jato Reversers?

Thu Jul 22, 2004 6:45 pm

Evergreen's DC-9-34F's are all ex-ONA. There's one flying for Airborne Express, N934F, I believe.
Molon Labe - Proud member of SMASH
 
gigneil
Posts: 14133
Joined: Fri Nov 08, 2002 10:25 am

RE: 732s Have Emergency Jato Reversers?

Thu Jul 22, 2004 7:03 pm


View Large View Medium
Click here for bigger photo!

Photo © Ed Saldana
View Large View Medium
Click here for bigger photo!

Photo © Willam W. Sierra



Great shots. Interesting technology.

N
 
N1641
Posts: 201
Joined: Thu May 18, 2000 2:10 pm

RE: 732s Have Emergency Jato Reversers?

Fri Jul 23, 2004 9:52 am

maybe he confused it for the compressor stall, is that the correct term? I work at a military tower and I say 50-60% of the C-141s kick out a little flash of flame when they put the reversers on.
 
HAL
Posts: 1742
Joined: Tue Jan 15, 2002 1:38 am

RE: 732s Have Emergency Jato Reversers?

Thu Aug 05, 2004 9:24 am

To get back to the original question, my guess was that most likely he saw a compressor stall, something that could happen to those old JT8D engines in a high powered reverse situation. That sometimes caused flames to come out the front of the engine, scaring the cr@p out of the people seated beside the engine intake. It was mostly hamless however.

HAL
One smooth landing is skill. Two in a row is luck. Three in a row and someone is lying.

Who is online

Users browsing this forum: Baidu [Spider], BobPatterson and 26 guests