Fly2HMO From , joined Dec 1969, posts, RR: Posted (9 years 5 months 2 weeks 2 days 14 hours ago) and read 3229 times:
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?
HaveBlue From United States of America, joined Jan 2004, 2081 posts, RR: 1 Reply 1, posted (9 years 5 months 2 weeks 2 days 12 hours ago) and read 3162 times:
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.
Phollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 6 Reply 4, posted (9 years 5 months 2 weeks 2 days 3 hours ago) and read 3050 times:
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 From United States of America, joined Jan 2004, 2081 posts, RR: 1 Reply 5, posted (9 years 5 months 2 weeks 1 day 20 hours ago) and read 2949 times:
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.
SlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 69 Reply 7, posted (9 years 5 months 2 weeks 1 day 20 hours ago) and read 2942 times:
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.
Phollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 6 Reply 9, posted (9 years 5 months 2 weeks 19 hours ago) and read 2784 times:
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 From , joined Dec 1969, posts, RR: Reply 10, posted (9 years 5 months 1 week 1 day 7 hours ago) and read 2580 times:
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?
HAL From United States of America, joined Jan 2002, 2500 posts, RR: 53 Reply 15, posted (9 years 4 months 2 weeks 4 days 18 hours ago) and read 2126 times:
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.
One smooth landing is skill. Two in a row is luck. Three in a row and someone is lying.