Flight152 From United States, joined Nov 2000, 3138 posts, RR: 12 Posted (3 years 3 months 3 weeks 3 days 19 hours ago) and read 3806 times:
I came across these pictures and wondered more about them: A Cartridge start. As far as I can tell they are used when little ground support equipment is used on 70's era military aircraft to start up, but wondered more about them.
TWAL1011727 From United States, joined Mar 2006, 547 posts, RR: 0 Reply 2, posted (3 years 3 months 3 weeks 3 days 19 hours ago) and read 3794 times:
We have a Canberra sitting in MLB on the FIT Aviation ramp. When Hurricane Frances came thru here in Sept 2004, It was started up to fly it out - but ended up shutting down with other mech issues. The mechanical problems have never been addressed and the airplane is now a home for wasps/mud dobbers and the like. It sounded pretty humorous when started up.
Bri2k1 From United States, joined Dec 2004, 844 posts, RR: 4 Reply 3, posted (3 years 3 months 3 weeks 3 days 15 hours ago) and read 3728 times:
A cartridge start fires a blank shell into a specially designed chamber of some engines. The expanding hot gases turn the engine and it can be started. Both old and new versions of The Flight of the Phoenix movie demonstrated this.
The B-57 is one example of an airplane that used such a system. A bunch of sound files, including some taken while performing cartridge starts, is located at http://www.b-57canberra.org/b-57sounds.htm though I can't say I've found them to be particularly humorous.
Moose135 From United States, joined Oct 2004, 1128 posts, RR: 13 Reply 4, posted (3 years 3 months 3 weeks 3 days 14 hours ago) and read 3698 times:
Back when we pulled alert in KC-135s, (the old A-models) we used cartridge starts (during exercise starts - never had to make a "real-world" cart start on alert!) Normal ops called for carts in #1 & #4 engines. As Bri2k1 said, a cartridge of black powder was fired, and the hot gases turn the engine. The carts were used in place of an external air supply. As RPMs came up, you went through the normal start up.
For some exercises, or hightened alert conditions, we used a "Quick-Start" mode, where we had carts installed on all 4 engines. That made for some tricky work in the cockpit getting them all started at the same time.
B-52s used the same start procedure on alert, although I don't know how many carts they normally used, we didn't have BUFFs at KGUS.
Tech question: yes, the starter cartridge in the older marks of Canberra was just a huge shotgun shell, albeit without the shot. There was an explosive release of gases which was channeled to the turbine to wind the thing up. The earliest marks B2, T4, TT18 had only 1 fitted per engine, so, after a failed start, it would take several minutes for the area to cool enough for the cartridge to be replaced, often resulting in a delay of 20 minutes or more.
The latter (early) marks, PR7, E15, T17, T22 had 3 per engine, 2 as spares. The last mark, PR9, used a really nasty explosive fuel called AVPIN, which was volatile in the extreme. One of our jeeps carrying the stuff through a small town, fortunately in an unpopulated area, caught fire spontaneously, the driver bailed, and the resultant conflagration melted the concrete of the sidewalk. You can imagine the effect this had on the local populous - we were thereafter banned from transporting it through residential areas.
The explosion from the starter cartridge was impressive: 4-foot flames would leap from 3 vents in the engine casing, the whole area would be wreathed in pungent cordite smoke, and pilot and supervising technician would watch the engine and each other nervously in case of engine fire. In 3 years, I only had to evacuate once because of a suspected fire, which turned out to be a false alarm. However, you can imagine that when the plane was fully fueled, we were out of there in a flash and up and running!
The gas release should take the engine up to about 2000 RPM, which was enough to energize the igniters and allow the engine to work with the start inertia to get it up to normal idling RPM (I forget the figure). The main thing you were watching at this stage was either for an internal fire, in which case the EGT gages would leap off the scale, or compressor surge, usually accompanied by a lot of popping and banging. In both cases, the actions would be the same: throttle closed, HP cock closed, LP pump off; for a fire of course, additional actions would be fire extinguisher shot through the engine (only 1 available) and evacuate (run for the hills!).
Moose135 From United States, joined Oct 2004, 1128 posts, RR: 13 Reply 9, posted (3 years 3 months 3 weeks 2 days 17 hours ago) and read 3499 times:
Quoting SlamClick (Reply 8): Are you saying that the gases turn the engine itself? I always thought they turned an inertia starter like a common jet engine air starter.
No, you're right, the cart was used to turn the starter in place of a ground power unit, I guess I should have been more specific.
David L From United Kingdom, joined May 1999, 8274 posts, RR: 41 Reply 10, posted (3 years 3 months 3 weeks 2 days 1 hour ago) and read 3424 times:
Quoting SlamClick (Reply 8): Did the USAF fly any English Electric Canberras? I thought all of their B-57s were license-built by Martin.
I'm not aware of any Canberras in USAF service but I'm hardly an expert. I'm sure there would have been other differences but the most noticeable difference was the the tandem cockpit in the B-57 rather than the side-by-side cockpit of the Canberra.
Ptrjong From Netherlands, joined Mar 2005, 3040 posts, RR: 23 Reply 11, posted (3 years 3 months 3 weeks 1 day 18 hours ago) and read 3376 times:
Quoting SlamClick (Reply 8): Did the USAF fly any English Electric Canberras? I thought all of their B-57s were license-built by Martin.
The British supplied two Canberra B.Mk.2s two Martin, WD940 and WD932, and these officially entered in the USAF inventory as 51-17352 and 51-17387. All other US aircraft were built by Martin.
Quoting David L (Reply 10): the most noticeable difference was the the tandem cockpit in the B-57 rather than the side-by-side cockpit of the Canberra.
The B-57A version didn't have the tandem cockpit yet.
Ryan h From Australia, joined Aug 2001, 1221 posts, RR: 0 Reply 12, posted (3 years 3 months 3 weeks 1 day 17 hours ago) and read 3358 times:
On the subject of cartride starters, I was fortunate to wutness the engine start of a Constellation recently and I was surprised how much smoke was generated.
747Teach From United States, joined Nov 2000, 176 posts, RR: 2 Reply 15, posted (3 years 3 months 3 weeks 1 day 13 hours ago) and read 3328 times:
Flight152: I was an Air Force F-4 crew chief for three years; I can tell you a bit about cartridge starts on those aircraft. Under the belly is an access panel just below the starter, which you open to access the breech. The pneumatic starter on each engine has a "breech," a cylinder about 6" in diameter and about 9" long attached by a quick release coupling. You would slide the handle back and turn the breech about 90 degrees to remove it. The cartridges were sized to fit the breech, and made of something like solid rocket propellant. They would produce high-pressure, high-volume, hot gas for about 25 seconds. They had an electrical connection that fit into the top of the breech. The exhaust end of the cartridge was open, exposing the propellant. Drop the cartridge in, install the breech by placing it on the coupling and turning 90 degrees, and slide the handle up to lock it. The electrical connection was made through the handle. To start the engine, the crew had only to turn the battery on, the ignition on, and hit the start switch, electrically firing the cartridge. The gas produced by the cartridge exited through the starter, turning it the same way the ground pneumatic connection from the -60 did. In the photo, the F-4 appears to be using the newer "smokeless" cartridge, which still produced much smoke, but far less the the older "smoke-type" cartridges, that produced enormous amounts of solid black smoke. Occasionally a cartridge failed to ignite, so the crew chief would have to go under the belly, remove the breech and cartridge, and install another one. Always risky. Sometimes they would fire off then go out, causing an even more dangerous removal. They would sometimes "torch," meaning instead of producing hot gas, they would produce raw flame instead, which upon exiting the starter outlet would set anything under the plane on fire. Always exciting. And every once in a while they would just explode, blowing the breech off the starter and damaging the plane. Always ugly. Our F-4s could carry a spare set of cartridges in cavities under the inboard bottom of the wing root, accessible by removing a small panel. This cavity carries the casting for attaching the catapult bridle on Navy models. Air Force models, not having the casting, had instead a bracket to mount the cartridge in. We would sometimes carry spares if we were deploying to a base that didn't have sufficient ground equipment. We also installed cartridges on all the alert aircraft, as it was faster to start engines with the cartridges than firing up the -60 and dragging the hose around. Hope you find this informative. Regards,
Gt1 From United States, joined Feb 2001, 128 posts, RR: 0 Reply 17, posted (3 years 3 months 2 weeks 2 days 12 hours ago) and read 3163 times:
Quoting Moose135 (Reply 4): B-52s used the same start procedure on alert, although I don't know how many carts they normally used, we didn't have BUFFs at KGUS.
In the B-52G's on alert at Loring AFB in the mid 80's, sometimes just engines 4 and 5 had them, but more often then not, they used the quick start procedure with all 8 having "carts". The crew cheif had to wear a poison gas mask it was so bad.
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