Retrotechtacular: The J-57 Afterburner Engine

The J-57 afterburner engine appeared in many airplanes of notable make, including the F-101, -102, and -103. This USAF training film shows the parts of the J-57, explains the complex process by which the engine produces thrust, and describes some maintenance and troubleshooting procedures.

The name of this game is high performance. Precision thrust requires careful rigging of the engine’s fuel control linkage through a process called trimming. Here, the engine fuel control is adjusted with regard to several different RPM readings as prescribed in the manual.

One of the worst things that can happen to a J-57 is known as overtemping. This refers to high EGT, or exhaust gas temperature. If EGT is too high, the air-fuel ratio is not ideal. Troubleshooting a case of high EGT should begin with a check of the lines and the anti-icing valve. If the lines are good and the valve is closed, the instruments should be checked for accuracy. If they’re okay, then it’s time for a pre-trimming inspection.

In addition to EGT, engine performance is judged by RPM and PP7, the turbine discharge pressure. If RPM and PP7 are within spec and the EGT is still high, the engine must be pulled. It should be inspected for leaks and hot spots, and the seals should be examined thoroughly for cracks and burns. The cause for high EGT may be just one thing, or it could be several small problems. This film encourages the user to RTFM, which we think is great advice in general.

Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.

15 thoughts on “Retrotechtacular: The J-57 Afterburner Engine

  1. I worked on the j-52-p408-b. It’s a non afterburner, but this above is essentially a standard diagnostic for high EGT in most all turbo jet engines. The major difference with an after burner is the addition of the spray ring on the output stage after the turbine output. High velocity air and pressurized jet fuel are mixed and ignited increasing the displacement. Efa

  2. Then-Colonel Chuck Yeager once got 101% power out of a Super Sabre by having the ground tech crank in the trim tabs on the exhaust nozzle. This was technically out of spec, but he knew just how much he could exceed the spec and still not harm the engines. He beat a later-model (and more powerful) Super Sabre in a speed race this way. The story’s in his autobiography, Yeager. Great read.

  3. Does anyone know if they are using walnut shells to clean these engines? I’ve worked on industrial turbines used for compressing natural gas on pipelines and 20 years ago Solar, a division of Caterpillar, changed from walnut shells to water washing. I believe the term that Solar used was coke cleaning. It’s amazing how dirt on the impeller blades can reduce efficiency on turbines.

  4. Some time ago I went to the crash site of an RF101 in the mountains nearby (in France).
    Most of the frame and wings were removed since a long time but there were still the engines, landing gear and many other parts to be found. The crash took place in the early 60′ in a very remote location. It was very impressive.

  5. The inventor of the afterburner is a friend of mine. Joe Holden was only 17 at the time, and already had degrees from both Oxford and Cambridge and had been working for Rolls Royce for a year when he invented the afterburner; he later went on to become an OSS officer. His real life makes James Bond look like Austin Powers. Fascinating guy. There should be a movie about him (I’m pretty sure the movie Firefox is based on something he did in North Korea during the Korean war).

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