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Clarification on Shot Peening Big Cracks (don't try this at home)

To clarify the question about shot peening large cracks, there was an article that mentions the peening of a large crack in an engine. I'm not advocating this as a standard practice but cite it as an example of the benefits available upon application of peening.

From A.S.N.E. Journal, November 1951, The Story of Shot Peening,

Leghorn:

We have already mentioned the ancient use of hammer peening and it is well to note that the shot size in this instance was the size of the ball on the hammer. Another interesting anecdote along this line was told by a professor of metallurgy at the University of California to the effect that an early Wright diesel airplane engine owned by an Alaskan bush pilot developed a crack in a critical area and this crack gradually propagated until it became a matter of extreme concern to the pilot.

Rather than be put out of operation while waiting for a new part, the pilot took a chance and heavily ball peened the metal at the end of the crack.

This engine was used for over five years in the cracked and peened state and was taken out of service for general debility and not because of the crack. This is a case where a crack (stress raiser) propagating by fatigue could not penetrate through a compressively stressed metal area.

Name witheld by request

European ELT Manufacturer ELTA Chimes In

I very much enjoyed reading your article on ELT testing in the most recent issue of Aviation Maintenance. There is currently a lot of debate on how the new 406 Mhz ELTs should be tested as there is currently no defined international testing requirement for airlines. There is also the added complication that airlines carry both the automatic-fixed and survival ELTs, some of which have no built in test capability.

I'm not sure where you got your list of ELT manufacturers from but I note that there is no mention of any European manufacturers, and in addition to those you mention only Artex and Honeywell are (to the best of my knowledge) manufacturing the 406 Mhz ELTs.

ELTA, based in Toulouse France, has specialised in ELTs since the beginning of the Cospas Sarsat organisation in the 1980s and is now the worldwide leader in the supply of automatic fixed ELTs to the commercial aviation market.

ELTA's ELTs equip more than 100 airlines in the world, including key customers such as Japan Airlines, Air France, Ryanair, Emirates, ILFC, Iberia, Lufthansa, Qatar Airways, Singapore Airlines, and South African Airways. Driven by this success we have developed a worldwide network of customer service centers.

Our new ELT, the ADT 406, is superior to any other product currently available on the market thanks to its unique features, and in addition to winning new business with airlines has also been selected by Airbus for the A380. Talking of transmitting a signal, we have added a unique back-up antenna that functions on the 406 Mhz frequency should the integrity of the external antenna operation be damaged. ELTA is a ISO9001-2000 company and also holds EN9100 approval.

Philip Male
Head of ELT Worldwide Sales
ELTA