SL721
Sat Dec 11, 2004 1:59 pm
I just got back from a Project North Star Christmas gathering. I had a chance to speak to Earl Chapman, who is the person responsible for the maintenance of SL721.
Apparently the wings and tail of SL721 were removed for the road trip back to Gatineau from Geneseo. Since the airframe was disassembled it was considered the perfect time to go ahead a do the annual inspection, so that is underway now. It is expected that the tail will be re-mated to the fuselage next week.
Apparently the prop strike damage was not severe, mainly due to the soft ground and the wooden prop absorbing most of the energy. It was explained to me that the first blade that stuck wore a groove in the ground at it was broken, and blade #2 passed through the same groove with much less damage. By this point the nose had lowered a little more and the #3 blade suffered damage like #1, and number #4 passed through the groove deepened by #3. It was described to me that the engine stopped by then.
Questions put to the Merlin experts resulted in the Mr. Potter's team learning that the prop assembly is designed to break away under a certain amount of stress before damage to the engine can take place, but due to the soft ground and wooden blades the strike was not all that severe. Don't quote me on this as I am certainly not an aircraft mechanic, or a mechanic of any kind. However as an electical engineer I can say that a fuse in an electrical circuit provides the equivalent functionality of weak component designed to break under increased stress in a mechanical system.
The prop assembly is not back from England where it was sent for rebuild. I was told the prop hub was not damaged. It will be the same hub reinstalled with new blades as I understand it.
Anyway... SL721 reassembly and care is coming along fine, and we can expect it to be flying again by next summer.
Regards,
Mike
Apparently the wings and tail of SL721 were removed for the road trip back to Gatineau from Geneseo. Since the airframe was disassembled it was considered the perfect time to go ahead a do the annual inspection, so that is underway now. It is expected that the tail will be re-mated to the fuselage next week.
Apparently the prop strike damage was not severe, mainly due to the soft ground and the wooden prop absorbing most of the energy. It was explained to me that the first blade that stuck wore a groove in the ground at it was broken, and blade #2 passed through the same groove with much less damage. By this point the nose had lowered a little more and the #3 blade suffered damage like #1, and number #4 passed through the groove deepened by #3. It was described to me that the engine stopped by then.
Questions put to the Merlin experts resulted in the Mr. Potter's team learning that the prop assembly is designed to break away under a certain amount of stress before damage to the engine can take place, but due to the soft ground and wooden blades the strike was not all that severe. Don't quote me on this as I am certainly not an aircraft mechanic, or a mechanic of any kind. However as an electical engineer I can say that a fuse in an electrical circuit provides the equivalent functionality of weak component designed to break under increased stress in a mechanical system.
The prop assembly is not back from England where it was sent for rebuild. I was told the prop hub was not damaged. It will be the same hub reinstalled with new blades as I understand it.
Anyway... SL721 reassembly and care is coming along fine, and we can expect it to be flying again by next summer.
Regards,
Mike
Last edited by mrhenniger on Mon Dec 13, 2004 8:07 am, edited 1 time in total.
Sat Dec 11, 2004 10:27 pm
Great news Mike
Thanks for the up date. I hope that I can see it fly next year at Geneseo. It Dec and I already can't wait for Geneseo Airshow
Thanks for the up date. I hope that I can see it fly next year at Geneseo. It Dec and I already can't wait for Geneseo Airshow
Sat Dec 11, 2004 10:47 pm
Good show Mike, thanks for the update!
