Sikorsky FireHawk
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Sikorsky FireHawk
I have been enthralled by these beasts and ask your collective wisdom on this aircraft.
1. How are they going during the busy fire season? Much downtime?
2. Operating costs?
3. Size of belly tank.
4. Are they in a restricted category or on the civilian register?
Extremely interested.
Many thanks chaps/chappettes.
1. How are they going during the busy fire season? Much downtime?
2. Operating costs?
3. Size of belly tank.
4. Are they in a restricted category or on the civilian register?
Extremely interested.
Many thanks chaps/chappettes.
I heard the government owned ones stay broke....and have real availability problems...but do not know that for a fact.
Also heard they are very expensive to operate as compared to comparable sized aircraft.
Also heard they are very expensive to operate as compared to comparable sized aircraft.
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The Honorable Board of Supervisors
County of Los Angeles
383 Kenneth Hahn Hall of Administration
500 West Temple Street
Los Angeles, CA 90012
Dear Supervisors:
AUTHORIZE THE PURCHASING AGENT TO COMPLETE AND EXECUTE ALL
NECESSARY DOCUMENTS RELATIVE TO THE ACQUISITION OF A 500-HOUR
MAINTENANCE INSPECTION AND SERVICE FOR THE SIKORSKY S-70 FIREHAWK
HELICOPTER
(ALL DISTRICTS) (3-VOTES)
IT IS RECOMMENDED THAT YOUR BOARD ACTING AS THE GOVERNING BODY OF
THE CONSOLIDATED FIRE PROTECTION DISTRICT:
Authorize the County Purchasing Agent to complete and execute all necessary purchasing
documents relative to the acquisition of a 500-hour maintenance inspection and service for the
Sikorsky S-70 Firehawk Helicopter, not to exceed $200,000.
PURPOSE/JUSTIFICATION OF THE RECOMMENDED ACTION
The purpose of this recommended action is to authorize issuance of a purchase order to
provide a 500-hour maintenance inspection and service of the Sikorsky S-70 Firehawk
Helicopter #16, Serial Number 702453, as required by our “Total Assurance Program”
maintenance agreement with Sikorsky Aircraft Corporation. Labor, expenses, and service for
the 500-hour maintenance inspection will be performed at Barton Heliport and shall include six
helicopter mechanics and one quality assurance representative.
----
FISCAL IMPACT/FINANCING:
Pursuant to the Budget Correction Plan that was transmitted to your Board on August 18, 2000, these replacement helicopters and related equipment will be 100% leased-purchased in order to maintain a minimal prudent reserve over the next three years. The Chief Administrative Office and the Internal Services Department has negotiated a ten year lease-purchase financing package provided through Sikorsky by GE Capital Public Finance for the following items (costs include sales/use tax):
· $21.1 million for two S-70A FIREHAWKS from Sikorsky.
· $ 2.0 million for EMS interiors/avionics from Air Methods.
· $ 1.3 million for water tanks/extended landing gear from Aero Union.
· $ 0.6 million for ground support equipment from Sikorsky that our mechanics will need to maintain the helicopters.
The projected annual cost for this lease-purchase is $3.4 million ($1.6 million for 2000-01). Each of the vendors for this acquisition will be funded from an escrow fund established under an escrow agreement among the County, GE Capital and the State Street Bank as escrow agent. The $25 million in purchase costs will be deposited by GE Capital into the escrow fund upon execution of the Sales Agreement and then funds will be disbursed at County direction according to the payment terms established in the purchasing documents.
Under the TAP, there is a minimum annual requirement of six hundred flight hours and the flight hour rate is fixed at $924 hour through December 31, 2003, resulting in a minimum annual cost of $554,000 during this period. The TAP hourly flight rates are then increased for the next three calendar years: $989 for calendar year 2004, $1063 for calendar year 2005, and $1148 for calendar year 2006. For the remaining six calendar years, the increase each calendar year will be a minimum of 1.5%. The maximum increase that can be imposed in any one calendar year is capped at 11%, with any excess being recovered in future years of the agreement. However, the actual hourly flight rate used during these six calendar years will be determined by a formula using the U.S. Department of Labor, Bureau of Labor Statistics Producer Price Index-Commodities for aircraft parts and auxiliary equipment. Both the District and Sikorksy have the right under TAP to ask for a change in this formula if either party believes that the formula is not equitable to that party based on a schedule of actual part prices to be provided annually by Sikorsky. The hourly flight rate used for the last six months of the TAP agreement (January through June of 2013) will be the rate used for calendar year 2012.
The Department will pay TAP costs due in the current fiscal year (estimated at $100,000) from available funds in its Services & Supplies budget. The information provided by Conklin and de Decker indicate that using TAP to procure helicopter parts will cost us $1.2 million more over the 12 year term of the agreement than if the District were to purchase these parts on an as-needed basis. However, this cost is offset by avoiding an up-front parts inventory cost of at least $4.5 million (which would have to be immediately replenished for critical parts) and the fact that TAP serves as insurance that the District will not incur substantial unexpected costs due to catastrophic failure of parts. In addition, the District will no longer be incurring costs to purchase parts for the three Bell 205’s.
Following the appropriation adjustments from the Department’s Helicopter ACO Fund included in Attachment III, our District will have sufficient funding to pay for the helicopter training and lease-purchase costs of the helicopters due in the current fiscal year. The $1.6 million in lease payments due in the current fiscal year will be funded from the Department’s Other Charges budget through a combination of the $1.4 million budget adjustment attached. The $655,000 for Sikorsky training services due in 2000-01 will be funded from the Department’s Services & Supplies budget by the attached reallocation to the budget. Future TAP costs will be funded by annual increases in revenue received by the District from property taxes and reimbursement for services provided to other agencies.
Attachment IV is the Sales Agreement with Sikorsky for the helicopters, ground support equipment. Attachment V is the TAP Agreement with Sikorsky. Both agreements have been approved as to form by County Counsel.
We will be selling the three Bell 205’s and associated parts as surplus once the FIREHAWKS are operational. These sales are expected to provide approximately $4.6 million of one-time monies to help finance future lease-purchase payments. If in the future we were in a cash position to
buyout the lease-purchase, we would go back to the Board for the authority necessary to do that in order to minimize financing costs.
County of Los Angeles
383 Kenneth Hahn Hall of Administration
500 West Temple Street
Los Angeles, CA 90012
Dear Supervisors:
AUTHORIZE THE PURCHASING AGENT TO COMPLETE AND EXECUTE ALL
NECESSARY DOCUMENTS RELATIVE TO THE ACQUISITION OF A 500-HOUR
MAINTENANCE INSPECTION AND SERVICE FOR THE SIKORSKY S-70 FIREHAWK
HELICOPTER
(ALL DISTRICTS) (3-VOTES)
IT IS RECOMMENDED THAT YOUR BOARD ACTING AS THE GOVERNING BODY OF
THE CONSOLIDATED FIRE PROTECTION DISTRICT:
Authorize the County Purchasing Agent to complete and execute all necessary purchasing
documents relative to the acquisition of a 500-hour maintenance inspection and service for the
Sikorsky S-70 Firehawk Helicopter, not to exceed $200,000.
PURPOSE/JUSTIFICATION OF THE RECOMMENDED ACTION
The purpose of this recommended action is to authorize issuance of a purchase order to
provide a 500-hour maintenance inspection and service of the Sikorsky S-70 Firehawk
Helicopter #16, Serial Number 702453, as required by our “Total Assurance Program”
maintenance agreement with Sikorsky Aircraft Corporation. Labor, expenses, and service for
the 500-hour maintenance inspection will be performed at Barton Heliport and shall include six
helicopter mechanics and one quality assurance representative.
----
FISCAL IMPACT/FINANCING:
Pursuant to the Budget Correction Plan that was transmitted to your Board on August 18, 2000, these replacement helicopters and related equipment will be 100% leased-purchased in order to maintain a minimal prudent reserve over the next three years. The Chief Administrative Office and the Internal Services Department has negotiated a ten year lease-purchase financing package provided through Sikorsky by GE Capital Public Finance for the following items (costs include sales/use tax):
· $21.1 million for two S-70A FIREHAWKS from Sikorsky.
· $ 2.0 million for EMS interiors/avionics from Air Methods.
· $ 1.3 million for water tanks/extended landing gear from Aero Union.
· $ 0.6 million for ground support equipment from Sikorsky that our mechanics will need to maintain the helicopters.
The projected annual cost for this lease-purchase is $3.4 million ($1.6 million for 2000-01). Each of the vendors for this acquisition will be funded from an escrow fund established under an escrow agreement among the County, GE Capital and the State Street Bank as escrow agent. The $25 million in purchase costs will be deposited by GE Capital into the escrow fund upon execution of the Sales Agreement and then funds will be disbursed at County direction according to the payment terms established in the purchasing documents.
Under the TAP, there is a minimum annual requirement of six hundred flight hours and the flight hour rate is fixed at $924 hour through December 31, 2003, resulting in a minimum annual cost of $554,000 during this period. The TAP hourly flight rates are then increased for the next three calendar years: $989 for calendar year 2004, $1063 for calendar year 2005, and $1148 for calendar year 2006. For the remaining six calendar years, the increase each calendar year will be a minimum of 1.5%. The maximum increase that can be imposed in any one calendar year is capped at 11%, with any excess being recovered in future years of the agreement. However, the actual hourly flight rate used during these six calendar years will be determined by a formula using the U.S. Department of Labor, Bureau of Labor Statistics Producer Price Index-Commodities for aircraft parts and auxiliary equipment. Both the District and Sikorksy have the right under TAP to ask for a change in this formula if either party believes that the formula is not equitable to that party based on a schedule of actual part prices to be provided annually by Sikorsky. The hourly flight rate used for the last six months of the TAP agreement (January through June of 2013) will be the rate used for calendar year 2012.
The Department will pay TAP costs due in the current fiscal year (estimated at $100,000) from available funds in its Services & Supplies budget. The information provided by Conklin and de Decker indicate that using TAP to procure helicopter parts will cost us $1.2 million more over the 12 year term of the agreement than if the District were to purchase these parts on an as-needed basis. However, this cost is offset by avoiding an up-front parts inventory cost of at least $4.5 million (which would have to be immediately replenished for critical parts) and the fact that TAP serves as insurance that the District will not incur substantial unexpected costs due to catastrophic failure of parts. In addition, the District will no longer be incurring costs to purchase parts for the three Bell 205’s.
Following the appropriation adjustments from the Department’s Helicopter ACO Fund included in Attachment III, our District will have sufficient funding to pay for the helicopter training and lease-purchase costs of the helicopters due in the current fiscal year. The $1.6 million in lease payments due in the current fiscal year will be funded from the Department’s Other Charges budget through a combination of the $1.4 million budget adjustment attached. The $655,000 for Sikorsky training services due in 2000-01 will be funded from the Department’s Services & Supplies budget by the attached reallocation to the budget. Future TAP costs will be funded by annual increases in revenue received by the District from property taxes and reimbursement for services provided to other agencies.
Attachment IV is the Sales Agreement with Sikorsky for the helicopters, ground support equipment. Attachment V is the TAP Agreement with Sikorsky. Both agreements have been approved as to form by County Counsel.
We will be selling the three Bell 205’s and associated parts as surplus once the FIREHAWKS are operational. These sales are expected to provide approximately $4.6 million of one-time monies to help finance future lease-purchase payments. If in the future we were in a cash position to
buyout the lease-purchase, we would go back to the Board for the authority necessary to do that in order to minimize financing costs.
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Lotta words, but SASless, you are wrong again!
$1000 per hour to haul 10,000 lbs of water per trip is mighty fine.
Nick
BTW That pretty Huey of yours weighs 10,000 lbs doesn't it? Firehawk could load and drop one every three minutes, huh?
$1000 per hour to haul 10,000 lbs of water per trip is mighty fine.
Nick
BTW That pretty Huey of yours weighs 10,000 lbs doesn't it? Firehawk could load and drop one every three minutes, huh?
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Thanks Rotormatic. Very in depth.
There are obviously aircraft out there that are alot more cost effective per gallon/litre of water than many others and by the sounds of it the FireHawk is one of the cost effective ones.
Of course we can't all have these big machines flying around dropping huge amounts of water and many places only have access to the smaller AS350, BK117, B205, B412 and the like which would have a much higher cost per litre of water than the big machines.
I saw an Aussie news story the other day about two AS350's with water tanks fitted fighting a blaze near Brisbane and the cost/litre per hour for those aircraft dropping 1000 litres would be fairly high. Even worse when you use a B412 dropping 1500 litres!
There are obviously aircraft out there that are alot more cost effective per gallon/litre of water than many others and by the sounds of it the FireHawk is one of the cost effective ones.
Of course we can't all have these big machines flying around dropping huge amounts of water and many places only have access to the smaller AS350, BK117, B205, B412 and the like which would have a much higher cost per litre of water than the big machines.
I saw an Aussie news story the other day about two AS350's with water tanks fitted fighting a blaze near Brisbane and the cost/litre per hour for those aircraft dropping 1000 litres would be fairly high. Even worse when you use a B412 dropping 1500 litres!
Nick,
How many private sector companies are operating FireHawks?
I am not knocking the airframe...just the concept of Taxpayers taking it in the shorts for something that could be done far better and cheaper by the private sector.
Throw us an Excel spread sheet of the program costs would you? I want you to convince me that the total cost of the Two Firehawks is as stated in that document....and I do not mean the per hour flight charges alone....weight the per hour cost to include all costs...lease, insurance, manpower costs, overhead, real estate costs, right on down the line....lets see a line item by line item cost breakdown of the FireHawk Program and see what the taxpayer is paying for 1,200 flying hours per year. If those per hour costs are increased at the max rate of 11% as stated....that becomes a darn nice rate....especially when all the other costs are factored in.
Throw in the cost of the bases, fuel, personnel, retirements, workman's compensation....depreciation...all of the costs and one sees a much different set of numbers.
The private sector is the correct place for firefighting aircraft to come from....in that they can be used for other work when not needed for fires and can be used in jurisdictions other than just the one that owns them if publically owned.
Commerical operators employ people that pay taxes...and pay property taxes...fuel taxes...payroll taxes...out of proceeds earned from their services. Public Agencies only spend tax money....that comes from private business and private citizens....and that is bad business if the government is doing something that private business can do.
As these public agencies grow their own airforces...the assets within the private sector disappear....and in times of crisis are then not available to respond to disasters.
You take away fire work from commerical operators....and sooner or later...they will wither and die on the vine.
The Firehawks are an expenditure that only public agencies can afford in that they do not have to make a profit
The most cost effective method of fighting wildfires is prevention followed by aggressive suppression before the fires develop any size. That has been proven by the disastrous fires a few years ago when the CDF elected not to send aircraft as it was approaching dark and the fire took off overnight and nearly burned down Southern California.
Anytime a public agency starts telling me how cost effective they are....I know someone is lying.
How many private sector companies are operating FireHawks?
I am not knocking the airframe...just the concept of Taxpayers taking it in the shorts for something that could be done far better and cheaper by the private sector.
Throw us an Excel spread sheet of the program costs would you? I want you to convince me that the total cost of the Two Firehawks is as stated in that document....and I do not mean the per hour flight charges alone....weight the per hour cost to include all costs...lease, insurance, manpower costs, overhead, real estate costs, right on down the line....lets see a line item by line item cost breakdown of the FireHawk Program and see what the taxpayer is paying for 1,200 flying hours per year. If those per hour costs are increased at the max rate of 11% as stated....that becomes a darn nice rate....especially when all the other costs are factored in.
Throw in the cost of the bases, fuel, personnel, retirements, workman's compensation....depreciation...all of the costs and one sees a much different set of numbers.
The private sector is the correct place for firefighting aircraft to come from....in that they can be used for other work when not needed for fires and can be used in jurisdictions other than just the one that owns them if publically owned.
Commerical operators employ people that pay taxes...and pay property taxes...fuel taxes...payroll taxes...out of proceeds earned from their services. Public Agencies only spend tax money....that comes from private business and private citizens....and that is bad business if the government is doing something that private business can do.
As these public agencies grow their own airforces...the assets within the private sector disappear....and in times of crisis are then not available to respond to disasters.
You take away fire work from commerical operators....and sooner or later...they will wither and die on the vine.
The Firehawks are an expenditure that only public agencies can afford in that they do not have to make a profit
The most cost effective method of fighting wildfires is prevention followed by aggressive suppression before the fires develop any size. That has been proven by the disastrous fires a few years ago when the CDF elected not to send aircraft as it was approaching dark and the fire took off overnight and nearly burned down Southern California.
Anytime a public agency starts telling me how cost effective they are....I know someone is lying.
Last edited by SASless; 24th Sep 2005 at 21:48.
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Nick
Are the FireHawks able to be put on the civil register or are they under the restricted category??
I would be interested to hear from any of the pilots who fly the FireHawk.
Are the FireHawks able to be put on the civil register or are they under the restricted category??
I would be interested to hear from any of the pilots who fly the FireHawk.
I'm not sure about the system in the US but in Australia the S70C should be able to be registed as the C model was for civil use and for sale to countries with problems getting military versions eg; China, Taiwan, Hong Kong, though the main problem would lie in the spare parts supply as with only about 30 or so C models build any part available are actually for UH60 /S70A so the problem of military parts on civil machines rears its head.
The problem of maintenance , yes the Blackhawk is a high maintenance aircraft but not through Sikorsky's doing , if It was operated and maintained along the lines of most civil Helos, the maintenance would be greatly reduced, I worked on Blackhawks for 5 years and have worked on Super Pumas for 7 years now and I know which is easier to maintain and it aint the Super Pussy!!
If you look in Europe the average Super Puma flys well over 1000 hrs per year while a military S Puma is lucky to do 500 if you carried out the maintenance on a civil macine like a military one it would be on the ground more than it flys , a military 500hrly i have seen with Swedish, French and German S Pumas has taken up to 6-8 weeks while a civil one will be lucky to be down for a week or the serviceing is broken into zones for progresive maintenance, the maintenance is not to a lesser standard than the military operators, but the military machines are over maintained and on differant maintenance systems ,I believe if the Firehawk was maintained in a staggered maintenance system like cvil machines and not based on the US army system the costing would be lower and servicability higher. I think the Firehawk is a great Helo but unfortunatly there are only military operators of the Blackhawk family in general and unlike the S Puma which has a large civil as well as military operating base there is not the experiance base to draw on for civil use
The problem of maintenance , yes the Blackhawk is a high maintenance aircraft but not through Sikorsky's doing , if It was operated and maintained along the lines of most civil Helos, the maintenance would be greatly reduced, I worked on Blackhawks for 5 years and have worked on Super Pumas for 7 years now and I know which is easier to maintain and it aint the Super Pussy!!
If you look in Europe the average Super Puma flys well over 1000 hrs per year while a military S Puma is lucky to do 500 if you carried out the maintenance on a civil macine like a military one it would be on the ground more than it flys , a military 500hrly i have seen with Swedish, French and German S Pumas has taken up to 6-8 weeks while a civil one will be lucky to be down for a week or the serviceing is broken into zones for progresive maintenance, the maintenance is not to a lesser standard than the military operators, but the military machines are over maintained and on differant maintenance systems ,I believe if the Firehawk was maintained in a staggered maintenance system like cvil machines and not based on the US army system the costing would be lower and servicability higher. I think the Firehawk is a great Helo but unfortunatly there are only military operators of the Blackhawk family in general and unlike the S Puma which has a large civil as well as military operating base there is not the experiance base to draw on for civil use
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"BTW That pretty Huey of yours weighs 10,000 lbs doesn't it? Firehawk could load and drop one every three minutes, huh?"
Humm... someone from GE told me that the CT-7 engine was never evaluated for RHL operations, and threatened turning my company into the FAA if we ever operated an aircraft with the CT-7 engines performing RHL operations....
How does the Firehawk do that?
Does the S92 TC limitation for 4 lifts an hour have anything to do with the engine design?
"R00024BO Revision 4 Sikorsky Model S-92A April 26, 2005"
"NOTE 10 External lift operations limited to 4 lifts per hour."
The S92 and the Firehawk share the same basic engine family right? One is the commercial version, and one is a military version.
Do the TM's for the engine in the Firehawk address RHL?
Humm... someone from GE told me that the CT-7 engine was never evaluated for RHL operations, and threatened turning my company into the FAA if we ever operated an aircraft with the CT-7 engines performing RHL operations....
How does the Firehawk do that?
Does the S92 TC limitation for 4 lifts an hour have anything to do with the engine design?
"R00024BO Revision 4 Sikorsky Model S-92A April 26, 2005"
"NOTE 10 External lift operations limited to 4 lifts per hour."
The S92 and the Firehawk share the same basic engine family right? One is the commercial version, and one is a military version.
Do the TM's for the engine in the Firehawk address RHL?
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Rotormatic and SASless,
You started this stuff the last time Firehawk was discussed, and you were told you were wrong then, too. I guess your selective memory only remembers what it wants to, huh?
The engines on the Firehawk are just fine, thank you. They are part of the TAP package.
Oogle, the aircraft is certified as Restricted catagory, as it is not FAA certified to a normal catagory. It is operated by LA County, who are public use, and therefore need no certificate at all, anyway. They operate it under its flight manual, of course.
The sensitivity that SASless and rotormatic show is the jealosy that some operators have when public entities assume tasks that they think they can charge for. They do not want to have cities, counties or states operate, rather they want to have contracts to do that work.
Most US cities have police and fire professionals who are publicl employees. Having a county owned fire/rescue helicopter is just like that, but not good enough for rotormatic or SASless, whose jealousy shines through in their posts.
My son flys a government-owned Army helicopter in Iraq. Why don't you bid on that job, guys? I don't hear you grubbing for that contract. Give LA County a break, they are doing a tough job.
You started this stuff the last time Firehawk was discussed, and you were told you were wrong then, too. I guess your selective memory only remembers what it wants to, huh?
The engines on the Firehawk are just fine, thank you. They are part of the TAP package.
Oogle, the aircraft is certified as Restricted catagory, as it is not FAA certified to a normal catagory. It is operated by LA County, who are public use, and therefore need no certificate at all, anyway. They operate it under its flight manual, of course.
The sensitivity that SASless and rotormatic show is the jealosy that some operators have when public entities assume tasks that they think they can charge for. They do not want to have cities, counties or states operate, rather they want to have contracts to do that work.
Most US cities have police and fire professionals who are publicl employees. Having a county owned fire/rescue helicopter is just like that, but not good enough for rotormatic or SASless, whose jealousy shines through in their posts.
My son flys a government-owned Army helicopter in Iraq. Why don't you bid on that job, guys? I don't hear you grubbing for that contract. Give LA County a break, they are doing a tough job.
Last edited by NickLappos; 27th Sep 2005 at 20:32.
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National Aeronautics and Space Administration
Washington, DC 20546–0001
And
U.S. Army Research Laboratory
Adelphi, Maryland 20783–1145
Simulation of Crack Propagation in Engine Rotating Components Under Variable
Amplitude Loading
The crack propagation life of tested specimens has been repeatedly shown to strongly depend on the loading history. Overloads and extended stress holds at temperature can either retard or accelerate the crack growth rate. Therefore, to accurately predict the crack
propagation life of an actual component, it is essential to approximate the true loading history.
In military rotorcraft engine applications, the loading profile (stress amplitudes, temperature, and number of excursions) can vary significantly depending on the type of mission flown.
To accurately assess the durability of a fleet of engines, the crack propagation life distribution of a specific component should account for the variability in the missions performed (proportion of missions flown and sequence). In this report, analytical and
experimental studies are described that calibrate/validate the crack propagation prediction capability for a disk alloy under variable amplitude loading. A crack closure based model was adopted to analytically predict the load interaction effects. Furthermore, a
methodology has been developed to realistically simulate the actual mission mix loading on a fleet of engines over their lifetime.
A sequence of missions is randomly selected and the number of repeats of each mission in the sequence is determined assuming a Poisson distributed random variable with a given mean occurrence rate. Multiple realizations of random mission histories are generated in this manner and are used to produce stress, temperature, and time points for fracture mechanics calculations.
The result is a cumulative distribution of crack propagation lives for a given, life limiting, component location. This information can be used to determine a safe
retirement life or inspection interval for the given location.
Several assumptions have been made to simplify the FASTRAN II simulation and to fill in for certain unknowns about the actual usage of the engine. First, it was assumed that the engines are ‘pooled’ at the depot. By this it is meant that an engine returned to the depot for maintenance will not necessarily return to the original ‘owner’ but will go to the first unit requiring an engine. This allows us to model the selection of each block of missions with an appropriately partitioned uniform random variable.
The probability of selecting a particular mission and ambient condition is directly linked to the fraction of time the engine is expected to spend performing that mission/ambient condition combination as described by the Army mission mix specification
Another, and perhaps oversimplifying, assumption is that, while stationed with a unit, the aircraft will perform one mission exclusively. For example, aircraft stationed at a training facility perform only the training mission. It was also assumed that the block length (number of missions between removal of the engines for overhaul at the depot) could be modeled as a Poisson process. The purpose of using a Poisson distributed random variable, as opposed to a fixed block length, was to more closely model the
actual engine usage (the T700 has no scheduled overhaul interval).
Summary and Conclusions
The FASTRAN II crack propagation analysis code, which is based on the crack closure model, accurately predicts crack propagation in surface cracked Kb bar specimens under variable amplitude loading.
A method of estimating crack propagation life distribution of helicopter engine rotating components subjected to thirty different missions of varying severity, length, and probability of occurrence, has been developed. This method utilizes several random variables to generate simulated engine histories that are then fed into the FASTRAN II crack propagation analysis code.
There is a direct correlation between the mean number of missions between removal for
inspection/overhaul and the variance in the predicted crack propagation lifetimes. Extra caution is therefore necessary when determining the retirement life or a safe inspection interval for critical rotating components. A more accurate accounting of the actual usage of the engines would also seem prudent.
Washington, DC 20546–0001
And
U.S. Army Research Laboratory
Adelphi, Maryland 20783–1145
Simulation of Crack Propagation in Engine Rotating Components Under Variable
Amplitude Loading
The crack propagation life of tested specimens has been repeatedly shown to strongly depend on the loading history. Overloads and extended stress holds at temperature can either retard or accelerate the crack growth rate. Therefore, to accurately predict the crack
propagation life of an actual component, it is essential to approximate the true loading history.
In military rotorcraft engine applications, the loading profile (stress amplitudes, temperature, and number of excursions) can vary significantly depending on the type of mission flown.
To accurately assess the durability of a fleet of engines, the crack propagation life distribution of a specific component should account for the variability in the missions performed (proportion of missions flown and sequence). In this report, analytical and
experimental studies are described that calibrate/validate the crack propagation prediction capability for a disk alloy under variable amplitude loading. A crack closure based model was adopted to analytically predict the load interaction effects. Furthermore, a
methodology has been developed to realistically simulate the actual mission mix loading on a fleet of engines over their lifetime.
A sequence of missions is randomly selected and the number of repeats of each mission in the sequence is determined assuming a Poisson distributed random variable with a given mean occurrence rate. Multiple realizations of random mission histories are generated in this manner and are used to produce stress, temperature, and time points for fracture mechanics calculations.
The result is a cumulative distribution of crack propagation lives for a given, life limiting, component location. This information can be used to determine a safe
retirement life or inspection interval for the given location.
Several assumptions have been made to simplify the FASTRAN II simulation and to fill in for certain unknowns about the actual usage of the engine. First, it was assumed that the engines are ‘pooled’ at the depot. By this it is meant that an engine returned to the depot for maintenance will not necessarily return to the original ‘owner’ but will go to the first unit requiring an engine. This allows us to model the selection of each block of missions with an appropriately partitioned uniform random variable.
The probability of selecting a particular mission and ambient condition is directly linked to the fraction of time the engine is expected to spend performing that mission/ambient condition combination as described by the Army mission mix specification
Another, and perhaps oversimplifying, assumption is that, while stationed with a unit, the aircraft will perform one mission exclusively. For example, aircraft stationed at a training facility perform only the training mission. It was also assumed that the block length (number of missions between removal of the engines for overhaul at the depot) could be modeled as a Poisson process. The purpose of using a Poisson distributed random variable, as opposed to a fixed block length, was to more closely model the
actual engine usage (the T700 has no scheduled overhaul interval).
Summary and Conclusions
The FASTRAN II crack propagation analysis code, which is based on the crack closure model, accurately predicts crack propagation in surface cracked Kb bar specimens under variable amplitude loading.
A method of estimating crack propagation life distribution of helicopter engine rotating components subjected to thirty different missions of varying severity, length, and probability of occurrence, has been developed. This method utilizes several random variables to generate simulated engine histories that are then fed into the FASTRAN II crack propagation analysis code.
There is a direct correlation between the mean number of missions between removal for
inspection/overhaul and the variance in the predicted crack propagation lifetimes. Extra caution is therefore necessary when determining the retirement life or a safe inspection interval for critical rotating components. A more accurate accounting of the actual usage of the engines would also seem prudent.
Years ago I worked on a 214ST (sn 28102) with Lloyd Helicopters in Australia , before Lloyds got the a/c it was used for Logging in New Zealand , supposedly without the knowledge of Bell or GE, because before the a/c was used for offshore the engines were replaced by GE and all the dynamic system went back to Bell for o/haul. When I asked about the engines as i'd worked on Blackhawks which may to multiple lifts in a short time , I was told that the CT7 was not approved for high lift cycles unlike the CT58 which was and the T700 was military and under a differant set of rules. Has this changed with the CT7-6/8 .
Nick, I actualy worked on 214ST\'s in Australia and Europe for a few years and it is my second favorite helo after the Blackhawk and I much prefer the ST to the Super Puma or S76.
Nick, I actualy worked on 214ST\'s in Australia and Europe for a few years and it is my second favorite helo after the Blackhawk and I much prefer the ST to the Super Puma or S76.
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Nick: Wake up! Sasless and Rotormatic are right on. The government needs to stay out of the commercial helicopter business. We can't afford them. Have you turned your TV on yet and watched the Army Helicopters moving the sand bags? Last weekend we watched one of Carson's S-61 lap the entire field every turn. If I am a tax payer I want the S-61. Save the Army for war which is what they are suppose to be doing. Did you see the Army with the water bucket? I think they close their eyes before the drop. Not their fault but it's not what they are trained for. The government needs to stay out of the EMS and Fire business. Leave it to the pros.
I wish your son the best in Iraq. I can also tell you some are bidding on contracts in Iraq. And yes there are privately owned Gunships......
Open your eyes!
I wish your son the best in Iraq. I can also tell you some are bidding on contracts in Iraq. And yes there are privately owned Gunships......
Open your eyes!
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Brainerd Helicopters out of Florida operate two S-70s on US Forest Service CWN contracts. They don't have tanks fitted as far as I know. Everytime I've worked with them, they have been using a Bambi bucket/long line with a video camera/cockpit screen for bucket work.
The story I was told, as near as I can remember, is that one of the aircraft came from the Sultan of Brunei (or one of his daughters) and the other was came from the Queen of England (via an engine manufacturer who was using it to test their engines for a possible engine alternative)
The story I was told, as near as I can remember, is that one of the aircraft came from the Sultan of Brunei (or one of his daughters) and the other was came from the Queen of England (via an engine manufacturer who was using it to test their engines for a possible engine alternative)
Nick,
If I am so wrong....produce that Excel spread sheet with the cost data I asked for. I am not from Missouri...but they have the right idea...."Show Me!".
I am not jealous of the Guvmint and their fancy helicopters...but I am damn sure not inclined to look favorably at the guvmint using my tax dollars to compete with private business.
The police and fire department are standard government operations....usually because it cannot be done effectively by private industry and in the case of the Police...require government powers that cannot be delegated to private business.
Forest fire fighting...brush fire fighting...using helicopters and airplanes is and should be a business done by private industry. SAR can be done by private enterprise....case in point is Bristow Helicopters in the UK undercontract to the Coastguard there. I would suggest with the pisspoor SAR coverage offered in the Gulf of Mexico by our USCG....we should do the same thing there...hire civilians.
There is no way a government run operation dedicated solely to firefighting can be as cost effective as private industry.....prove it to me otherwise by posting your cost analysis.
As Mustang Pilot rightly states....watching the video of Army Blackhawks and Chinooks slinging those big white bags of dirt/rocks/concrete to the levee's made my heart hurt. A total waste of assets......the Blackhawk fighting the building fire along with the three fire boats was a real study in frustration.
Those two scenes were plainly obivious the wrong crews and aircraft were dedicated to the task....no insult to the crews...they were doing their best but were not experienced or equipped to do that work. Civilian longline pilots simply out work the military when it comes to specialized flying that the civilians are doing on a daily basis and the military rarely does and then does it poorly to begin with.
If I am so wrong....produce that Excel spread sheet with the cost data I asked for. I am not from Missouri...but they have the right idea...."Show Me!".
I am not jealous of the Guvmint and their fancy helicopters...but I am damn sure not inclined to look favorably at the guvmint using my tax dollars to compete with private business.
The police and fire department are standard government operations....usually because it cannot be done effectively by private industry and in the case of the Police...require government powers that cannot be delegated to private business.
Forest fire fighting...brush fire fighting...using helicopters and airplanes is and should be a business done by private industry. SAR can be done by private enterprise....case in point is Bristow Helicopters in the UK undercontract to the Coastguard there. I would suggest with the pisspoor SAR coverage offered in the Gulf of Mexico by our USCG....we should do the same thing there...hire civilians.
There is no way a government run operation dedicated solely to firefighting can be as cost effective as private industry.....prove it to me otherwise by posting your cost analysis.
As Mustang Pilot rightly states....watching the video of Army Blackhawks and Chinooks slinging those big white bags of dirt/rocks/concrete to the levee's made my heart hurt. A total waste of assets......the Blackhawk fighting the building fire along with the three fire boats was a real study in frustration.
Those two scenes were plainly obivious the wrong crews and aircraft were dedicated to the task....no insult to the crews...they were doing their best but were not experienced or equipped to do that work. Civilian longline pilots simply out work the military when it comes to specialized flying that the civilians are doing on a daily basis and the military rarely does and then does it poorly to begin with.
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1-1. PURPOSE. This order prescribes how the Federal Aviation Administration (FAA) certifies restricted category aircraft. It applies to Aircraft Certification Service (AIR) personnel, Flight Standards Service personnel, anyone designated by the Administrator, and organizations associated with the certification process. This order details the responsibilities and procedures for certification of restricted category aircraft under Title 14 of the Code of Federal Regulations (14 CFR) § 21.25. It supplements Order 8110.4, Type Certification; Order 8120.2, Production Approvals and Certificate Management Procedures; and Order 8130.2, Airworthiness Certification of Aircraft and Related Products.
a. When the FAA certifies military-derived aircraft, the aircraft includes the airframe, engines, and propellers. The FAA does not award military engines and propellers stand-alone engine or propeller TCs.
4-12. LIFE-LIMITED PARTS. The applicant must determine and include all life limits and mandatory inspections in the airworthiness limitations section of the maintenance manuals. The FAA must approve the life limits and mandatory inspections. The existing limitations associated with the military usage can be applied to the special purpose, if the applicant shows such operation is equivalent to the military design specifications and how the military used the aircraft. The applicant must justify how the new special purpose usage conforms to the military loads and fatigue design objectives.
a. If the aircraft or engine load and fatigue spectra in the special purpose operating environment is not the same as that in the military, the applicant must develop the required data to substantiate and set appropriate airworthiness limitations. This would likely require the applicant to develop a fatigue or damage tolerance methodology.
b. The applicant should account for previous service history in terms of accumulated fatigue damage for each individual life-limited component, when determining fatigue lives, inspection requirements, or any other limitation for the special purpose operation.
----
Inquiries were made of the major manufacturers, those whose products are routinely used
for fire suppression missions. The manufacturers were asked, did or does the fire fighting
mission, in and of itself have a significant influence in determining the fatigue lives of the
flight critical parts and/or components on your products? The following responses have
been paraphrased
Sikorsky’s engineering test pilot, with responsibility for their S-70 “Firehawk”
program, also stated that no special allowances had to be made relative to
the “fire fighting mission”.
a. When the FAA certifies military-derived aircraft, the aircraft includes the airframe, engines, and propellers. The FAA does not award military engines and propellers stand-alone engine or propeller TCs.
4-12. LIFE-LIMITED PARTS. The applicant must determine and include all life limits and mandatory inspections in the airworthiness limitations section of the maintenance manuals. The FAA must approve the life limits and mandatory inspections. The existing limitations associated with the military usage can be applied to the special purpose, if the applicant shows such operation is equivalent to the military design specifications and how the military used the aircraft. The applicant must justify how the new special purpose usage conforms to the military loads and fatigue design objectives.
a. If the aircraft or engine load and fatigue spectra in the special purpose operating environment is not the same as that in the military, the applicant must develop the required data to substantiate and set appropriate airworthiness limitations. This would likely require the applicant to develop a fatigue or damage tolerance methodology.
b. The applicant should account for previous service history in terms of accumulated fatigue damage for each individual life-limited component, when determining fatigue lives, inspection requirements, or any other limitation for the special purpose operation.
----
Inquiries were made of the major manufacturers, those whose products are routinely used
for fire suppression missions. The manufacturers were asked, did or does the fire fighting
mission, in and of itself have a significant influence in determining the fatigue lives of the
flight critical parts and/or components on your products? The following responses have
been paraphrased
Sikorsky’s engineering test pilot, with responsibility for their S-70 “Firehawk”
program, also stated that no special allowances had to be made relative to
the “fire fighting mission”.