S97 Raider
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CTR- I hope you'll pardon the fact that I'm not an Army pilot, but here is how Lockheed-Martin-Sikorsky management apparently sees the S-97 being applied to the US Army's future rotorcraft needs.
https://www.flightglobal.com/news/ar...er-fvl-422666/
"The 5,00kg (11,000lb) pusher-prop assault platform – which achieves speed and agility via Sikorsky’s X2-derived advanced rigid rotor and drive system – is already flying at West Palm Beach, Florida, and would be Lockheed’s go-to offer if the army were to launch an Armed Aerial Scout follow-on through its next-generation first future vertical lift (FVL) rotorcraft acquisition plan.......Sikorsky president Dan Schultz told Flightglobal after a media briefing at the Heli-Expo show that the Raider fits nicely within CS1, and that Lockheed-Sikorsky will respond in kind."
https://www.flightglobal.com/news/ar...er-fvl-422666/
"The 5,00kg (11,000lb) pusher-prop assault platform – which achieves speed and agility via Sikorsky’s X2-derived advanced rigid rotor and drive system – is already flying at West Palm Beach, Florida, and would be Lockheed’s go-to offer if the army were to launch an Armed Aerial Scout follow-on through its next-generation first future vertical lift (FVL) rotorcraft acquisition plan.......Sikorsky president Dan Schultz told Flightglobal after a media briefing at the Heli-Expo show that the Raider fits nicely within CS1, and that Lockheed-Sikorsky will respond in kind."
@CTR
F-16 is single engine
F-35 is single engine.
To answer your question in part, engine reliability appears to have gotten to where the risk is at an acceptable level from the "whole system" design perspective. Kicking a few thoughts around, Comanche had two engines. How that figured into the ultimate decision to cancel that program I do not know (if it figured at all).
F-16 is single engine
F-35 is single engine.
To answer your question in part, engine reliability appears to have gotten to where the risk is at an acceptable level from the "whole system" design perspective. Kicking a few thoughts around, Comanche had two engines. How that figured into the ultimate decision to cancel that program I do not know (if it figured at all).
Thanks for thoughts, but still wanting Army Pilot answer
RR and LW,
Thank you for your responses, but really would like an Army pilot POV. Especially in light of the Army's dropping all single engine training helicopters and auto to ground training.
As far as any comparisons with fighter aircraft, the missions and environments are completely different. The S-97 will be down and dirty where a momentary engine failure and contact with said dirt are a seconds away. With the exception of the Ti tub A-10 (with two engines), even in ground support the F-16 and F-35 live up high where there is time to relight an engine failure.
Also, the S-97 will not be equipped with six ejection seats for the passengers in economy seating.
Cheers
CTR
Thank you for your responses, but really would like an Army pilot POV. Especially in light of the Army's dropping all single engine training helicopters and auto to ground training.
As far as any comparisons with fighter aircraft, the missions and environments are completely different. The S-97 will be down and dirty where a momentary engine failure and contact with said dirt are a seconds away. With the exception of the Ti tub A-10 (with two engines), even in ground support the F-16 and F-35 live up high where there is time to relight an engine failure.
Also, the S-97 will not be equipped with six ejection seats for the passengers in economy seating.
Cheers
CTR
Hooah, and such.
Lone Wolf, since you flew for the USN, you may already know the Navy is keeping their TH-57 single engine trainers and continuing to teach autorotation to ground techniques. Seems smart.
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Lonewolf_50 brings up a good point in post #143 about improved engine reliability. The S-97 currently uses the YT706, but I'm sure Sikorsky intends to use the ITEP engine (GE3000 or HPW3000) when it becomes available. The ITEP engine is designed to replace the T700 on existing airframes.
Two goals of the ITEP engine program were improved performance at a wide speed range, and greater tolerance to ingestion of debris/sand. Page 2 of this ATEC white paper briefly discusses these issues.
Two goals of the ITEP engine program were improved performance at a wide speed range, and greater tolerance to ingestion of debris/sand. Page 2 of this ATEC white paper briefly discusses these issues.
Riff-Raff,
Thank you for posting the link on the dual spool engine technology. I believe the section on page two you are referencing is
" Because there are two rotating assemblies that can vary in speed,
the engine more capable and better at handling sand ingestion than a single spool engine, which would incur much greater degradation to engine components. As a result, a dual-spool design fosters greater time-on-wing and less down time for maintenance."
However what the text is referring to is Maintenance Reliability, versus Critical Failure Reliability. Maintenance Reliability covers mean time between overhauls and required scheduled maintenance. Critical Failure Reliability is a measure of the probability of a failure that can cause the loss of an flight critical component. In a single engine aircraft, loss of engine function classifies as a critical failure for many flight conditions.
Thank you for posting the link on the dual spool engine technology. I believe the section on page two you are referencing is
" Because there are two rotating assemblies that can vary in speed,
the engine more capable and better at handling sand ingestion than a single spool engine, which would incur much greater degradation to engine components. As a result, a dual-spool design fosters greater time-on-wing and less down time for maintenance."
However what the text is referring to is Maintenance Reliability, versus Critical Failure Reliability. Maintenance Reliability covers mean time between overhauls and required scheduled maintenance. Critical Failure Reliability is a measure of the probability of a failure that can cause the loss of an flight critical component. In a single engine aircraft, loss of engine function classifies as a critical failure for many flight conditions.
I am also aware that NAVAIR has not done the greatest job ever of finding a follow on helicopter trainer even though Bell support is getting more expensive all the time ... but that's a different topic. The TH-57 is in some ways a victim of its own success: the way they fly them in Milton, with hot pumps and multiple student events per cycle, they get fantastic output for input. Nothing that follows them is likely to be even close to as inexpensive per flight hour. With the Navy's pilot force 50% and greater being helicopter sorts, boosting that system cost has some unattractive impacts on budgets that keep shrinking. Sorry for the derail. I learned to auto in a TH-57. Good bird.
When is Enough Enough?
It is amazing how the conversation tends to make a full swing back to a discussion of single vs twin engine. In the early phases of the LHX program, that later became the AH-66 Comanche program there were many discussions surrounding the required number of engines. I for one supported the side that would have opted for a single. Having flown more than 3 and a ½ years and many flight hours at HT-18 in the venerable H-1 series and many day and night operations in the B-206L-4 I have more than enough confidence that robustly designed single engine aircraft would be a safe cost effective solution for many missions. After almost 20 years in development the Comanche had grown in complexity and cost that ultimately resulted in its extinction.
The governments and military’s desires for aircraft requirements that do much more than what is typically required for 90+ percent of missions drives cost and complexity to unattainable levels. The Canadian S-92 and the VH-71 are two examples where extreme mission requirements resulted in program delays or cancellation. In the meantime day to day operations continue safely in 30 and 40 year old VH-3s OH-58s and even the OH-6 single engine Little Birds. The big question is when is enough enough?
The governments and military’s desires for aircraft requirements that do much more than what is typically required for 90+ percent of missions drives cost and complexity to unattainable levels. The Canadian S-92 and the VH-71 are two examples where extreme mission requirements resulted in program delays or cancellation. In the meantime day to day operations continue safely in 30 and 40 year old VH-3s OH-58s and even the OH-6 single engine Little Birds. The big question is when is enough enough?
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CTR- In your post of March 7, you voiced concern about "momentary engine failure" when the S-97 would be flying close to ground level. What type of event do you see causing a momentary engine failure? All of the flight critical systems/components in a rotorcraft drivetrain are designed for a level of operational fault tolerance that takes into account operating conditions and crew safety.
If you have time I'd recommend reading the RFP solicitation docs for the ITEP engine. Lots of stuff on what the Army wants with regards to the engine FMEA (Failure Modes and Effects Analysis) and identifying Critical Items.
https://www.fbo.gov/utils/view?id=91...274ed48b9acad6
https://www.fbo.gov/utils/view?id=e2...e8fea63b103d57
If you have time I'd recommend reading the RFP solicitation docs for the ITEP engine. Lots of stuff on what the Army wants with regards to the engine FMEA (Failure Modes and Effects Analysis) and identifying Critical Items.
https://www.fbo.gov/utils/view?id=91...274ed48b9acad6
https://www.fbo.gov/utils/view?id=e2...e8fea63b103d57
Sultan,
As an ex-Sikorsky guy I had also wondered. It has been pretty quiet even from my old X2 buddies. I recently heard they have been quietly making progress. No doubt they are keeping it under wraps to protect themselves from your scathing criticism. It is an awesome machine.
As an ex-Sikorsky guy I had also wondered. It has been pretty quiet even from my old X2 buddies. I recently heard they have been quietly making progress. No doubt they are keeping it under wraps to protect themselves from your scathing criticism. It is an awesome machine.
IFMU
Sikorsky was putting out press releases if they painted it or added a new fairing. I think if they flew beyond the boundaries of the field it would be splashed everywhere for meer mortals to behold. Getting old, I forgot first flight was May 2015, so 15 months with no reported progress.
The Sultan
Sikorsky was putting out press releases if they painted it or added a new fairing. I think if they flew beyond the boundaries of the field it would be splashed everywhere for meer mortals to behold. Getting old, I forgot first flight was May 2015, so 15 months with no reported progress.
The Sultan
Sikorsky Priorities
Perhaps envelope expansion for the S-97 is currently pretty low on the list of Sikorsky priorities?
Engineering manpower is a choke point for all aerospace companies.
The CH-53K, Canadian Cyclone, and FVL SB>1 are all government funded programs with contracted progress payments and performance penalties.
The S-97 is not part of any government contract, currently has no customers, and is fully funded by Sikorsky and teaming suppliers.
It is no surprise to me that the S-97 is on hold. If I were Sikorsky management, all of the S-97 engineering possible would be redeployed to money generating programs.
The real question on my mind is where are the expected press releases for the SB>1 build progress? But that could be it's own thread.
Engineering manpower is a choke point for all aerospace companies.
The CH-53K, Canadian Cyclone, and FVL SB>1 are all government funded programs with contracted progress payments and performance penalties.
The S-97 is not part of any government contract, currently has no customers, and is fully funded by Sikorsky and teaming suppliers.
It is no surprise to me that the S-97 is on hold. If I were Sikorsky management, all of the S-97 engineering possible would be redeployed to money generating programs.
The real question on my mind is where are the expected press releases for the SB>1 build progress? But that could be it's own thread.
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Originally Posted by IFMU
I have no idea what they are up to on the Defiant.
Boeing Future Vertical Lift chief Pat Donnelly said most components of the rigid-rotor coaxial compound helicopter are already under construction and will start coming together later this year.
Donnelly says Swift Engineering of San Clemente, California will ship the core composite structure to Boeing's AH-64 Apache production plant in Mesa, Arizona by mid-year for design limit testing, before it continues east to Sikorsky’s rotorcraft facility in West Palm Beach, Florida in the September timeframe.
“The aircraft will be stuffed with all the hydraulics and mechanical components,” says Donnelly. “It’ll undergo final assembly and we’ll fly it down there.”
Donnelly says Swift Engineering of San Clemente, California will ship the core composite structure to Boeing's AH-64 Apache production plant in Mesa, Arizona by mid-year for design limit testing, before it continues east to Sikorsky’s rotorcraft facility in West Palm Beach, Florida in the September timeframe.
“The aircraft will be stuffed with all the hydraulics and mechanical components,” says Donnelly. “It’ll undergo final assembly and we’ll fly it down there.”
“We’re in the process of building a one-off flying demonstrator," says Jeff Shelton, senior manager for JMR/FVL global sales and marketing. "We are in the manufacturing stage now, and will start assembling later this year at West Palm Beach in Florida, where the flight testing will also take place.”
The aircraft will be flown at the end of next year and into 2019.
The aircraft will be flown at the end of next year and into 2019.
I have see the words. But are there any photos of Defiant hardware?
"Quietly making progress is not the same as on hold" I concur, I have been on programs where company priorities robbed me of most of my team. The hand full of us that remained achieved many innovations while leadership concentrated their micro managing and demands for daily status reports on priority programs. But our program schedule became greatly stretched. I believe the same is occurring on the S-97.
"Quietly making progress is not the same as on hold" I concur, I have been on programs where company priorities robbed me of most of my team. The hand full of us that remained achieved many innovations while leadership concentrated their micro managing and demands for daily status reports on priority programs. But our program schedule became greatly stretched. I believe the same is occurring on the S-97.
7 is not part of any government contract, currently has no customers, and is fully funded by Sikorsky and teaming suppliers.
Occam's razor suggests technical issues.
