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The engines on many light single-engine aircraft (e.g. Lycoming O-360). While variants and modest improvements have been made, it is still the same 1950s engine

The engines on many light single-engine aircraft (e.g. Lycoming O-360). While variants and modest improvements have been made, it is still the same 1950s engine at the core. Safety requirements have evolved massively since then, but if you keep making the same engine with modest changes it can grandfathered. Kind of makes you wonder if grandfathering should have a limit (e.g. 50 years?).

CydeWeys 8y ago
The Soyuz definitely counts too. It was designed in the 60s and hasn't changed too much since then. The craziest aspect of the Soyuz that makes it obvious how legacy it is is how its engines are ignited: https://www.popularmechanics.com/space/rockets/a19966/russia-actually-lights-it-rockets-with-a-giant-match/ https://www.popularmechanics.com/space/rockets/a19966/russia... You literally put something not too dissimilar from a wooden chair directly beneath the rocket nozzles, then set it on fire right before launch. When the rocket's engines start up, the fuel is ignited by the fire from the burning wood, and combustion begins. Now that's legacy. It's also reliable enough that they've never had to redesign it.
- bunderbunder 8y ago
  "Wooden chair" seems like a rather drastic oversimplification. Yeah, the bulk of the device, and its combustible material, is made of wood. But it's also got two igniters (for redundancy) and a sensor for ensuring that the device has successfully ignited. Some engineering thought went into this. Comparing it to putting a burning piece of furniture under the rocket nozzles makes the whole design sound a lot more jerry-rigged than it really is.
  - Xylakant 8y ago
    Notably, the ignition device, while seemingly low tech, works pretty much without flaws and fails safely. “This setup is not as simple as a regular match, but it is surprisingly reliable and has worked for six decades on hundreds of rockets” So why attempt to fix such a safety critical thing?
    - petschge 8y ago
      The one reason to go from external match sticks to internal ignition using hypergolic fuels is to be able to relight in flight after an engine shutdown.
      - bunderbunder 8y ago
        Yep. Which seems like a fairly unnecessary requirement for an expendable first stage. I'm no rocket engineer, but my guess would be that, if you're shutting down an engine at that stage in the flight, your only realistic options are going to be redirecting fuel to the remaining engines for a longer burn, or cutting all engines and activating the launch escape system. I can't imagine there's any practical reason to plan on shutting down and re-igniting engines during the first stage of a launch, and I also can't imagine trying to decide whether an engine is safe to re-light during the few seconds you'll have between when you executed the emergency shutdown and when it's time to jettison the first stage entirely.
a1369209993 8y ago
> Kind of makes you wonder if grandfathering should have a limit (e.g. 50 years?). That's not grandfathering. Grandfathering is "This engine was built before we made the law, so you can keep using it until it breaks."; what you're describing is just blatant selective enforcement.
- Scoundreller 8y ago
  What’s it called when the thing was designed before the law, and therefore allowed to be manufactured for eternity?
  - a1369209993 8y ago
    "Criminally[0] negligent duty-derelictive non-enforcement of safely regulations"? 0: or not-technically-criminally if they planned ahead well enough.
- Someone1234 8y ago
  The term "grandfathered" is used in FAA literature for both pre-date (literally) and the designed before a regulation came into being. The reason it exists is otherwise the FAA could release a new requirement that would halt a pre-existing production line that didn't meet it. > Because part 135 operators will have limited ETOPS operations, the FAA has decided to grandfather from today's rule all part 135 airplanes manufactured up to 8 years from the effective date of the rule. For purposes of airworthiness requirements, part 135 operators may use these airplanes in ETOPS without certification under § 25.1535. This is a change from the NPRM, which proposed grandfathering only those airplanes that were on an operator's operations specifications up to 8 years after the rule. Under the NPRM, they would then have had to remain on the operator's operations specifications to continue to operate ETOPS. https://www.federalregister.gov/documents/2007/01/16/07-39/extended-operations-etops-of-multi-engine-airplanes#h-28 https://www.federalregister.gov/documents/2007/01/16/07-39/e... > b. This Advisory Circular (AC) provides guidance to affected U.S. operators that operate aircraft outside the United States with aircraft that were never required to be noise certified. If you have such an aircraft, this AC outlines the noise certification requirement dates so you can confirm that your aircraft indeed pre-dates the requirements and should be considered acceptable. We use the term “grandfathered” for these aircraft. We strongly recommend operators of such aircraft to use the FAA form in Appendix 1 that includes a grandfather clause. https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/99995 https://www.faa.gov/regulations_policies/advisory_circulars/... > These seats should provide adequate vision to the pilot's panel and forward windows in visual system models. "Grandfather rights" prevail on previously approved simulators; however, efforts should be made to improve surveillance visibility. These observer seats need not represent the aircraft seats. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_121-14B.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
Scoundreller 8y ago
Exactly. If the new standards are so extreme that it’s uneconomical to build to, it just makes old investments more valuable and impossible to enter the market.
- sgt101 8y ago
  Unless the old technology is ruled illegal. Which is both fair and appropriate and proportional if it means that people don't die.

CydeWeys 8y ago

The Soyuz definitely counts too. It was designed in the 60s and hasn't changed too much since then. The craziest aspect of the Soyuz that makes it obvious how legacy it is is how its engines are ignited: https://www.popularmechanics.com/space/rockets/a19966/russia-actually-lights-it-rockets-with-a-giant-match/ https://www.popularmechanics.com/space/rockets/a19966/russia... You literally put something not too dissimilar from a wooden chair directly beneath the rocket nozzles, then set it on fire right before launch. When the rocket's engines start up, the fuel is ignited by the fire from the burning wood, and combustion begins. Now that's legacy. It's also reliable enough that they've never had to redesign it.

bunderbunder 8y ago
"Wooden chair" seems like a rather drastic oversimplification. Yeah, the bulk of the device, and its combustible material, is made of wood. But it's also got two igniters (for redundancy) and a sensor for ensuring that the device has successfully ignited. Some engineering thought went into this. Comparing it to putting a burning piece of furniture under the rocket nozzles makes the whole design sound a lot more jerry-rigged than it really is.
- Xylakant 8y ago
  Notably, the ignition device, while seemingly low tech, works pretty much without flaws and fails safely. “This setup is not as simple as a regular match, but it is surprisingly reliable and has worked for six decades on hundreds of rockets” So why attempt to fix such a safety critical thing?
  - petschge 8y ago
    The one reason to go from external match sticks to internal ignition using hypergolic fuels is to be able to relight in flight after an engine shutdown.
    - bunderbunder 8y ago
      Yep. Which seems like a fairly unnecessary requirement for an expendable first stage. I'm no rocket engineer, but my guess would be that, if you're shutting down an engine at that stage in the flight, your only realistic options are going to be redirecting fuel to the remaining engines for a longer burn, or cutting all engines and activating the launch escape system. I can't imagine there's any practical reason to plan on shutting down and re-igniting engines during the first stage of a launch, and I also can't imagine trying to decide whether an engine is safe to re-light during the few seconds you'll have between when you executed the emergency shutdown and when it's time to jettison the first stage entirely.

a1369209993 8y ago

> Kind of makes you wonder if grandfathering should have a limit (e.g. 50 years?). That's not grandfathering. Grandfathering is "This engine was built before we made the law, so you can keep using it until it breaks."; what you're describing is just blatant selective enforcement.

Scoundreller 8y ago
What’s it called when the thing was designed before the law, and therefore allowed to be manufactured for eternity?
- a1369209993 8y ago
  "Criminally[0] negligent duty-derelictive non-enforcement of safely regulations"? 0: or not-technically-criminally if they planned ahead well enough.
Someone1234 8y ago
The term "grandfathered" is used in FAA literature for both pre-date (literally) and the designed before a regulation came into being. The reason it exists is otherwise the FAA could release a new requirement that would halt a pre-existing production line that didn't meet it. > Because part 135 operators will have limited ETOPS operations, the FAA has decided to grandfather from today's rule all part 135 airplanes manufactured up to 8 years from the effective date of the rule. For purposes of airworthiness requirements, part 135 operators may use these airplanes in ETOPS without certification under § 25.1535. This is a change from the NPRM, which proposed grandfathering only those airplanes that were on an operator's operations specifications up to 8 years after the rule. Under the NPRM, they would then have had to remain on the operator's operations specifications to continue to operate ETOPS. https://www.federalregister.gov/documents/2007/01/16/07-39/extended-operations-etops-of-multi-engine-airplanes#h-28 https://www.federalregister.gov/documents/2007/01/16/07-39/e... > b. This Advisory Circular (AC) provides guidance to affected U.S. operators that operate aircraft outside the United States with aircraft that were never required to be noise certified. If you have such an aircraft, this AC outlines the noise certification requirement dates so you can confirm that your aircraft indeed pre-dates the requirements and should be considered acceptable. We use the term “grandfathered” for these aircraft. We strongly recommend operators of such aircraft to use the FAA form in Appendix 1 that includes a grandfather clause. https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/99995 https://www.faa.gov/regulations_policies/advisory_circulars/... > These seats should provide adequate vision to the pilot's panel and forward windows in visual system models. "Grandfather rights" prevail on previously approved simulators; however, efforts should be made to improve surveillance visibility. These observer seats need not represent the aircraft seats. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_121-14B.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/...

Scoundreller 8y ago

Exactly. If the new standards are so extreme that it’s uneconomical to build to, it just makes old investments more valuable and impossible to enter the market.

sgt101 8y ago
Unless the old technology is ruled illegal. Which is both fair and appropriate and proportional if it means that people don't die.