FAA involvement with KC46 certification ?

[rb1957]

Why is the FAA so involved with the certification of the KC-46 ? Why is Boeing getting an STC for it ?? ... I guess question 2 answers question 1 but then why get an STC for something that won't (?) be offered commercially ?

I'd've thought that the USAF would operate and control the types valid for refueling. An IOC would have a limited number of types approved to refuel, and as further types are validated then more types are approved.

I'd've thought the USAF would certify their own types.

another day in paradise, or is paradise one day closer ?

 

[VEBill]

Not exactly my area, but I wonder if it is related to the following?

FAA AC 20-169 page

PDF 20-169 - Guidance for Certification of Military and Special Mission Modifications and Equipment for Commercial Derivative Aircraft (CDA)

 

[rb1957]

thx, clearly relevant. It does say the obvious, that military airworthiness authority can ask for FAA support.

I'm sure this wasn't the model for earlier tankers (like KC135). It sounds like the USAF doesn't have confidence in itself.

another day in paradise, or is paradise one day closer ?

 

[VEBill]

I've noticed that the Military exception * is being diminished over time. Some may choose to describe this as the military bringing their own standards into better alignment with the civilian standards. I presume that it's because the modern more-technical approach to airspace management demands common technical standards, but it may also be related to the general move away from having military standards for everything. [Speculation Alert]

* E.g. Canadian Aviation Regulations (102.01) "These Regulations do not apply in respect of (a) military aircraft of Her Majesty in right of Canada when they are being manoeuvred under the authority of the Minister of National Defence;"

 

[rb1957]

yes, I've been hearing "why should we (USAF) take on the certification risk?".

I'm alittle surprised that the FAA took on the role ... how much do they know about air-to-air refueling ?
I'd've thought (clearly wrongly !) that the USAF would be SME for this task, would have understood the risks.

another day in paradise, or is paradise one day closer ?

 

[rb1957]

the latest article in Flight only raises my confusion ... the issues presented are operational not certification (IMHO) so the FAA should be in a position to issue the STC. The fact that the customer doesn't want the performance issues is a separate discussion. The two could (IMHO) be sensibly brought together if the USAF was certifying ('cause part of their certification could cover operational aspects).

another day in paradise, or is paradise one day closer ?

 

[dgapilot]

Keep in mind that Congress has pressed the military to purchase Commercial Derivative Aircraft because of the alleged cost savings. Whenever possible, each branch tries to get commercial aircraft and modify them. Each service has their own Airworthiness Office, but they all cooperate and can accept the others and the FAAs airworthiness determination. All the military services pay FAA to maintain the Military Certification Office, so while FAA is processing the STC, the Air Force is actually paying for it.

When the military buys a commercial airplane, they don't but the data developed for the original TC, so to modify it they would have to reverse engineer it. By going with FAA certification, the government actually saves money by processing the STC through the FAA rather than processing the modifications through the military engineering competencies. The contractor is in most cases the TC holder, but even if it isn't, the contractor is the one paying for the DERs and DARs and developing the certification data, not the government.

 

[WKTaylor]

This quirk is due to 'spares commonality' issues.

IF this acft was solely certificated by the USAF, then it would needs its own/independent supply train... logistics, maintenance, etc... much like the KC-135, E-3, etc... which is counter to expected cost savings if commercially certificated by FAA.

IF this is an FAA certificated aircraft then it may share spare parts/assys/components... engines, actuators, landing gear, control surfaces, etc... with other certificated aircraft drawing from the same spares pool. Example: Military acft typically use different hydraulic fluids and oils than commercial for a variety of reasons... such as synthetic hydrocarbon hydraulic oils... VS commercial acft which are certificated using only Skydrol hydraulic fluid.

MIL certification can be more rigorous/variable since military criteria are intended help an aircraft service in a hostile/combat environment [including battle damage]. IF this national air refueling asset even gets close to combat, then it is in the 'wrong place, at the wrong time'.

See MIL-HDBK-516 AIRWORTHINESS CERTIFICATION CRITERIA.

Unfortunately for the military, anyone doing work on a certificated aircraft will likely have to have special maintenance and engineering training/certification and/or an FAA mechanic's license.... with all the attendant paperwork and restrictions.

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[dgapilot]

For all the Navy CDAs, we use commercial providers, require Part 145 repair stations do most of the depot level work. Since most bases have access restrictions, the O level work is done by contractors and most of those contracts require an A&P certificate. We also require following FAA paperwork (337s) although they don't get sent to Ok City. While any military aircraft does not have to comply with the maintenance and inspection requirements of Parts 21,43, and 91, we add it into the contract. While they aren't bound to it by regulation, they are bound by contract requirements.

 

[Worldtraveller]

I am not involved with the KC46 in any way. However, I worked on the production line of the military's primary trainer, the T-6 (A, B & now C models) for over 8 years. That aircraft was a modified Pilatus (PC-9) and the certification was also coordinated through the FAA. In theory, that aircraft had a 'kit' modification that could be applied, and it could be sold for civilian use. I don't think it has been, but it's there.

For much of the application, especially since this aircraft is 'just' a trainer, it makes sense. There's little the aircraft does that a civilian aerobatic aircraft doesn't also do, so using the FAA/regulations for certification makes sense. In addition, as mentioned above, there are spares and logistics issues that give the program more flexibility.

 

[rb1957]

This just got (in my mind) even sillier ... from Flight ...
so the FAA certify the boom and drogue installation, but not it's use !? and the USAF certify the use of this equipment for aerial refueling.
and wasn't the latest delay (to STC) because the system misrepresented the fuel load transferred ??

The US Federal Aviation Administration has awarded the Boeing KC-46 Pegasus tanker a supplemental type certificate (STC), thus completing the type’s FAA certification process.

“To receive its STC, Boeing’s team completed a series of lab, ground and flight tests, which commenced in 2015,” says the airframer. “As part of the required flight testing, the team validated the KC-46’s boom and drogue aerial refueling systems met FAA certification criteria.”

Boeing completed STC flight tests in the first half of 2018.

The STC follows an Amended Type Certificate in December 2017 for the 767-2C aircraft on which the KC-46 is based. A US Air Force Military Type Certificate is expected “in the coming months,” adds Boeing.

The MTC covers systems that the FAA cannot certify, such as aerial refueling, defensive, and other military-specific systems, says Boeing.






another day in paradise, or is paradise one day closer ?

 

[Worldtraveller]

rb1957, that's typical of how the FAA operates with military programs. They help with the certification, then the OEM adds exemptions as needed to actually operate the aircraft in the designed manner. It's not silly, so much as practical considerations that the aircraft operates in an airspace with civilian traffic, over civilian areas, etc., and so much be expected to meet certain safe minimums, just like the commercial version. It's generally less expensive and slightly faster to use the FAA as a resource in this way, rather than trying to do everything separately, from the ground up.

But the FAA doesn't touch the operational aspect, except in specific requirements like placarding and safety equipment. I have worked similar programs as noted, but even on other special project aircraft, the FAA's role is similar. For instance, lots of border patrol and narcotics enforcement aircraft have various external sensors that are not standard. The operators will get FAA approval (STC) for the installation of this equipment, but will only get involved in the operational aspect as much as requiring it to fly 'limited category' and similar restrictions.

 

[rb1957]

I guess ...

I can see (very easily) that the FAA would issue an STC to cover the "kludged up" version of the 767 that is the KC46 (mixing and matching different structures from different 767 models). I guess they could get involved in the carriage of fuel, but all things related to operating the refueling system should IMHO be MTC'd. But I thought there were several FAA issues related to the refueling system ?

I work on special missions planes too, completely in the civil STC world (though I guess they could do things to the plane afterwards). I'm surprised that you can get an STC that allows you to turn off the nav/position/anti-collison lights ! That's something I thought you'd do outside the civilian STC.

But, meh ...

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