RAVN ex-RoKAF Hawk Mk 67 aircraft

[walbut]

As a retired BAE Hawk Flight Systems Design Authority, I was intrigued to see that there were a couple of ex-RoKAF Hawk Mk 67 aircraft, N504XX and N508XX operating out of Lakenheath and flying around my local area of East Yorkshire this afternoon. I am curious to know how the modifications to these aircraft were cleared, presumably at the instigation of their current operator RAVN. Have they been life extended beyond the original cleared 6000 flying hours and 20 years? I know the the RoKAF flew them very gently and they had very low fatigue consumption but I think they had quite high flying hours when they retired and they must be over 30 years old now. I had some interesting times doing the early customer acceptance work at BAE Systems Warton around 1993. Presumably they are operating on a USA experimental aircraft permit of some sort. Does anybody know how it was done?

[bobward]

I can't answer your technical questions I'm afraid. However, I can tell you that four jets turned up at the end of December 23. They started flying with the resident 48FW in early Jan 24.
Prior to that, Top Aces were operating three Alphajets and an A4 there, for, I assume, DACT missions. I'm not sure if the top Aces jets are still there though.

Hope this helps a bit.

[teeonefixer]

Reference "Fighter Control" website, there are only 2 Top Aces Alphajets there now, the A4 and other Alphas have returned to Germany.
They state that one of the ex-Korean Hawks appears to have been upgraded with an ELTA EL/M-2052 AESA Radar.and this may be the one registered NX508XX i.e. an experimental registration.
A question for CAeBR maybe?

[SLXOwft]

RAVN aero used to be know as AirUSA and have had the AESA / Link-16 modded Mk 67s for some time. Duck Dodgers made some interesting comments on them in the past https://www.pprune.org/military-aviation/641527-all-hawk-t1s-will-gone-31-march-2022-a-9.html?highlight=aesa#post11122039 (https://www.pprune.org/military-aviation/641527-all-hawk-t1s-will-gone-31-march-2022-a-9.html?highlight=aesa#post11122039)

They were discussed on this thread: https://www.pprune.org/military-aviation/656191-ravens-lakenheath.html#post11551141 , all the ones pictured appear to have radomes.

[CAEBr]

As stated above, US Air/RAVN have modified the jets to include the radar, presumably all four now at Lakenheath, not sure how many of their others have been similarly modded.
As Mk67s were built with the 100 series longer nose but kept the 60 series internal fit/equipment they were well suited to the mod compared to the T1/50/60 series fleets.
With regard to the clearance, they are indeed on a US civil experimental registration, and accepted in the UK under reciprocal arrangements which makes a mockery of the number of hoops that the long term Design Organisation has to jump through to modify and fly UK aircraft.
After US Airs' two early accidents, which included one ground fatality, the USN/USMC blocked any further contracts. I'm not sure quite what the USAF's stance was at that time but after a company name change they are now using them without any Design Organisation support or approval of life extension past that when they were certified for the RoKAF.

[fdr]

As a retired BAE Hawk Flight Systems Design Authority, I was intrigued to see that there were a couple of ex-RoKAF Hawk Mk 67 aircraft, N504XX and N508XX operating out of Lakenheath and flying around my local area of East Yorkshire this afternoon. I am curious to know how the modifications to these aircraft were cleared, presumably at the instigation of their current operator RAVN. Have they been life extended beyond the original cleared 6000 flying hours and 20 years? I know the the RoKAF flew them very gently and they had very low fatigue consumption but I think they had quite high flying hours when they retired and they must be over 30 years old now. I had some interesting times doing the early customer acceptance work at BAE Systems Warton around 1993. Presumably they are operating on a USA experimental aircraft permit of some sort. Does anybody know how it was done?

As stated above, US Air/RAVN have modified the jets to include the radar, presumably all four now at Lakenheath, not sure how many of their others have been similarly modded.
As Mk67s were built with the 100 series longer nose but kept the 60 series internal fit/equipment they were well suited to the mod compared to the T1/50/60 series fleets.
With regard to the clearance, they are indeed on a US civil experimental registration, and accepted in the UK under reciprocal arrangements which makes a mockery of the number of hoops that the long term Design Organisation has to jump through to modify and fly UK aircraft.
After US Airs' two early accidents, which included one ground fatality, the USN/USMC blocked any further contracts. I'm not sure quite what the USAF's stance was at that time but after a company name change they are now using them without any Design Organisation support or approval of life extension past that when they were certified for the RoKAF.

Before we have a repeat of the Shoreham discussion, the aircraft discussed here are FAA registered, are they not?

If so, then the requirement for the issue of their COA in 14CFR Part 21 is:

§21.185(b), which states:

Other aircraft. An applicant for a restricted category airworthiness certificate for an aircraft type certificated in the restricted category, that was either a surplus aircraft of the Armed Forces or previously type certificated in another category, is entitled to an airworthiness certificate if the aircraft has been inspected by the FAA and found by him to be in a good state of preservation and repair and in a condition for safe operation.

§21.191 defines the general versions of SAWC that exist.

§21.193 states the requirements for the issuance of a SAWC.

There is a missing component when joining the dots in this, and it exists, but is not within the Part specifically, and that is:

A restricted category special airworthiness certificate is issued to operate aircraft that have been type certificated in the restricted category. Operation of restricted category aircraft is limited to special purposes identified in the applicable type design. These special purpose operations include the following: ....

Any other operation specified by the Administrator.

That specification can be incorporated into the SAWC and permits the operation of an aircraft that wasn't in the US DOD inventory, is heavier than a few tons, and is not a balloon etc to be used in restricted category, under FAR's.
The FAA rules are reasonable, and for Restricted Category SAWC, much as ICAO acknowledges with State Aircraft, there is some benefit to the public that may arise by having C-130H, P-3s, S-2's etc undertaking fire fighting, and the same applies to DOD support operations. Not all civil operated aircraft in DOD support duties are Restricted SAWC, but most are.

What may raise more eyebrows in the old world is that the operation is likely to also be Part 91 General Operations... Not all are. That raises some boundary issues under ICAO however, but is normally accepted by the NAA's involved.

If I am asked whether this is a sound use of sovereign wealth, having been involved in DOD support ops, I'm not so sure, but given the current state of many nations defence spending, the number of failed procurement programs, and the ability for lemmings to be happy to commit seppuku rather than continue being a part of an established regional governance system (how's Brexit going there for the UK DOD and tax payers?), then if there is economy in provision of services by these groups, which generally use former flight crew that are otherwise lost to the DOD, then perhaps there is merit, it might soften the grab to your tax receipts, and provide maintenance or even increase in readiness and capabilities.

[walbut]

Thanks for the additional information everyone. I will keep an eye out for any developments in the Hawk Mk 67 fleet. I did not realise that US Air and RAVN were the same company. Sounds a bit like the Hermes to Evri name change. Hopefully they have now mastered the technique for taking off with external tanks fitted.

[DuckDodgers]

Different owners, different leadership. The jets all have between 4400 and 5400 hrs on the frames. Only one has EL\M-2052 radar, none have Link 16, RWR, EW or IRST. Mods done under DER, ac operate spec airworthiness in experimental category. Applied to CAA to operate in U.K. airspace just as Top Aces did.

[teeonefixer]

I seem to remember (although I wasn't directly involved) the RoKAF managing their fleet as they were getting close to the 6000 fhr (and maybe +10% granted) life. I'm happy to be corrected, but possibly these are the "best" airframes.
Interesting that DD says they aren't equipped with all the electronic equipment stated earlier, which makes them not much capable than the former 100 Sqn T1's. The Draken L159s have got radar, RWR and Chaff+Flare at least.

[walbut]

DuckDodgers, Thanks very much for that info. I thought the RoKAF Mk 67 fleet were much closer to the 6000 flying hour nominal life but I guess there was more scatter and the lowest hours airframes were purchased. I can sleep easier at night and take my tin hat off now.

I did have an amusing moment at Warton in the early 1990's when the aircraft were first being accepted by the customers rep, a RoKAF Major. The aircraft were late, primarily because of issues in production caused by the movement of work from Kingston and Dunsfold to Brough and Warton and also some major (and somewhat irrational) changes in the Production organisation. We were contracted to provide pilot training to the RoKAF using the first 6 aircraft to achieve the required hours. I was working at Warton providing Flight Systems support to Flight Test and Production which involved some pretty long weeks, 80 hours was not unusual and getting rung up in the middle of the night to come in and carry out a nosewheel steering test was a common occurrence. We only had the first two aircraft off test to do the flying training but once we got into the swing of it the aircraft stayed serviceable and we were able to keep up the training schedule by flying both aircraft for 3 or 4 flights per day. After a few weeks of this the RoKAF rep, Major Son, approached me and the hangar supervisor Chris Foster looking quite worried. He said he was very concerned that if we kept up this flying rate the aircraft were going to get tired. Major Son's English was quite good but we were unsure whether he was concerned about the fatigue life consumption or some other rather obscure issue. After a bit of discussion we were able to reassure him that the fatigue life consumption was not an issue, the flying being done was not particularly damaging and it would help fleet management to start with some aircraft fleet leaders rather than all 20 arriving in country in quick succession with similar hours. I also told him that in my experience, the more frequently the aircraft were flown, the more reliable they would be. He went away reassured and as more aircraft came off test the situation improved.

[SLXOwft]

Different owners, different leadership. The jets all have between 4400 and 5400 hrs on the frames. Only one has EL\M-2052 radar, none have Link 16, RWR, EW or IRST. Mods done under DER, ac operate spec airworthiness in experimental category. Applied to CAA to operate in U.K. airspace just as Top Aces did.

So RAVN's publicity is 'economical with the actualité', why am I not suprised? I did think one of the radomes was a different shape to the others but thought I might be imagining it.

Manufactured in Great Britain by BAE Systems. The Hawk is an advanced trainer with a two-man tandem cockpit, a low-mounted cantilever wing and is powered by a single turbofan engine. The Hawk was designed to be reliable and have low operating costs. The Hawk is noted for its agility, in particular its roll rate and turn handling. The aircraft is capable of supersonic flight.

​Features.

AESA Radar
ACAP Pod (EW)
Joint Helmet Mounted Cueing System (JHMCS)
Electronic Attack
Advanced IRST (Infrared Search and Track)
Link 16
Night Live CAS Capable

30mm Cannon

[DuckDodgers]

ADAIR companies expanding the actual position of capability, surely not. Wait until you see where the waveform return data is likely to end up from those equipped with certain AESA systems.

[Davef68]

Did the 67 have a radar to begin with? As I recall, it was the only two seater to have a radome. Weather set?

[teeonefixer]

No, they only had the Mk.60 series equipment fit, limited by even 80's standards. Radar was only fitted to the 200 (single seat) variants

[DuckDodgers]

No, they only had the Mk.60 series equipment fit, limited by even 80's standards. Radar was only fitted to the 200 (single seat) variants

Pretty sure the 67 had a simple ranging radar but most likely wrong. 66H in the 200 series, could squeeze quite a good modern AESA in there today if you can match SW&P plus cooling.

[Davef68]

Pretty sure the 67 had a simple ranging radar but most likely wrong. 66H in the 200 series, could squeeze quite a good modern AESA in there today if you can match SW&P plus cooling.

That's what I thought (I typed weather when I meant ranging, I blame age and the storm!), otherwise I don't see the need for the radome and the unique nose on the S Korean aircraft. I did find a couple of online references to it, but nothing definitive.

[teeonefixer]

Pretty sure the 67 had a simple ranging radar but most likely wrong. 66H in the 200 series, could squeeze quite a good modern AESA in there today if you can match SW&P plus cooling.
I'm sure they could, but that, and the corresponding ballast in the rear fuselage, would have a significant effect on the centre fuselage top longeron fatigue life, especially at the joints. The 100 series and onwards needed progressive improvements and mods as the equipment fit (e.g. FLIR&Laser) and requirements (10,000 - 12,000 flying hours) were demanded by customers. Although the Mk.67 is essentially a 100 series fuselage, so has some scope, changes would still all need to be assessed and cleared by a suitable authority - which is where we started in the OP !

[Davef68]

I'm sure they could, but that, and the corresponding ballast in the rear fuselage, would have a significant effect on the centre fuselage top longeron fatigue life, especially at the joints. The 100 series and onwards needed progressive improvements and mods as the equipment fit (e.g. FLIR&Laser) and requirements (10,000 - 12,000 flying hours) were demanded by customers. Although the Mk.67 is essentially a 100 series fuselage, so has some scope, changes would still all need to be assessed and cleared by a suitable authority - which is where we started in the OP !

But if they were fitted from new (and the mk 67 had the radome from new) then BAE would be the design authority? Or did they have a radome but no radar?

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/609x210/image_da582d5e69dbce11ae45eb2fd08e702835eff435.png

[teeonefixer]

But if they were fitted from new (and the mk 67 had the radome from new) then BAE would be the design authority? Or did they have a radome but no radar?

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/609x210/image_da582d5e69dbce11ae45eb2fd08e702835eff435.png
Its not a radome, its only a nosecap

[CAEBr]

Its not a radome, its only a nosecap
Quite, simply a 60 series aircraft with 60 series 'standard' avionics fitted in a 100 series nose structure. The nose cap is a structural nose cap, not a radome, so the incorporation of the nose radar radome along with the radar would presumably have needed a birdstrike test. No idea if that has taken place, but could make a good guess :eek:

[SLXOwft]

(I have amended my previous post to strike out the bolleaux I was repeating.)

I too have read something about a ranging radar but can't find it now but anyway I consider CAEBr has definitively refuted that myth. When Air USA/RAVN Aero were trying to sell them in 2022 the only radar mentioned was the sole:O ELTA EL/M-2052.

At the time of the two incidents Air USA had with N509XX and N506XX BAES were not supporting their operation and the FAA appeared to be happy with them applying the OEM maintenance procedures with no external supervision - BAES suspended talks following the write off 506 I haven't seen anything to the effect they later agreed to support them. They were also using USAF owned but not BAES approved SUU-20 practice munitions dispensers fot the installation of which they had commisioned a structural comparision report from a FAA DER (Designated Engineering Representative) but nothing on aerodynamic effects of using them and non-OEM approved munitions. I hope this isn't indicative of a tendancy to sail too close to the wind.

[CAEBr]

SLXO, we didn't really suspend talks after the second loss, we never really engaged in the first place. US Air contacted us as well as MBA and RR, telling each (when we compared notes) that the other two were content and just waiting for the third member to sign up. All of us were unhappy, and never took them up on the offer.
We supported both field investigations to ensure the company information was correctly available and assessed for which the NTSB was grateful. The second loss (ground fatality) was captured on a rear cockpit go pro (without the apparent knowledge of the pilot) and confirmed the prior assessment of a botched take off compromised further by the carriage of an unapproved long store.

[SLXOwft]

CAEBr - thanks for inside track, my only source of information was the NTSB reports and I probably read more into the wording than I should.

I can't claim any real knowledge of the COMRA regulations in the UK and how they apply, if at all, to a US based company operating US registered aircraft under contract to the US Government but wonder if they like FAA Title 14 Part 91 were really intended to be stretched to cover such a situation, which takes us back to Walbut's original question.

I'll shut up about this now as I am probably continuing to talk bolleaux.

[Wetstart Dryrun]

Got involved in a bit of production testing of mk 67....

Maybe 20 hours.
​​​

No recollection of radar at all, at all.

Long time ago

[Davef68]

Thanks all, another myth busted! Gives it a more elegant shape than the 'chisel' 100 series nose.

[DuckDodgers]

To add clarity, all that RAVN or any other operator requires to operate a non-type certificated FAA registered aircraft with a Special Airworthiness Cert in the Exp category in the U.K. is to obtain a Foreign Carrier Permit under Article 252 of the Air Navigation Order 2016. This applies to those operating under Transport Canada regs who are also partaking in these AUAs. An example is below, CAA don’t care one iota if there’s an active DA unless it’s on the G Reg under their purview.
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1166x1558/img_7279_a81b46c677c8ad3cbb2eacaefc6a8e68a000b5a3.jpeg