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A few questions

Started by pyro-manic, June 03, 2008, 06:41:08 PM

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pyro-manic

I have a few questions relating to a couple of models I'm currently building, and I'm hoping that someone can help me out. :)

Firstly, did anyone ever equip a Hawker Hunter for in-flight refuelling? I'm trying to build a probe for a 1:72 Hunter, and I'm wondering where the best place to attach it would be. I thought either the right side of the fuselage next to the cockpit, or out of the leading edge of the wing, next to the intake. Are these good/bad locations, or is there a better one? I'm thinking the Swiss or Singapore AF might have done something like this, given the extensive upgrades made to their Hunter fleets, but I can't find any photos or information on the interweb showing something like this. The wing would be easier to make, but would mean a rather long probe, while the nose one would be shorter, but would require more fiddly scuplting to fair it in properly.

Secondly, I have the Hasegawa 1:72 F-20 kit, and it has what looks like an arrestor hook under the rear fuselage. Is this in fact what it is? I haven't found anything to suggest that the Tigershark was carrier-capable, so I'm a bit stumped as to what else it could be.

Sorry if these are stupid questions, but I can't progress on my builds until I can resolve these issues.


Many thanks in advance,

pyro. :)
Some of my models can be found on my Flickr album >>>HERE<<<

AeroplaneDriver

#1
First the F-20...like the F-5 before it and many other land based tactical aircraft it has a hook for airfield arrestor gear.  This is a cable system on many military airfields desinged to stop aircraft landing without brakes and other systems like flaps and slats that reduce landing speed.  You'll find hooks on most of the Century series, the Lightning, the F-15, F-16, etc.  They're not as strong as carrier hooks, as the runway arrestor gear has a much lower deceleration rate, and they are only designed for emergency use.

As for the Hunter question.  I've got a couple of Hunter books, but I've never read about IFR being fitted.  Not sure which would be most practical in the real world, but I've built two whif Hunters with probes, both wing mounted.  For my USAF F-99 c.1962 I had an F-100 probe under the left wing, for my RAF Hunter F.15 c.2000 I had a probe from an A-4 directly mounted into the leading edge of the right wing.



So I got that going for me...which is nice....

Weaver

#2
The key thing with an IFR probe is that it has to be in such a position that the pilot can see the probe, the drogue and the tanker all in the same "sight picture", however note that real probes achive this to varying degrees. The probe also needs to be well clear of the intakes so that spilt fuel doesn't go down them and cause an engine surge (especially on a single-engined type). You also need to be able to get the fuel from the probe plumbed into the tanks, of course (not always straightforward).

With all due respect to AeroplaneDriver (and those are two beautiful models, by the way... :wub: :wub:), I think his probes are a little too low and inboard. I think that a wing-mounted probe on the Hunter would be more like that on the Lightning, i.e. a bit further outboard and dog-legged upwards to bring the tip more into the pilot's field of view. In fact, it would probably be best located just inboard of the inner pylon where, logically, there must be plumbing intot the tanks.

Another option would be to have a fixed, Buccaneer-style probe next to the cockpit. Given how tight a Hunter's forward fuselage is, it's unlikely it would be retractable, and it would almost certainly have to have an external pipe running back past the cockpit to the fuselage tanks.

Just my twopenneth................
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r16

#3
ı have read that  watching the drogue is actually  counterproductive and some aircraft especially Harriers have their drogues to the side of the pilot .F-100s did likewise . (Though this seems to be depending on pilots' own ideas  and experiences .I would be for the boom , ı think .)

Weaver

Quote from: r16 on June 04, 2008, 02:16:41 AM
ı have read that  watching the drogue is actually  counterproductive and some aircraft especially Harriers have their drogues to the side of the pilot .F-100s did likewise . (Though this seems to be depending on pilots' own ideas  and experiences .I would be for the boom , ı think .)

As I understand it, staring at the drogue fixedly is a bad idea because the pilot starts to unconsciously follow it's bobbing movement. However, he does have to be aware of it's position simply to avoid a collision.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Morpheus in Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones '

Mossie

The Harrier option might be a good one for the Hunter.  Early Harriers had a removal probe that only tended to be fitted for ferry flights or if the mission dictated it.  The probe was mounted behind the pilot & the tip of the probe stretched in front & above.



Harrier II's have the probe semi-recessed in a fairing.  Again, it's mounted behind the pilot but when deployed the tip is in front & above.




I imagine the early configuration would suit the Hunter, either fixed like the Bucc, or detachable like the Harrier.  It's not in a great position regarding fuel ingestion, but to be honest most 'male' style refuelling systems tend to be the same.  I'm not dissing Nicks Hunters though, several jets of the Hunters vintage had the probe in this position, the Lightning being one of the most notable.  Not the best place, but often often there due to engineering necessity.
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pyro-manic

Thanks guys. Most helpful. I'll have a look at the probes on the Lightning and Buccaneer, and see what I can do about scratch-building something suitable. -_-
Some of my models can be found on my Flickr album >>>HERE<<<

NARSES2

Well the final episode of "War in the Air" has 3 Meteors refueling from what looks like a B29/B50 conversion and their probes are dead central front of the nose
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Weaver

Quote from: NARSES2 on June 05, 2008, 03:39:54 AM
Well the final episode of "War in the Air" has 3 Meteors refueling from what looks like a B29/B50 conversion and their probes are dead central front of the nose

Yes, they tested this facility. It worked okay on the Meteor because any spillage from the drogue went over the inner wings, clear of the intakes. If you tried the same setup on a Hunter though, it would go straight into the engines.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Morpheus in Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones '

pyro-manic

OK, here's what I've got so far. I'm torn between the nose one (more practical), and the wing one (more attractive IMO). The piece is just blu-tacked on, so ignore that part. The probe is just a bit of paperclip wire bent to shape, and looks ok to me. I may have to do something about the valve, though - it's looking a bit funny like that (just a bit of the paper clip's plastic covering cut to size). Maybe I'll try and scavenge a kit part from somewhere.

EDIT: If I go for the nose placement, I'll probably make it a bit shorter - it's a tad long as-is I think.
Some of my models can be found on my Flickr album >>>HERE<<<

kitnut617

If I'm not building models, I'm out riding my dirtbike

Jeffry Fontaine

#11
Quote from: pyro-manic on June 03, 2008, 06:41:08 PMI have a few questions relating to a couple of models I'm currently building, and I'm hoping that someone can help me out. :)<snip>I have the Hasegawa 1:72 F-20 kit, and it has what looks like an arrestor hook under the rear fuselage. Is this in fact what it is? I haven't found anything to suggest that the Tigershark was carrier-capable, so I'm a bit stumped as to what else it could be.<snip>
No, the F-20 was not capable of surviving carrier operations.  The feature that you are referring to is standard kit on all F-5, T-38, and F-20 aircraft.  It is there to engage the arresting cables at the end of the runway prior to the aircraft going into the dirt when it runs out of asphalt during an emergency.  These types of arresting hooks are also pretty much standard on any USAF high performance aircraft.  Check any F-16, or F-15 and you will find the same kind of hook.  The F-117 had a hook as well but it was hidden under a door.  F-100 and F-104 were also fitted with this feature.  F-101, not too sure about, but it was and is pretty much standard on all modern aircraft in the American inventory. 

Regarding your IFR probe, the F-100 had two types of probe during service.  The straight probe as featured on the Hawker Hunter in the image and a later version that was bent to get it closer to the pilots field of vison without physically moving the location of the probe.  The Monogram F-100 kit and the ESCI kit provided both types of probe but the Monogram parts were much more robust looking.  Not sure if the smaller F-100 kit provided such a selection but it is worth checking into.  The IFR probe was attached to the underside of the wing between the inboard and center wing pylons.  Your Hunter could benefit from that location as well instead of punching a hole in the wing leading edge which in real life was probably not as easy to access. 

Another option is to consider the kinked IFR probe that is provided in the A-4 Skyhawk kits, this kinked probe was fitted to the side of the fuselage and the original design was a straight shot to the end of the probe which caused issues with excess fuel spray into the engine intakes and it also caused a problem with the location of the ECM antennas around the nose of the aircraft.  A simple kink in the probe resolved both issues and all later models of the A-4 were fitted with the kinked probe.  You could create the same kind of IFR probe on your Hunter and had it mounted low on the fuselage with the entry point to the fuselage behind the intake and have it run up along the side of the fuselage and out where it would be in the pilots field of view for an IFR evolution. 
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r16

regarding arrestor hooks on non carrier capable aircraft they can be very  useful if the infrastructure is there , about 5 years ago an F-16 of  THK had a malfunctioning engine that could not be throttled down . The pilot took the wire but the base was for T-38s and the wire could not take the Falcon , the pilot died .

pyro-manic

kitnut617: Thanks for that pic. I did consider a folding probe, but my aim is for a simple, cheap method, so a fixed probe is better.  &lt;_&lt; Plus a folding probe will be a pain to build in comparison.

Jeffry Fontaine: I wasn't aware that so many land-based aircraft had hooks. I've looked at the Skyhawk probe, and I may well do something similar. Maybe have the pipe running "over the shoulder" of the wing and into the top, rather than underneath - the underside is already rather cluttered on my build.

Thanks guys, your answers have all been really useful. :) Hopefully I'll have a WIP thread up tomorrow for the Hunter, and soon-ish for the Tigershark, and you can see what I'm doing.
Some of my models can be found on my Flickr album >>>HERE<<<