Shipbucket
http://shipbucket.com/forums/

FD Aircraft design challenge
http://shipbucket.com/forums/viewtopic.php?f=27&t=6172
Page 8 of 9

Author:  Tobius [ August 23rd, 2015, 1:42 am ]
Post subject:  Re: FD Aircraft design challenge

Quote:
The problem that prevented me of placing the probe above the roof are the escape hatches of the crew... I´m not sure how they can interfere in a evacuation... Safety first!]
Flight engineer and navigator? Change the bailout path to the sides or down or delete the two unneeded crew. As the BUFF is being re-engined and FADEC is part of the new engine fit, why do you need the engineer? And as for the navigator, the AI pilot crammed in between the copiliot and pilot is installed in the latest USAF mods. Reduced crew is an added benefit of the re-engine B-52s.

As a piece of color commentary, the NIMROD is an example where the RAF puts mission ahead of safety.
Quote:
If I remember correctly , the issue about using current receptacle location is that the two systems use different philosophies ... while the tanker's boom operator is responsible for guiding it into the receptacle, in the probe and drogue system the pilot of the receiver aircraft is responsible of making the contact, so I consider direct view of the probe a "must"
The flying boom (rigid pipe) method is USAF preferred because fuel flow, if the pump fails, can still be gravity fed. There are no hose kinks and the USAF swears the fuel transfer rate is much faster and safer through the pipe as opposed going through the hose. Docking with a hose is simpler mechanically and supposedly easier for station keeping.

Author:  Progress [ August 23rd, 2015, 3:04 pm ]
Post subject:  Re: FD Aircraft design challenge

Tobius wrote:
Flight engineer and navigator? Change the bailout path to the sides or down or delete the two unneeded crew. As the BUFF is being re-engined and FADEC is part of the new engine fit, why do you need the engineer? And as for the navigator, the AI pilot crammed in between the copiliot and pilot is installed in the latest USAF mods. Reduced crew is an added benefit of the re-engine B-52s.
I agree that a crew reduction is possible taking advantage of avionics refits, but I'm worried with pilot/co-pilot hatches, as the space between them seems very small to fit a fuel pipe without being sure of causing some issues as they pop out...

I´m aware of those advantages/disadvantages (well, not about the gravity feed issue ;) ), but I was mainly referring to the tanker's boom operator vs probe-equipped aircraft pilot responsibilities & roles, and as I said before, a clear direct vision of the probe tip is a "must" for me.

Author:  Tobius [ August 23rd, 2015, 5:36 pm ]
Post subject:  Re: FD Aircraft design challenge

Progress wrote:
[ img ]

If I remember correctly , the issue about using current receptacle location is that the two systems use different philosophies ... while the tanker's boom operator is responsible for guiding it into the receptacle, in the probe and drogue system the pilot of the receiver aircraft is responsible of making the contact, so I consider direct view of the probe a "must"
The four cockpit crew members use assisted boost rail guided ejector seats. It does not matter for the pilot and co-pilot as their blow out panels are the windowed escape routes ahead of the recessed boom receiver as you can see from the photo above. The two eliminated positions I grant you would have to be relocated with the bombardier in the nose belly behind the forward landing gear wheel well if you insist on keeping them.

Referring to the direct vision of probe to drogue?

Are you saying that there is something 'special' about US Navy pilots that they can do what others can't? :?:

Author:  Thiel [ August 23rd, 2015, 5:52 pm ]
Post subject:  Re: FD Aircraft design challenge

Tobius wrote:
Referring to the direct vision of probe to drogue?

Are you saying that there is something 'special' about US Navy pilots that they can do what others can't? :?:
The probe is perfectly visible from the pilots seat in an F-8
[ img ]

Author:  Tobius [ August 23rd, 2015, 11:55 pm ]
Post subject:  Re: FD Aircraft design challenge

It's to the left, below, and behind the shoulder of the pilot actually.

As it is above and behind the right shoulder of the pilot visible through the top window (check the refueling socket as seen in the B-52 photo). from the B-52 as I edited it.

That Crusader pilot flies it in blind, the last three meters..

Author:  Hood [ August 24th, 2015, 7:41 am ]
Post subject:  Re: FD Aircraft design challenge

Why not just go for the usual RAF style of a fixed probe above the cockpit on the centreline?
I think there would be room, it would be external with a bit of fairing and the internal plumbing could still use the same layout as for the boom receptacle.

Author:  Tobius [ August 24th, 2015, 9:26 pm ]
Post subject:  Re: FD Aircraft design challenge

Because that interferes with the normal USAF (Boeing) cockpit layout for their large bombers?

Author:  Hood [ August 26th, 2015, 7:36 am ]
Post subject:  Re: FD Aircraft design challenge

I think it would fit.

See the details of the Hercules fit on this google preview of Richard Tanner's 'History of Air-To-Air Refuelling: https://books.google.co.uk/books?id=PId ... be&f=false

The probe is not that wide and should fit between the hatches. I think the fuel pipe from the boom receptacle could still be used, but if not some replumbing would be needed.
I don't think its a deal breaker.

Just as a question to throw out there, given the fuel efficiency of the four RB.211s, what would the likely range be of this Anglo B-52 on internal fuel only? I'm guessing it will be slightly more than the standard B-52H.

Author:  Progress [ August 26th, 2015, 6:57 pm ]
Post subject:  Re: FD Aircraft design challenge

My greatest worry and doubt was during opening/release of the pilot/co-pilot hatches, I feared that they maybe could swing inward, but after some research I found that they are hinged aft, so… YES, roof probe running between hatches seems plausible; :) it’s on my immediate drawing board.
Personally, I still have my doubts about safety margins (I don't want to be guilty of another “Top Gun´s Goose” dead if the hatch fails to separate cleanly because the probe :? ), the need of skin reinforcing plates (as you can see in the C-130 probe illustrations) and probe's interference while using AN/ALQ-122 jammer (the trapezoid between cockpit eyebrows windows), so I still think ;) that my original unorthodox side mounted probe is “safer” and less risky, but I agree that a roof mounted one it's a far more conventional and usual installation, and, using existing receptacle's plumbing, a simpler one… ;)

Author:  Tobius [ August 26th, 2015, 11:04 pm ]
Post subject:  Re: FD Aircraft design challenge

All valid points worth considering. Just as a side note, those hinges become moot once the ejector seats fire off. The cover pops clear as the ram over the person's head hits that hatch.

Hollywood aside (they got Goose wrong.) there are no guarantees when a Martin Baker goes off. The escape is a violent one that often crushes spines, breaks arms and legs and that is if the escape is successful. Fail to fire or the canopy failing to separate at the break points as the ram hits it, all too common. I figure it to be akin to hitting the wall in a Formula 1 car at over 220 k/h. You have a chance with the safety features, but it's just that; a chance. Nobody guarantees you will survive it unhurt if everything goes right. And with more than fifty things that have to happen in 1/2 second, the chances of something going wrong approaches unity.

Addendum: I would have to move the ALQ 122 jammer to the hunchback behind the fuel probe. That's another reason to angle the probe that way. Prevent a radio spike point. Glad you noticed. I actually missed it.

Page 8 of 9 All times are UTC
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/