A-6 Radar Display?

[Nick Coleman]

Just started re-reading Coont's Flight of the Intruder, and his
description of the capabilities of the terrain radar is interesting.

Early in the book he describes a training flight through canyons and
valleys in IMC, using the radar for avoidance.

I'm curious what the BN would actually see in his scope? Would it be a
like a line drawing of the terrain (quite visual and not needing much
interpretation) or would it be more like a staticy TV with 'blobs' that
needed skill to interpret what they represented? Or something else
completely, like an oscilloscope type of display?

Thanks in advance. Tried googling, but didn't really know what to
search for.

Nick

[Mike Kanze]

Nick,

I've loaned out my copy of FOTI so I can't immediately refer to it in trying
to answer your question. Try I will, though.

First, the setting for FOTI is the later years of the VN conflict. This is
important because the A-6A was the current Intruder model at that time. The
A-6E had not yet entered fleet service and some of the whistles and bells of
the A system were eliminated or very greatly changed in the E system -
including a couple of terrain-clearance toys that Coonts likely describes in
FOTI.

Second, one must remember that the A-6A was the "first" of its kind - the
first aircraft with full integration of its various sensors into a digital
(not analog, like the Norden bombsight) computer. In this respect it was
also very much "bleeding edge." The personal computing dictum about being
especially wary of Version 1 of anything could as well have been written by
those of us in the A-6A.

Search Radar Terrain Clearance

One terrain clearance toy was a feature called Search Radar Terrain
Clearance (SRTC). As its name implies, SRTC used the A's AN/APQ-92 search
radar to generate a synthetic terrain display on the pilot's Vertical
Display Indicator (VDI), the very large cathode ray tube (CRT) display in
the center of the pilot's console, right under the gunsight. The synthetic
display showed vertical terrain development in a 53 degree by 26 degree
window about the projected flight path. For example, if the Intruder was
heading for a valley between two hills, the pilot would see return generally
in the shape of two hills (one on either side of the display), with a
curving "V" notch in the center between them. (This is somewhat difficult
to describe without a graphic.) The return would slide "down" toward the
bottom of the VDI as the flight progressed and radar return for these
terrain features was processed.

The B/N would not normally monitor the VDI, unless he happened to look over
at the pilot's console. Instead the same radar return was presented on the
B/N's Direct View Indicator (DVI), the CRT in the center of the B/N's
console as a Plan Position Indicator (PPI) information covering an arc of
about 50 degrees and a range of about 27 miles. (A PPI display looks like a
slice of pie whose point is at the bottom of the DVI. The "point" of the
pie slice is where your aircraft is now and the 50 degree arc covers the
terrain ahead of the projected flight path.) PPI information does not give
the crew any indication of terrain elevation so its use alone for terrain
clearance monitoring was not conducive to mission prosecution or crew
longevity. <g>

By the time I completed type training in the A-6 (1972), we were not using
or receiving significant training with SRTC. The primary reason for this
was
SRTC's inability to detect smaller man-made features - like cables that the
bad guys could suspend across a valley. Every now and then, though, we'd
light up SRTC especially if we were flying a training route like Whidbey's
OB-16 whose features were well-known and for which both crew would establish
a mutually agreeable safety margin. (Humorous example: "300 additional
feet of clearance for each wife, plus 100 additional feet for each kid.")

Elevation Scan

Another feature in the A was Elevation Scan (E-scan). With E-scan the A's
AN/APQ-112 track radar was used to generate vertical terrain development on
the Pilot's Horizontal Display (PHD) the CRT immediately below the VDI on
the pilot's side. The pilot read vertical development "left to right" on
the PHD, with obstructions closer to the aircraft appearing on the left side
of the PHD and those at greater range lying more to the right. (Again, I
apologize. This is hard to describe without a graphic.) E-scan return
would gradually slide from right side of the display (farther away) to the
left (closer) as the flight progressed and new return for the same terrain
was processed. The information displayed on the PHD in E-scan also included
a flight path line and a clearance line. The pilot would scan both the VDI
and the PHD while flying in E-scan mode, performing the necessary spatial
interpretation gymnastics to deduce how close the A was to a possible prang.

The B/N could not observe E-scan on his DVI. His viewing pleasure was
limited to search radar input, usually shown as PPI information while the A
was in E-scan mode.

Like SRTC, E-scan's day had passed by the time I reached type training - if
in fact it ever had a "day" to enjoy. Aside from being a clumsy way of
figuring out how close to pranging you might be, E-scan was further limited
by the track radar's relatively poor reliability.

Hope this helps.

--
Mike Kanze

"Owl", B/N
A-6A, A-6B (PAT ARM), KA-6D


"Nick Coleman" > wrote in message
...
>
> Just started re-reading Coont's Flight of the Intruder, and his
> description of the capabilities of the terrain radar is interesting.
>
> Early in the book he describes a training flight through canyons and
> valleys in IMC, using the radar for avoidance.
>
> I'm curious what the BN would actually see in his scope? Would it be a
> like a line drawing of the terrain (quite visual and not needing much
> interpretation) or would it be more like a staticy TV with 'blobs' that
> needed skill to interpret what they represented? Or something else
> completely, like an oscilloscope type of display?
>
> Thanks in advance. Tried googling, but didn't really know what to
> search for.
>
> Nick

[Nick Coleman]

Many thanks for this very detailed explanation, Mike. I can visualise
exactly what you are saying when reading the book.

(The episode I mentioned is on p 33 of the hardback edition, where Jake
is remembering a training flight in which Morgan is giving a running
commentary from his scope and then saves their lives by looking into
his scope* and screaming, "Pull up" after Jake had relaxed and
forgotten his scan. Sounds like Coonts may have used a bit of poetic
licence in giving the BN's scope elevation info.)

Thanks again,
Nick

* Coonts' terminology


Mike Kanze wrote:

> Nick,
>
> I've loaned out my copy of FOTI so I can't immediately refer to it in
> trying
> to answer your question. Try I will, though.
>
> First, the setting for FOTI is the later years of the VN conflict.
> This is
> important because the A-6A was the current Intruder model at that
> time. The A-6E had not yet entered fleet service and some of the
> whistles and bells of the A system were eliminated or very greatly
> changed in the E system - including a couple of terrain-clearance toys
> that Coonts likely describes in FOTI.
>
> Second, one must remember that the A-6A was the "first" of its kind -
> the first aircraft with full integration of its various sensors into a
> digital
> (not analog, like the Norden bombsight) computer. In this respect it
> was also very much "bleeding edge." The personal computing dictum
> about being especially wary of Version 1 of anything could as well
> have been written by those of us in the A-6A.
>
> Search Radar Terrain Clearance
>
> One terrain clearance toy was a feature called Search Radar Terrain
> Clearance (SRTC). As its name implies, SRTC used the A's AN/APQ-92
> search radar to generate a synthetic terrain display on the pilot's
> Vertical Display Indicator (VDI), the very large cathode ray tube
> (CRT) display in
> the center of the pilot's console, right under the gunsight. The
> synthetic display showed vertical terrain development in a 53 degree
> by 26 degree
> window about the projected flight path. For example, if the Intruder
> was heading for a valley between two hills, the pilot would see return
> generally in the shape of two hills (one on either side of the
> display), with a
> curving "V" notch in the center between them. (This is somewhat
> difficult to describe without a graphic.) The return would slide
> "down" toward the bottom of the VDI as the flight progressed and radar
> return for these terrain features was processed.
>
> The B/N would not normally monitor the VDI, unless he happened to look
> over
> at the pilot's console. Instead the same radar return was presented
> on the B/N's Direct View Indicator (DVI), the CRT in the center of the
> B/N's console as a Plan Position Indicator (PPI) information covering
> an arc of
> about 50 degrees and a range of about 27 miles. (A PPI display looks
> like a
> slice of pie whose point is at the bottom of the DVI. The "point" of
> the pie slice is where your aircraft is now and the 50 degree arc
> covers the
> terrain ahead of the projected flight path.) PPI information does not
> give the crew any indication of terrain elevation so its use alone for
> terrain clearance monitoring was not conducive to mission prosecution
> or crew longevity. <g>
>
> By the time I completed type training in the A-6 (1972), we were not
> using
> or receiving significant training with SRTC. The primary reason for
> this was
> SRTC's inability to detect smaller man-made features - like cables
> that the
> bad guys could suspend across a valley. Every now and then, though,
> we'd light up SRTC especially if we were flying a training route like
> Whidbey's OB-16 whose features were well-known and for which both crew
> would establish
> a mutually agreeable safety margin. (Humorous example: "300
> additional feet of clearance for each wife, plus 100 additional feet
> for each kid.")
>
> Elevation Scan
>
> Another feature in the A was Elevation Scan (E-scan). With E-scan the
> A's AN/APQ-112 track radar was used to generate vertical terrain
> development on the Pilot's Horizontal Display (PHD) the CRT
> immediately below the VDI on
> the pilot's side. The pilot read vertical development "left to right"
> on the PHD, with obstructions closer to the aircraft appearing on the
> left side
> of the PHD and those at greater range lying more to the right.
> (Again, I
> apologize. This is hard to describe without a graphic.) E-scan
> return would gradually slide from right side of the display (farther
> away) to the left (closer) as the flight progressed and new return for
> the same terrain
> was processed. The information displayed on the PHD in E-scan also
> included
> a flight path line and a clearance line. The pilot would scan both
> the VDI and the PHD while flying in E-scan mode, performing the
> necessary spatial interpretation gymnastics to deduce how close the A
> was to a possible prang.
>
> The B/N could not observe E-scan on his DVI. His viewing pleasure was
> limited to search radar input, usually shown as PPI information while
> the A was in E-scan mode.
>
> Like SRTC, E-scan's day had passed by the time I reached type training
> - if
> in fact it ever had a "day" to enjoy. Aside from being a clumsy way
> of figuring out how close to pranging you might be, E-scan was further
> limited by the track radar's relatively poor reliability.
>
> Hope this helps.
>

--
Nick
Mandrake 9.2
KDE 3.1.3

[Nick Coleman]

As an aside, I forgot to mention this book was one of the seminal reads
of my life. I know that sounds corny, but occasionally a book or a
movie comes out that changes the way you see the world.

The two first 'practical' books I read about Vietnam were 'Chickenhawk'
and FOTI. I was just a youth during Vietnam and everything I'd read
before was dry and historical. These two books brought the common
aviator to life.

I sometimes wonder what eventually happened to the author of
Chickenhawk; did he make it in his life afterwards or not.

Nick

[Guy Alcala]

Nick Coleman wrote:

<snip>

> I sometimes wonder what eventually happened to the author of
> Chickenhawk; did he make it in his life afterwards or not.

You can read the sequel, "Chickenhawk: Back in the World" and find out.
See

http://www.robertcmason.com/Books/chbitw.html

Guy

[Pechs1]

spam bucket-<< The two first 'practical' books I read about Vietnam were
'Chickenhawk'
and FOTI. I was just a youth during Vietnam and everything I'd read
before was dry and historical. These two books brought the common
aviator to life. >><BR><BR>

'Everything we had'-Al Santoli



P. C. Chisholm
CDR, USN(ret.)
Old Phart Phormer Phantom, Turkey, Viper, Scooter and Combat Buckeye Phlyer

[Mike Kanze]

Nick,

Got back my copy of FOTI this weekend and turned to the segment you mention.

From Coonts' narrative, the route sounds a bunch like the OB-16 route.
IIRC, OB-16 started in northern Oregon and ended at the B-16 nuclear
bullseye at NAS Fallon, NV. The early legs of this route took one into the
canyons of the John Day River system, including one particular canyon that
runs almost exactly N-S. After watching canyon walls go by for about 20 nm,
the terrain begins to broaden and you change course to roughly SSE for a ~70
nm leg to Harney Lake. The few charts I saved of this area confirm the
existence of some low hills and shallow valleys along this otherwise
flattening route. I would guess these are the hills Coonts was visualizing
as threats to Jake and Morg when he wrote this segment.

(For those among you who are limited to the likes of a Rand-McNally road
atlas, the route starts at a little burg named Kimberly which is about 60 nm
SSW of Umatilla, OR.)

There's no specific thing that Coonts mentions in his narrative that would
cause Morg to scream for a pull-up. Morg has just put his head back into
the hood, so he is not looking at the pilot's VDI. (Neither apparently is
Jake, since he is not maintaining the 1,000 feet of clearance he has cranked
into the VDI's offset impact bar.) Since Jake is viewing SRTC on the VDI,
Morg is limited to a PPI display on his DVI. Morg may have noted a
way-too-strong radar return too close-in for comfort. Or maybe things just
"didn't look right" to him, the sound of that little voice we all carry
within us. Or maybe this was just some artistic license taken by Coonts.

Night or IMC conditions are absolutely the most demanding environment for
low-level flight. Jake clearly has let his scan deteriorate away from the
SRTC info and (as the narrative states) dwell too much upon other things
like engine instruments and fuel state. Unless you're heading directly for
a canyon wall, your radar altimeter readings do not deteriorate from 1,000
feet to 100 feet in only an instant.

Coonts' narrative is one of many good examples of the value of having two
pairs of eyeballs sitting side by side. For attack work - including
low-level, all wx ops - this was the gold standard of that era. The
situational awareness such an arrangement facilitates - and demands - of
both pilot and B/N undoubtedly saved many a mission, bird and crew.

--
Mike Kanze

"It was like being a rat living under a bowling alley."

- Willem Dafoe, commenting on what it was like to sleep in a compartment
just below the flight deck of an aircraft carrier.



"Nick Coleman" > wrote in message
...
> Many thanks for this very detailed explanation, Mike. I can visualise
> exactly what you are saying when reading the book.
>
> (The episode I mentioned is on p 33 of the hardback edition, where Jake
> is remembering a training flight in which Morgan is giving a running
> commentary from his scope and then saves their lives by looking into
> his scope* and screaming, "Pull up" after Jake had relaxed and
> forgotten his scan. Sounds like Coonts may have used a bit of poetic
> licence in giving the BN's scope elevation info.)
>
> Thanks again,
> Nick
>
> * Coonts' terminology
>
>
> Mike Kanze wrote:
>
>> Nick,
>>
>> I've loaned out my copy of FOTI so I can't immediately refer to it in
>> trying
>> to answer your question. Try I will, though.
>>
>> First, the setting for FOTI is the later years of the VN conflict.
>> This is
>> important because the A-6A was the current Intruder model at that
>> time. The A-6E had not yet entered fleet service and some of the
>> whistles and bells of the A system were eliminated or very greatly
>> changed in the E system - including a couple of terrain-clearance toys
>> that Coonts likely describes in FOTI.
>>
>> Second, one must remember that the A-6A was the "first" of its kind -
>> the first aircraft with full integration of its various sensors into a
>> digital
>> (not analog, like the Norden bombsight) computer. In this respect it
>> was also very much "bleeding edge." The personal computing dictum
>> about being especially wary of Version 1 of anything could as well
>> have been written by those of us in the A-6A.
>>
>> Search Radar Terrain Clearance
>>
>> One terrain clearance toy was a feature called Search Radar Terrain
>> Clearance (SRTC). As its name implies, SRTC used the A's AN/APQ-92
>> search radar to generate a synthetic terrain display on the pilot's
>> Vertical Display Indicator (VDI), the very large cathode ray tube
>> (CRT) display in
>> the center of the pilot's console, right under the gunsight. The
>> synthetic display showed vertical terrain development in a 53 degree
>> by 26 degree
>> window about the projected flight path. For example, if the Intruder
>> was heading for a valley between two hills, the pilot would see return
>> generally in the shape of two hills (one on either side of the
>> display), with a
>> curving "V" notch in the center between them. (This is somewhat
>> difficult to describe without a graphic.) The return would slide
>> "down" toward the bottom of the VDI as the flight progressed and radar
>> return for these terrain features was processed.
>>
>> The B/N would not normally monitor the VDI, unless he happened to look
>> over
>> at the pilot's console. Instead the same radar return was presented
>> on the B/N's Direct View Indicator (DVI), the CRT in the center of the
>> B/N's console as a Plan Position Indicator (PPI) information covering
>> an arc of
>> about 50 degrees and a range of about 27 miles. (A PPI display looks
>> like a
>> slice of pie whose point is at the bottom of the DVI. The "point" of
>> the pie slice is where your aircraft is now and the 50 degree arc
>> covers the
>> terrain ahead of the projected flight path.) PPI information does not
>> give the crew any indication of terrain elevation so its use alone for
>> terrain clearance monitoring was not conducive to mission prosecution
>> or crew longevity. <g>
>>
>> By the time I completed type training in the A-6 (1972), we were not
>> using
>> or receiving significant training with SRTC. The primary reason for
>> this was
>> SRTC's inability to detect smaller man-made features - like cables
>> that the
>> bad guys could suspend across a valley. Every now and then, though,
>> we'd light up SRTC especially if we were flying a training route like
>> Whidbey's OB-16 whose features were well-known and for which both crew
>> would establish
>> a mutually agreeable safety margin. (Humorous example: "300
>> additional feet of clearance for each wife, plus 100 additional feet
>> for each kid.")
>>
>> Elevation Scan
>>
>> Another feature in the A was Elevation Scan (E-scan). With E-scan the
>> A's AN/APQ-112 track radar was used to generate vertical terrain
>> development on the Pilot's Horizontal Display (PHD) the CRT
>> immediately below the VDI on
>> the pilot's side. The pilot read vertical development "left to right"
>> on the PHD, with obstructions closer to the aircraft appearing on the
>> left side
>> of the PHD and those at greater range lying more to the right.
>> (Again, I
>> apologize. This is hard to describe without a graphic.) E-scan
>> return would gradually slide from right side of the display (farther
>> away) to the left (closer) as the flight progressed and new return for
>> the same terrain
>> was processed. The information displayed on the PHD in E-scan also
>> included
>> a flight path line and a clearance line. The pilot would scan both
>> the VDI and the PHD while flying in E-scan mode, performing the
>> necessary spatial interpretation gymnastics to deduce how close the A
>> was to a possible prang.
>>
>> The B/N could not observe E-scan on his DVI. His viewing pleasure was
>> limited to search radar input, usually shown as PPI information while
>> the A was in E-scan mode.
>>
>> Like SRTC, E-scan's day had passed by the time I reached type training
>> - if
>> in fact it ever had a "day" to enjoy. Aside from being a clumsy way
>> of figuring out how close to pranging you might be, E-scan was further
>> limited by the track radar's relatively poor reliability.
>>
>> Hope this helps.
>>
>
> --
> Nick
> Mandrake 9.2
> KDE 3.1.3

[Mike Kanze]

Nick,

Got back my copy of FOTI this weekend and turned to the segment you mention.

From Coonts' narrative, the route sounds a bunch like the OB-16 route.
IIRC, OB-16 started in northern Oregon and ended at the B-16 nuclear
bullseye at NAS Fallon, NV. The early legs of this route took one into the
canyons of the John Day River system, including one particular canyon that
runs almost exactly N-S. After watching canyon walls go by for about 20 nm,
the terrain begins to broaden and you change course to roughly SSE for a ~70
nm leg to Harney Lake. The few charts I saved of this area confirm the
existence of some low hills and shallow valleys along this otherwise
flattening route. I would guess these are the hills Coonts was visualizing
as threats to Jake and Morg when he wrote this segment.

(For those among you who are limited to the likes of a Rand-McNally road
atlas, the route starts at a little burg named Kimberly which is about 60 nm
SSW of Umatilla, OR.)

There's no specific thing that Coonts mentions in his narrative that would
cause Morg to scream for a pull-up. Morg has just put his head back into
the hood, so he is not looking at the pilot's VDI. (Neither apparently is
Jake, since he is not maintaining the 1,000 feet of clearance he has cranked
into the VDI's offset impact bar.) Since Jake is viewing SRTC on the VDI,
Morg is limited to a PPI display on his DVI. Morg may have noted a
way-too-strong radar return too close-in for comfort. Or maybe things just
"didn't look right" to him, the sound of that little voice we all carry
within us. Or maybe this was just some artistic license taken by Coonts.

Night or IMC conditions are absolutely the most demanding environment for
low-level flight. Jake clearly has let his scan deteriorate away from the
SRTC info and (as the narrative states) dwell too much upon other things
like engine instruments and fuel state. Unless you're heading directly for
a canyon wall, your radar altimeter readings do not deteriorate from 1,000
feet to 100 feet in only an instant.

Coonts' narrative is one of many good examples of the value of having two
pairs of eyeballs sitting side by side for attack work. For low-level, all
wx ops this was the gold standard of that era. The
situational awareness such an arrangement facilitates - and demands - of
both pilot and B/N undoubtedly saved many a mission, bird and crew.

--
Mike Kanze

"It was like being a rat living under a bowling alley."

- Willem Dafoe, commenting on what it was like to sleep in a compartment
just below the flight deck of an aircraft carrier.



"Nick Coleman" > wrote in message
...
> Many thanks for this very detailed explanation, Mike. I can visualise
> exactly what you are saying when reading the book.
>
> (The episode I mentioned is on p 33 of the hardback edition, where Jake
> is remembering a training flight in which Morgan is giving a running
> commentary from his scope and then saves their lives by looking into
> his scope* and screaming, "Pull up" after Jake had relaxed and
> forgotten his scan. Sounds like Coonts may have used a bit of poetic
> licence in giving the BN's scope elevation info.)
>
> Thanks again,
> Nick
>
> * Coonts' terminology
>
>
> Mike Kanze wrote:
>
>> Nick,
>>
>> I've loaned out my copy of FOTI so I can't immediately refer to it in
>> trying
>> to answer your question. Try I will, though.
>>
>> First, the setting for FOTI is the later years of the VN conflict.
>> This is
>> important because the A-6A was the current Intruder model at that
>> time. The A-6E had not yet entered fleet service and some of the
>> whistles and bells of the A system were eliminated or very greatly
>> changed in the E system - including a couple of terrain-clearance toys
>> that Coonts likely describes in FOTI.
>>
>> Second, one must remember that the A-6A was the "first" of its kind -
>> the first aircraft with full integration of its various sensors into a
>> digital
>> (not analog, like the Norden bombsight) computer. In this respect it
>> was also very much "bleeding edge." The personal computing dictum
>> about being especially wary of Version 1 of anything could as well
>> have been written by those of us in the A-6A.
>>
>> Search Radar Terrain Clearance
>>
>> One terrain clearance toy was a feature called Search Radar Terrain
>> Clearance (SRTC). As its name implies, SRTC used the A's AN/APQ-92
>> search radar to generate a synthetic terrain display on the pilot's
>> Vertical Display Indicator (VDI), the very large cathode ray tube
>> (CRT) display in
>> the center of the pilot's console, right under the gunsight. The
>> synthetic display showed vertical terrain development in a 53 degree
>> by 26 degree
>> window about the projected flight path. For example, if the Intruder
>> was heading for a valley between two hills, the pilot would see return
>> generally in the shape of two hills (one on either side of the
>> display), with a
>> curving "V" notch in the center between them. (This is somewhat
>> difficult to describe without a graphic.) The return would slide
>> "down" toward the bottom of the VDI as the flight progressed and radar
>> return for these terrain features was processed.
>>
>> The B/N would not normally monitor the VDI, unless he happened to look
>> over
>> at the pilot's console. Instead the same radar return was presented
>> on the B/N's Direct View Indicator (DVI), the CRT in the center of the
>> B/N's console as a Plan Position Indicator (PPI) information covering
>> an arc of
>> about 50 degrees and a range of about 27 miles. (A PPI display looks
>> like a
>> slice of pie whose point is at the bottom of the DVI. The "point" of
>> the pie slice is where your aircraft is now and the 50 degree arc
>> covers the
>> terrain ahead of the projected flight path.) PPI information does not
>> give the crew any indication of terrain elevation so its use alone for
>> terrain clearance monitoring was not conducive to mission prosecution
>> or crew longevity. <g>
>>
>> By the time I completed type training in the A-6 (1972), we were not
>> using
>> or receiving significant training with SRTC. The primary reason for
>> this was
>> SRTC's inability to detect smaller man-made features - like cables
>> that the
>> bad guys could suspend across a valley. Every now and then, though,
>> we'd light up SRTC especially if we were flying a training route like
>> Whidbey's OB-16 whose features were well-known and for which both crew
>> would establish
>> a mutually agreeable safety margin. (Humorous example: "300
>> additional feet of clearance for each wife, plus 100 additional feet
>> for each kid.")
>>
>> Elevation Scan
>>
>> Another feature in the A was Elevation Scan (E-scan). With E-scan the
>> A's AN/APQ-112 track radar was used to generate vertical terrain
>> development on the Pilot's Horizontal Display (PHD) the CRT
>> immediately below the VDI on
>> the pilot's side. The pilot read vertical development "left to right"
>> on the PHD, with obstructions closer to the aircraft appearing on the
>> left side
>> of the PHD and those at greater range lying more to the right.
>> (Again, I
>> apologize. This is hard to describe without a graphic.) E-scan
>> return would gradually slide from right side of the display (farther
>> away) to the left (closer) as the flight progressed and new return for
>> the same terrain
>> was processed. The information displayed on the PHD in E-scan also
>> included
>> a flight path line and a clearance line. The pilot would scan both
>> the VDI and the PHD while flying in E-scan mode, performing the
>> necessary spatial interpretation gymnastics to deduce how close the A
>> was to a possible prang.
>>
>> The B/N could not observe E-scan on his DVI. His viewing pleasure was
>> limited to search radar input, usually shown as PPI information while
>> the A was in E-scan mode.
>>
>> Like SRTC, E-scan's day had passed by the time I reached type training
>> - if
>> in fact it ever had a "day" to enjoy. Aside from being a clumsy way
>> of figuring out how close to pranging you might be, E-scan was further
>> limited by the track radar's relatively poor reliability.
>>
>> Hope this helps.
>>
>
> --
> Nick
> Mandrake 9.2
> KDE 3.1.3

[Mike Kanze]

Nick,

Got back my copy of FOTI this weekend and turned to the segment you mention.

From Coonts' narrative, the route sounds a bunch like the OB-16 route.
IIRC, OB-16 started in northern Oregon and ended at the B-16 nuclear
bullseye at NAS Fallon, NV. The early legs of this route took one into the
canyons of the John Day River system, including one particular canyon that
runs almost exactly N-S. After watching canyon walls go by for about 20 nm,
the terrain begins to broaden and you change course to roughly SSE for a ~70
nm leg to Harney Lake. The few charts I saved of this area confirm the
existence of some low hills and shallow valleys along this otherwise
flattening route. I would guess these are the hills Coonts was visualizing
as threats to Jake and Morg when he wrote this segment.

(For those among you who are limited to the likes of a Rand-McNally road
atlas, the route starts at a little burg named Kimberly which is about 60 nm
SSW of Umatilla, OR.)

There's no specific thing that Coonts mentions in his narrative that would
cause Morg to scream for a pull-up. Morg has just put his head back into
the hood, so he is not looking at the pilot's VDI. (Neither apparently is
Jake, since he is not maintaining the 1,000 feet of clearance he has cranked
into the VDI's offset impact bar.) Since Jake is viewing SRTC on the VDI,
Morg is limited to a PPI display on his DVI. Morg may have noted a
way-too-strong radar return too close-in for comfort. Or maybe things just
"didn't look right" to him, the sound of that little voice we all carry
within us. Or maybe this was just some artistic license taken by Coonts.

Night or IMC conditions are absolutely the most demanding environment for
low-level flight. Jake clearly has let his scan deteriorate away from the
SRTC info and (as the narrative states) dwell too much upon other things
like engine instruments and fuel state. Unless you're heading directly for
a canyon wall, your radar altimeter readings do not deteriorate from 1,000
feet to 100 feet in only an instant.

Coonts' narrative is one of many good examples of the value of having two
pairs of eyeballs sitting side by side for attack work. For low-level, all
wx ops this was the gold standard of that era. The
situational awareness such an arrangement facilitates - and demands - of
both pilot and B/N undoubtedly saved many a mission, bird and crew.

--
Mike Kanze

"It was like being a rat living under a bowling alley."

- Willem Dafoe, commenting on what it was like to sleep in a compartment
just below the flight deck of an aircraft carrier.



"Nick Coleman" > wrote in message
...
> Many thanks for this very detailed explanation, Mike. I can visualise
> exactly what you are saying when reading the book.
>
> (The episode I mentioned is on p 33 of the hardback edition, where Jake
> is remembering a training flight in which Morgan is giving a running
> commentary from his scope and then saves their lives by looking into
> his scope* and screaming, "Pull up" after Jake had relaxed and
> forgotten his scan. Sounds like Coonts may have used a bit of poetic
> licence in giving the BN's scope elevation info.)
>
> Thanks again,
> Nick
>
> * Coonts' terminology
>
>
> Mike Kanze wrote:
>
>> Nick,
>>
>> I've loaned out my copy of FOTI so I can't immediately refer to it in
>> trying
>> to answer your question. Try I will, though.
>>
>> First, the setting for FOTI is the later years of the VN conflict.
>> This is
>> important because the A-6A was the current Intruder model at that
>> time. The A-6E had not yet entered fleet service and some of the
>> whistles and bells of the A system were eliminated or very greatly
>> changed in the E system - including a couple of terrain-clearance toys
>> that Coonts likely describes in FOTI.
>>
>> Second, one must remember that the A-6A was the "first" of its kind -
>> the first aircraft with full integration of its various sensors into a
>> digital
>> (not analog, like the Norden bombsight) computer. In this respect it
>> was also very much "bleeding edge." The personal computing dictum
>> about being especially wary of Version 1 of anything could as well
>> have been written by those of us in the A-6A.
>>
>> Search Radar Terrain Clearance
>>
>> One terrain clearance toy was a feature called Search Radar Terrain
>> Clearance (SRTC). As its name implies, SRTC used the A's AN/APQ-92
>> search radar to generate a synthetic terrain display on the pilot's
>> Vertical Display Indicator (VDI), the very large cathode ray tube
>> (CRT) display in
>> the center of the pilot's console, right under the gunsight. The
>> synthetic display showed vertical terrain development in a 53 degree
>> by 26 degree
>> window about the projected flight path. For example, if the Intruder
>> was heading for a valley between two hills, the pilot would see return
>> generally in the shape of two hills (one on either side of the
>> display), with a
>> curving "V" notch in the center between them. (This is somewhat
>> difficult to describe without a graphic.) The return would slide
>> "down" toward the bottom of the VDI as the flight progressed and radar
>> return for these terrain features was processed.
>>
>> The B/N would not normally monitor the VDI, unless he happened to look
>> over
>> at the pilot's console. Instead the same radar return was presented
>> on the B/N's Direct View Indicator (DVI), the CRT in the center of the
>> B/N's console as a Plan Position Indicator (PPI) information covering
>> an arc of
>> about 50 degrees and a range of about 27 miles. (A PPI display looks
>> like a
>> slice of pie whose point is at the bottom of the DVI. The "point" of
>> the pie slice is where your aircraft is now and the 50 degree arc
>> covers the
>> terrain ahead of the projected flight path.) PPI information does not
>> give the crew any indication of terrain elevation so its use alone for
>> terrain clearance monitoring was not conducive to mission prosecution
>> or crew longevity. <g>
>>
>> By the time I completed type training in the A-6 (1972), we were not
>> using
>> or receiving significant training with SRTC. The primary reason for
>> this was
>> SRTC's inability to detect smaller man-made features - like cables
>> that the
>> bad guys could suspend across a valley. Every now and then, though,
>> we'd light up SRTC especially if we were flying a training route like
>> Whidbey's OB-16 whose features were well-known and for which both crew
>> would establish
>> a mutually agreeable safety margin. (Humorous example: "300
>> additional feet of clearance for each wife, plus 100 additional feet
>> for each kid.")
>>
>> Elevation Scan
>>
>> Another feature in the A was Elevation Scan (E-scan). With E-scan the
>> A's AN/APQ-112 track radar was used to generate vertical terrain
>> development on the Pilot's Horizontal Display (PHD) the CRT
>> immediately below the VDI on
>> the pilot's side. The pilot read vertical development "left to right"
>> on the PHD, with obstructions closer to the aircraft appearing on the
>> left side
>> of the PHD and those at greater range lying more to the right.
>> (Again, I
>> apologize. This is hard to describe without a graphic.) E-scan
>> return would gradually slide from right side of the display (farther
>> away) to the left (closer) as the flight progressed and new return for
>> the same terrain
>> was processed. The information displayed on the PHD in E-scan also
>> included
>> a flight path line and a clearance line. The pilot would scan both
>> the VDI and the PHD while flying in E-scan mode, performing the
>> necessary spatial interpretation gymnastics to deduce how close the A
>> was to a possible prang.
>>
>> The B/N could not observe E-scan on his DVI. His viewing pleasure was
>> limited to search radar input, usually shown as PPI information while
>> the A was in E-scan mode.
>>
>> Like SRTC, E-scan's day had passed by the time I reached type training
>> - if
>> in fact it ever had a "day" to enjoy. Aside from being a clumsy way
>> of figuring out how close to pranging you might be, E-scan was further
>> limited by the track radar's relatively poor reliability.
>>
>> Hope this helps.
>>
>
> --
> Nick
> Mandrake 9.2
> KDE 3.1.3

[Nick Coleman]

<posted & mailed>

Mike, thanks for the details and for taking the time to do it. I can't
really add much because you've said everything <g>.

Enjoy reading this stuff from the guys who have actually done it; much
appreciated.

Nick



Mike Kanze wrote:

> Nick,
>
> Got back my copy of FOTI this weekend and turned to the segment you
> mention.
>
> From Coonts' narrative, the route sounds a bunch like the OB-16 route.
> IIRC, OB-16 started in northern Oregon and ended at the B-16 nuclear
> bullseye at NAS Fallon, NV. The early legs of this route took one
> into the canyons of the John Day River system, including one
> particular canyon that
> runs almost exactly N-S. After watching canyon walls go by for about
> 20 nm, the terrain begins to broaden and you change course to roughly
> SSE for a ~70
> nm leg to Harney Lake. The few charts I saved of this area confirm
> the existence of some low hills and shallow valleys along this
> otherwise
> flattening route. I would guess these are the hills Coonts was
> visualizing as threats to Jake and Morg when he wrote this segment.
>
> (For those among you who are limited to the likes of a Rand-McNally
> road atlas, the route starts at a little burg named Kimberly which is
> about 60 nm SSW of Umatilla, OR.)
>
> There's no specific thing that Coonts mentions in his narrative that
> would
> cause Morg to scream for a pull-up. Morg has just put his head back
> into
> the hood, so he is not looking at the pilot's VDI. (Neither
> apparently is Jake, since he is not maintaining the 1,000 feet of
> clearance he has cranked
> into the VDI's offset impact bar.) Since Jake is viewing SRTC on the
> VDI,
> Morg is limited to a PPI display on his DVI. Morg may have noted a
> way-too-strong radar return too close-in for comfort. Or maybe things
> just "didn't look right" to him, the sound of that little voice we all
> carry
> within us. Or maybe this was just some artistic license taken by
> Coonts.
>
> Night or IMC conditions are absolutely the most demanding environment
> for
> low-level flight. Jake clearly has let his scan deteriorate away from
> the SRTC info and (as the narrative states) dwell too much upon other
> things
> like engine instruments and fuel state. Unless you're heading
> directly for a canyon wall, your radar altimeter readings do not
> deteriorate from 1,000 feet to 100 feet in only an instant.
>
> Coonts' narrative is one of many good examples of the value of having
> two
> pairs of eyeballs sitting side by side. For attack work - including
> low-level, all wx ops - this was the gold standard of that era. The
> situational awareness such an arrangement facilitates - and demands -
> of both pilot and B/N undoubtedly saved many a mission, bird and crew.
>

[J. McEachen]

Was the A6F/A-6A "first of its kind" with a digital bombing system? I
bombed from A3D-2/A-3B bombers, ours had the Norden electro-mechanical
analog computer with ASB-1A bombing system radar. I heard, but never
saw, that the 147xxx buno A-3B's, all delivered to Whidbey heavy attack
squadrons, had a digital ASB-7 bombing system. The ASB-1A system had a
1,200' margin of error, all who were inducted into the HATWINGONE "Bulls
Eye Club" were said to be victims of this error tolerance.
Does anyone here know of the ASB-7 systems? I don't know how long they
stayed in operation as bombers, the East coast VAH squadrons were
transitioning to the Vigilante starting 1961, the West coast A-3's seem
to have transitioned to KA-3B's and EKA-3B'shortly thereafter so this
all digital ASB-7 probably did little bombing.
Joel McEachen VAH-5

Mike Kanze wrote:
> Nick, I've loaned out my copy of FOTI so I can't immediately refer to
> it in trying to answer your question. Try I will, though.
>
> First, the setting for FOTI is the later years of the VN conflict.
> This is important because the A-6A was the current Intruder model at
> that time. The A-6E had not yet entered fleet service and some of
> the whistles and bells of the A system were eliminated or very
> greatly changed in the E system - including a couple of
> terrain-clearance toys that Coonts likely describes in FOTI.
>
> Second, one must remember that the A-6A was the "first" of its kind -
> the first aircraft with full integration of its various sensors into
> a digital (not analog, like the Norden bombsight) computer. In this
> respect it was also very much "bleeding edge." The personal computing
> dictum about being especially wary of Version 1 of anything could as
> well have been written by those of us in the A-6A.

[Mike Kanze]

Joel,

Thanks for enlightening me about the Whale's capabilities. The fact that
the ASB-7 was digital was unknown to me. Some of the other info I only
vaguely recall, since much of it came in ready room and O-Club conversations
from those former heavy attack types who migrated into the Intruder program.

I probably should have emphasized more the successful integration of the A-6
system in my original post. Certainly there were other digital bombing
systems in use prior to the A-6's ASQ-61. More precisely, the A-6 was the
first aircraft to integrate "successfully enough" all of its key sensors -
thermal, pitot-static, INS, radars, etc. into its computer (and with
computer feedback to some of these systems like the INS) - enabling it to
launch, successfully prosecute an attack and return to the ship without any
external visual reference until ball-call. Our term back then for this was
"full-system capable."

Of course this was the theory. The actuality was a system with an average
MTBF of less than a hop. A 1,200 foot error margin for the ASB-1A is
something we "old" B/Ns can identify with, since the Q-61 could go
squirrelly. I probably have a tighter CEP for manual range line attacks (a
typical form of A-6A degraded system attack) than for full-system work.

--
Mike Kanze

"John Kerry has promised to take this country back from the wealthy. Who
better than the guy worth $700 million to take the country back? See, he
knows how the wealthy think. He can spy on them at his country club, at his
place in Palm Beach, at his house in the Hamptons. He's like a mole for the
working man."

- Jay Leno


"J. McEachen" > wrote in message
...
> Was the A6F/A-6A "first of its kind" with a digital bombing system? I
> bombed from A3D-2/A-3B bombers, ours had the Norden electro-mechanical
> analog computer with ASB-1A bombing system radar. I heard, but never saw,
> that the 147xxx buno A-3B's, all delivered to Whidbey heavy attack
> squadrons, had a digital ASB-7 bombing system. The ASB-1A system had a
> 1,200' margin of error, all who were inducted into the HATWINGONE "Bulls
> Eye Club" were said to be victims of this error tolerance.
> Does anyone here know of the ASB-7 systems? I don't know how long they
> stayed in operation as bombers, the East coast VAH squadrons were
> transitioning to the Vigilante starting 1961, the West coast A-3's seem to
> have transitioned to KA-3B's and EKA-3B'shortly thereafter so this all
> digital ASB-7 probably did little bombing.
> Joel McEachen VAH-5
>
> Mike Kanze wrote:
>> Nick, I've loaned out my copy of FOTI so I can't immediately refer to
>> it in trying to answer your question. Try I will, though.
>>
>> First, the setting for FOTI is the later years of the VN conflict.
>> This is important because the A-6A was the current Intruder model at
>> that time. The A-6E had not yet entered fleet service and some of
>> the whistles and bells of the A system were eliminated or very
>> greatly changed in the E system - including a couple of
>> terrain-clearance toys that Coonts likely describes in FOTI.
>>
>> Second, one must remember that the A-6A was the "first" of its kind -
>> the first aircraft with full integration of its various sensors into
>> a digital (not analog, like the Norden bombsight) computer. In this
>> respect it was also very much "bleeding edge." The personal computing
>> dictum about being especially wary of Version 1 of anything could as
>> well have been written by those of us in the A-6A.

[John R Weiss]

"Mike Kanze" > wrote...

> I probably have a tighter CEP for manual range line attacks (a typical
> form of A-6A degraded system attack) than for full-system work.

MRLs were still alive and well in the A-6E TRAM in the late 80s! I can't claim
a great CEP with them, but they worked with a good B/N.

OTOH, I got one of my bullseye patches with a 5' hit on a high loft with a Mk76.
When a system was tight, it could be PFM!

[Mike Kanze]

John,

>When a system was tight, it could be PFM!

Absolutely! Those were the hops A-6A B/Ns would "almost" give up a testicle
to fly. Usually one didn't know until airborne how nice things would be, so
every time you manned up you hoped for the best. Flying the OB-16 route at
night with a tight system was "the stuff dreams are made from." (Apologies
to Sam Spade / Humphrey Bogart.)

--
Mike Kanze

"John Kerry has promised to take this country back from the wealthy. Who
better than the guy worth $700 million to take the country back? See, he
knows how the wealthy think. He can spy on them at his country club, at his
place in Palm Beach, at his house in the Hamptons. He's like a mole for the
working man."

- Jay Leno


"John R Weiss" > wrote in message
news:gxAad.159906$wV.63195@attbi_s54...
> "Mike Kanze" > wrote...
>
>> I probably have a tighter CEP for manual range line attacks (a
>> typical form of A-6A degraded system attack) than for full-system work.
>
> MRLs were still alive and well in the A-6E TRAM in the late 80s! I can't
> claim a great CEP with them, but they worked with a good B/N.
>
> OTOH, I got one of my bullseye patches with a 5' hit on a high loft with a
> Mk76. When a system was tight, it could be PFM!
>
>

[Paul Michael Brown]

> Flying the OB-16 route at night with a tight system was
> "the stuff dreams are made from."

What was the OB-16 route, and why was it so much fun to fly it with a
tight system at night?

[Mike Kanze]

Paul Michael Brown,

The OB-16 route was a low-level high speed (360 knots +) training route that
worked its way through the canyons of the John Day River system in eastern
Oregon, generally south-southeastward into northwestern Nevada, ending at
the B-16 target area near the Fallon (Nevada) Naval Air Station.

The route was specifically laid out as a means for west coast A-6 crews to
employ the Intruder's various sensors (aircraft and human) in as realistic a
way as possible in the prosecution of a single-aircraft attack against a
radar-significant target. The early route segments included terrain-masking
/ terrain-avoidance practice by flying IN the John Day River canyon (à la
Luke Skywalker on his landspeeder), practice in more typical
terrain-avoidance of low rolling hills and buttes, all leading to a
high-speed delivery of weapons on the target range. Each route segment had
specific checkpoints, system update points, leg speeds, leg times, and all
other manner of stuff a good crew needed to do well, to remain A-6 Jedi
Masters. This was fun because, with a good system and an experienced-enough
crew, one could play with all of the Intruder's then-state-of-the-art toys
in a very realistic way.

The remoteness and sparse population along the route made it an ideal
training environment, due to the realism offered by the widely varying
terrain and the reduced chance of disturbing the civilian population.

Flying IN the canyon or very close to the ground or obstructions enroute was
optional, and usually depended upon the combination of system "tightness",
wx and visibility, crew experience, and how many family members the crew
might widow /orphan if they pranged. <g> IIRC, in the 1972 - 1974 period
the A-6 was cleared to as low as 200 feet AGL in the canyon at the crew's
option. (I'm writing this from memory. Others with better info please jump
in.)

A similar but shorter training route - called the Tailhook Route - started
at roughly the same place but stayed entirely within eastern Oregon and
ended at the Boardman target range near Umatilla, on the Columbia River.

There used to be quite a number of OB routes throughout the US, used by all
of the flying service branches. These were laid out with the training needs
and equipment capabilities of the users in mind, jointly by the "customer"
service branch and the FAA. Don't know how many remain, or what they're
called anymore.

"OB" (in the OB-16 name) used to stand for "oil burner," a reference to the
effect that such low-level, high speed flight had on reciprocating engines -
as in the Douglas A-1. In 1974, the forces of political correctness and the
aftermath of the 1973 oil embargo conspired to cause a name change.

To "Olive Branch." <g>

--
Mike Kanze

"John Kerry has promised to take this country back from the wealthy. Who
better than the guy worth $700 million to take the country back? See, he
knows how the wealthy think. He can spy on them at his country club, at his
place in Palm Beach, at his house in the Hamptons. He's like a mole for the
working man."

- Jay Leno


"Paul Michael Brown" > wrote in message
...
>> Flying the OB-16 route at night with a tight system was
>> "the stuff dreams are made from."
>
> What was the OB-16 route, and why was it so much fun to fly it with a
> tight system at night?

[Allen Epps]

In article >, Mike Kanze
> wrote:

> Paul Michael Brown,
>
> The OB-16 route was a low-level high speed (360 knots +) training route that
> worked its way through the canyons of the John Day River system in eastern
> Oregon, generally south-southeastward into northwestern Nevada, ending at
> the B-16 target area near the Fallon (Nevada) Naval Air Station.
>
IIRC this route was later renamed to VR-1354 for us Prowler guys and
the IR-346 for the IMC flyers. Could be wrong about that.

The route I mostly remember fondly was the VR-1355. Once went by the
crags north of the lake above hwy 90 (point Echo maybe?) well below a
group of climbers as we were at 200 agl and 450kts+. At the Whidbey
airshow that year a group of boy scouts came up when I was standing by
the jet and apparently that was them, and said it made their trip. I
was on the Brooks ski lift at Stevens Pass go up to ski the bowl once
and had a section of VAQ-138 Prowlers go over at max warp, one inverted
pulling over the ridge, the other knife edge. You saw the clue light
come on when they saw the lodge and realized they were east of the
route and over a "noise sensitive". Everyone on the lift was cheering
them on though.

Pugs

[Mike Kanze]

Allen,

Great share. Thanks.

>Once went by the crags north of the lake above hwy 90 (point Echo maybe?)
>well below a group of climbers as we were at 200 agl and 450kts+.

One of the routes - Tailhook, maybe - had a leg that transited Lake Abert
from SE to NW (south central Oregon on your Rand-McNally road atlas). The
SE shore of the lake abuts a high rim and the approach to the rim was a
gentle up-slope, low-level leg. It was always fun to do a barrel roll after
passing the rim since there was quite a sudden drop-off from the rim level
to the lake level.

>Everyone on the lift was cheering them on though.

So much depends on the context of the moment. There have been two or three
times since 9/11 where pointy-nosed military aircraft have overflown UC
Berkeley's Memorial Stadium in conjunction with the National Anthem just
before a Cal home football game, and the crowd has LOVED it.

Yes - even in ultra-left Berkeley!

--
Mike Kanze

"John Kerry has promised to take this country back from the wealthy. Who
better than the guy worth $700 million to take the country back? See, he
knows how the wealthy think. He can spy on them at his country club, at his
place in Palm Beach, at his house in the Hamptons. He's like a mole for the
working man."

- Jay Leno


"Allen Epps" > wrote in message
et...
> In article >, Mike Kanze
> > wrote:
>
>> Paul Michael Brown,
>>
>> The OB-16 route was a low-level high speed (360 knots +) training route
>> that
>> worked its way through the canyons of the John Day River system in
>> eastern
>> Oregon, generally south-southeastward into northwestern Nevada, ending at
>> the B-16 target area near the Fallon (Nevada) Naval Air Station.
>>
> IIRC this route was later renamed to VR-1354 for us Prowler guys and
> the IR-346 for the IMC flyers. Could be wrong about that.
>
> The route I mostly remember fondly was the VR-1355. Once went by the
> crags north of the lake above hwy 90 (point Echo maybe?) well below a
> group of climbers as we were at 200 agl and 450kts+. At the Whidbey
> airshow that year a group of boy scouts came up when I was standing by
> the jet and apparently that was them, and said it made their trip. I
> was on the Brooks ski lift at Stevens Pass go up to ski the bowl once
> and had a section of VAQ-138 Prowlers go over at max warp, one inverted
> pulling over the ridge, the other knife edge. You saw the clue light
> come on when they saw the lodge and realized they were east of the
> route and over a "noise sensitive". Everyone on the lift was cheering
> them on though.
>
> Pugs