F-105 and A-4 loss rates over North Vietnam

As everybody here probably knows, USAF F-105 Thunderchiefs and USN A-4
Skyhawks bore the brunt of the Rolling Thunder campaign from 1965 to
1968 and suffered accordingly. The F-105 and A-4 losses over North
Vietnam were 282 and 173 respectively.

Now the harder part. What were their loss rates (losses/sorties) and
how they compare? What factors contributed to the difference?

"KDR" wrote in message
oups.com...
As everybody here probably knows, USAF F-105 Thunderchiefs and USN A-4
Skyhawks bore the brunt of the Rolling Thunder campaign from 1965 to
1968 and suffered accordingly. The F-105 and A-4 losses over North
Vietnam were 282 and 173 respectively.

Now the harder part. What were their loss rates (losses/sorties) and
how they compare? What factors contributed to the difference?

Just figures like 282 and 173 do not a loss rate make. You need to take the
number of flight hours divided by the losses. One reason so many were lost
was that there were a LOT of them flying. During February 1969 I had about
120 F-105s on my flightline at Takhli.

Regards,

Tex Houston

Tex Houston wrote:
"KDR" wrote in message
oups.com...
As everybody here probably knows, USAF F-105 Thunderchiefs and USN A-4
Skyhawks bore the brunt of the Rolling Thunder campaign from 1965 to
1968 and suffered accordingly. The F-105 and A-4 losses over North
Vietnam were 282 and 173 respectively.

Now the harder part. What were their loss rates (losses/sorties) and
how they compare? What factors contributed to the difference?

Just figures like 282 and 173 do not a loss rate make. You need to take the
number of flight hours divided by the losses. One reason so many were lost
was that there were a LOT of them flying. During February 1969 I had about
120 F-105s on my flightline at Takhli.

Regards,

Tex Houston

Yes I know your point. So I asked "loss rates (losses/sorties)" in my
post.

Does anybody have each type's total sorties and flight hours?

On 9 Apr 2006 19:36:26 -0700, "KDR" wrote:


Tex Houston wrote:
"KDR" wrote in message
oups.com...
As everybody here probably knows, USAF F-105 Thunderchiefs and USN A-4
Skyhawks bore the brunt of the Rolling Thunder campaign from 1965 to
1968 and suffered accordingly. The F-105 and A-4 losses over North
Vietnam were 282 and 173 respectively.

Now the harder part. What were their loss rates (losses/sorties) and
how they compare? What factors contributed to the difference?

Just figures like 282 and 173 do not a loss rate make. You need to take the
number of flight hours divided by the losses. One reason so many were lost
was that there were a LOT of them flying. During February 1969 I had about
120 F-105s on my flightline at Takhli.

Regards,

Tex Houston

Yes I know your point. So I asked "loss rates (losses/sorties)" in my
post.

Does anybody have each type's total sorties and flight hours?

I think Tex' point was that the A-4 operations off the boat were of
much shorter duration and generally coastal, while the F-105 missions
tended to be significantly longer. That skews your statistic of
loss/sortie. Loss per combat hour isn't that good a metric either, as
there is considerable flexibility in what a "combat" hour actually is.

I'm sure there are some sources of those numbers buried in the
archives, but it would be a task to dig them out. I just scanned Wayne
Thompson's excellent book, "To Hanoi and Back" which covers USAF
operations only. It's got a lot of numbers of aircraft, sorties,
tonnages, losses, etc., but not the flying hours.

Seems necessary to note here that Thompson reports a max of 108 F-105s
in theater during 1968 and 70 in 1969, so Tex might have been double
counting. During the summer of '66 when I was there, we had three
squadrons at Tahkli (3x18=54) and we started the summer with two
squardrons at Korat and then expanded to four (36 aircraft and then
72). During the six months I was there, we lost 101 F-105s between the
two wings. Replacements came in from Bitburg and Spangdahlem in
Germany which re-equipped with F-4s as well as from Seymour Johnson
and McConnell in the states.


Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
www.thunderchief.org
www.thundertales.blogspot.com

"Ed Rasimus" wrote in message
...

Seems necessary to note here that Thompson reports a max of 108 F-105s
in theater during 1968 and 70 in 1969, so Tex might have been double
counting. During the summer of '66 when I was there, we had three
squadrons at Tahkli (3x18=54) and we started the summer with two
squardrons at Korat and then expanded to four (36 aircraft and then
72). During the six months I was there, we lost 101 F-105s between the
two wings. Replacements came in from Bitburg and Spangdahlem in
Germany which re-equipped with F-4s as well as from Seymour Johnson
and McConnell in the states.

I chose February 1969 for a reason. Korat was down to two F-105 Squadrons
(34th and 44th) as the F-4C conversion had begun. While the runway was
being repaired at Korat the F-105 squadrons were TDY to Takhli giving us
five squadrons at Takhli. While 18 was the squadron UE, we sometimes had
more, frequently had less. This was the basis for my comment. Probably the
most ever assembled on one airpach except AMARC.

Regards,

Tex

Ed Rasimus wrote:

On 9 Apr 2006 19:36:26 -0700, "KDR" wrote:


Tex Houston wrote:
"KDR" wrote in message
oups.com...
As everybody here probably knows, USAF F-105 Thunderchiefs and USN A-4
Skyhawks bore the brunt of the Rolling Thunder campaign from 1965 to
1968 and suffered accordingly. The F-105 and A-4 losses over North
Vietnam were 282 and 173 respectively.

Now the harder part. What were their loss rates (losses/sorties) and
how they compare? What factors contributed to the difference?

Just figures like 282 and 173 do not a loss rate make. You need to take the
number of flight hours divided by the losses. One reason so many were lost
was that there were a LOT of them flying. During February 1969 I had about
120 F-105s on my flightline at Takhli.

Regards,

Tex Houston

Yes I know your point. So I asked "loss rates (losses/sorties)" in my
post.

Does anybody have each type's total sorties and flight hours?

I think Tex' point was that the A-4 operations off the boat were of
much shorter duration and generally coastal, while the F-105 missions
tended to be significantly longer. That skews your statistic of
loss/sortie. Loss per combat hour isn't that good a metric either, as
there is considerable flexibility in what a "combat" hour actually is.

I'm sure there are some sources of those numbers buried in the
archives, but it would be a task to dig them out. I just scanned Wayne
Thompson's excellent book, "To Hanoi and Back" which covers USAF
operations only. It's got a lot of numbers of aircraft, sorties,
tonnages, losses, etc., but not the flying hours.

Been off-line for a month or so, as I occasionally need to take a break from the
10^-6 S/N ratio that (far too often) prevails on the NGs. Having at least
partially recharged my batteries and starting to wade my way through 9,700+
messages waiting for me on r.a.m., I'll jump in. While not breaking out F-105/A-4
loss rates specifically (I'd like to know what they were myself), "On Yankee
Station" does include areas of loss by service, total number of sorties and % in
each area, % causes of losses, etc.

Fixed-Wing Combat Sorties, % of total.

SEA, 4/1965- 3/1973

USAF 1,766,000 (68%)

USN 510,000 (20%)

USMC 320,000 (12%)


NVN, 4/1965 - 3/1973, % of total.

USAF 275,000 (52%)

USN 226,000 (43%)

USMC 27,000 (5%)

From the above, it can be seen that the USAF flew far more total SEA combat
sorties, while the USN flew a higher proportion of their combat sorties over NVN
(USN 226,000/510,000 = 44.3%: USAF 275,000/1,766,000 = 15.6%: USMC 27,000/320,000 =
8.4%), while the USMC flew almost all their sorties over SVN (as you'd expect given
their primary CAS mission).

Areas of In-Flight Battle Damage in NVN/SVN/Laos/Other or Unknown

USAF 39% / 33% / 25% / 3%

USN 82% / 5% / 11% / 2%

USMC 17% / 71% / 10% / 2%

The above shows similar biases as the sortie locations although skewed reflecting
the varying defenses of the different areas.

Causes of In-flight Fixed-Wing Losses, USAF/USN/USMC

AAA 26% / 37% / 14%

Unk. 16% / 25 % / 33%

SA/AW 47% / 18% / 50%

SAM 7% / 15% / 2%

Own Ord. 1% / 3% / ?%

MiGs 4% / 2% / -1%

Looking at the above, the relationship between the percentage of sorties flown by
each service in each area, the types of defenses in that area and the loss rates
to each cause is apparent, although whether any of the variations of loss
percentages are statistically significant will have to wait for someone with
expertise in that subject.

For instance, ISTR seeing it claimed (possibly in Jenkins' F-105 book) that the
Navy's use of track breakers like the ALQ-51 was less effective against SAMs than
the USAF's use of QRC-160 series noise jammers such as the ALQ-71/87, and the later
noise/deception QRC-335/ALQ-101 series. The USN flew almost 3 times the percentage
of their flights over NVN as the USAF did (44.3% vs. 15.6%), but suffered just over
twice (82% vs. 39%) as high a percentage of battle damage there, as well as just
over twice the loss rate to SAMs (15% vs. 7%), so at first glance there doesn't
seem to be any major difference. Without having data breaking down the NVN loss
rates by RP and period as well as # of sorties, I don't know that you can prove
anything by this.

What is notable is the % doubling of USAF losses to MiGs compared to the Navy. I
suspect this is due to several factors, including the greater VPAF warning time of
USAF strikes coming from Thailand as well as better ACM-trained USN pilots (F-8s
originally, then the F-4 types as well). But I think one of the reasons was due to
the VPAF generally stationing/tasking the missile-armed MiG-21s against the faster
USAF strikes coming from Thailand while using the slower, gun-armed MiG-17s largely
against the slower navy strikes (at least in 1972-73, when the MiG-17-equipped
923rd Fighter Regiment was normally based at Kep, with the MiG-21/-19s usually at
Noi Bai [Phuc Yen] and Yen Bai). By 1968 the MiG-17s were virtually ineffective
against the high-speed USAF strikes, so it made sense to send them against the USN
strikes which couldn't easily outrun them.

BTW, the cruise speeds of the USAF and USN strikes also need to be taken into
consideration when making any comparisons about the depth (and thus time over
Indian country) of USAF and USN strikes. Loaded A-4s cruising at 350 IAS don't
have to be as deep to spend equal or greater time being shot at as F-4s/F-105s
cruising 100+ KIAS faster; when it was time to get out of Dodge they also didn't
have the option of doing so at the speed of heat, as the AF birds did.

Guy

Thanks a million for your detailed reply.

Was there any big difference in tactics between the F-105 and A-4?
Ingress altitude, delivery profile, etc.
I wonder if the small size of the A-4 could have made it a more
difficult target for AAA.

In article ,
"Tex Houston" wrote:

"KDR" wrote in message
oups.com...
As everybody here probably knows, USAF F-105 Thunderchiefs and USN A-4
Skyhawks bore the brunt of the Rolling Thunder campaign from 1965 to
1968 and suffered accordingly. The F-105 and A-4 losses over North
Vietnam were 282 and 173 respectively.

Now the harder part. What were their loss rates (losses/sorties) and
how they compare? What factors contributed to the difference?

Just figures like 282 and 173 do not a loss rate make.

He didn't say they did, did he?

He specifically *asked* for rate information.

You need to take the number of flight hours divided by the losses.

That would be losses/flt. hour, but he was asking about losses/sortie.

One reason so many were lost
was that there were a LOT of them flying. During February 1969 I had about
120 F-105s on my flightline at Takhli.