This question is for current or former KC-135 pilots. On the KC-135, if takeoff is made at a flap setting of 30: during clean-up do you retract the flaps first to 20 and then UP or do you retract to UP from 30 without stopping at 20? Or does it depend on other factors?

Also . . . A Boeing 707 pilot told me that one flew the takeoff in the 707 to 800 feet, retracted the flaps to UP and then reduced to climb thrust. Is this also SOP for the KC-135? My understanding is that for many airliners, the process is: takeoff to 1,000 or 1,500 feet agl then reduce [or accelerate] to climb speed and only then clean up the wing. Don't know the military procedure.

Thanks so much for any information!

I couldn't find any cabin view landings in the KC-135 but I found a nice one of a KC-135R landing in Guam which shows flap movement...

https://youtu.be/gVgb5DWLL1M

I've never been on the KC-135 but I've been on 707s and I remember that "squeak" the tires made when the mains touched done. A bit different from the thump I am used to on other airliners.

convair880mfan wrote:

Also . . . A Boeing 707 pilot told me that one flew the takeoff in the 707 to 800 feet, retracted the flaps to UP and then reduced to climb thrust. Is this also SOP for the KC-135?

IIRC the last KC-135E retired in 2009 or 10 so the old SOPs for the older engines wouldn't apply. My guess would be the engine operating limits on the -135R are considerably less conservative than on TF33 aircraft.

convair880mfan wrote:

My understanding is that for many airliners, the process is: takeoff to 1,000 or 1,500 feet agl then reduce [or accelerate] to climb speed and only then clean up the wing. Don't know the military procedure.

When to retract flaps will depend on a lot of variables including aircraft weight, stage length, departure routing, operator SOPs, weather conditions, and so on.

This is a great clip of a landing in a NATO 707 w/wing view:

https://www.youtube.com/watch?v=w3bdUeWcaBo

Yes, that's a nice, nice video. Thanks Aaron747. Is that a compressor stall after touchdown or something else?

convair880mfan, the KC-135 uses two climb profiles: AC-CL (Accelerate-Climb) and MAX.

Generally AC-CL 20 is the preferred profile; however, MAX 20 and MAX 30 are used occasionally, particularly to satisfy obstacle clearance and specific climb gradient criteria.

The AC-CL profile provides for a constant acceleration to enroute climb speed; once airborne and above minimum flap retraction speed and above a specified altitude--usually 500 feet AFE--the flaps are retracted and you continue to accelerate to climb speed.

The MAX profile maintains a constant airspeed--V2 + 10--to 2,000 feet AFE, at which time the nose is lowered slightly to allow for acceleration, and then the flaps are retracted on schedule.

As I recall, you maintain TRT (Takeoff Rated Thrust) or Reduced Thrust, as appropriate, until flaps are retracted, then set MCT (Maximum Continuous Thrust). As I recall, TRT was limited to 5 minutes.

Flaps are normally retracted in sequence--30 / 20 / Flaps up.

Quoting Aaron747 (Reply # 2), "When to retract flaps will depend on a lot of variables including aircraft weight, stage length, departure routing, operator SOPs, weather conditions, and so on."

In the KC-135, it's a fairly structured procedure, really not dependent on many variables other than command-specified procedures at some special operations airports. It's the same way in the A320 series--the flap retraction procedure--NADAP1/NADAP2 is generally the same for every takeoff, except as modified for a few special ops locations. I don't recall aircraft gross weight, stage length, departure routing (except for SID restrictions), weather conditions, etc., having much impact on when flaps are retracted. My company wants the flap retraction process to be very standardized and consistent to the maximum extent possible. It was the same in USAF.

convair880mfan, might I suggest in the future, place a question such as this in the "Military Aviation & Space Flight" Forum. There may be active KC-135 pilots who surf that forum and can provide you with much more detailed and current information.

e38

Thank you e38. That was just great information. Helped a lot. I should have posted this in the Military Forum.

Was flying the KC-135 a real blast? I know some had turbojets, some turbofans and some those CFM engines. If it isn't too personal a question, which kind did you pilot?

If you can find it, Robert S Hopkins' book (initial or later edition) on the KC-135 will give you about as much information about the type as any lay reader is likely to want. The accidents section details a number of crashes that, from my recollection, were in part attributable to the marginal performance of the KC-135A when operating at high gross weights. https://books.google.ie/books/about/The ... edir_esc=y

convair880mfan wrote:

Was flying the KC-135 a real blast? I know some had turbojets, some turbofans and some those CFM engines. If it isn't too personal a question, which kind did you pilot?

I flew the original A-model - like I tell people, "We were gods, we made water burn..."

I always enjoyed flying the -135, a good, solid airplane, I don't think she ever did anything that surprised me. A few nail biters along the way, but always got us home at the end of the day. Back then, in the SAC days, we sat a lot of alert, flew a lot of sorties that involved giving some gas to a B-52, flying a nav leg using the sextant to figure out where we were, then beating up the pattern back home. Did get to fly some neat refueling missions - West German Tornados over the "buffer zone" along the boarder with East Germany, the Looking Glass EC-135, plenty of fighters, and the final B-1A on its last flight, being retired to the Air Force Museum at Wright-Patt. I was fortunate to be at Grissom AFB, as we flew all of the odd-ball tankers, including the only KC-135s equipped for receiver air refueling - pulling up behind a KC-10 at night and having it blot out the sky is memorable.

Bob Hopkins and I were young co-pilots together at Grissom and we reconnected here on A.net about 10 years ago. Great guy, knows about all there is to know about the -135. Definitely check out his book if you want to learn more about this old bird.