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PC Dave 04-11-2005 04:25 PM

Quote:

Originally Posted by nglitz
I flew B-52Gs and a few D models for most of the seventies. Griffiss AFB in upstate NY, Guam for some jungle visits and dropped into a few other stateside bases.

Norm, did you spend Christmas '72 on Linebacker II? That must have been an experience for all involved.

dmorrison 04-12-2005 12:27 AM

Quote:

Originally Posted by nglitz
Just stumbled on to this thread as I usually don't frequent the open discussions. I flew B-52Gs and a few D models for most of the seventies. Griffiss AFB in upstate NY, Guam for some jungle visits and dropped into a few other stateside bases. We did indeed (and still do) have crosswind landing gear. Unlike most airplanes with heavily loaded main gear & lightly loaded nose or tail wheels, the four main gear (two tires each) on a buf are all fairly equally loaded. All four castor pretty freely and will take up the crab in a landing. We also have little training wheels out near the tip to keep from dragging the tip tanks so the "wing low" method is out. There's a big knob in the center console right behind the autopilot controls that can preposition the gear to a crab. It can be done on the ground to plan on a takeoff crab or in the air to prepare for a landing crab. Great fun to swivel it back & forth while taxiing at a strange base & see the people staring at a sideways airplane. IIRC 30 degrees of crab was about the limit. I was lucky enough to never need that much.

Norm great to here form a real Bongo-52 pilot. What was the maximum demonstrated crosswind. With 30 degrees of crag that should be a lot. I guess Boeing really liked the gear setup they also used it on the B47.

Dave

Brian Carlton 04-12-2005 12:17 PM

Quote:

Originally Posted by dmorrison
Norm great to here form a real Bongo-52 pilot. What was the maximum demonstrated crosswind. With 30 degrees of crag that should be a lot. I guess Boeing really liked the gear setup they also used it on the B47.

Dave

I have a question concerning crosswind with such an airplane.

If, for example, you had a 50 kt. crosswind and the airplane would touchdown at 120 kt., would the relative angle of the wind be the angle between those vectors? In this case, 22 degrees?

Could you land a B-52 in a 50 kt. crosswind by holding it in a 22 degree crab?

I understand the risks of such an approach if the crosswind is not steady (and it never is), so the actual limit might be somewhat lower.

BamaMB 04-13-2005 09:40 PM

Your correct about the airplane nose being 22 degrees off the centerline of the runway in the example you gave. The trick is to get the nose back inline with the runway prior to touchdown by using a combination of the rudder and ailerons on the wings.

Back to the question that started this thread, noise is a big factor these days on determining which runway is used. I fly cargo planes in the middle of the night , and we are often faced with landing with less than favorable winds in order to avoid noise sensitive areas.

BamaMB 04-13-2005 09:48 PM

Just some more "bad day at the office" photos.


http://www.aviationpics.de/appr/app.htm

Brian Carlton 04-13-2005 09:59 PM

Quote:

Originally Posted by BamaMB
Your correct about the airplane nose being 22 degrees off the centerline of the runway in the example you gave. The trick is to get the nose back inline with the runway prior to touchdown by using a combination of the rudder and ailerons on the wings.

If the gear on the B-52 can be swiveled to 22 degrees, can you simply land the airplane in a 22 degree crab? The wheels are pointed directly down the runway and the airplane is pointed directly into the relative wind. :confused:

tangofox007 04-13-2005 10:10 PM

Quote:

Originally Posted by BamaMB
The trick is to get the nose back inline with the runway prior to touchdown by using a combination of the rudder and ailerons on the wings.

Not in airplanes with crosswind landing gear, like the B-52.

tangofox007 04-13-2005 10:24 PM

Quote:

Originally Posted by Brian Carlton
If the gear on the B-52 can be swiveled to 22 degrees, can you simply land the airplane in a 22 degree crab? The wheels are pointed directly down the runway and the airplane is pointed directly into the relative wind. :confused:

The airplane touches down in a crab, equal to the wind correction angle. However, the term "relative wind" does not really apply here. (If the airplane were heading directly into the relative wind, there would be no drift.) In order to have a relative wind that differs from the natural wind, the runway would have to be moving. Which is exactly the case with an aircraft carrier. Because the landing deck is offset 10 degrees from the centerline of the ship, the ships heading and speed are adjusted so that the relative wind (resulting from the natural wind and the ship's movement) is ten degrees off the port bow at 25 knots. That way landing aircraft have no crosswind component.

Brian Carlton 04-13-2005 10:35 PM

Quote:

Originally Posted by tangofox007
The airplane touches down in a crab, equal to the wind correction angle. However, the term "relative wind" does not really apply here. (If the airplane were heading directly into the relative wind, there would be no drift.) In order to have a relative wind, the runway would have to be moving. Which is exactly the case with an aircraft carrier. Because the landing deck is offset 10 degrees from the centerline of the ship, the ships heading and speed are adjusted so that the relative wind (resulting from the natural wind and the ship's movement) is ten degrees off the port bow at 25 knots. That way landing aircraft have no crosswind component.

Got it, thanks. ;)

Additionally got me to thinking about this aircraft carrier scenario:

There is a possibility of a small crosswind component if the natural wind is dead calm. The ship can't compensate for the ten degree offset of the runway. The crosswind component would be about 4 knots, correct? :confused:

BamaMB 04-14-2005 12:27 AM

If the gear on the B-52 can be swiveled to 22 degrees, can you simply land the airplane in a 22 degree crab? The wheels are pointed directly down the runway and the airplane is pointed directly into the relative wind.


Yes, the B52 lands with the wheel pointed down the runway and the nose pointed to one side.

tangofox007 04-14-2005 10:44 AM

Quote:

Originally Posted by Brian Carlton
Got it, thanks. ;)

Additionally got me to thinking about this aircraft carrier scenario:

There is a possibility of a small crosswind component if the natural wind is dead calm. The ship can't compensate for the ten degree offset of the runway. The crosswind component would be about 4 knots, correct? :confused:

That is exactly right. That situation is called "MYOW." "Make your own wind." The ship has to do 25 knots, and the relative wind is straight off the bow. The good news is that there is no need to turn into the wind, which always seems to blow in the opposite direction as the next port call.

TwitchKitty 04-14-2005 10:57 AM

Are carrier landings still strictly a hands-on procedure or can they land a plane on a carrier using computers only?

I know I am asking for information that is not in the news or in the movies.

A quick google search revealed this:
Quote:

Naval Aviation entered a new era on April 23, 2001,
aboard USS Theodore Roosevelt (CVN 71) as the Navy's Joint
Precision Approach and Landing System (JPALS) program set a
historic first. An F/A-18A Hornet touched down on deck
performing the first fully automated landing at sea using
Global Positioning System (GPS) satellites.
http://www.chinfo.navy.mil/navpalib/news/navywire/nws01/nws010427.txt

The link will take you to a text page that has a bunch of other stuff. Use the find on this page tool under your edit button.

Wes Bender 04-14-2005 11:56 AM

Quote:

Originally Posted by dmorrison
Norm great to here form a real Bongo-52 pilot. What was the maximum demonstrated crosswind. With 30 degrees of crag that should be a lot. I guess Boeing really liked the gear setup they also used it on the B47.

Dave

There was a subtle difference between the gear on the '47 and the '52. The general configuration was the same, but the B-47 didn't have crosswind crab capability. The B-47 only had two main wheels forward and two aft and the outrigger landing gear (attached to the wing at the inboard engine pod struts) actually provided stability and were needed to keep the aircraft from tilting to the left or right on the ground. On the B-52, these were positioned well out toward the wingtip and were called tip-protection gear.

The "bicycle" type gear on the B-47 made landing a bit tricky. The airplane sat in a nose high position and needed to be landed that way too. Touching the forward main gear down first generally resulted in the aircraft "porpoising" and there was enough lag in response to the controls that things could get interesting. Anyone here ever land one at Lakenheath with the celebrated "Lakenheath hump" in the middle of the runway?

(No, I didn't either, I was just a lowly crewchief who couldn't see enough from my fourth man position to get scared.......) :D

Wes

tangofox007 04-14-2005 02:09 PM

Quote:

Originally Posted by TwitchKitty
Are carrier landings still strictly a hands-on procedure or can they land a plane on a carrier using computers only?

.

The Automatic Carrier Landing System (ACLS) has been around for years. It has the capability for hands-off approaches and landings, but is seldom used in the fully automatic mode. More typically it is used to drive course and glidepath needles that the pilot tracks by hand.


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