Launch Pad McQuack

It started as the Beech 18. Then for military service was designated the C-45 Expeditor. There were quite a few variants but the AT-11 was the bomber training design.

glasscock

You got it!! You're up. Here are a couple of links with more info on the AT-11 "Kansan".

Dave

http://www.warbirdalley.com/at11.htm
http://twinbeech.com/at-11project.htm

Launch Pad McQuack

Ok guys sorry was gone for the day but let’s get this going again. This is my last question so will make it a good one. This may test you guys I had never heard this till recently when a friend who is a pilot just got checked out in the Collins foundation P-51C. We were discussing the differences from all his time in D models to the B/C model.

What design change happened between the early P-51B/C’s and the later P-51D’s that actually made the D models a bit slower than the earlier B’s. Will tell you right now it the answer has nothing to do with the change over to the bubble canopy.

jharkin

My Feedback: (2)

Damn thats a tough one.

I know that the loaded weight of the D increased around 500lb due to the 2 extra guns, extra ammo and some wing strengthening. But power on the latest V-1650 was also up another 150hp or so do to the change in supercharger gearing... so I don't think its a power to weight issue.

hmmm.

Other major structural change is that they added that kink in the inboard LE of the wing to accommodate changes to the main gear mechanism. This change increased wing area and specifically the wing area in the prop slipstream. Im going to guess that somehow the kink was the cause of the 3pmh decrease?

~Jeremy

Evil_Merlin

My Feedback: (13)

The D's did weigh 200lbs more. 7,450 pounds for the B and 7,635 pounds for the B/C, the wing also had greater chord at the root of the wing, even if it was a small increase.

Launch Pad McQuack

You guys are on the right track but not quite there. This was an aerodynamic change and the change was due to a short coming with the B/C's in combat conditions. So they decided to fix the short coming and the resulting airframe change created a slower aircraft.

on_your_six

My Feedback: (11)

I believe that the addition of the Dorsal Fin caused the speed loss.

The P-51 Bs and Cs and the newer Ds and Ks experienced low-speed handling problems that could result in an involuntary "snap-roll" under certain conditions of air speed, angle of attack, gross weight, and center of gravity. Several crash reports tell of P-51Bs and Cs crashing because horizontal stabilizers were torn off during maneuvering. As a result of these problems, a modification kit consisting of a dorsal fin was manufactured. One report stated:

"Unless a dorsal fin is installed on the P-51B, P-51C and P-51D airplanes, a snap roll may result when attempting a slow roll. The horizontal stabilizer will not withstand the effects of a snap roll. To prevent recurrence, the stabilizer should be reinforced in accordance with T.O. 01-60J-18 dated 8 April 1944 and a dorsal fin should be installed. Dorsal fin kits are being made available to overseas activities"

These kits became available in August 1944 and were fitted to Bs and Cs and to Ds and Ks. Also incorporated was a change to the rudder trim tabs, which would help prevent the pilot over-controlling the aircraft and creating heavy loads on the tail unit.

masteromodels

My Feedback: (11)

Just out of the blue could it have been a larger ( wider air scope ) then what was on the B model for more radiator area?

thanks bob

Launch Pad McQuack

Nope keep them coming no one has hit on it yet.

masteromodels

My Feedback: (11)

Another bolt out of the blue. Did then change the airfoil slightly to accomadate the changing of the guns to a upright position instead of laying flat in the B models to prvent thre jaming of the guns?

thanks bob

Evil_Merlin

My Feedback: (13)

It was because of the change for the M2 machine guns. The B/C was of course armed with 2 M2's per wing, however they were mounted rather unusally, they were tilted. This resulted in some rather nasty incidents of feed jamming while under combat manuvers. The D wing was slightly "thicker" to allow for the M2's to be mounted flat, and of course add a third machine gun per wing.

Don't forget the Dorsal fin was actually a retro fit. It was added to most P-51's (including B/C's) after its advantages were found to prevent the lack of directional stability that some time occured.

Launch Pad McQuack

Master and Evil are correct. The issue with the guns jamming in the early models was corrected in the D's. This made for a slightly thicker chord and in turn about 5 kts slower. Guess the guys a North American figured speed was of no use if the guns were not working. So master you had it first just before Evil so your up.

on_your_six

My Feedback: (11)

Kind of funny occurrence... within hours of researching this question, I was at the National Air & Space Museum Near Dulles Airport standing about 6 feet from the A6M1 ... but for a couple of weeks (the war ended), there were plans in effect to use one of these submarine mounted planes to bomb Washington. Can you imagine the effect of that raid? History was very much alive for me yesterday.

glasscock

OnUr6,

That is interesting. Expand on the submarine mounted Jap plane.

Dave

masteromodels

My Feedback: (11)

I will make this one easy. How can you tell the difference between a P-40B and a P-40C from the outside of the plane?

Rebel Flyer

At a glance, 197 litre drop tank?

Rebel

masteromodels

My Feedback: (11)

That is pretty much it, the C model had the schakles to carry a bomb or drop tank. You up next.

thanks bob

Rebel Flyer

There were quite a few internal changes to the P-40B like self sealing fuel tanks, and better armor protection for the pilot. Space for more bullets too.

Is it my turn? Here goes...

What aircraft had problems with the outer portion of the wingtips blowing off in high speed dives, and how was it corrected.

Rebel

800mZero

My Feedback: (2)

The F8F Bearcat was originally designed with outer wing panels that broke off if 7.5Gs were exceeded. Then to prevent asymmetric wingtip shedding, the panels were installed with primer cord along the seam, to blow the recalcitrant tip off if one went away.

Rebel Flyer

That was about 10 minutes !!! Nice going 800mZero. You are correct. Grumman later strengthened the tip and removed the explosive charge, and limited the aircraft to 7.5 G's

You're up...

Rebel

800mZero

My Feedback: (2)

Already what was a common modification done to warbird pilot's vehicles once they returned home after the war?

Ram-bro

My Feedback: (101)

painted WW on the fuse for war weary?

glasscock

The blue star tradition?

dvs1

They would essentially turn their vehicles into hot rods, basically adding more power to make them go faster. Most pilots needed more of an adrenaline rush from their own vehicles after being pilots and used to the speed in WWII

800mZero

My Feedback: (2)

dvs basically got it-the biggest thing I have read was noise!!! They would basically either kick off, or hack off the muffler to get the proper growl. Evil Merlin also pmed me about them putting Landing lights on instead of headlights!

DVS is up!