In the old days when we flew by the seat of our pants and the grace of God we scoffed at new-fangled instruments, weight and balance charts and the like. If the plane looked ok and we figured there was an even chance of making it, we took her off (or went through the barbed wire fence which was a trademark of the cow pastures we used for landing strips ).

What a different gang we are today. Only this morning one of the boys who barnstormed in a Jennie "squawked" a plane because she had too great a rearward CG. Ridiculous, you say? No, it isn't. The '38 is a fighting man's airplane and if you expect the best performance you first must insure that the plane is in perfect fighting trim. All the power, ammunition and the armor-plate won't be of much help in combat if your plane is unstable and you find yourself fighting both the plane and the enemy.

However, due to the careful designing of our engineers you fellows in combat do not have to worry too much about CG, because the '38 with full complement of guns, ammunition, and fuel (including external reserve tanks) has a CG within the permissible range. Unless some forgetful mechanic leaves 'his tool box in the baggage compartment or you take off without one of your guns (which is unlikely) the CG will not exceed its limits.

We have become very CG conscious around here because we frequently test hop the 38's minus guns and ammunition; and if the crew chief has his mind on the little blond timekeeper rather than securely stowing compensating ballast in the nose we are liable to stall out before getting our gear and flaps up. We make a practice of checking the loading chart and also inspecting the baggage compartment in the right boom before each flight. We figure it pays.

*Army Test Pilot for more than three years
Over 4,000 hours
Army Service since 1930(Reserve and National Guards)
Commercial Pilot
Flown over 1,000 P-38 Airplanes
Test Pilot on Experimental models at Lockheed and other factories

Have you ever been in a plane that just feels terrible; the kind that is about as stable as an elephant on a billiard ball? When we get a plane like this we have to determine what is wrong, and one of our first checks is the CG. 

We first extend the gear and flaps full down and then roll the elevator tab all the way back. The Speed at which the plane stabilizes is the key to the CG condition. If we stabilize at 130 MPH it in,dicates that a full forward CG exists. Or if at 90 MPH stability is reached a full rearward CG is indicated. If the CG is within limits the 38 will stabilize at approximately 110 MPH.

These same conditions apply to you fellows in twin engine pursuit schools where you have occasion to fly 38's minus armament. Our field men report that some of you have been in jams or have decided that the 38 is unstable, when upon investigating it was found that the particular ship's CG was far exceeding the limits. Make sure that all the guns (or equivalent ballast) are in. In the case of ballast be sure it is secured. If those bags of shot start shifting around while you're in the air you'll really have a bucking bronco on your hands. Check your gas load, and your baggage compartment. You owe it to yourself and to the plane to see to it that the airplane is loaded correctly.

THE FOLLOWING TABLE WILL GIVE YOU AN IDEA OF THE EFFECTS OF IMPROPER CG:

CG TOO FAR AFT:

1. Creates neutrally stable to unstable condition. Particularly bad in accelerated stalls and in dives because of elevator force reversal.

2. Increases stall tendency.

3. Decreases speed.

4. Increases pilot strain in instrument flying.

5. Results in dangerous condition if tail structure is damaged or surface is shot away.

CG TOO FAR FORWARD:

1. Increases difficulty in flaring out during landing.

2. Overstresses nose wheel.

The picture below is the first in a series of six drawings by Lt. Fredric L. Kohn of Los Angeles who recently returned from combat duty over Tunisia, Sardinia, Sicily, and Italy. While flying P-38's over there he was awarded the Distinguished Flying Cross and the Air Medal with nine Clusters.

Lt. Kohn, a veteran of fifty combat missions and over 190 hours of combat, has put on paper the indelible memories of fatal mistakes made by members of his own squadron. Because they are authentic and depict errors that anyone may make, we consider it a privilege to be allowed to reproduce them in Hangar Flying. Poster-size reproductions are being mailed to all Army Air Bases and if there are any of our readers desirous of being included on the mailing list please let us know as soon as possible.

LOOK AROUND!

Prepared under the supervision of the IV Fighter Command

(This is an actual incident as seen and illustrated by Fredric Kohn.)