Earhart Project Research Bulletin #26
August 10, 2000

Update, 11/25/01

Subsequent analysis by Photek has determined that the “bent” pitot tubes are an optical illusion and were, in fact, undamaged at the time of takeoff. The conclusion that the belly antenna is missing remains unchanged.

 
The Lost Antenna II

The image below is a higher-resolution version of the Lae takeoff photo featured in The Lost Antenna. This photograph has not been sharpened, altered or enhanced in any way. It clearly shows that, although the loop, dorsal mast, pitot tube, and possibly the center ventral mast are present, the aft ventral mast appears to be missing.

Electra 1

Electra 1 Annotated

It could be argued, however, that our inability to see the mast does not prove that it wasn’t there. (You can not prove a negative hypothesis.) However, it now appears that there is positive evidence of the suspected takeoff accident that deprived the aircraft of its belly wire antenna.

TIGHAR has advanced the hypothesis that between the time the aircraft taxiied out for takeoff and the time it made its actual takeoff run, the aft central mast suffered a ground strike which broke it loose from the fuselage and left it dragging on the ground by the wire still attached to the center mast and the starboard side pitot tube.

Pitot TubeThe most likely time for the suspected ground strike may have been while the tail of the overloaded aircraft was being swung around at the far end of the runway to position the airplane for takeoff. The mast was not stressed for side loads. An abrupt puff of dust visible in the takeoff film may be the broken mast, dragged by the antenna wire, snagging on the ground and tearing the wire loose. Such an event would put a tremendous strain on the wire’s anchor point – the starboard pitot – and might logically deform that structure rearward. The takeoff photo shows quite clearly that the Earhart Electra has suffered exactly this kind of damage.

The “pitot” (pronounced PEE-toh) tubes are the “L” shaped devices protruding from the “chin” of the aircraft. All aircraft have them. They are part of the system that determines how fast the aircraft is moving through the air. The pressure exerted by “ram” air entering through the open end of the forward-pointing tube is compared with “static” air collected at a “dead” spot somewhere on the fuselage, and the difference is displayed to the pilot via the airspeed indicator in the cockpit. Earhart’s Electra had two pitot tubes because she had two airspeed indicators, one on the pilot’s side of the cockpit and a backup on the copilot’s side. The pitot tube on the copilot’s side also doubled as a forward anchor point for the belly wire antenna. It is, of course, essential for the proper functioning of the pitot that the ram air tube be aligned with the aircraft’s longitudinal axis, as illustrated in this photo taken of NR16020 taken immediately prior to its departure on the second World Flight attempt. If you look closely you can even see the antenna wire attached to the back of the starboard pitot a few inches above the ram air tube.

Pitot Tubes AnnotatedThe light seems to be catching only one of the two pitots in the Lae takeoff photo, but drawing the same lines as in the photo above leaves no doubt that the pitot tube that is visible has been significantly deformed downward and backward.

Pitot 2 Annotated

It is inconceivable that the aircraft would have left the hangar with such an obvious defect. However, it is also clear that by the time the aircraft was photographed during its takeoff run, one of the pitot tubes had suffered serious damage. The port side pitot was not attached to any external structure and it’s hard to imagine how it could have sustained such damage short of the aircraft colliding nose-first into something. The conclusion, therefore, seems inescapable that the pitot tube visible in the photo is the staboard side unit and that the deformation that is apparent was caused by the events suggested by the absence of the aft mast and the evidence of impact (puff) seen during the takeoff run.

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