Warbird Information Exchange

Old Crow's canopy contains some D-model parts, enabling it to be half-open, whereas Impatient Virgin's canopy can only be closed, or all the way open.

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"There are two types of people here; airshow whores and airshow prostitutes. The whores, like you and I, do airshow stuff for free, whereas the prostitutes are paid" - Reg Urschler

Blown canopies are not identical from one to the next.

Cool! Can't wait to see it!

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-Al Sauer
http://www.flickr.com/photos/spookythecat

Not sure what you mean by that, I think I get it, but please explain. Are you talking about the two new "malcolm" hoods today? or WW2 hoods? Also were these "malcolm" hoods "field" modifications. or something that was factory line assemblies? Also from your statement, would you be also refering to P-51D model hoods as well? ....

Mark the confused

Basically you clamp the sheet of canopy plastic into a form the shape of the canopy frame, heat up the assembly, then "inflate" the plastic from underneath and cool. The canopy is thus "blown" or inflated to shape by air pressure after it has been heated to a softened state. The fact that it has been evenly stretched by air pressure results in excellent optical properties but somewhat of a free form. If you were to vacuum or stretch form the canopy you would get some markoff from the mold or some uneven stretching that would negatively impact the optical quality but would yield a much more repeatable shape.

Look at a Bell 47 helicopter bubble and you can imagine how it might be blown up to shape like a balloon.

All the P-51 Macolm hoods were field mods- none left the factory that way.

Thx bdk, good stuff, all makes sense to me, how many "malcolm" mustangs would you guess there were modified in the field? Most all P-51B/C's or just a select few before the P-51D's showed up? I also heard a rumor that many mustang pilots liked the B/C's better than the D's .... Any truth to this?

I looked into this myself and it seems that it would be very hard to come up with a strong answer as to how many were fitted with Malcolm hoods by the end of the war. The P-51B/C's which had priority to be fitted with the Malcolm hoods were those based in the ETO, both RAF and USAAF, and I believe that the recon versions had even higher priority (even the Allison powered recon types opperated by the USAAF). By the end of the war not every B/C in the ETO was fitted with a Malcolm hood because production never caught up with demand, though it was very rare to find one operating still with a bidcage canopy. How rare? I don't exactly know. In general most B/C's in the ETO had Malcolm hoods by late 1944, and almost without exception all photo-recon B/C's were fitted with Malcolm hoods by late 1944. Once the Malcolm hoods were in production, I have read that the RAF would not send a B/C (Mk.III) to a squadron without the Malcolm hood already installed.

The task to remove the old canopy and install the Malcolm hood was an intensive task. I have read that it took anywhere from 130-140 manhours to complete, typically at service depots, as the task was so complex, requiring more than changing out canopy parts, but also requiring structural work, building up the canopy rails, riveting skin, and removing and installing a new antenna setup.

The best way I can imagine you would be able to get a good estimate at the percentage of ETO Mustangs which were fitted with a Malcolm hood by the end of the war, would be to study photo essays of fighter groups that operated B/C's in the ETO. I have found it almost impossible to find any mid-1945 photos of combat B/C's still operating with the birdcage canopy, with only minor exceptions.

My father crewed a P-51B in a recon unit and stated they did the Malcolm hood mod in the field. He said it was basically removing the old bird cage canopy, bolting the rails to the side of the fuselage, and installing the new canopy.

Some here more educated than me might say this is BS, but my dad told me his Hellcats were terrible at seeing behind them. They actually considered some sort of "field' modification (like the malcolm hood) to improve rear vision. Anyone know anything better about this theory than I?