Quote of the Day
Lack of confidence kills more dreams than lack of ability. Talent matters—especially at elite levels—but people talk themselves out of giving their best effort long before talent becomes the limiting factor. You're capable of more than you know. Don't be your own bottleneck.
Many years ago, at the start of my career, I worked with an excellent safety engineer who had served in WW2 as a fighter pilot in Europe with the US Army Air Corps (USAAC). You could tell that flying was the love of his life. Though we were working on naval weapons systems, our lunchtime talks often focused on his experiences flying aircraft during the war. His war service began in a P-47 (Figure 1) and his unit later transitioned to the P‑51 (Figure 2).
Most of his flying was over Europe doing bomber escort. While he generally had good things to say about both aircraft, most of his stories were about the P-51. One day I asked him if he had a preference between the P‑47 and P‑51. He answered with no delay and I found his response so interesting that I wrote it down in my collection of quotes.
I wanted to be flying a P‑47 if someone was going to be shooting at me because there was no coolant to leak from its radial engine if I was hit. If I was just going flying, then I wanted to be flying a P‑51. The P‑47 could dive very fast, but it did not climb well.
I started to wonder about units transitioning from one aircraft to another during the war. I decided to look at the Army Air Forces Statistical Digest (Hyperwar Site) to see if there was any information about fighter inventories during WW2. It turns out this document has several tables of aircraft inventory throughout the war. I used Power Query to Extract, Transform, and Load (ETL) the data into a quick report.
For those who like to follow along, my Excel Workbook can be downloaded here.
Excluding some obsolete fighters, the P-39 and P-40 were the main USAAC fighters on December 7, 1941. While both of these fighters had their strengths, they both had weaknesses relative to fighters like the Luftwaffes's BF-109 and Imperial Japanese Navy's A6M Zero. As quickly as possible, the P-39 and P-40 were replaced with the P-38, P47, and P-51. My workbook will look at this transition and how quickly it occurred.
My analysis method is straightforward:
- Use Power Query to directly download the download the data from the Hyperwar web site.
- Because the data is in multiple tables, develop a function that could process each table the same way.
- Apply the cleaning function to each table and consolidate the data.
- Plot the data.
Figure 3 shows the USAAC's on-hand first-line fighters during WW2. We can make some observations about how the on-hand fighter inventory varied:
- The P-47 numbers ramped up starting in mid-1942 and pretty much flattened out by mid-1944.
- The P-51 numbers started to ramp up in the second quarter of 1942 and continued to ramp until just before Victory of Japan Day (VJ-Day).
- P-39 and P-40 numbers began to decrease in early-1944. The P-39 did provide good service with the Soviets and the P-40 did well on ground support in the Mediterranean and North Africa.
The on-hand inventory data shows that the P-47 was the most numerous USAAC fighter through most of WW2. Its numbers stayed roughly constant after April-1944. The P-51 inventory ramp-up started later and was more gradual than that of the P-47, but they ended the war with similar on-hand numbers.