# Boeing Model 40B

> mailplane series by Boeing

**Wikidata**: [Q21034528](https://www.wikidata.org/wiki/Q21034528)  
**Source**: https://4ort.xyz/entity/boeing-model-40b


## References

1. Passenger Airliners of the United States 1926-1986
2. The Complete Encyclopedia of Flight 1848-1939, Chartwell Edition