OnMark Engineering Company
| OnMark Eng. Co. | |||
|---|---|---|---|
 | |||
| Type: Private Company | |||
| Active: | |||
| Founder: | |||
| Headquarters: Van Nuys, CA | |||
| Business: Modifications | |||
| Employees: | |||
OnMark Engineering was a noted aerospace company that specialized in modifying Douglas Invader airframes. In fact, aside from the Invader modifications, their only other project was the modification of a Boeing 377 Stratocruiser into the prototype Pregnant Guppy for Aero Spacelines.
The building itself was located on the north side of the airport, off to the right of the approach end of runway 16R. The building now appears to be owned by Moulton Logistics.
Company History
Invader Models
Civil
OnMark Executive
OnMark Marketeer
OnMark Marksman
Military
YB-26K - 1 unit
B-26K - 40 units
(Note: The YB-26K was converted into a production B-26K model, so only 40 airframes were used for the B-26K project in total.)
Planes
B-26Ks
| Serial Number | Old Serial | Date Converted | Comments |
|---|---|---|---|
| 64-17640 | 44-35896 | 20 May 1964 | On Static Display at the South Dakota Air & Space Museum. |
| 64-17641 | 44-35322 | 13 Aug 1964 | Shot down 29 Dec 1967. |
| 64-17642 | 44-35345 | 9 Jul 1964 | Shot down 27 Aug 1967. |
| 64-17643 | 44-34392 | 3 Aug 1964 | Crashed 25 Jul 1966. |
| 64-17644 | 44-35451 | 13 Aug 1964 | Scuttled in Vietnam in 1975. |
| 64-17645 | 44-35546 | 13 Aug 1964 | Scuttled in Vietnam in 1975. |
| 64-17646 | 44-35375 | 12 Aug 1965 | Shot down 8 Jul 1969. |
| 64-17647 | 44-35904 | 23 Aug 1964 | Scrapped. |
Timeline
The following timeline has been constructed from cross referencing USAF Aerospace Vehicle Inventory Reports, Civil FAA Records, and accounts from OnMark employees.
1964
May
20 - 64-17640 conversion is complete
25 - 64-17640 test flight.
Jun
15 - 64-17640 accepted by USAF.
Jul
9 - 64-17642 accepted by USAF.
Aug
3 - 64-17643 accepted by USAF.
12 - 64-17646 accepted by USAF.
13 - 64-17641, 64-17644, & 64-17645 accepted by USAF.
23 - 64-17647 accepted by USAF.
Dec
21 - 64-17640 returns to OnMark.
31 - 64-17641 returns to OnMark.
1965
Jan
22 - 64-17641 leaves OnMark for 1st Air Commando Wing.
Feb
27 - 64-17640 leaves OnMark for 1st Air Commando Wing.
1967
Jul
12 - 64-17641 returns to OnMark for the third time.
Aug
29 - 64-17640 returns to OnMark for the third time.
Oct
19 - 64-17640 leaves OnMark for Sacramento Air Material Area (SMAAR).