HobbyBoss 1/32 Northrop P-61B Tweaking Notes
By Steve Sobieralski
- TYPE: Northrop P-61B
- SCALE: 1/32
- COMPANY: HobbyBoss
- KIT NUMBER: 83209
- MOLD CREATION DATE: 2013
KIT DATABASE ENTRY:
http://www.largescaleplanes.com/kitdb/details.php?kit=2029
OVERVIEW
As part of this process, and for my own curiosity, I have produced the following list of differences between the various sub-types of both the A and B models, and the modifications to the kit required to produce that particular type. I am not a P-61 “expert”, but over a period of years I have acquired most of the available references on the P-61 and I have used these, as well as information available on-line. I am sure that this list is neither complete nor without error and there are several areas where changes are mentioned in the literature, but with no descriptions or illustrations that I have been able to find. These include the original hydraulic actuation for the landing gear doors, early cockpit heating system, differences between the early and later radar units, wing landing light changes, and several others.
The steps below refer to the 1/32 HobbyBoss P-61B kit instructions. Because of the step-by-step nature of the list I am afraid it is a bit redundant in some areas.
Note: Some later As and early Bs were apparently fitted with gun turrets in the field, mostly fixed to fire forward and operated by the pilot. (Edit 9/14/13)
BUILDING THE P-61A-1
Step 2
- If you delete the gun turret (see Step 21) I believe that you should also delete the gunner's and R/O's gun sights, parts W1-4, W6-7, WW12, W26 and W32. You may also consider deleting the gunner's seat altogether, although I have read that turret-less P-61s sometimes carried an observer in the gunner's position as an extra pair of eyes (Edit 9/14/2013).
- Delete parts Z15, Z16 and fill the hole in part K35, which is the pyrotechnic locker and should not have an oxygen hose attached to it.
Step 4
- Delete parts K2, K3 and J47. P-61As had a different heating system. The P-61 pilot’s manual states that the P-61A pilot’s seat was mounted on tracks to move fore and aft.
Step 9
- Delete parts K8, K11 and Z1. P-61As had a different heating system.
Step 10
- There should be an oxygen regulator and hose, similar to parts K25 and Z11, provided for the gunner.
Step 13
- Delete parts L5, V9, X32, L20 and X34. I don't believe P-61As had any forward landing gear lights.
Step 14
- Delete part L18 and replace with hydraulic struts. Mechanical actuation of the front gear doors was introduced on the P-61B.
Step 17
- Parts H1 and H3, remove the forward part (8 scale inches) of the fuselage back to the front of the wheel bay. Delete part Z14, there should be an oxygen regulator and hose, similar to parts K25 and Z11, provided for the R/O.
Step 18
- The radar in the P-61A was an earlier model than that in the P-61B. I don’t know which one the kit represents or what the visible differences were, if any.
Step 20
- I believe that parts K30 and K31 should be deleted and the indentations on the fuselage sides that receive them should be filled. I have yet to find a photo of a P-61A that shows these air scoops fitted. Note that parts K39 and K41, or H16, N2 and N17, may be deleted if the turret is deleted in Step 21. (Edit 9/14/2013)
Step 21
- Delete turret unless building one of first 37 A-1s.
Step 23
- If not installing turret use blanking plate part RA2.
Step 28
- Instead of using parts PA11 and PA18 use (2) parts PA10. P-61A-1s used R-2800-10 engines, which had a different ignition system than the R-2800-65s used by later p-61A's and B's.
Step 29
- Part G11 is incorrect, there were no closing bulkheads at the rear of the main wheel wells-they were open to the interior of the tail booms. There should be six oxygen bottles at this location which are not provided with the kit.
Step 31
- Delete parts PE2, PE3, Q1, Q3, Q5, Q8 and Q10 if showing controls in a neutral position. (Spoilers on one wing could be shown deployed in conjunction with appropriately defected ailerons and turned pilot’s control wheel.) Parts M1and C3, remove the stubs for the under-wing hard-points Most photos of P-61As do not show the wing edge lights, Parts X14 and X21. Some photos show the light positions covered with what could either metal covers or clear covers painted to match the overall scheme. (Edit 9/14/2013)
Step 33
- Everything between the rear of the engine and the front of the firewall is fictional on this kit. The exhaust system, engine mounts, and lack of duct-work are all incorrect. Use of Part Q7 will make this unimportant because none of this will be seen (assuming that you paint clear Part WC1, of course.) If Part Q15 is used the rear of the exhaust stubs should be somewhat visible, but not having them will not be too noticeable. If any cowling or access panels are to be opened, however, major scratch-building will be required behind the engine for an accurate look. I now believe that all P-61s were fitted with under-wing lights, part X25. (Edit 9/14/2013)
- Part G17 is incorrect, there were no closing bulkheads at the rear of the main wheel wells-they were open to the interior of the tail booms. There should be six oxygen bottles at this location which are not provided with the kit.
Step 36
- Delete parts PE1, PE4, Q2, Q4, Q6, Q8 and Q11 if showing controls in a neutral position. (Spoilers on one wing could be shown deployed in conjunction with appropriately defected ailerons and turned pilot’s control wheel.) Parts A3 and M6, remove the stubs for the under-wing hard-points. Most photos of P-61As do not show the wing edge lights, Parts X13 and X20. Some photos show the light positions covered with what could either metal covers or clear covers painted to match the overall scheme. (Edit 9/14/2013)
Step 38
- Everything between the rear of the engine and the front of the firewall is fictional on this kit. The exhaust system, engine mounts and lack of duct-work are all incorrect. Use of Part Q14 will make this a moot point because none of it will be seen (assuming that you paint clear Part WC2, of course.) If Part Q16 is used the rear of the exhaust stubs should be somewhat visible, but not having them will not be too noticeable. If any cowling or access panels are to be opened, however, major scratch-building will be required behind the engine for an accurate look.I now believe that all P-61s were fitted with under-wing lights, part X26. (Edit 9/14/2013)
BUILDING THE P-61A-5
Follow Steps for P-61A-1 With These Exceptions:
Step 2
- Since these aircraft did not have the gun turret (see Step 21) I believe that you should delete the gunner's and R/O's gun sights, parts W1-4, W6-7, WW12, W26 and W32. You may also consider deleting the gunner's seat altogether, although I have read that turret-less P-61s sometimes carried an observer in the gunner's position as an extra pair of eyes.(Edit 9/14/2013)
Step 20
- Note that parts K39 and K41, or H16, N2 and N17, may be deleted if the gunner's seat is deleted in Step 2. (Edit 9/14/2013)
Step 21
- Delete turret.
Step 23
- Use blanking plate Part RA2.
Step 28
- Use Parts PA11 and PA18 as shown, these are the GE “Turtle-back” distributors used on the R-2800-65. Remove the magneto on the top of PA21 and fashion a rectangular blanking plate to cover the opening. The GE distributors had integral magnetos.
BUILDING THE P-61A-10
No external differences from P-61A-5.
BUILDING THE P-61A-11
Follow Steps for P-61A-10 With These Exceptions:
Step 31
- Part M1, remove the stub for the under-wing hard-point. Part C3, retain the stub for the under-wing hard-point. (Edit 9/14/2013)
Step 36
- Part M6, remove the stub for the under-wing hard-point. Part A3, retain the stub for the under-wing hard-point. (Edit 9/14/2013)
BUILDING THE P-61B-1
Step 2
- Since these aircraft did not have the gun turret (see Step 21) I believe that you should delete the gunner's and R/O's gun sights, parts W1-4, W6-7, WW12, W26 and W32. You may also consider deleting the gunner's seat altogether, although I have read that turret-less P-61s sometimes carried an observer in the gunner's position as an extra pair of eyes.(Edit 9/14/2013)
Step3
- Delete parts Z15, Z16 and fill the hole in part K35, which is the pyrotechnic locker and should not have an oxygen hose attached to it.
Steps 4, 10, 11 and 12
- Night binoculars were introduced on the P-61B, but are not included in the kit (nor are they included in either the Avionics or Eduard cockpit upgrade sets.)
Step 10
- There should be an oxygen regulator and hose, similar to parts K25 and Z11, provided for the gunner.
Step 17
- Delete part Z14, there should be an oxygen regulator and hose, similar to parts K25 and Z11, provided for the R/O.
Step 20
- Note that Part SB1 does not have the correct configuration for a P-61B nosecone.
- I have found very few photos of P-61Bs that show the air scoops, parts K30 and K31, fitted. Check your resources for the specific aircraft that you are modelling. Note that parts K39 and K41, or H16, N2 and N17, may be deleted if the gunner's seat is deleted in Step 2. (Edit 9/14/2013)
Step 21
- Delete turret.
Step 23
- Use blanking plate Part RA2.
Step 28
- Use Parts PA11 and PA18 as shown, these are the GE “Turtle-back” distributors used on the R-2800-65. Remove the magneto on the top of PA21 and fashion a rectangular blanking plate to cover the opening. The GE distributors had integral magnetos.
Step 29
- Part G11 is incorrect, there were no closing bulkheads at the rear of the main wheel wells-they were open to the interior of the tail booms. There should be six oxygen bottles at this location which are not provided with the kit. But, if you modify the landing gear doors as described in Step 33, none of this will be readily visible.
Step 31
- Parts C3 and M1, remove the stubs for the under-wing hard-points. Parts N12 and N14, fill in the seam lines for the aileron trim tabs. (Thanks to Mark H.) Many photos of P-61Bs do not show the wing edge lights, Parts X14 and X21. Some photos show the light positions covered with what could either metal covers or clear covers painted to match the overall scheme. Check your resources for the specific aircraft you are building.(Edit 9/14/2013)
Step 33
- Everything between the rear of the engine and the front of the firewall is fictional on this kit. The exhaust system, engine mounts and lack of duct-work are all incorrect. Use of Part Q7 will make this unimportant because none of this will be seen (assuming that you paint clear Part WC1, of course.) If Part Q15 is used the rear of the exhaust stubs should be somewhat visible, but not having them will not be too noticeable. If any cowling or access panels are to be opened, however, major scratch-building will be required behind the engine for an accurate look. Cut parts G32 and G42 along the line ahead of the wheel bulge. With the landing hear down the rear doors should be closed.
Step 34
- Part G17 is incorrect, there were no closing bulkheads at the rear of the main wheel wells-they were open to the interior of the tail booms. There should be six oxygen bottles at this location which are not provided with the kit. But, if you modify the landing gear doors as described in Step 38, none of this will be readily visible.
Step 36
- Parts A3 and M6, remove the stubs for the under-wing hard-points. Parts N13 and N15, fill in the seam lines for the aileron trim tabs. (Thanks to Mark H.)
Step 38
- Everything between the rear of the engine and the front of the firewall is fictional on this kit. The exhaust system, engine mounts and lack of duct-work are all incorrect. Use of Part Q14 will make this unimportant because none of this will be seen (assuming that you paint Part WC2, of course.) If Part Q16 is used the rear of the exhaust stubs should be somewhat visible, but not having them will not be too noticeable. If any cowling or access panels are to be opened, however, major scratch-building will be required behind the engine for an accurate look. Cut parts G22 and G33 along the line ahead of the wheel bulge. With the landing hear down the rear doors should be closed. Many photos of P-61Bs do not show the wing edge lights, Parts X13 and X20. Some photos show the light positions covered with what could either metal covers or clear covers painted to match the overall scheme. Check your resources for the specific aircraft you are building.(Edit 9/14/2013)
BUILDING THE P-61B-2
Follow steps for the P-61B-1 with these exceptions:
Step 31
- Part M1, remove the stub for the under-wing hard-point, Part C3, retain the stub for the under-wing hard-point.
Step 36
- Part M6, remove the stub for the underwing hardpoint, Part A3, retain the stub for the under-wing hard-point.
BUILDING THE P-61B-6
There are references in the P-61 literature to this model, but I have been unable to determine what its specific features were.
BUILDING THE P-61B-10
Follow steps for P-61B-2 with these exceptions:
Step 31
- Part M1, retain the stub for the under-wing hard-point.
Step 36
- Part M6, retain the stub for the under-wing hard-point.
BUILDING THE P-61B-11
Follow steps for P-61B-10 with these exceptions:
Step 2
- Install the gunner's and R/O's gun sights, parts W1-4, W6-7, WW12, W26 and W32. (Edit 9/14/2013)
Step 21
- Install turret with two machine guns.
BUILDING THE P-61B-15
Follow steps for P-61B-11 with these exceptions:
Step 21
- Install turret with four machine guns.
BUILDING THE P-61B-16
- No external differences from P-61B-11.
BUILDING THE P-61B-20
- No external differences from P-61B-15.
BUILDING THE P-61B-25
- Gun-laying radar added, not aware of any external differences from P-61B-20.
FINAL NOTES
That's about it, at least for major visual differences among the variants. As always, check your references for the specific plane you are modeling, as individual airframes sometimes had non-standard factory or field modifications. Apologies for any errors and/or omissions, and any comments, additions, and/or corrections that anyone may wish to contribute are more than welcome.
© Steve Sobieralski 2013
This article was published on Friday, August 05 2016; Last modified on Friday, August 05 2016