Aer-R-10-RFF

MEMORANDUM

20 May 1944

From: Military Requirements.
To: Chief, BuAer.
Subj: Cancellation of XTB2F Project - Recommendation for.

1. The Mock-up Board for the XTB2F convened at Grumman Aircraft Engineering Corporation 1 to 4 May. While the board was immediately concerned with the way in which the essentials of the mock-up conformed to the specification, there was much general discussion relative to the operational limits imposed by the weight and size of the model.

2. Military Requirements recommends that the XTB2F project be cancelled and that no further development of this model he undertaken.

(a) This plane because of its weight and size can only be used from CVB, and their weight and clearances make even this use appear impractical.

(b) In comparison with other types, the XTB2F is only slightly faster, 310 mph. as against 293 mph. for the TBY, and not up to the speeds of new design attack planes.

(c) The carrier take-off run is exceedingly long. Take off with 700 gallons (reduced fuel) is 449 feet, indicating an operational spot of 600 feet from the bow. Take-off with 960 gallons (full internal fuel) is 646 feet, indicating an operational spot of 725 feet from the bow.

(d) the large size of the plane greatly reduces the number of planes which can be carried per ship. Studies indicate that only 5 1/2 planes per 100 feet of flight deck can be accommodated, while current VTB types spot 10 to 12 planes per 100 feet of deck.

(e) The weight of the plane (35,000 lbs.) is greater than that for which the flight deck of the CVB is stressed (26,000 lbs.). An emergency landing immediately after take-off would require complete jettisoning of the bomb load which would still leave the plane at approximately 33,000 lbs.

(f) The height of the plane, 20' 1" over the tail, requires the use of unproven arrangement of a nose wheel extending device which lowers the tail to 17'. Handling in the hangar will be marginal, even on the CVB. Although the plane, 52'6" x 36.0' folded, will operate, unloaded only, on the two deck elevators, which are 54' x 46', it will not operate on the side elevator 54' x 34'.

Elevator operating strength:

26,000 lbs

46 seconds

Overload:

35,000 lbs

53 seconds

3. The advantages intended to be gained in this type were:

(a) Increased load and armament
(b) Increased rate of climb
(c) Increased range

Although the load and armament per plane is doubled, the number of planes that can be carried is less than one-half. It is considered that carrier types must maintain performance, as against range, equal or superior to other enemy types, both land and ship based. A carrier attack cannot be based on surprise alone. Surprise will no longer be achieved with enemy use of radar. Carrier success, then, must be based upon superior performance and local control of the air during raids, both over own carriers and over the target. Long range carrier types in which performance is sacrificed for range are inconsistent with this policy. For carrier VB and VTB, range equal only to that of VF is deemed necessary.

4. Military Requirements recommends that this project be cancelled for the following reasons:

(a) Marginal handling characteristics aboard ship.

(1) Overloads deck
(2) Overloads elevators
(3) Overloads catapults
(4) Increases maintenance difficulties
(5) Reduces utility and operational mobility
(6) Makes hangar clearance marginal

(b) Fewer planes per ship resulting in smaller bomb load per air group.
(c) Too much has been sacrificed for long range.

5. It is further believed that no useful purpose could be gained by building this plane as a Navy land-based plane.

(a) Its speed and range do not justify land-based use.
(b) Shore-based attack planes are not properly a function of the Navy.

APPROVED:
R.F. FARRINGTON
Lt. Comdr., U.S.N.

J.S. RUSSELL
Captain, USN
Director, Military Requirements Division

Lt. Comdr. Farrington
5-20-44
S.E. Kuusisto