, what "Winkle" Brown had to say about the Vengeance in his book, "Wings of the Weird and Wonderfull".
Although of American origin, the Vultee Vengeance owed its existence to the British. It happened like this. The RAF’s Air Staff had been so impressed with the blitzkrieg effectiveness of the Stuka dive bombers, that it decided it must go into the dive-bombing business, and so in 1940 the British Purchasing Commission initially ordered 400 of Vultee’s dive bomber design, the V-72 or Vengeance. Most of these early Mk.I and II aircraft went to the Royal Australian and Indian Air Forces, and the few that came to Britain were primarily for performance and handling assessment.
The USAAF purchased 600 Mk.IAs, Mk.IIs and Mk.IIIs for Lend-Lease and also retained some Mk.IIs for their own operation. A decision to continue purchasing V-72s for Lend-Lease led to some redesign. The zero wing incidence was changed to reduce the aircraft’s nose-up flight characteristics, and the armament changes saw 0.50 in. guns replace the four 0.30 in.wing guns, and a single 0.50 in. replace the two 0.30 in. guns in the rear cockpit. This was designated the A-35A, and 99 were built for the USAAF.
The significance of the different Marks of Vengeance were that the Mk.I was built by Northrop on direct British contract, the Mk.IA by Northrop on USAAF contract, the MK.II by Vultee on direct British contract, the Mk.III by Vultee on USAAF contract.
Further modifications were introduced in the RAF Vengeance IV and USAAF A-35B. Wing armament was increased to six guns, the bomb load doubled to 2,000 lb. and a more powerful version of the Wright Cyclone installed. A simplified fuel system was fitted, together with spring tabs to all control surfaces.
We received Vengeance IV FD2l8 at RAE Farnborough in August 1944 for comparison with other types of dive-bomber we were testing, and also to assess the effects of the design improvements over the Mk.I, which had four major faults, namely poor take-off, bad view in normal flying attitude, a complex fuel system, and heavy out-of-trim rudder foot loads in the dive.
My first impression of the Vengeance was that it was big for a single-engined aeroplane, and its mid-wing had a most unusual planform. The flat centre section had marked sweepback on the leading edges, while the trailing edges were straight. The outer wing panels, which were set at a slight dihedral angle, had straight leading edges, while the trailing edges swept sharply forward to squared-off wing tips. Dive brakes were fitted both above and below the outer wing panels, hinging upwards and backwards, and forward and downwards respectively.
The Vengeance cockpit was in the roomy American style, but instrumentation layout was haphazard with no thought given to rational grouping for the operational task.
The controls consisted of statically and aerodynamically balanced fabric covered elevators and rudder, with controllable trim-tabs in the rudder and port elevator, while the differentially-operated metal ailerons both had electrically operated trim-tabs.
Starting up the Cyclone produced that powerful throaty growl I have always associated with that engine, which in this case drove a Hamilton Standard Hydromatic constant-speed airscrew.
The undercarriage, in spite of its laborious gyration backwards through 90 degrees to lie flat beneath the wings in “bathtub” fairings, retracted remarkably smartly, and the tail wheel partially disappeared into the tail cone. Once the ironmongery was raised and the slotted trailing edge flaps followed suit, the rate of climb became fairly respectable, with stability neutral round all three axes.
At 10,000 ft. I levelled off into the cruise at 215 mph and again stability was neutral. View dead ahead was poorish due to the slightly nose-up normal flying altitude of the aircraft, but the controls were quite well harmonised. Then up to 15,000 ft. to check the stalling characteristics, which were remarkably mild, with slight buffet some 8 mph before the nose dropped gently.
And so to the main objective — to assess the Vengeance IV as a dive bomber. On the run-in a shallow dive is usually entered to build up speed and at this stage the bomb doors are opened, so the higher their permitted operating speed the better. The Vengeance had a high restricting speed of 335 mph thus allowing great operational flexibility in that respect. In the light of the poor view ahead I found it best to approach the target keeping it in sight on either bow until it drew abeam to disappear under the wing tip, and then peel off on to it.
On entering the dive the ailerons on FD2l8 were suprisingly light and the elevator force small, but the aircraft soon started to yaw to starboard and this had to be trimmed out. Speed build up to 270 mph was quite fast, requiring constant directional trimming to avoid skid, but the rudder foot load was light because of the spring tab.
At that speed I popped the dive brakes, which opened rapidly without affecting trim. However, to open the brakes necessitated removing one’s hand from the throttle, as the control was at one’s left elbow. Also the actuating lever had to be returned to neutral after completion of the operating movement.
Terminal velocity with the dive brakes extended was 300 mph and this was also the restricting speed for operating the brakes — a significant operational advantage. Although the elevator force built up progressively after 270 mph it never reached a force that could not easily be held by pushing on the stick without using the trimmer. The yaw to starboard still required constant trimming to avoid skid. Any corrections for line on the target are made by rolling in the dive, and the Vengeance IV’s ailerons remained delightfully light and effective throughout the speed range.
In the actual dive the view over the nose was excellent for the top cowling was flat and smooth, and the front windscreen panel wide enough to accommodate a dive bombing sight without completely obliterating direct vision sectors.
The Vengeance’s natural dive angle seemed to be about 70 degrees, which feels to the pilot more like 90 degrees, and pull-out after bomb release only required a light stick force per ‘g’ so that it was easy for the pilot to black himself out. However, the aeroplane was so highly stressed there was little fear of causing structural damage.
The dive brakes were closed immediately the bombs were released and pull- out commenced, but the bomb doors were only closed on resuming level flight so as to avoid trapping the bomb displacement gear, and their action was very quick thus speeding up the vital getaway.
The whole dive bombing sequence was so efficient with the Vengeance IV that it seems incredible that items such as trimmers should be so inefficiently designed in the cockpit. There was no indicator for the aileron trimmers, that of the rudder a mere electric bulb which lit up when the trimmer was at full nose right setting, while the elevator trim position was crudely painted on a disc above the operating handle.
In my opinion the trimmers for dive bombing should be low geared wheels working in the conventional sense and placed on a level with the pilot’s seat on the left-hand side, and should have pointer indicators marked in degrees of tab setting to each side of neutral.
The internal bomb bay accommodated two 500 lb. bombs, and as overload two further 250 lb. bombs could be carried on external wing racks. This gave the Vengeance a useful punch, which delivered with high accuracy because of the aircraft’s good dive-bombing characteristics, made it a potentially powerful attack weapon.
Surprisingly the Vengeance had a reputation of being somewhat difficult to land, but one must remember that it was being operated mainly in hot and high conditions, and often from hastily prepared strips hewn out of the jungle and of limited dimensions.
Actually the approach speed of 125 mph was quite high, but a lot of speed could be killed off in the last 100 ft. of height before touch down at 105 mph, and indeed the dive brakes could be extended at 10-15 ft. off the ground to give a positive sink on to a three point landing and at the same time act as drag brakes to reduce the landing run. However, once on the ground the view ahead vanished and the pilot had to keep his wits about him to keep straight on a narrow strip on an aircraft with comparatively narrow track undercarriage. I have read a number of pilot impressions of the Vengeance I and the great majority of these are far from enthusiastic, so Vultee did a great improvement job on the Mk.IV, albeit a little late for it to reap the operational benefits.
After the Ju.87, the Vengeance IV is the best dive bomber I have flown. The irony of this aeroplane is that although it was a vast improvement on the previous Marks of the type, only the latter saw operational service, while the Mk.IV arrived at a time when the Air Staff had gone cool on dive bombing, and so it was relegated to the ignominious task of target towing. The early Vengeances earned themselves a bad reputation, and therefore it is a great pity the Vengeance IV was not given a chance to redeem that situation.