This slight shift farther back from the missile’s normal ‘hot’ aiming point actually made the difference when it came to the survivability of the two aircraft.
Israel relied on France as its principal supplier of arms for more than a decade, but by the mid-1960s its desire to purchase more advanced and capable US weapons saw it buy the combat-proven Douglas A-4 Skyhawk to perform light strike missions. Some 48 A-4Hs were initially ordered in 1966, and these soon formed the backbone of the Israeli Air Force’s attack arm.
Entering service two years later, the Skyhawk (dubbed the Ahit, or Eagle, in Israel) flew thousands of sorties during the 1967-70 War of Attrition with Egypt. Hostilities along the Lebanese and Syrian borders also triggered Ahit operations. Israel had introduced additional A-4 aircraft of several sub-types by 1973, and in October of that year, five Skyhawk squadrons saw combat during the Yom Kippur War.
More than 50 Skyhawks were lost during the 19-day conflict due to the high-risk multi-role missions flown by the attack squadrons and to the presence of plenty of mobile and shoulder SAMs.
As explained by Shlomo Aloni in his book Israeli A-4 Skyhawk Units in Combat, beyond refined attack patterns and improved evasive tactics, Skyhawk pilots began to release chaff bundles against radar-guided SAMs. Eventually, flares would also be added to chaff dispensers to defeat heat-seeking SAMs as well, but they were not available during the Yom Kippur War. Skyhawk anti-heat-seeking SAM countermeasures were hastily introduced, however, during the closing stages of the Yom Kippur War.
During 1968, the IDF/AF had launched a Super Mystere upgrade programme that included powerplant replacement, the French Atar 101 giving way to the American Pratt & Whitney J52. One in a long list of reasons for such a swap was commonality with the J52-powered Skyhawk, then entering service as the Super Mystere replacement. In order to fit the J52 into the French attack aircraft, major structural modifications had to be made primarily because of the differing dimensions and weight of the two powerplants. The French engine was also equipped with afterburner and the J52 was not. The nozzle of the improved Super Mystere had to be reshaped with a longer tailpipe that ended well aft of the tail section’s vertical and horizontal flying surfaces.
During the Yom Kippur War, improved Super Mysteres and Skyhawks flew similar missions and faced identical threats. Yet, the improved Super Mystere suffered fewer losses and less damage to heat-seeking SA-7s. Wartime analysis of this phenomenon indicated that the modified tail-pipe of the improved Super Mystere kept the explosion of the missile’s proximity-fused warhead away from the vital parts of the jet. This slight shift farther back from the missile’s normal ‘hot’ aiming point actually made the difference when it came to the survivability of the two aircraft.
The A-4’s nozzle ended well ahead of the tail section’s vertical and horizontal flying surfaces, so when a missile’s proximity fuse exploded the warhead slightly behind the nozzle, the resulting fragments sprayed the Skyhawk’s tail section, holing the flying surfaces and puncturing the crucial hydraulic fluid pipes.
A suggestion from the field triggered No 22 Air Maintenance Unit at Tel Nof to design a tailpipe modification for the Skyhawk. It came up with a nozzle extension that in plan view ended behind the rear of the tail section’s vertical and horizontal flying surfaces, as with the improved Super Mystery. The modification was hastily designed and No 22 Air Maintenance Unit prepared a prototype installation. Flight Test Centre pilots then made four flights in the modified Skyhawk within 24 hours and cleared the modification for squadron service. Within a further 24 hours the modification was operational.
Colloquially known among IAF ranks as the ‘Barrel’, the first Skyhawk destined to be fitted with this modification was flown from Tel Nof to the Israel Aircraft Industries facility at Lod Airport on the evening of Oct, 20, 1973 The `Barrel’-modified A-4N was returned to No 115 Sqn the following morning.
Israeli A-4 Skyhawk Units in Combat is published by Osprey Publishing and is available to order here.
Photo credit: Israeli Air Force and Oren Rozen via Wikipedia