After an initial tenure of 4 years on the Marut in 220 Squadron, I was posted to 31 Squadron in Hindon. Within a few months this squadron moved back to Jodhpur. So I was back to my old hunting grounds. Our second Marut Trainer aircraft D1697 was allotted in from HAL Bangalore. The first was D1696. Wg Cdr CKK Menon was to ferry in the trainer and every time he got airborne for the ferry, his R/T would fail in flight and he would land back in Bangalore for rectification of the snag. On landing the R/T would come back on. HAL could not figure out what caused the R/T to fail only in flight. This happened on three occasions. Finally after completing a full recheck of the circuitry the aircraft was again cleared for the ferry. This time the ferry went off without a hitch.
On 6th February 1976, D1697 was offered for an acceptance check. (Late) Wg Cdr Alan Mascarenhas wanted to fly with me from the rear seat to familiarise himself with the rear seat operations. We got airborne and completed the acceptance check. On our return to base we decided to do a few aerobatics over the airfield. After a few maneuvers Mascy said he would like to try a loop from the rear cockpit. I hand him the controls. He built up speed and pulled up for a loop & as the aircraft went vertical I saw the speed washing off rapidly and looked inside & saw the airbrake white flag coming out. I tried to shout to Mascy to put the airbrakes in, but the R/T had failed. The rear cockpit air brake switch was the master switch, it over rode the switch in the front cockpit. Instinctively I held the control column and tried to do a high barrel roll. The aircraft was vertical and did two vertical rolls. The speed had washed of the clock, so I held the control column in the neutral position & locked the rudders and hoped like hell the aircraft would not go into a spin. Just then the aircraft did a clean smooth HAMMER STALL. I let the aircraft nose drop down way below the horizon & gradually opened full power, as both engines had stalled. By then Mascy had realized the air brake were out & he had put them in. The aircraft built up speed, I indicated to Mascy I had the controls. We joined circuit indicated to the ATC we had a R/T problem and landed. On landing Mascy apologized and said his knee had inadvertently brushed against the airbrake switch activating it while he was concentrating on going on the back of the loop and put them in only when the aircraft hammer stalled. This was a problem tall pilots had to look out for whilst operating from the rear cockpit due to the hump on the floor, which caused their knee to touch the throttle, which has the air brake switch. Well alls well that ends well. After this experience I realized the trainer would also never go into an inadvertent spin!! Subsequently as the R/T failure did not rectify itself the snag was detected on the ground to be from the front cockpit wiring which was found cut due to the seat butting on it. The last time I did a hammer stall was during intermediate training on Harvards. I spent a tenure of four and a half years in 31 Squadron totaling a tenure of eight and a half years on the Good old Marut.-The Winged Spirit.