Your friend is wrong.
The Tu-154 is one of the safest Soviet designs and certainly was not about to fall out of the sky when departing Frankfurt. However, it is indeed a noisy airplane and in order to minimize its noise impact would try to climb more steeply. The flight speeds for steepest climb is only three quarters of the speed for best climb, so it might seem that the Tupolev was flying more slowly when compared to more modern types with larger bypass ratio engines. This might look to the untrained eye like a stall being imminent, but that impression is plain wrong.
During approach the engines would run near idle speed, so noise would be less important. Now I have to speculate what made the Tu-154 look so different. Its large wing area and large flaps give it a very low approach and landing speed - might it be that also during approach your friend judged the airplane to be too slow?