All radar, electronic, lighting and other systems were fully operational at the airport where a Tu-134 airliner crashed last week killing 47 people, the Moscow-based Interstate Aviation Committee (MAK) said on Monday.
The RusAir Tu-134 crashed while landing at Petrozavodsk airport in northwest Russia on June 20, just before midnight.
"The shutdown of the signal equipment with low intensity lights was only temporary: Emergency standby power sources [diesel generators] activated promptly and power supply was restored within five seconds after shutdown," the committee said in a statement.
"The power cut at the airport was caused by the plane crashing."
Russia's Transport Ministry recommended on Thursday that the nation's fleet of Tupolev Tu-134 airliners be grounded.
The decision comes despite an earlier statement by MAK that the Tu-134 which crashed was fully serviceable.
The accident was also initially blamed on pilot error by Deputy Prime Minister Sergei Ivanov.
The Tu-134 entered service in 1967 and production ceased in 1980.
The Transport Ministry says that of the 852 Tu-134s built, 179 remain, of which 90 are still flying. Of those, 28 belong to UTair Express, one of Russia's largest airlines.
