It can be very difficult to see aircraft on the ground at night, especially when their strobes are not switched on.
“Another matter investigated by the NTSB was why the pilots of the two planes did not see each other in time to avoid the collision. Although the Metroliner didn’t have a cockpit voice recorder, rendering it impossible to say what the pilots were doing, it was hard to imagine that they could have seen a plane which was directly behind them. The USAir pilots, however, should have had an opportunity to spot the Metroliner. After all, it was a perfectly clear night, with at least 25 miles of visibility. But in his testimony before the Board, First Officer Kelly, the only surviving pilot from either plane, stated that the runway appeared perfectly clear — it was like the Metroliner wasn’t even there.
To understand why, investigators waited until a night with similar weather conditions, then positioned an identical Metroliner at intersection 45 on runway 24L at LAX. The investigators then flew several simulated approaches to runway 24L in a helicopter while the pilots of the Metroliner tested different lighting configurations. What they found was that if all of the Metroliner’s lights were turned on, it was possible to discern the aircraft, but in most configurations, it would blend almost perfectly into the runway lighting.
The Metroliner was equipped with an anti-collision beacon on the tail, navigation lights on the wingtips and tail, a taxi light on the nose, strobe lights on the tail and wingtips, and landing/recognition lights on the wings. However, normal Metroliner procedures called for the strobes, taxi light, and landing/recognition lights to be turned on only after receiving takeoff clearance. That left only the anti-collision lights and the navigation lights. An examination of the light bulbs confirmed that only these lights were illuminated at the time of the crash.
Testing showed that if these were the only lights on the Metroliner, it would have been very difficult to see. The navigation light on the tail blended perfectly with the runway centerline lighting, and the red anti-collision beacon was surprisingly dim. It was possible to spot the Metroliner if one knew it was there, but if one didn’t, it would have been a challenge. The findings therefore confirmed that it was unlikely that the pilots of USAir flight 1493 could have avoided the accident by seeing the Metroliner.”
source:
https://admiralcloudberg.medium.com/...s-5d24ab5fec46