Don’t Go Below The Hard Deck

We all find high-speed, low, altitude flying exhilarating to watch (if the box office that Top Gun: Maverick is doing is any indication). Still, the reality of the situation is that it is hazardous. The ground can be pretty unforgiving when traveling near Mach speeds.

Oh, and for the uninitiated, the “hard deck” is the altitude used during a training exercise to represent the ground. In combat, the hard deck is the ground.

In recent weeks the Russian Air Force has lost two Su-25 “Grach” or “Frogfoot” aircraft (and one pilot) in low-altitude crashes on their way to or from combat missions in Ukraine. The Sukhoi Su-25 Grach is a single-seat, twin-engine jet aircraft developed by the Soviet Union almost 50 years ago. It first took flight in 1975. They were designed to provide close air support for Soviet ground forces and have a top speed of 590 mph.

Losses of both fixed-wing and rotary-winged aircraft (helicopters) have been heavy over Ukraine in the first four months of the war. Both sides have lost about a fifth of their fixed-wing assets. Military analysts tell us that Ukraine has lost 39 human-crewed aircraft while Russia has lost 81. It’s hard to get an explicit confirmation on how many pilots have died, but most crashes likely involved at least one fatality.

Images of downed Frogfoot. Courtesy of @RALee85 and Twitter

Why So Many Losses?

The skies over Ukraine are dense, with overlapping air defense and detection systems employed by both sides. These include shoulder-fired surface-to-air missiles (SAMs), medium-range SAMs that are infrared or radar-guided, and longer-range SAMs. To help them see the bad guys coming, we’ve sent the Ukrainians AN/MPQ-64 Sentinel air surveillance radars capable of identifying approaching hostile aircraft (helicopters, fixed-wing, drones) and missiles.

In a nutshell, radar works by sending out signals and obtaining “returns” from objects in its operational area. Flying extremely low to the ground allows aircraft to get mixed in with the clutter of objects on the ground and therefore be harder to identify and target. Also, it goes without saying that soldiers on the ground carrying shoulder-fired missiles, Stingers, for example, can’t hit what they can’t see. On the other hand, aircraft flying extremely close to the ground at high-speed rates can appear and go over the horizon in seconds.

This is 2016 footage of a Ukrainian Air Force Su-25 doing an extremely low high-speed pass over a Lutsk airfield. Video courtesy of Vitaliy Labzenko and YouTube.

The Ukrainians employed the tactic of extremely low flying to resupply soldiers and civilians holed up at the Azovstol steel plant in occupied Mariupol. Instead of jets, these missions were flown by pairs of Mi-8MSB-V helicopters.

Video courtesy of @UAWeapons and Twitter

These flights were done at speeds up to 130 mph, sometimes only 8-10 feet from the ground. At those speeds and altitudes, power lines can become a real issue. The Russians eventually caught on to what the Ukrainians were doing, and they emplaced various types of SAMs along flight routes and managed to shoot down enough Ukrainian helicopters that they had to stop the resupply missions.

Because of the dangers inherent in ultra low altitude flight, the Russians are using experienced ex-Air Force pilots with lots of experience who are now working for the Wagner Group. Unfortunately, at least two Wagner pilots have been shot down over Ukraine. The recent crashes show us that even the most experienced pilots are not immune to the tiniest bit of human error when combining high speed with low altitude.