Category Archives: Aviation Safety

Video shows Syrian Navy Mi-14 anti-submarine helicopter (about to) crash land near Idlib

A Syrian Mi-14 ASW (Anti-Submarine Warfare) helicopter crash landed in the Idlib region.

On Mar. 22, a Syrian Navy Mil Mi-14 helicopter crash landed in the Idlib region, northwestern of the country.

According to the Syrian Observatory for Human Rights, at least four crew members (out of 6 probably aboard the helicopter) survived the incident and were captured by the Nusra Front and Islamic faction close to the capsized wreckage.

The helicopter was forced to attempt an emergency landing following a technical failure SOHR reported.

Here is a video, allegedly showing the Mi-14 going down earlier today:

H/T @hlk01 for the heads-up. Top image via @Tom_Antonov

 

U.S. drone crashed in Syria. Probably shot down by a Syrian SA-3 surface to air missile

An MQ-1 Predator crashed in Syria. According to Syria state media it was shot down by Syrian air defenses.

The U.S. lost contact with an unarmed MQ-1 Predator drone on Mar. 17.

Whilst Pentagon officials could not confirm whether the aircraft was shot down or crashed because of a failure, the Syrian SANA news agency reported that the unmanned aerial vehicle was shot down in the Latakia province by the Syrian air defenses.

Indeed, images of the wreckage of an aerial vehicle were later posted on social media: provided the photographs were really taken at the crash site, they show parts of the UAV (including a wheel of the landing gear) along with parts of what seems to be the body an S-125 Neva/Pechora (NATO reporting name SA-3 Goa) Soviet surface-to-air missile system: this may confirm the version of the Syrian State Media according to which the MQ-1, most probably operating out of Incirlik airbase, in Turkey, was shot down.

The event is interesting for several reasons:

1) it proves U.S. drones perform ISR (Intelligence Surveillance Reconnaissance) missions in a region (on the western coast of Syria) currently not interested by the air strikes targeting the Islamic State. Monitoring jihadist activities in the area? Keeping an eye on the fightings between rebels and loyalist forces? Monitoring shipments that reach Syria via sea?

2) if the shot down is confirmed, it proves that Assad fires back and Syrian air defenses can pose a threat to manned and unmanned aircraft that operate inside the Syrian airspace.

3) the area where the drone was allegedly shot down is the same where a Turkish RF-4E jet was shot down by a coastal air defense battery.

Image credit: U.S. Air Force

 

The amazing story of Bill Weaver: the Blackbird pilot who survived his SR-71 disintegration

The incredible story of a lucky SR-71 pilot who survived to a Blackbird disintegration at Mach 3+

Built as a strategic reconnaissance aircraft able to fly at 88,000 feet and Mach 3, the iconic Lockheed SR-71 required aircrews to wear a special silver pressure suit to ensure their safety. This proved to be much useful during the time, as the aircraft experienced several accidents at very high speeds and altitudes during its test flights.

The protection provided by these suits was put to test on Jan. 25, 1966 when Blackbird tail number 952 disintegrated mid-air during a systems evaluation flight. The mission was intended to investigate procedures designed to reduce trim drag and improve high Mach cruise performance while the center of gravity (CG) was located further aft than normal, reducing the Blackbird’s longitudinal stability.

The SR-71 was driven by Bill Weaver with a Lockheed flight test specialist, Jim Zwayer in the back seat and it took off from Edwards AFB at 11:20 am . They refueled from a KC-135, accelerated to Mach 3.2 and climbed to 78,000 feet, which was their initial cruise altitude.

During a programmed thirty-five-degree bank right turn they experienced an “inlet unstart” that caused the immediate unstart on the right J-58 engine, forcing the aircraft to roll further right and start to pitch up. An inlet unstart happened when a shock wave was rapidly ejected back outside the inlet. When an inlet unstart occurred a device called the cross-tie system was enabled to minimize the extreme rolling and yaw of the aircraft and to prevent the good inlet from unstarting. At the same time the cross-tie system also restarted the good engine. As Weaver himself told to former Blackbird pilot Col. Richard H. Graham in his book, “SR-71 The Complete Illustrated History of THE BLACKBIRD The World’s Highest, Fastest Plane”: “I jammed the control stick as far left and forward as it would go. No response. I instantly knew we were in for a wild ride.”

Since the chances to survive an ejection at Mach 3.18 and 78,000 feet weren’t very good, Weaver and Zwayer decided to stay with the aircraft to restore control until they reached a lower speed and altitude, but the cumulative effects of system malfunctions exceeded flight control authority. Everything seemed to unfold in slow motion, even if the time from event onset to catastrophic departure from controlled flight was only two to three seconds.

Weaver recalls that he was “still trying to communicate with Jim, I blacked out, succumbing to extremely high g-forces. Then the SR-71 literally disintegrated around us.”

Weaver struggled to realize what was really happening. “I could not have survived what had just happened. I must be dead. As full awareness took hold, I realized I was not dead. But somehow I had separated from the airplane. I had no idea how this could have happened; I hadn’t initiated an ejection. The sound of rushing air and what sounded like straps flapping in the wind confirmed I was falling, but I couldn’t see anything. My pressure suit’s face plate had frozen over and I was staring at a layer of ice.”

It was at that point that the pressure suit proved to be very effective protection for Weaver. In fact, once it was inflated, an emergency oxygen cylinder in the seat kit attached to the parachute harness was functioning. It not only supplied breathing oxygen, but also pressurized the suit, preventing Weaver’s blood from boiling at the extremely high altitude. In this way the suit’s pressurization had also provided physical protection from intense buffeting and g-forces. That inflated suit had become like a tiny escape capsule.

Another system conceived to safeguard the Blackbird aircrew during the bailout procedure was the SR-71’s parachute system. To prevent body tumbling motions and physical injury due to the centrifugal forces it was designed to automatically deploy a small-diameter stabilizing parachute shortly after ejection and seat separation.

Since Weaver had not intentionally activated the ejection sequence, he thought that stabilizing chute might not have deployed. But he quickly determined he was falling vertically and not tumbling, meaning that the little parachute had deployed and was doing its job. The next concern was for the main parachute, which was designed to open automatically at 15,000 feet, but again he had no assurance the automatic-opening function would work. So Weaver decided to open the faceplate, to estimate his height above the ground but as he reached for the faceplate, he felt the reassuring sudden deceleration of main parachute deployment.

After landing, Weaver was rescued by Albert Mitchell Sr., owner of a ranch in northeastern New Mexico, who helped him with the chute, then reached Zwayer who had landed not far away, with his own Hughes helicopter. Mitchell returned few minutes later reporting that Zwayer was dead: in fact he had suffered a broken neck during the aircraft’s disintegration and was killed almost instantly. Moreover Mitchell said that his ranch foreman would watch over Zwayer’s body until the arrival of the authorities and he flew Weaver to the Tucumcari hospital.

Investigation of the incident determined that the nose section of the Blackbird had broken off aft of the rear cockpit and crashed ten miles from the main wreckage. The resultant very high g-forces had literally ripped Weaver and Zwayer from the airplane. After this crash, testing with the CG aft of normal limits was discontinued, and trim-drag issues were resolved via aerodynamic means. Moreover the inlet control system was improved and the inlet unstarts almost stopped with the development of the Digital Automatic Flight and Inlet Control System.

Two weeks after the accident Weaver was back in a Blackbird. As he recalls: “It was my first flight since the accident, so a flight test engineer in the back seat was probably a little apprehensive about my state of mind and confidence. As we roared down the runway and lifted off, I heard an anxious voice over the intercom. “Bill! Bill! Are you there?” “Yeah George. What’s the matter?” “Thank God! I thought you might have left.” The rear cockpit of the SR-71 has no forward visibility – only a small window on each side – and George couldn’t see me. A big red light on the master-warning panel in the rear seat had illuminated just as we rotated, stating: “Pilot Ejected”. Fortunately, the cause was a misadjusted micro switch, not my departure.”

DF-ST-89-06278

Image credit: U.S. Air Force

 

Incredible dashcam footage captures Taiwan plane crash

Shocking footage shows the ATR-72 turboprop plane banking sharply, hitting a cab and clipping a bridge before crashing into Keelung river, near Taipei.

TransAsia flight GE 235, an ATR-72-600 with registration B-22816 from Taipei Songshan Airport to Kinmen islands, crashed at around 10.55 local time (02.55 GMT) into the Keelung River near Taipei.

According to Taiwan’s aviation agency, the turboprop plane was carrying 58 people (5 crew members and 53 passengers), 12 of those have died in the crash according to the latest reports (07.30 GMT).

The aircraft was filmed banking sharply, hitting a cab on a bridge and then crashing into the river by dash camera aboard a car.

Maximum speed recorded through ADS-B by Flightradar24 receivers in the area was 116 Knots (a bit low for a departing aircraft).

Taiwan crash

Image credit: Flightradar24.com

 

F-16’s automatic ground collision avoidance system: details, strengths and limitations

Ground Collision Avoidance Technology (GCAT)

On a recent flight in a Block 40 F-16 with our squadron’s weapons officer I was introduced to the new pilot-activated recovery system (PARS). Starting at about 20,000 feet (FL 200) we rolled inverted and started a rapid 30 degree nose-low dive. The pilot pressed a button initiating the PARS. Immediately the aircraft’s computer took command of the flight controls and we experienced a very intense 180-degree roll until wings level followed by a 5-G pull-up at 4 G’s/second until we were again flying straight and level. On the second demonstration we put the aircraft in a 30-40 degree nose-up attitude. After PARS initiation, the Viper went into autopilot controlling the roll and yaw of the aircraft while allowing the nose to slice down until we were again straight and level.

This PARS feature is part of the F-16’s newest upgrade to avoid mishaps due to controlled flight into terrain (CFIT). The entire fleet of F-16’s in the USAF received this important upgrade during the 2014 calendar year. This is incredibly EXCITING news for the fighter pilot community and hopefully will translate into hundreds of lives and billions of dollars saved. CFIT occurs for a variety of reasons and plagues aviation taking the lives of hundreds of military and general aviation pilots each year. Aside from PARS, the other application of this new capability is the Auto-GCAS (Ground Collision Avoidance System). Auto-GCAS provokes inputs to the flight controls similar to the PARS feature described above, but happens automatically without pilot initiation. The technology relies on sophisticated computer software, terrain maps, GPS and predictive algorithms that will ‘take the jet’ from the pilot when CFIT is predicted to be imminent.

A video HUD demo of the Auto-GCAS can be seen directly below, and further below a NASA video discussing how the GCAT technology was developed and works.

A Brief History of GCAT

The GCAT software was developed by NASA’s Armstrong Flight Research Center at Edwards AFB, in partnership with the Office of the Undersecretary for Personnel and Readiness, the Air Force Research Laboratory (AFRL), the Air Force Test Center (AFTC) and Lockheed Martin. The technology began development in the 1980’s and was ready for testing by the late 1990’s. By 2009, the Ground Collision Avoidance Technology was incorporated into an upgraded USAF Block 25 F-16D and underwent further testing at Edwards AFB, CA.

According to NASA: “The team conducted more than 556 test maneuvers during 49 flights, some of which involved diving at the ground and toward the sides of mountains. Key objectives included demonstrating that Auto-GCAS could significantly reduce the number of mishaps resulting from pilot spatial disorientation, loss of situational awareness, gravity-induced loss of consciousness, and landing-gear-up landings.

Air Force officials announced in 2013 that an operational Auto-GCAS system would be installed in the F-16 fleet and this largely took place throughout the 2014 calendar year. At the base I am currently stationed, we received the upgrade in Sep-Oct 2014. The application has also been tested for general aviation. In 2012, Auto-GCAS was adapted for a small, unmanned research aircraft and implemented as a smartphone application using the Android operating system linked to the aircraft’s autopilot. There remain plans to develop similar systems that can be incorporated into the F-22, F-35, and F-18.

Strengths & Limitations of GCAT

Two of the most common human factors conditions that lead to death or loss of aircraft in combat aviation are spatial disorientation and G-induced loss of consciousness (G-LOC). Spatial Disorientation is the inability to determine one’s position, location, and motion relative to their environment, and is covered in greater detail in a separate post. There are three types of Spatial D: Unrecognized, Recognized, and Incapacitating. The Pilot-Activated Recovery System (PARS) will save pilots suffering from recognized and capacitating Spatial-D as long as the pilot remains able to activate the technology. If a pilot is spatially disoriented but remains unable to initiate PARS, Auto-GCAS should theoretically still save him/her from CFIT. The other big killer, the notorious G-LOC (For more info on Pulling G’s see this post), is expected to occur less frequently with incorporation of the newer, more effective G-suit called ATAGS, but Auto-GCAS will also play a role to save pilot and aircraft if G-LOC were to occur. Lastly, gear up landings in any aircraft utilizing this technology should no longer occur.

Ground Collision Avoidance Technology has some significant software and hardware limitations. For example, the system is not able to make inputs on the throttle. If the throttle is in idle upon activation, the aircraft will quickly lose maneuverability and control authority. This will limit the efficiency and ability for inputs of the flight controls to produce their desired effect. In other cases, a reduction in power may be required for the optimal recovery. Pilots have been trained on this new system and are aware of these limitations. If the GCAT systems find that they are unable to initiate recovery due to the current throttle setting, all it can do is notify the pilot.

Although this technology will undoubtedly give fighter pilot spouses reason to sleep more peacefully, possible exceptional circumstances in which the Auto-GCAS cannot prevent CFIT still exist. The recent loss of an F-16 and death of Capt. Will “Pyro” DuBois after installation of GCAT remains a tragic example of the fact that even though new technologies are creating significant strides in safety, the risk inherent to combat aviation will always be present.

A tribute to PYRO can be found here.

REFERENCES

1. Peter Merlin, Public Affairs. NASA website. Auto-GCA Installed in USAF F-16s. Accessed 14 Dec 2014.

Adapted from an original article on the aerospace medicine blog called GoFlightMedicine, owned and edited by USAF Flight Surgeon, Capt Rocky ‘Apollo’ Jedick.

Top image credit: NASA