A $175,000,000 fuck up

Yeasty on Jun-14-2006 at 09:58 PM RST @ 71.200.169.37 This was released to the press late yesterday:

"The purpose of the accident investigation board is to determine the facts and circumstances that caused the aircraft to crash. Similar to the national transportation safety board process we use all available avenues to collect this information. In this case, the investigation board had the cockpit voice recordings, digital flight data system information, radar plots (Figure 2) of the aircraft flight and recordings from ground agencies that communicated with the mishap aircrew. We also interviewed members of the aircrew and passengers from the mishap flight. The accident investigation board team was very thorough in collecting and considering all these inputs in coming to our conclusions concerning this accident.

The safety of our airmen and passengers, along with the proper use of Air Force assets, is of utmost concern. We take these events and their investigation very seriously.

In this case, we were very lucky that all personnel, aircrew and passengers, survived the accident. The response from the Dover community, local hospitals and emergency response organizations is a testament to the outstanding support of the American public to the United States Air Force.

The accident investigation board conducted a thorough review of this mishap. The board assembled at Dover AFB, Delaware, only traveling outside Delaware to conduct aircrew interviews. During the course of this investigation, the board interviewed or consulted with the following personnel or agencies at the applicable locations: The mishap aircrew, Lockheed Martin representatives, 512th Airlift Wing standardization and evaluation, and Flight Safety. In addition, a member of the board flew on a Dover local C-5 mission, under conditions similar to the mishap, to verify the proper operation of the precision approach path indicators (PAPI) for runway 32. The board also completed event re-enactments in a C-5B avionics modernization program modified simulator, examined the damaged mishap aircraft, reviewed Air Force instructions, technical orders, data from the digital flight data recorder, cockpit voice recordings, recorded radio transmissions, maintenance training records, mishap aircraft forms, aircrew medical, flight evaluation, and training records. As a result of this investigation, we reached the following conclusions about this mishap:

There is clear and convincing evidence the primary cause of this mishap includes:

1) The pilots’ and flight engineers’ failure to use the number three, fully operational, engine. (Figure 4)

After departure and initial climb-out the aircrew shutdown the number two engine for a “Thrust Reverser Not Locked” indication. After maneuvering east of Dover AFB to land, mission pilot one reduced all engines to idle for descent and configuring of the aircraft. After reducing the remaining three throttles to idle, MP1 mistakenly moved the number two throttle (shutdown engine) in concert with engines one and four, but left the number three throttle (fully operational engine), in idle for the remainder of the flight. Mission pilot two and three, the instructor, and primary flight engineers, all failed to recognize mission pilot’s use of the number two throttle (failed engine) instead of the number three throttle (operating engine), to safely fly the final approach and landing. The accident investigation board performed numerous C-5B, avionics modified program, simulator flights using similar weather and aircraft conditions as the mishap flight. Utilizing the number three, fully operational, engine as late as 300 feet above the ground, during the same approach flown by the mishap crew (with full flaps), resulted in a safe final approach and landing.

2) Additionally, the instructor’s and primary flight engineer’s failure to brief, and pilots’ failure to consider or utilize either a 62.5 or 40% flap setting (instead of the 100% setting) as recommended in C-5 directives.

During approach and landing the aircraft weighed approximately 730,000 lbs. When flying non-precision approaches at a gross weight above normal landing weight, defined as aircraft weights over 635,850 lbs, runway conditions permitting, a 40% flap approach and landing is recommended by C-5 directives. A 40% flap approach and landing is flown at a higher approach and landing speed, and with less drag, than the full flap (100%) approach and landing. At this aircraft weight, and weather conditions, a 40% flap approach speed would have been 20 knots faster on final (166 knots versus the 146 knots used). If landing flaps (100%) are necessary or desired, they should be selected only after landing is assured. Mission pilot one selected full flaps (100%) passing 1,000 ft above the ground, over 4 miles from runway 32. At the mishap aircraft weight, speed, altitude, and position, this selection of full flaps (100%) was premature. The board performed numerous C-5B simulator flights using similar weather and aircraft conditions as the mishap flight. Utilizing either a 62.5 or 40% flap setting and approach speed (with the number two engine shutdown and number three engine in idle), during the same approach flown by the mishap crew, resulted in a safe final approach and landing.

3. Finally, the pilots’ failed attempt of a visual approach to runway 32, descending well below a normal glidepath for an instrument aided approach or the normal VFR pattern altitude of 1,800 ft.

Mission pilot one flew a heavyweight, full flap (100%), visual approach to runway 32, descending well below a normal glidepath for a safe landing. A normal glidepath would have been approximately 900 ft at three miles, 500 ft at 1.8 miles and 300 ft at one mile. The mishap aircraft was 500 ft at 3 miles, 300 ft at 1.8 miles, and 150 ft at one mile. Misson pilots two and three did not offer corrections, nor address their low altitude during final approach. The Precision Approach Path Indicator (PAPI) was flight tested and found to be operating normally. Additionally, the instrument landing system to runway 19 was available and offered by Dover approach control. TACAN Z (Figure 3) to runway 32 was also available, with a published approach altitude of 1200 ft at 3.8 miles from the approach end of runway 32. Simulator flights with full flaps (100%), similar engine settings as the mishap aircraft (i.e., only using engines one and four), and similar weather conditions, revealed that either an instrument landing system approach to runway 19 or the TACAN Z to runway 32, flown at published altitudes, would have resulted in a safe landing.

There is substantial evidence that one additional factor contributed to the mishap:

Mission pilot one, the aircraft commander, did not provide a complete approach briefing to the aircrew.

Items including nonstandard factors, configuration, landing distance and missed approach intentions were not addressed. A full briefing would have ensured all crewmembers understood a full flap (100%) approach was planned, which engines would be operated, a landing distance of 4,309 ft was calculated, and a missed approach was not possible at that weight and configuration. Had a full briefing occurred it is possible the other pilots or flight engineers would have further discussed these factors leading to a safe return to Dover AFB.

To summarize, the accident investigation board concluded that the cause of the mishap was the pilots’ and flight engineers’ failure to use the number three, fully operational, engine; the instructor’s and primary flight engineer’s failure to brief, and pilots’ failure to consider or utilize, a 62.5 or 40% flap setting (instead of a 100% flap setting); and the pilots’ attempt at a visual approach to runway 32, descending well below a normal glidepath for an instrument aided approach or the normal visual flight rules pattern altitude of 1,800 ft. There is substantial evidence that a contributing factor to this mishap was mission pilot’s failure to give a complete approach briefing, in that, nonstandard factors, configuration, landing distance, and missed approach intentions were not addressed."