Osprey’s rotor wash injures 10 in NYC park

This morning a V-22 Osprey tilt-rotor aircraft being demonstrated by the U. S. Marine Corp at a Staten Island park near New York City injured 10 spectators when the rotor wash sent debris flying. In the video below (link) you can see that the Osprey was flying slowly and at very low altitude over some trees when some large tree branches were broken off and smaller ones became projectiles along with other debris and dirt from an athletic field. Ten spectators were injured, and seven were transported to hospitals.

HERE is a link to another video of the incident.

On January 3, we wrote about this vertical take-off and landing aircraft replacing some of the Vietnam era CH-46E Sea Knight and CH-53 Super Stallion helicopters used by the Marine Corps, which are occasionally used for dropping water on wildfires. But the Osprey has never dropped a gallon of water on a fire, most likely due to the tremendous rotor wash generated by the huge propellers or rotors, and the very high-temperature exhaust that is directed down to the ground when the rotors are tilted in order to create lift. The exhaust has started wildfires, which would be at odds with a fire suppression mission objective.

Osprey. USAF photo
V-22 Osprey. USAF file photo.

The Osprey has a checkered past, having been involved in numerous crashes and incidents including one in 1992 when an onboard fire caused the aircraft to drop into the Potomac River in front of an audience of Congresspersons and other government officials at Quantico, Virginia, killing all seven crewmen and grounding the aircraft for 11 months. The most recent crash was on April 9, 2010 in Afghanistan, killing four. It was reported that the pilot flew too low in a brownout caused by the rotor wash, and struck a hill.

Will the Osprey ever fight fires?

Osprey. USAF photo
Osprey. USAF photo

The Osprey, a tilt-rotor, vertical take-off and landing aircraft, is replacing some of the Vietnam era CH-46E Sea Knight and CH-53 Super Stallion helicopters used by the Marine Corps. Since the disastrous wildfires in southern California in 2007, the U.S. Navy and the Marine Corps have had an agreement with Cal Fire making it possible to use their military helicopters on fires if Cal Fire is unable to handle the fires with their own aerial assets.

In July of 2008, CH-46E and CH-53E military helicopters made at least 574 drops on fires in California, delivering 217,000 gallons of water.

At first glance, the Osprey might seem like an excellent firefighting tool. It is fast (cruises at 277 mph), could haul 24-32 firefighters, and could carry 1,800 gallons of water externally. But it has never dropped a gallon of water on a fire and it is possible that it never will due to at least two potential problem areas.

Rotor Wash

As you can see in the photo above, the rotor wash or downdraft from an Osprey is extremely strong–far stronger than a conventional helicopter. Rotor wash from a helicopter can cause, and has caused, serious problems when the wind from the rotors spreads the fire in unexpected directions, sometimes doing more harm than good. Marines even worry that Osprey rotor wash may damage or destroy unrecorded archaeological sites in training areas.

According to a report from the Government Accountability Office, the rotor wash creates enough force to knock sailors and aircraft off a flight deck on a ship.

May CAUSE fires

The Osprey’s engines run extremely hot, so hot that the Navy is taking special precautions to prevent the engine exhaust from melting or buckling the aluminum decks of warships. A report from DARPA states:

The deployment of the MV-22 Osprey has resulted in ship flight deck buckling that has been attributed to the excessive heat impact from engine exhaust plumes… Navy studies have indicated that repeated deck buckling will likely cause deck failure before planned ship life.

DARPA has designed a “flight deck thermal management system” which would liquid-cool the deck from below or above while the aircraft are idling or launching. The military has put out a request for proposals for other permanent deck-cooling systems that could be retro-fitted or designed into new ships still on the drawing board.

Wildfire Today reported on May 30, 2009, that an Osprey made an unscheduled precautionary landing in North Carolina and started a 5-acre fire in a wet marsh. We wrote then:

Marines refueled the Osprey but according to WECT.com, upon taking off it “smashed into swamp mud, nose first”. During that takeoff attempt, heat from the engine exhaust started a vegetation fire which did some damage to the exterior of the aircraft.

A news release from the Marine Corp claims:

The grass fire was quickly extinguished by the crew chief, but caused an undetermined amount of heat damage to the aircraft exterior.

But Emergency Management Director Eddie King said the local fire department had to work through the night to extinguish a 5-acre fire, in an area infested with snakes and alligators, that was caused by the incident.

Osprey hauling a Humvee. U.S. Navy photo.
Osprey hauling a Humvee. U.S. Navy photo.

Osprey makes precautionary landing, starts fire

U.S. Marines jump from an Osprey

A MV-22 Osprey tiltrotor aircraft made an unscheduled landing Wednesday night in North Carolina after one of its engines ran low on fuel. The aircraft, based out of the Marine Corps Air Station in New River, N.C., was conducting low altitude training when it made a precautionary landing at 7 p.m. in Holly Shelter Game Land south of the air station. The crew of four was not hurt.

Marines refueled the Osprey but according to WECT.com, upon taking off it “smashed into swamp mud, nose first”.  During that takeoff attempt, heat from the engine exhaust started a vegetation fire which did some damage to the exterior of the aircraft.

A news release from the Marine Corp claims…

The grass fire was quickly extinguished by the crew chief, but caused an undetermined amount of heat damage to the aircraft exterior.

But Emergency Management Director Eddie King said the local fire department had to work through the night to extinguish a 5-acre fire, in an area infested with snakes and alligators, that was caused by the incident.

On Thursday afternoon the Osprey was flown back to the New River Air Station.

It is interesting that the Marine Corps said the precautionary landing was caused by an engine running low on fuel. The aircraft has a drive shaft through the wings that connects the two engines, making it possible for one engine to power both prop-rotors. This feature may have prevented it from completely losing control and crashing.

There have been at least four crashes involving Ospreys:

  • June 1991– a nacelle struck the ground while the aircraft was hovering, causing it to bounce and catch fire.
  • July 1992– An Osprey caught fire and crashed into the Potomac River at Quantico before an audience of Congressmen, killing all seven crewmen.
  • April 2000– At Marana airport in Arizona an Osprey descended too quickly and crashed, killing all 19 on board.
  • December 2000– A series of problems and design flaws, a swiss cheese effect, caused a crash into a forest near Jacksonville, North Carolina, killing all four on board.

The development budget of the Osprey, first estimated at $2.5 billion in 1986, will cost at least $54 billion before the program is complete according to Wikipedia. About two percent of that would have paid for an entire fleet of new purpose-built air tankers.